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CBSE 9TH Economics

ICH helps the Class IX Students of CBSE Economics ( free online Guide) to go through the latest updates by the CBSE Board.Here you will find information on CBSE Class IX Economics Sample Papers, CBSE IX Economics Guess Papers, CBSE Class IX Economics Syllabus and NCERT Texbook Solutions.

Social Science - Economics - Syllabus 2010 - CBSE IX

 

COURSE STRUCTURE

CLASS IX

Time : 3 Hrs. Marks : 80 + 20

Marks Periods

Unit 1 : India and the Contemporary World - I 18 40

Unit 2 : India -Land and the People 20 45

Unit 3 : Democratic Politics I 18 40

Unit 4 : Understanding Economics 16 40

Unit 5 : Disaster Management 8 25

Internal Assessment

1. Tests (Formative and Summative) 10

2. Assignments (School & Home) 05

3. Project Work 05

Class IX

Unit 1 : India and the Contemporary World - I 40 Period

Themes Objectives
Any two themes from each of the first two sub-units

and one from the third could be studied.

Sub-unit 1.1 : Events and processes.

In this unit the focus is on three events and

processes that have in major ways shaped the identity

of the modern world. Each represents a different form

of politics, and a specific combination of forces. One

event is linked to the growth of liberalism and

democracy, one with socialism, and one with a

negation of both democracy and socialism.

1. French revolution :

(a) The Ancient Regime and its crises.
(b) Thesocial forces that led to the revolution.
(c) The different revolutionary groups and ideas of the time.
(d) The legacy.

2. Russian Revolution.

(a) The crises of Tzarism.
(b) The nature ofsocial movements between 1905 and1917.
(c) The First World War andfoundation of Soviet state.
(d) The legacy.

3. Rise of Nazism.

(a) The growth of social democracy
(b) Thecrises in Germany.
(b) The basis of Hitler'srise to power.
(c) The ideology of Nazism.
(d) The impact of Nazism.

Sub-unit 1.2 : Economies and Livelihoods

The themes in this section will focus on how different social groups grapple with the changes in the contemporary world and how these changes  affect their lives.

4. Pastoralists in the modern world.

(a) Pastoralism as a way of life.
(b) Different  forms of pastoralism.
(c) What happens  to pastoralism under colonialism andmodern states?Case studies : focus on two pastoral groups, one from Africa and one from

India.

5. Forest society and colonialism :

(a) Relationship between forests and  livelihoods. (b) Changes in forest societies under colonialism.Case studies : focus on two forestmovements one in colonial India (Bastar)and one in Indonesia.

6. Farmers and peasants :

(a) Histories of the emergence of differentforms of farming and peasant societies. (b)Changes within rural economies in the modern world.

Case studies : focus on contrasting forms of rural change and different forms of rural societies (expansion of large-scale wheat and cotton farming in USA, rural economy and the Agricultural Revolution in England, and small peasant production in colonial India)

Sub-unit 1.3 : Culture, Identity and Society

The themes in this unit will consider how issues of culture are linked up to the making of contemporary world.

7. Sports and politics :

The story of cricket (a) The emergence of cricket

as an English sport. (b) Cricket and colonialism.

(c) Cricket nationalism and de-colonialization.

8. Clothes and cultures.

(a) A short history of changes in clothing. (b) Debates over clothing in colonial India. (c) Swadeshi and the movement for Khadi.

Sub-unit 1.4 : Map Work. (2 Marks).

  • In each of the themes in this unit students would

    be made familiar with extracts of speeches,

    political declarations, as well as the politics of

    caricatures, posters and engravings. Students

    would learn how to interpret these kinds of

    historical evidences.

     

  • Familiarize students with the names of people

    involved, the different types of ideas that inspired

    the revolution, the wider forces that shaped it.

  • Show how written, oral and visual material can

    be used to recover the history of revolutions.

  • Explore the history of socialism through a study

    of the Russian revolution.

  • Familiarize students with the names of people

    involved, the different types of ideas that inspired

    the revolution.

  • Discuss the critical significance of Nazism in

    shaping the politics of modern world.

  • Familiarize students with the speeches and

    writings of Nazi leaders.

     

  • Consider what happens to pastoralists and

    pastoralism in the modern world, with the

    formation of modern states, marking of

    boundaries, processes of sedentarization,

    contraction of pastures, and expansion of

    markets.

  • Point to the varying patterns of developments

    within pastoral societies in different places.

  • Look at the impact of colonialism on forest

    societies, and the implication of scientific forestry.

  • Discuss the social and cultural world of forest

    communities through the study of specific

    revolts.

  • Understand how oral traditions can be used to

    explore tribal revolts.

  • Show the different processes through which

    agrarian transformation may occur in the modern

    world.

     

  • Understand how agricultural systems in India are

    different from that in other countries.

  • Familiarize students with the idea that large scale

    farming, small scale production, shifting

    agriculture operate on different principles and

    have different histories.

  • Suggest how sports also have a history and that

    it is linked up with the politics of power and

    domination.

  • Introduce students to some of the stories in

    cricket that have historical significance.

  • Show how clothing has a history, and how it is

    linked to questions of cultural identity.

  • Discuss how clothing has been the focus of

    intense social battles

 

Unit 2 : India - Land and the Peopl

 
Themes Objectives
1. India : location, relief, structure, major

physiographic units

.

2. Climate : factors influencing the climate;

monsoon- its characteristics, rainfall and

temperature distribution; seasons; climate and

human life.

3. Drainage : major rivers and tributaries, lakes  and seas, role of rivers in the economy, pollutionof rivers, measures to control river pollution.

4. Natural Vegetation : vegetation types,distribution as well as altitudinal variation, needfor conservation and various measures.

5. Wildlife : major species, their distribution, needfor conservation and various measures.

6. Population : size, distribution, age-sx composition, population change-migration as a determinant of population change, literacy, health, occupational structure and national population policy : adolescents as under-served population group with special needs.

7. Map Work (4 marks).

To understand the major landform features and the

underlying geological structure; their association with

various rocks and minerals as well as nature of soil

types

To identify the various factors influencing the climate

and explain the climatic variaton of our country and

its impact on the life of the people.

Tor explain the importance and unifying role of

monsoons;

To understand the river systems of the country and

explain the role of rivers in the evolution of human

society.

To find out the nature of diverse flora and fauna as

well as their distribution;

To develop concern about the need to protect the

bio-diversity of our country;

To analyse the uneven nature of population

distribution and show concern about the large size of

our population;

To understand the various occupations of people and

explain various factors of population change;

To explain various dimension of national policy and

understand the needs of adolescents as underserved

group.

 

Project/Activity

 
Learners may identify songs, dances, festivals and special food preparations associated with certain seasons
 
 
 
in their particular region, and whether they have some commonality with other regions of India.
 

 

 
Collection of material by learners on the flora and fauna of the region in which their school is situated. It
 
 
 
should include a list of endangered species of the region and also information regarding efforts being made to save
 
 
 
them.
 

Posters

 

 
River pollution
 
 
 
Depletion of forests and ecological imbalance.
 

Unit - 3 : Democratic Politics I

40 Periods

 

Themes Learning Objectives
1. What is democracy? Why democracy?

What are the different ways of defining

democracy? Why has democracy become the

most prevalent form of government in our times?

What are the alternatives to democracy? Is

democracy superior to its available alternatives?

Must every democracy have the same institutions

and values?

2. Designing of Democracy in India

How and why did India become a democracy?

How was the Indian constitution framed? What

are the salient features of the Constitution? How

is democracy being constantly designed and

redesigned in India?

3. Electoral politics in democracy

Why and how do we elect representatives? Why

do we have a system of competition among

political parties? How has the citizens'

participation in electoral politics changed? What

are the ways to ensure free and fair elections?

4. Institutions of parliamentary democracy

How is the country governed? What does

Parliament do in our democracy? What is the

role of the President of India, the Prime Minister

and the Council of Ministers? How do these

relate to one another?

5. Citizens' rights in democracy

Why do we need rights in a constitution? What

are the Fundamental Rights enjoyed by the

citizen under the Indian constitution? How does

the judiciary protect the Fundamental Rights of

the citizen? How is the independence of the

judiciary ensured?

  • Develop conceptual skills of defining

    democracy

  • Understand how different historical processes

    and forces have promoted democracy.

  • Developing a sophisticated defence of

    democracy against common prejudices

  • Develop a historical sense of the choice and

    nature of democracy in India.

  • Introduction to the process of Constitution

    making

  • Develop respect for the Constitution and

    appreciation for Constitutional values

  • Recognise that constitution is a living document

    that undergoes changes.

  • Introduce the idea of representative democracy

    via competitive party politics

  • Familiarise with our electoral system and reasons

    for choosing this

  • Develop an appreciation of citizen's increased

    participation in electoral politics

  • Recognise the significance of the Election

    Commission

  • Provide an overview of central governmental

    structures

  • Sensitise to the key role of the Parliament and

    its procedures

  • Distinguish between nominal and real executive

    authorities and functions

  • Understand the parliamentary system of

    executive's accountability to the legislature

  • Develop a citizens' awareness of their rights
  • Introduction to and appreciation of the

    Fundamental Rights

  • Recognition of the ways in which these rights

    are exercised and denied in real life situations.

  • Introduction to judicial system and key

    institutions like the Supreme Court, High Courts

    and National Human Rights Commission.

 

Unit - 4 : Understanding Economics - I

 

Themes Objectives
1. The economic story of Palampore: Economic

transactions of Palampore and its interaction with

the rest of the world through which the concept

of production (including three factors of

production (land, labour and capital) can be

introduced.

2. People as Resource : Introduction of how

people become resource / asset; economic

activities done by men and women; unpaid work

done by women; quality of human resource ;

role of health and education; unemployment as

a form of nonutilisation of human resource; sociopolitical

implication in simple form

3. Poverty as a challenge facing India : Who is

poor (through two case studies one rural one

urban); indicators; absolute poverty (not as a

concept but through a few simple examples) -

why people are poor ; unequal distribution of

resources; comparison between countries; steps

taken by government for poverty alleviation

4. Food Security : Source of foodgrains- variety

across the nation - famines in the past - the need

for self sufficiency - role of government in food

security - procurement of foodgrains -

overflowing of granaries and people without food

- public distribution system - role of cooperatives

in food security (foodgrains, milk and vegetables

ration shops, cooperative shops, two-three

examples as case studies)

Familiarising the children with some basic

economic concepts through an imaginary story

of a village

Familiarisation of a few population related concepts

and sensitization of child that people as asset can

participate and contribute in nation building

Understanding of poverty as a challenge and

sensitization of the learner;

Appreciation of the government initiative to alleviate

poverty

Exposing the child to an economic issue which is basic

necessities of life;

Appreciate and critically look at the role of

government in ensuring food supply

 

 

Suggested Activities / Instructions :

Theme 1

 
: Give more examples of activities done by different workers and farmers.
 
 
 
Numerical problems can also be included.
 
 
 
Some of the ways through which description of villages are available in the writings of Prem Chand, MN Srinivas
 
 
 
and RK Narayan. They may have to be referred.
 

Theme II :

 
Discuss the impact of unemployment
 
 
 
Debate on whether all the activities done by women should be included or not. Why?
 
 
 
Is begging an economic activity? Discuss.
 
 
 
Is it necessary to reduce population growth or family size? Discuss.
 

Theme IV :

 
Visit a few farms in a village and collect the details of foodgrains cultivated;
 
 
 
Visit a nearby ration shop and collect the details of goods available;
 
 
 
Visit a regulated market yard and observe how goods are transacted and get the details of the places where the
 
 
 
goods come and go.
 

Unit - 5 : Disaster Management

25 Periods

 
1. Man made disasters - Nuclear, Biological and Chemical.
 
 
 
2. Common Hazards - Prevention and Mitigation
 
 
 
3. Community Based Disaster Management.

PRESCRIBED TEXTBOOKS :

 
1. India and the Contemporary World History - Published by NCERT 
2. Contemparary India - Geography - Published by NCERT 
3. Democratic Politics - Published by NCERT 
4. Economics - Published by NCERT 
5. Together, Towards a Safer India - Part II, a textbook on Disaster Management for class IX - Published by CBSE

 

CBSE Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 4

Question: 

4. Is it important to increase the area under irrigation? Why?

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Answer: 

Ans:- Yes. Because, not all the people engaged in agriculture have sufficient land for cultivation. About one third of the 450 families are landless, i.e. 150 families, most of them dalits, have no land for cultivation. 240 families cultivate small plots of land less than 2 hectares in size. Cultivation of such plots doesn’t bring adequate income to the farmer family.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur

CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 1

Question: 

1. Every village in India is surveyed once is ten years during the Census and some of details are presented in the following format. Fill up the following based on information on Palampur.
a. LOCATION:
b. TOTAL AREA OF THE VILLAGE:
c. LAND USE (in hectares):
d. FACILITIES

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Answer: 

d. FACILITIES
Educational –one high school and two primary school
Medical –a government primary health centre and private dispensary
Electricity Supply-most of the houses and tube wells have electric supply
Communication-Many kinds oftransport are visible on this road starting from bullock carts, tongas, bogeys (wooden cart drawn by buffalos) loaded with jaggery (gur) and other commodities to motor vehicles like motorcycles, jeeps, tractors and trucks.
Nearest Town-shahpur

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 2

Question: 

2. Modern farming methods require more inputs which are manufactured in industry. Do you agree?

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Answer: 

Ans:- Yes, modern farming methods require more inputs which are manufactured in industry. Farmers of Punjab, Haryana and Western Uttar Pradesh were the first to try out the modern farming method in India. The farmers in these regions had set up tube wells for irrigation, and made use of HYV seeds, chemical fertilizers and pesticides in farming. Some of them bought farm machinery like tractors and threshers, which made ploughing and harvesting faster. Here the inputs for modern farming is tube wells, HYV seeds , tractors, threshers etc..

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 3

Question: 

3. How did the spread of electricity help farmers in Palampur?

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Answer: 

Ans:-The Electricity powers all the tube wells in the fields and is used in various types of small scale industry.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 4

Question: 

4. Is it important to increase the area under irrigation? Why?

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Answer: 

Ans:- Yes. Because, not all the people engaged in agriculture have sufficient land for cultivation. About one third of the 450 families are landless, i.e. 150 families, most of them dalits, have no land for cultivation. 240 families cultivate small plots of land less than 2 hectares in size.
Cultivation of such plots doesn’t bring adequate income to the farmer family.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 5

Question: 

5. Construct a table on the distribution of land among the 450 families of Palampur.

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Answer: 

Ans:- Total Family - 450
Dalits, 150 families, have no land
Remaining 120 Family have small plots of land less than 2 hectares in size
Remaining 60 families of medium and large farmers have more than 2 hectares of land
Few of the large farmers have land extending over 10 hectares or more.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 6

Question: 

6. Why are the wages for farm labourers in Palampur less than minimum wages?

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Answer: 

Ans:- There is heavy competition for work among the farm labourers in Palampur, so people agree to work for lower wages.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 7

Question: 

7. In your region, talk to two labourers. Choose either farm labourers or labourers working at construction sites. What wages do they get? Are they paid in cash or kind? Do they get work regularly? Are they in debt?

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Answer: 

Ans:- In our region Daya and Rani are two farm labourer working at construction site. They get wages around Rs 35–40. Yes, they are paid in cash. No mostly they don't get work regularly, because so many people agree to work for lower wages. Yes they are in huge debt because with such a low wage they can not meet the two ends of the family.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 8

Question: 

8. What are the different ways of increasing production on the same piece of land? Use examples to explain.

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Answer: 

Ans:- To grow more than one crop on a piece of land during the year is known as multiple cropping. It is the most common way of increasing production on a given piece of land. All farmers in Palampur grow atleast two main crops; many are growing potato as the third crop in the past fifteen to twenty years.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 9

Question: 

9. Describe the work of a farmer with 1 hectare of land.

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Answer: 

Ans:- In Palampur, the yield of wheat grown from the traditional varieties was 1300 kg per hectare. With the HYV seeds, the yield went up to 3200 kg per hectare, because of the modern farming method in India.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 10

Question: 

10. How do the medium and large farmers obtain capital for farming? How is it different from the small farmers?

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Answer: 

Ans:- Medium and large farmers supply wheat to the market. And they obtain capital for farming while Most small farmers have to borrow money to arrange for the capital. They borrow from large farmers or the village money lenders or the traders.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 11

Question: 

11. On what terms did Savita get a loan from Tajpal Singh? Would Savita’s condition be different if she could get a loan from the bank at a low rate of interest?

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Answer: 

Ans:- Tejpal Singh agreed to give Savita the loan at an interest rate of 24 per cent for four
months, which is a very high interest rate. Savita also has to promise to work on his
field as a farm labourer during the harvest season at Rs 35 per day.
Yes, the interest rates for bank is lower. And there are many schemes for small farmers

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 13

Question: 

13. What are the non-farm production activities taking place in your region? Make a short list.

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Answer: 

Ans:-Dairy, Small scale Industry , poultry.

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CBSE 9th Economics - Chap 1 - The Story Of Village Palampur - Page 14 - Q 14

Question: 

14. What can be done so that more non-farm production activities can be started in villages?

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Answer: 

Ans:-There are few Non farm activities like dairy, poultry, small factories can be started in the village.

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CBSE 9th Economics - Chap 2 - People As Resources

CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 1

Question: 

1. What do you understand by 'people as a resource'?

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Answer: 

Ans:- 'People as Resource' is a way of referring to a country’s working people in terms of their existing productive skills and abilities. Looking at the population from this productive aspect emphasises its ability to contribute to the creation of the Gross National Product. Like other resources, population also is a resource — a 'human resource'.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 2

Question: 

2. How is human resource different from other resources like land and physical capital?

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Answer: 

Ans:-The basic difference between human resources and other resources is that human resource can make use of land and capital. While Land and capital cannot become useful on its own.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 3

Question: 

3. What is the role of education in human capital formation?

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Answer: 

Ans:- The role of education in human capital formation can be understand by this way As we know that a large population has been considered a liability rather than an asset .But It can
be turned into a productive asset by investment in human capital for example, by spending resources on education .education added to the quality of labour. This enhanced the total productivity. Total productivity adds to the growth of the economy. This in turn pays an
individual through salary or in some other form as human capital . investments made
on her education can yield a high return in the future in the form of higher earnings and greater contribution to society. education contributes towards the growth of society also. It enhances the national income, cultural richness and increases the efficiency of governance.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 4

Question: 

4. What is the role of health in human capital formation?

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Answer: 

Ans:- The role of education in human capital formation can be understand by this way As we know that if any employ people who might not work efficiently as a healthy worker because of ill health. And hence the ill people can not assessing the future progress of the country. The health of a person helps him to realise his potential and the ability to fight illness. improvement in the health status of the population has been the priority of the country. Our national policy, too, aimed at improving the accessibility of health care, family welfare and nutritional service with special focus on underprivileged segment of population.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 5

Question: 

5. What part does health play in the individual’s working life?

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Answer: 

Ans:- The health of an individual person helps to realise his potential and the ability to fight illness. An unhealthy person becomes a liability for an organisation indeed; health is an indispensable basis for realising one’s well being.A family welfare and nutritional service can also be provide by healthy person in his working life .

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 6

Question: 

6. What are the various activities undertaken in the primary sector, secondary sector and tertiary sector?

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Answer: 

Ans:- The various activities have been classified into three main sectors i.e., primary, secondary and tertiary. Primary sector includes agriculture, forestry, animal husbandry, fishing, poultry farming, and mining. Quarrying and manufacturing is included in the secondary sector. Trade,
transport, communication, banking, education, health, tourism, services, insurance etc. are included in the tertiary sector. The activities in this sector result in the production of goods and services. These activities add value to the national income. These activities are called economic activities.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 7

Question: 

7. What is the difference between economic activities and non-economic activities

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Answer: 

Ans:- The various activities have been classified into three main sectors i.e., primary, secondary and tertiary. Primary sector includes agriculture, forestry, animal husbandry, fishing, poultry farming, and mining. Quarrying and manufacturing is included in the secondary sector. Trade,transport, communication, banking, education, health, tourism, services, insurance etc. are included in the tertiary sector. The activities in this sector result in the production of goods and services. These activities add value to the national income. These activities are called economic activities. While economic activities have two parts -market activities and non-market activities here non market activities Non-market activities is same as non economic activity the production for self-consumption.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 8

Question: 

8. Why are women employed in low paid work?

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Answer: 

Ans:- Women are paid low compared to men. Most women work where job security is not there. Various activities relating to legal protection is meagre. Employment in this sector is characterised by irregular and low income.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 9

Question: 

9. How will you explain the term unemployment?

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Answer: 

Ans:- Unemployment is said to exist when people who are willing to work at the going wages and cannot find jobs.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 10

Question: 

10. What is the difference between disguised unemployment and seasonal unemployment?

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Answer: 

Ans:- In case of rural areas, there is seasonal and disguised unemployment. Seasonal unemployment happens when people are not able to find jobs during some months of the year. People dependant upon agriculture usually face such kind of problem. There are certain
busy seasons when sowing, harvesting, weeding, threshing is done. Certain months do not provide much work to the people dependant on agriculture. In case of disguised unemployment
people appear to be employed. They have agricultural plot where they find work. This usually happens among family members engaged in agricultural activity. The work requires the service of five people but engages eight people. Three people are extra. These three people also work in the same plot as five people. The contribution made by the three extra people does not add to the contribution made by the five people. If three people are removed the productivity of the field
will not decline. The field requires the service of five people and the three extra people are disguisedly employed.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 11

Question: 

11. Why is educated unemployed, a peculiar problem of India?

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Answer: 

Ans: Educated unemployment has become a common phenomenon. Many youth with matriculation, graduation and post graduation degrees are not able to find job. A study showed that unemployment of graduate and post-graduate has increased faster than among matriculates. Unemployment leads to wastage of manpower resource People who are an asset for the economy turn into a liability. There is a feeling of hopelessness and despair among the youth. People do not have enough money to support their family. Inability of educated people who are willing to work to find gainful employment implies a great social waste. Unemployment tends to increase economic overload, due to which India faces unemployment problems.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 12

Question: 

12. In which field do you think India can build the maximum employment opportunity?

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Answer: 

Ans: Small scale Manufacturing sector is the most labour absorbing.Also various new services are now appearing like biotechnology, information technology and so on are very useful to build the maximum employment.

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 13

Question: 

13. Can you suggest some measures in the education system to mitigate the problem of the educated unemployed?

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 14

Question: 

14. Can you imagine some village which initially had no job opportunities but later came up with many?

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Answer: 

 

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CBSE 9th Economics - Chap 2 - People As Resources - Page 27 - Q 15

Question: 

15. Which capital would you consider the best — land, labour, physical capital and human capital? Why?

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Answer: 

Ans:-As I feel human capital is the best among all others capital population need not be a liability. It can be turned into a productive asset by investment in human capital (for example,by spending resources on education and health for all, training of industrial and agricultural workers in the use of modern technology, useful scientific researches and so on).Because human capital is in one way superior to other resources like land and physical capital: human resource can make use of land and capital. Land and capital cannot become useful on its own!

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CBSE 9th Economics - Chap 3 - Poverty As Challenge

CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 1

Question: 

1. Describe how the poverty line is estimated in India.

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Answer: 

Ans:- The poverty line in India, estimated which is based on the desired calorie requirement. Food
items such as cereals, pulses, vegetable, milk, oil, sugar etc. among the economic groups, the most vulnerable groups are the rural agricultural labour households and the urban casual labour households.

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 2

Question: 

2. Do you think that present methodology of poverty estimation is appropriate?

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Answer: 

Ans:- From my point of view present methodology of poverty estimation can not be ignored because with the spread of irrigation and the Green revolution, many job opportunities
were created in the agriculture sector. But the effects were limited to some parts of India. The industries, both in the public and the private sector, did provide some jobs. But these were not enough to absorb all the job seekers.

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 3

Question: 

3. Describe poverty trends in India since 1973.

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Answer: 

s:-Poverty trend in India since 1973 can be explain by this way It is clear that there is
substantial decline in poverty ratios in India from about 55 per cent in 1973. A person is
considered poor if his or her income or consumption level falls below a given “minimum level” necessary to fulfill basic needs. While determining the poverty line in India, a minimum level of food requirement, clothing, footwear, fuel and light, educational and medical requirement etc. are determined for subsistence. These physical quantities are multiplied by their prices in rupees.

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 4

Question: 

4. Discuss the major reasons for poverty in India.

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Answer: 

Ans:- One historical reason is the low level of economic development under the British
colonial administration. The policies of the colonial government ruined traditional handicrafts and discouraged development of industries like textiles. The low rate of growth persisted until the nineteen eighties. This resulted in less job opportunities and low growth rate of incomes. the growth rate of per capita income very low. One of the major reasons for this is the unequal distribution of land and other resources.

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 5

Question: 

5. Identify the social and economic groups which are most vulnerable to poverty in India.

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Answer: 

Ans:- Social groups which are most vulnerable to poverty are scheduled caste and scheduled tribe households. Similarly, among the economic groups, the most vulnerable groups are the rural agricultural labour households and the urban casual labour households.

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 6

Question: 

6. Give an account of interstate disparities in poverty in India.

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 7

Question: 

7. Describe global poverty trends.

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Answer: 

Ans:- The proportion of people in developing countries living in extreme economic poverty— defined by the World Bank as living on less than $1 per day—has fallen from 28 per cent in 1990 to 21 per cent in 2001. Although there has been a substantial reduction in global poverty, it
is marked with great regional differences.As-In China and Southeast Asian countries as a result
of rapid economic growth and massive investments in human resource development. Number of poors in China has come down from 606 million in 1981 to 212 million in 2001. In the countries of South Asia (India, Pakistan, Sri Lanka, Nepal, Bangladesh, Bhutan) the decline has not been as rapid. Because of different poverty line definition, poverty in India is also shown higher than the national estimates.

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 8

Question: 

8. Describe current government strategy of poverty alleviation.

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Answer: 

Ans:- The current anti-poverty strategy of the government is based broadly on two planks (1) promotion of economic growth (2) targeted anti-poverty programmes. The higher growth rates have helped significantly in the reduction of poverty. Therefore, it is becoming clear that there
is a strong link between economic growth and poverty reduction.And for targeted anti-poverty
programmes. Although there are so many schemes which are formulated to affect poverty directly or indirectly, some of them mentioned1. National Rural Employment Guarantee Act (NREGA) 2005 2. Prime Minister Rozgar Yozana (PMRY) 3. Rural Employment Generation Programme 4. Swarnajayanti Gram Swarozgar Yojana (SGSY) 5. Pradhan Mantri Gramodaya Yozana (PMGY) 5. Antyodaya Anna Yozana (AAY)

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CBSE 9th Economics - Chap 3 - Poverty As Challenge - Page 40 - Q 9

Question: 

9. Answer the following questions briefly
(i) What do you understand by human poverty?
(ii) Who are the poorest of the poor?
(iii) What are the main features of the National Rural Employment Guarantee Act 2005?

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Answer: 

(i) What do you understand by human poverty?
Ans:- It is about a “minimum” subsistence level of living rather than a “reasonable” level of living.

(ii) Who are the poorest of the poor?
Ans:- Women, children (especially the girl child) and old people are poorest of the poor.

(iii) What are the main features of the National Rural Employment Guarantee Act 2005?
Ans:- There are so many schemes which are formulated to affect poverty directly or indirectly, some of them are worth mentioning. National Rural Employment Guarantee Act (NREGA) 2005
was passed in September 2005. The Act provides 100 days assured employment every year to every rural household in 200 districts. Later, the scheme will be extended to 600 districts. One third of the proposed jobs would be reserved for women. The central government will also
establish National Employment Guarantee Funds. Similarly state governments will establish State Employment Guarantee Funds for implementation of the scheme. Under the programme if an applicant is not provided employment within fifteen days she/he will
be entitled to a daily unemployment allowance.

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CBSE 9th Economics - Chap 4 - Food Security In India

CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 1

Question: 

1. How is food security ensured in India?

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Answer: 

Ans:- Food security is ensured in a country only if (1) enough food is available for all the persons (2) all persons have the capacity to buy food of acceptable quality and (3) there is no barrier on access to food.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 2

Question: 

2. Which are the people more prone to food insecurity?

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Ans:- The SCs, STs and some sections of the OBCs (lower castes among them) who have either poor land-base or very low land productivity are prone to food insecurity.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 3

Question: 

3. Which states are more food insecure in India?

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Answer: 

Ans:- The states of Uttar Pradesh (eastern and south-eastern parts), Bihar, Jharkhand, Orissa, West Bengal,Chattisgarh, parts of Madhya Pradesh and Maharasthra account for largest number of food insecure people in the India.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 4

Question: 

4. Do you believe that green revolution has made India self-sufficient in food grains? How?

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Answer: 

Ans:-Yes, I believe that green revolution has made India self-sufficient because After independence, India is aiming at Self-sufficiency in Foodgrains since independence. After independence, Indian policy makers adopted all measures to achieve self-sufficiency in food grains. India adopted a new strategy in agriculture, which resulted in the ‘Green Revolution’ especially in the production of wheat and rice. the Green revolution in agriculture by releasing a ‘Wheat Revolution’ in July 1968. The success of wheat was later replicated in rice. The increase in foodgrains was, however, disproportionate. The highest rate of growth was achieved in Punjab and Haryana, where foodgrain production jumped from 7.23 million tonnes in
1964–65 to reach an all-time high of 30.33 million tonnes in 1995–96. Tamil Nadu and Andhra Pradesh, on the other hand, recorded significant increases in rice yield. India has become self-sufficient in foodgrains during the last thirty years because of a variety of crops grown all over the country. The availability of foodgrains (even in adverse weather conditions or otherwise) at the country level has further been ensured with a carefully designed food security system by the government.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 5

Question: 

5. A section of people in India are still without food. Explain?

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Answer: 

Ans:- The food insecure people are disproportionately large in some regions of the country, such as economically backward states with high incidence of poverty, tribal and remote areas, regions more prone to natural disasters etc. a large section of people suffer from food and nutrition insecurity in India, the worst affected groups are landless people with little or no land to depend upon, traditional artisans, providers of traditional services, petty self-employed workers and destitute including beggars. In the urban areas, the food insecure families are those whose working members are generally employed in ill-paid occupations and casual labour market. These workers are largely engaged in seasonal activities and are paid very low wages that just ensure bare survival.

Ans:- The food insecure people are disproportionately large in some regions of the country, such as economically backward states with high incidence of poverty, tribal and remote areas, regions more prone to natural disasters etc. a large section of people suffer from food and nutrition insecurity in India, the worst affected groups are landless people with little or no land to depend upon, traditional artisans, providers of traditional services, petty self-employed workers and destitute including beggars. In the urban areas, the food insecure families are those whose working members are generally employed in ill-paid occupations and casual labour market. These workers are largely engaged in seasonal activities and are paid very low wages that just ensure bare survival.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 6

Question: 

6. What happens to the supply of food when there is a disaster or a calamity?

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Answer: 

Ans:- Due to a natural calamity, say drought, total production of foodgrains decreases. It creates a shortage of food in the affected areas. Due to shortage of food, the prices go up. At the high prices, some people cannot afford to buy food. If such calamity happens in a very wide spread area or is stretched over a longer time period, it may cause a situation of starvation. A massive starvation might take a turn of famine. A famine is characterised by wide spread deaths due to starvation and epidemics caused by forced use of
contaminated water or decaying food and loss of body resistance due to weakening from starvation.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 7

Question: 

7. Differentiate between seasonal hunger and chronic hunger?

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Answer: 

Ans:- Chronic hunger is a consequence of diets persistently inadequate in terms of quantity and/or quality. Poor people suffer from chronic hunger because of their very low income and in turn inability to buy food even for survival. Seasonal hunger is related to cycles of food growing and harvesting. This is prevalent in rural areas because of the seasonal nature of agricultural activities and in urban areas because of the casual labour, e.g., there is less work for casual construction labour during the rainy season. This type of hunger exists when a person is unable to get work for the entire year.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 8

Question: 

8. What has our government done to provide food security to the poor? Discuss any two schemes launched by the government?

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Answer: 

Ans:- Public Distribution System (PDS) is the most important step taken by the Government of India (GoI) towards ensuring food security. In the beginning the coverage of PDS was universal with no discrimination between the poor and non-poor. Over the years, the policy related to PDS has been revised to make it more
efficient and targeted. In 1992, Revamped Public Distribution System (RPDS) was introducted in 1,700 blocks in the country. The target was to provide the benefits of PDS to remote and backward areas. From
June 1997, in a renewed attempt, Targeted Public Distribution System (TPDS) was introduced to adopt the principle of targeting the ‘poor in all areas’. It was for the first time that a differential price policy was adopted for poor and non-poor. In 2000, two special schemes were launched viz., Antyodaya Anna Yojana*** (AAY) and the Annapurna Scheme (APS) with special target groups .The functioning of these two schemes was linked with the existing network of the PDS. The PDS has proved to be the most effective instrument of government policy over the years in stabilising prices and making food available to consumers at affordable prices. AAY was launched in December 2000. Under the scheme one crore of the poorest among the BPL families covered under the targeted public distribution system were identified. Poor families were identified by the respective state rural development departments through a Below Poverty Line (BPL) survey. Twenty five kilograms of foodgrains were made available to each eligible family at a highly subsidised+ rate of Rs 2 per kg for wheat and Rs 3 per kg for rice.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 9

Question: 

9. Why is a buffer stock created by the government?

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Answer: 

Ans:- Buffer Stock is the stock of food grains, namely wheat and rice procured by the government through Food Corporation of India (FCI). The FCI purchases wheat and rice from the farmers in states where there is surplus production. The farmers are paid a pre-announced price for their crops. This buffer stock can be used during any natural calamity such as drought or earth quake.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 10

Question: 

10. Write notes on:
(a) Minimum support price
(b) Buffer stock
(c) Issue price
(d) Fair price shops

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Answer: 

(a) Minimum support price
Ans: The FCI purchases wheat and rice from the farmers in states where there is surplus production. The
farmers are paid a pre-announced price for their crops. This price is called Minimum Support Price.

(b) Buffer stock
Ans: Buffer Stock is the stock of food grains, namely wheat and rice procured by the government through Food Corporation of India (FCI). The FCI purchases wheat and rice from the farmers in states
where there is surplus production. The farmers are paid a pre-announced price for their crops. This buffer stock can be used during any natural calamity such as drought or earth quake.

(c) Issue price
Ans; To distribute foodgrains in the deficit areas and among the poorer strata of society at a price lower than the market price also known as Issue Price.

(d) Fair price shops
Ans: Ration shops also known as Fair Price Shops keep stock of foodgrains, sugar, kerosene oil for cooking. These items are sold to people at a price lower than the market price.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 11

Question: 

11. What are the problems of the functioning of ration shops?

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Answer: 

Ans:- PDS dealers are sometimes found resorting to malpractices like diverting the grains to open market to get better margin, selling poor quality grains at ration shops, irregular opening of the shops, etc. It is common to find that ration shops regularly have unsold stocks of poor quality grains left. This has proved to be a big problem.

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CBSE 9th Economics - Chap 4 - Food Security In India - Page 53 - Q 12

Question: 

12. Write a note on the role of cooperatives in providing food and related items.

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Answer: 

Ans:- The cooperatives are also playing an important role in food security in India especially in the southern and western parts of the country. The cooperative societies set up shops to sell low priced goods to poor people. In Delhi, Mother Dairy is making strides in provision of milk and vegetables to the consumers at controlled rate decided by Government of Delhi. Amul is another success story of cooperatives in milk and milk products from Gujarat. It has brought about the White Revolution in the country. These are a few examples of many more cooperatives running in different parts of the country ensuring food security of different sections of society.

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CBSE 9TH English

CBSE English - Chap 1 - The Fun They Had

CBSE English - Chap 1 - The Fun They Had - P10 - Q1

Question: 

I. Answer these questions in a few words or a couple of sentences each.
1. How old are Margie and Tommy?
2. What did Margie write in her diary?
3. Had Margie ever seen a book before?
4. What things about the book did she find strange?
5. What do you think a telebook is?
6. Where was Margie’s school? Did she have any classmates?
7. What subjects did Margie and Tommy learn?

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Answer: 

1. How old are Margie and Tommy?
Ans. Margie is eleven and Tommy is thirteen yrs old.
 
2. What did Margie write in her diary?
Ans. She wrote “Today Tommy found a real book!”.
 
3. Had Margie ever seen a book before?
Ans. No, she hadn’t.
 
4. What things about the book did she find strange?
Ans. The things she found strange about the book were-
*All stories were printed on paper.
*They turned the pages then, which were yellow and crinkly.
*It was awfully funny to read words that stood still instead of moving the way they were supposed to — on a screen.
*And then when they turned back to the page before, it had the same words on it that it had had when they read it the first time.
 
5. What do you think a telebook is?
Ans. A telebook is a virtual book which you can see and read on a television screen. The words and pages there scroll up and you don’t have to turn any pages to read further.
 
6. Where was Margie’s school? Did she have any classmates?
Ans. Margie’s school was in her home, right next to her bedroom. And no, she didn’t have any classmates.
 
7. What subjects did Margie and Tommy learn?
Ans. Geography, Arithmatic etc.

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CBSE English - Chap 1 - The Fun They Had - P10 - Q2

Question: 

II. Answer the following with reference to the story.

1. “I wouldn’t throw it away.”
(i) Who says these words?
(ii) What does ‘it’ refer to?
(iii) What is it being compared with by the speaker?

2. “Sure they had a teacher, but it wasn’t a regular teacher. It was a man.”
(i) Who does ‘they’ refer to?
(ii) What does ‘regular’ mean here?
(iii) What is it contrasted with?

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Answer: 
1. “I wouldn’t throw it away.”
(i) Who says these words?
Ans. Tommy said these words.
 
(ii) What does ‘it’ refer to?
Ans. ‘It’ refers to the television screen which shows all the telebooks content.
 
(iii) What is it being compared with by the speaker?
Ans. ‘It’ is being compared to a real book.
 
2. “Sure they had a teacher, but it wasn’t a regular teacher. It was a man.”
(i) Who does ‘they’ refer to?
Ans. ‘They’ refers to the children living centuries back, i.e., children like us.
 
(ii) What does ‘regular’ mean here?
Ans. ‘Regular means normal, of the usual kind.
 
(iii) What is it contrasted with?
Ans. It is contrasted with a mechanical teacher.

 


 

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CBSE English - Chap 1 - The Fun They Had - P10 - Q3

Question: 

III. Answer each of these questions in a short paragraph (about 30 words).
1. What kind of teachers did Margie and Tommy have?
2. Why did Margie’s mother send for the County Inspector?
3. What did he do?
4. Why was Margie doing badly in geography? What did the County Inspector do to help her?
5. What had once happened to Tommy’s teacher?
6. Did Margie have regular days and hours for school? If so, why?
7. How does Tommy describe the old kind of school?
8. How does he describe the old kind of teachers?

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Answer: 
1. What kind of teachers did Margie and Tommy have?
Ans. They had a mechanical teacher with a big screen on which all the lessons were shown and the questions were asked. It had a slot where they had to put homework and test papers. And they had to write them out in a punch code.
 
2. Why did Margie’s mother send for the County Inspector?
Ans. Margie’s mother sent for the CountyInspector because the mechanical teacher had been giving her test after test in geography and she had been doing worse and worse.
 
3. What did he do?
Ans. He smiled at Margie and gave her an apple, then took the teacher apart. He finally put it together again after an hour or so, making it right.
 
4. Why was Margie doing badly in geography? What did the County Inspector do to help her?
Ans. Margie was doing badly because the geography sector was geared a little too quick. So the CountyInspector slowed it up to an average ten-year level, to help her.
 
5. What had once happened to Tommy’s teacher?
Ans. They had once taken Tommy’s teacher away for nearly a month because the history sector had blanked out completely.
 
6. Did Margie have regular days and hours for school? If so, why?
Ans. Yes Margie had to attend her school on at the same time every day except Saturday and Sunday, because her mother said that little girls learned better if they learned at regular hours.
 
7. How does Tommy describe the old kind of school?
Ans. Tommy described the old kind of school as the one which existed centuries ago. A special building where all kids went together and where the teacher was a man.
8. How does he describe the old kind of teachers?
Ans. Tommy said that the old kind of teacher was a man and he lived in a special building where all kids went together. And he just told the boys and girls things and gave them homework and asked them questions.

 


 

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CBSE English - Chap 1 - The Fun They Had - P10 - Q4

Question: 

IV. Answer each of these questions in two or three paragraphs (100 –150 words).

1. What are the main features of the mechanical teachers and the schoolrooms that Margie and Tommy have in the story?

2. Why did Margie hate school? Why did she think the old kind of school must have been fun?

3. Do you agree with Margie that schools today are more fun than the school in the story? Give reasons for your answer.

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Answer: 

 

1. What are the main features of the mechanical teachers and the schoolrooms that Margie and Tommy have in the story?
Ans. Being robots the mechanical teacher could live in the house and the schoolrooms could be made in the house as well. The books used were telebooks whose words and pages scrolled up for reading. Millions of these telebooks could be stored in the memory and could be flashed on screen. The mechanical teacher was voice enabled too, so as to instruct the kids and ask questions. The homeworks and test papers were were written in a punch code and the mechanical teacher could calculate the marks in no time. The added advantage to this system was that the teacher could be adjusted to fit the mind of each boy and girl it taught.
 
2. Why did Margie hate school? Why did she think the old kind of school must have been fun?
Ans. She hated school because there she had to sit alone and listen to the mechanical teacher. She had started hating it more because recently there was a problem in the geography sector which was geared a little too quick. So the mechanical teacher gave her test after test and she kept doing worse and worse. So she started hating the complete slot where she had to put the homework and testpapers after writing them in the punch code.
She thought that the old school system must have been fun because there all the kids from the whole neighborhood came, laughing and shouting in the schoolyard, sitting together in the schoolroom and going home together at the end of the day. They learned the same things, so they could help one another with the homework and talk about it. And the teachers were people.
 
3. Do you agree with Margie that schools today are more fun than the school in the story? Give reasons for your answer.
Ans. Yes, the schools today are more fun than the school in the story. This is because today, all kids come together to study. The learn and grow together learning the same thing. They make friends there and enjoy the environment. The teachers being human, have feelings and they understand the problems of the students. If anyone has any problem, they can come front and ask their doubt. No such case is available with the mechanical teacher. Further learning together with kids of the same age makes them help each other and teaches them co operation and team work.
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CBSE English - Chap 1 - The Fun They Had - P11 - Q1 - Think about Languages

Question: 

I. Adverbs
Read this sentence taken from the story:
They had once taken Tommy’s teacher away for nearly a month because the history sector had blanked out completely.
The word complete is an adjective. When you add –ly to it, it becomes an adverb.

1. Find the sentences in the lesson which have the adverbs given in the box below.
awfully sorrowfully completely loftily
carefully differently quickly nonchalantly

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Answer: 
1. Find the sentences in the lesson which have the adverbs given in the box below.
 
Awfully: They turned the pages, which were yellow and crinkly, and it was awfully funny to read words that stood still instead of moving the way they were supposed to — on a screen, you know.
 
Sorrowfully: The mechanical teacher had been giving her test after test in geography and she had been doing worse and worse until her mother had shaken her head sorrowfully and sent for the CountyInspector.
 
Completely: They had once taken Tommy’s teacher away for nearly a month because the history sector had blanked out completely.
 
Loftily and Carefully: He added loftily, pronouncing the word carefully, “Centuries ago.”
 
Differently: But my mother says a teacher has to be adjusted to fit the mind of each boy and girl it teaches and that each kid has to be taught differently.
 
Quickly: “I didn’t say I didn’t like it,” Margie said quickly.
 
Nonchalantly: “May be,” he said nonchalantly.

 


 

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CBSE English - Chap 1 - The Fun They Had - P11 - Q2 - Think about Languages

Question: 

2. Now use these adverbs to fill in the blanks in the sentences below.

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Answer: 
(i) The report must be read carefully so that performance can be improved.
(ii) At the interview, Sameer answered our questions nonchalantly, shrugging his shoulders.
(iii) We all behave differently when we are tired or hungry.
(iv) The teacher shook her head sorrowfully when Ravi lied to her.
(v) I forgot about it completely.
(vi) When I complimented Revathi on her success, she just smiled loftily and turned away.
(vii) The President of the Company is awfully busy and will not be able to meet you.
(viii) I finished my work so that I could go out to play quickly.

 


 

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CBSE English - Chap 2 - The Sound of Music

Part I: Evelyn Glennie Listens to Sound without Hearing It - P20 - Q1

Question: 

I. Answer these questions in a few words or a couple of sentences each.
1. How old was Evelyn when she went to the Royal Academy of Music?
2. When was her deafness first noticed? When was it confirmed?

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Answer: 

1. How old was Evelyn when she went to the Royal Academy of Music?
Ans. She was sixteen yrs old.
 
2. When was her deafness first noticed? When was it confirmed?
Ans. Her deafness was first noticed at an age of eight by her mother. Then it was confirmed at the age of eleven.

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Part I: Evelyn Glennie Listens to Sound without Hearing It - P20 - Q2

Question: 

II. Answer each of these questions in a short paragraph (30–40 words).
1. Who helped her to continue with music? What did he do and say?
2. Name the various places and causes for which Evelyn performs.

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Answer: 
1. Who helped her to continue with music? What did he do and say?
Ans. She was helped by a percussionist called Ron Forbes. He began by tuning two large drums to different notes and asked her not to listen through her ears but try sensing it some other way.
 
2. Name the various places and causes for which Evelyn performs.
Ans. Apart from the regular concerts, Evelyn performs free concerts in prisons and hospitals.
She also gives high priority to classes for young musicians.

 


 

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Part I: Evelyn Glennie Listens to Sound without Hearing It - P20 - Q3

Question: 

III. Answer the question in two or three paragraphs (100–150 words).
1. How does Evelyn hear music?

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Answer: 

 

Evelyn says that music pours in through every part of her body. It tingles in her skin, her cheekbones and even in her hair. When she plays the xylophone, she can sense the sound passing up the stick into her fingertips. By leaning against the drums, she can feel the resonances flowing into her body. On a wooden platform she removes her shoes so that the vibrations pass through her bare feet and up her legs.
            God may have taken her hearing but he has given her back something extraordinary. What we hear, she feels – far more deeply than any of us.
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Part II: The Shehnai of Bismillah Khan - P26 - Q 3 - Thinking about the Text

Question: 

III. Answer these questions in 30–40 words.
1. Why did Aurangzeb ban the playing of the pungi?
2. How is a shehnai different from a pungi?
3. Where was the shehnai played traditionally? How did Bismillah Khan change this?
4. When and how did Bismillah Khan get his big break?
5. Where did Bismillah Khan play the shehnai on 15 August 1947? Why was the event historic?
6. Why did Bismillah Khan refuse to start a shehnai school in the U.S.A.?
7. Find at least two instances in the text which tell you that Bismillah Khan loves India and Benaras.

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Answer: 

 

1. Why did Aurangzeb ban the playing of the pungi?
Ans. Emperor Aurangzeb banned the playing of a musical instrument called pungi in the royal residence for it had a shrill unpleasant sound. Pungi became the generic name for reeded noisemakers.
 
2. How is a shehnai different from a pungi?
Ans. Shehnai is an advanced form of pungi with improved tonal quality. Structurewise it differs from pungi in the sense that it is a single hollow pipe with seven holes in it.
 
3. Where was the shehnai played traditionally? How did Bismillah Khan change
this?
Ans. Traditionally the Shehnai was played only in temples or weddings, or at a king’s ‘darbar’. Bismillah Khan changed this by bringing the shehnai to the classical stage.
 
4. When and how did Bismillah Khan get his big break?
Ans. With the opening of the All India Radio in Lucknow in 1938 came Bismillah’s big break. He soon became an often-heard shehnai player on radio.
 
5. Where did Bismillah Khan play the shehnai on 15 August 1947? Why was
the event historic?
Ans. On 15th August 1947, Bismillah Khan played the shehnai from the red fort. This event is historic because we got our national independence on this day.
 
6. Why did Bismillah Khan refuse to start a shehnai school in the U.S.A.?
Ans. Bismillah Khan refused to start a shehnai school in the school for his love for Benaras, Dumraon and river Ganga. Though his student promised to recreate the atmosphere of Benaras by replicating the temples there, Bismillah Khan asked him if he can transport river Ganga as well?
 
7. Find at least two instances in the text which tell you that Bismillah Khan
loves India and Benaras.
Ans. On Independence day, he poured his heart out in Raag Kafi while playing shehnai from the Red Fort.
And when asked to move out to USA, he refused saying that river Ganga is not there.
 
 
 
 

 

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Part II: The Shehnai of Bismillah Khan - P26 - Q1 - Thinking about Languages

Question: 

I. Look at these sentences.
• Evelyn was determined to live a normal life.
• Evelyn managed to conceal her growing deafness from friends and teachers.

The italicised parts answer the questions: “What was Evelyn determined to do?” and “What did Evelyn manage to do?” They begin with a to-verb (to live, to conceal).
Complete the following sentences. Beginning with a to-verb, try to answer the questions in brackets.

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Answer: 

 

1. The school sports team hopes (What does it hope to do?) to win.
2. We all want (What do we all want to do?) to be successful.
3. They advised the hearing-impaired child’s mother (What did they advise her to do?) to send him to a special school.
4. The authorities permitted us to (What did the authorities permit us to do?) celebrate in the hostel.
5. A musician decided to (What did the musician decide to do?) play his favourite composition.

 

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Part II: The Shehnai of Bismillah Khan - P26 - Q2 - Thinking about Language

Question: 

 

II. From the text on Bismillah Khan, find the words and phrases that match these definitions and write them down. The number of the paragraph where you will find the words/phrases has been given for you in brackets.

 

 

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Answer: 

 

1. The home of royal people (1): Palace
2. The state of being alone (5): Solitude
3. A part which is absolutely necessary (2): indispensable
4. To do something not done before (5): Invent
5. Without much effort (13): Effortlessly
6. Quickly and in large quantities (9): Thick and fast

 

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Part II: The Shehnai of Bismillah Khan - P26 - Q3 - Thinking about Languages

Question: 

III. Underline the right answer.

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Answer: 

 

1. When something is revived, it (remains dead/lives again).
2. When a government bans something, it wants it (stopped/started).
3. When something is considered auspicious, (welcome it/avoid it).
4. When we take to something, we find it (boring/interesting).
5. When you appreciate something, you (find it good and useful/find it of no use).
6. When you replicate something, you do it (for the first time/for the second time).

7. When we come to terms with something, it is (still upsetting/no longer upsetting)

 

 

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CBSE English - Chap 3 - The Little Girl

CBSE English - Chapter 3 - The Little Girl - Page 38 - Q1

Question: 

Given below are some emotions that Kezia felt. Match the emotions in Column A with the items in Column B.

Column A Column B
1. fear or terror (i) father comes into her room to give her a goodbye kiss
2. glad sense of relief (ii) noise of the carriage grows fainter
3. a “funny” feeling, perhaps (iii) father comes home of understanding
(iv) speaking to father
(v) going to bed when alone at home
(vi) father comforts her and falls asleep
(vii) father stretched out on the sofa, snoring

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Answer: 

1. Fear or terror -- (iv) speaking to father
2. Glad sense of relief -- (ii) noise of the carriage grows fainter
3. A “funny” feeling, perhaps of understanding -- (vi) father comforts her and falls asleep

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CBSE English - Chapter 3 - The Little Girl - Page 38 - Q2

Question: 

Answer the following questions in one or two sentences.
1. Why was Kezia afraid of her father?
2. Who were the people in Kezia’s family?
3. What was Kezia’s father’s routine?
(i) before going to his office?
(ii) after coming back from his office?
(iii) on Sundays?
4. In what ways did Kezia’s grandmother encourage her to get to know her father better?

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Answer: 

1. Why was Kezia afraid of her father?
Ans. Kezia was afraid of her father because she thought he was too big — his hands and his neck, especially his mouth when he yawned. Thinking about him alone was like thinking about a giant for her.

2. Who were the people in Kezia’s family?
Ans. Kezia’s family constituted of her grandmother, her father, mother and herself.

3. What was Kezia’s father’s routine?
(i) before going to his office?
Ans. Every morning before going to work he came into her room and gave her a casual kiss.
(ii) after coming back from his office?
Ans. After coming back from his office he asked for his tea, newspaper and his slippers.
(iii) on Sundays?
Ans. On Sundays he preferred stretching out on the sofa, his handkerchief on his face, his feet on one of the best cushions, sleeping soundly and snoring.

4. In what ways did Kezia’s grandmother encourage her to get to know her father better?
Ans. On Sunday afternoons, Kezia’s grandmother sent her down to the drawing-room to have a “nice talk with Father and Mother”. She also suggested her to make a pin-cushion out of a beautiful piece of yellow silk, as a birthday gift for her father.

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CBSE English - Chapter 3 - The Little Girl - Page 38 - Q3

Question: 

Discuss these questions in class with your teacher and then write down your answers in two or three paragraphs each.
1. Kezia’s efforts to please her father resulted in displeasing him very much. How did this happen?
2. Kezia decides that there are “different kinds of fathers”. What kind of father was Mr Macdonald, and how was he different from Kezia’s father?
3. How does Kezia begin to see her father as a human being who needs her sympathy?

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Answer: 

1. Kezia’s efforts to please her father resulted in displeasing him very much. How did this happen?
Ans. As suggested by her Granny, Krezia was making a pin cushion out of a beautiful piece of yellow silk, as a gift for her father’s birthday.
She stitched three sides laboriously with double cotton but was not sure of what to fill it with. And as her grandmother was out in the garden, she wandered into her mother’s bedroom to look for scraps. On the bed-table she discovered a great many sheets of fine paper. So she gathered them up, tore them into tiny pieces, and stuffed her case, then sewed up the fourth side.
But to her horror, it turned out to be her father’s great speech for the Port Authority. And so her father got displeased from her very much.

2. Kezia decides that there are “different kinds of fathers”. What kind of father was Mr Macdonald, and how was he different from Kezia’s father?
Ans. The Macdonalds lived next door. They had five children. Looking through a gap in the fence Kezia saw them playing ‘tag’ in the evening. The father with the baby, Mao, on his shoulders, two little girls hanging on to his coat pockets ran round and round the flower-beds, shaking with laughter. Once she saw the boys turn the hose on him—and he tried to catch them laughing all the time.
So she decided that there were different kinds of father because her father never played with her or behave so lovingly.

3. How does Kezia begin to see her father as a human being who needs her sympathy?
Ans. One night Kezia’s mother fell ill and was admitted to the hospital. Her granny also stayed in the hospital. So she was left to sleep alone in her room. That night when she woke up, afraid from a nightmare, she found her father standing beside her with a candle in his hand. He then caught her up in his arms and took her to his bedroom and laid beside her and asked her to rub her feet against his to get some warmth. Being afraid and half asleep Krezia then crept close to him, snuggled her head under his arm and held tightly to his shirt.
But being tired, her father slept off before her. Krezia had never seen her father caring so much about her. It was then that she realized that her father was not so big. He was also a human being who after working the whole day could not behave like Mr. MacDonald. And she had torn his important speech, so he had to get angry.

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CBSE English - Chap 4 - A Truly Beautiful Mind

CBSE English - Chapter 4 - A Truly Beautiful Mind - Page 51 - Q2

Question: 

2. Who had these opinions about Einstein?
(i) He was boring.
(ii) He was stupid and would never succeed in life.
iii) He was a freak.

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Answer: 

2. Who had these opinions about Einstein?
(i) He was boring.
Ans. His playmates.
(ii) He was stupid and would never succeed in life.
Ans. His headmaster.
(iii) He was a freak.
Ans. His mother.

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CBSE English - Chapter 4 - A Truly Beautiful Mind - Page 51 - Q3

Question: 

3. Explain what the reasons for the following are.
(i) Einstein leaving the school in Munich for good.
(ii) Einstein wanting to study in Switzerland rather than in Munich.
(iii) Einstein seeing in Mileva an ally.
(iv) What do these tell you about Einstein?

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Answer: 

3. Explain what the reasons for the following are.
(i) Einstein leaving the school in Munich for good.
Ans. Einstein was a revolutionarist . He hated the school’s regimentation, and often clashed with his teachers. So he felt stifled there and finally quit the school.
(ii) Einstein wanting to study in Switzerland rather than in Munich.
Ans. Einstein didn’t like the regimentation in Munich schools. And since his parents had also shifted to Milan, he decided to study in Switzerland because it was more liberal than Munich, and also the people there spoke German.
(iii) Einstein seeing in Mileva an ally.
Ans. Einstein saw an ally in Mileva because she was intelligent and she was also against the “philistines”— those people in his family and at the university with whom he was constantly at odds.
(iv) What do these tell you about Einstein?
Ans. All this is an indication that Einstein was a revolutionarist. He didn’t like his ideas to be shackled in chains of regimentation. He was also a very broad minded person who liked women getting higher degrees.

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CBSE English - Chapter 4 - A Truly Beautiful Mind - Page 51 - Q4

Question: 

4. What did Einstein call his desk drawer at the patent office? Why?

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Answer: 

4. What did Einstein call his desk drawer at the patent office? Why?
Ans. Einstein called his desk drawer as the “bureau of theoretical physics.” This was because he kept all his innovative ideas and works in that drawer.

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CBSE English - Chapter 4 - A Truly Beautiful Mind - Page 51 - Q5

Question: 

5. Why did Einstein write a letter to Franklin Roosevelt?

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Answer: 

5. Why did Einstein write a letter to Franklin Roosevelt?
Ans. Einstein was worried about the fact that the Nazis were developing an atom bomb. He was aware of the impact that an atom bomb could bring in. So he warned the then US president, Franklin D. Roosevelt in his letter.

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CBSE English - Chapter 4 - A Truly Beautiful Mind - Page 51 - Q6

Question: 

6. How did Einstein react to the bombing of Hiroshima and Nagasaki?

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Answer: 

6. How did Einstein react to the bombing of Hiroshima and Nagasaki?
Ans. Einstein was deeply shaken by the extent of the destruction brought in to Hiroshima and Nagasaki by the use of atom bomb there. So he wrote a public missive to the United Nations. In it he proposed the formation of a world government. But unlike the letter to Roosevelt, this one made no impact.
Over the next decade, Einstein got even more involved in politics — agitating for an end to the arms buildup and using his popularity to campaign for peace and democracy.

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CBSE English - Chapter 4 - A Truly Beautiful Mind - Page 51 - Q7

Question: 

7. Why does the world remember Einstein as a “world citizen”?

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Answer: 

7. Why does the world remember Einstein as a “world citizen”?
Ans. Einstein was born in Germany, but he lived in many countries in his life time. He was a peace messenger and supported humanity, rather than the power quest of different countries. Though he was born in Germany, and was in America then, he was worried about the impact of the atom bomb if the Nazis used it and was agitated when the Americans actually used it. He also participated in politics to protest against the use of nuclear weapons throughout the world. That is why, we remember him as a world citizen.

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CBSE English - Chap 5 - The Snake and The Mirror

CBSE English - Chapter 5 - The Snake And The Mirror - Page 60 - Q1

Question: 

I. Discuss in pairs and answer each question below in a short paragraph (30–40 words).
1. “The sound was a familiar one.” What sound did the doctor hear? What did he think it was? How many times did he hear it? (Find the places in the text.) When and why did the sounds stop?
2. What two “important” and “earth-shaking” decisions did the doctor take while he was looking into the mirror?
3. “I looked into the mirror and smiled,” says the doctor. A little later he says, “I forgot my danger and smiled feebly at myself.” What is the doctor’s opinion about himself when
(i) he first smiles
(ii) he smiles again? In what way do his thoughts change in between, and why?

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Answer: 

1. “The sound was a familiar one.” What sound did the doctor hear? What did he think it was? How many times did he hear it? (Find the places in the text.) When and why did the sounds stop?
Ans. The Dr. heard the sound of a snake moving on the beam. He thought it were the regular sound of rats running on the beam. He heard it three times.
The sounds finally stopped because the snake had stopped moving and was about to fall from the beam.
2. What two “important” and “earth-shaking” decisions did the doctor take while he was looking into the mirror?
Ans. The doctor was young and unmarried. He was also a great admirer of beauty in those days, so he thought he should look handsome. In that jovial mood while looking at himself in the mirror, he decided that he would shave daily and would grow a thin moustache. Another important decision was to keep an attractive smile on his face always.

3. “I looked into the mirror and smiled,” says the doctor. A little later he says, “I forgot my danger and smiled feebly at myself.” What is the doctor’s opinion about himself when
(i) he first smiles
Ans. First time when the doctor smiled, looking at himself in the mirror, he thought that he looks handsome with that attractive smile on his face. And so he decides that he would always keep smiling.
(ii) he smiles again? In what way do his thoughts change in between, and why?
Ans. This time when the doctor smiled, his left arm had a cobra coiled around it and whose hood was a few inches away from his face. Death was lurking four inches away. So the doctor started thinking about the medicines required if the cobra struck. He then realized that there were no medicines in that room and he didn’t even have the money to buy them. At this thought, he sarcastically smiled at his condition.
Earlier while the doctor was thinking to look handsome as he was unmarried and a doctor on top of it, later he finds himself helpless and thinks that he was nothing but a poor, foolish and stupid doctor. But this change of feeling was certainly temporary in the view of natural helplessness. There was nothing he could do at that time but to pity on his situation.

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CBSE English - Chap 6 - My ChildHood

CBSE English - Chapter 6 - My Childhood - Page 75 - Q1

Question: 

Answer these questions in one or two sentences each.
1. Where was Abdul Kalam’s house?
2. What do you think Dinamani is the name of? Give a reason for your answer.
3. Who were Abdul Kalam’s school friends? What did they later become?
4. How did Abdul Kalam earn his first wages?
5. Had he earned any money before that? In what way?

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Answer: 

1. Where was Abdul Kalam’s house?
Ans. Abdul Kalam’s house was on the Mosque Street in Rameswaram.

2. What do you think Dinamani is the name of? Give a reason for your answer.
Ans. Dinamani should be the name of a newspaper. We can say this because in the time about which Dr. Kalam has talked (1939), India had not seen the radio, television or internet. So the only facility available then to get the headlines was a newspaper.

3. Who were Abdul Kalam’s school friends? What did they later become?
Ans. Kalam had three close friends in school – Ramanadha Sastry, Aravindan and Sivaprakasan. Ramanadha Sastry was the son of Pakshi Lakshmana Sastry, the high priest of the Rameswaram templeso later, he took over the priesthood of the Rameswaram temple from his father; Aravindan went into the business of arranging transport for visiting pilgrims; and Sivaprakasan became a catering contractor for the Southern Railways.

4. How did Abdul Kalam earn his first wages?
Ans. When India was forced to join the Allied Forces and an emergency was declared, the first casualty came in the form of the suspension of the train halt at Rameswaram station. As a result the newspaper had to be bundled and thrown out from the moving train on the Rameswaram Road between Rameswaram and Dhanuskodi. This forced Kalam’s cousin Samsuddin, who distributed newspapers in Rameswaram, to look for a helping hand to catch the bundles. So he employed Kalam for the job, and in this way, he earned his first wages.

5. Had he earned any money before that? In what way?
Ans. Yes he had earned some money before this.
With the breaking out of the Second World War in 1939, a sudden demand for tamarind seeds erupted in the market. So Kalam used to collect the seeds and sell them to a provision shop on Mosque Street. A day’s collection fetched him one anna.

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CBSE English - Chapter 6 - My Childhood - Page 75 - Q2

Question: 

Answer each of these questions in a short paragraph (about 30 words) 1. How does the author describe: (i) his father, (ii) his mother, (iii) himself? 2. What characteristics does he say he inherited from his parents?

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Answer: 

1. How does the author describe: (i) his father, (ii) his mother, (iii) himself? Ans. Kalam calls his father an austere person who used to avoid all inessential comforts and luxuries. However, he provided his family with all necessities, in terms of food, medicine or clothes. His father, Mr. Jainulabdeen, had neither much formal education nor much wealth. But despite these disadvantages, he possessed great innate wisdom and a true generosity of spirit. Kalam’s mother Mrs. Ashiamma was an ideal helpmate to his father. She fed far more outsiders along with the members of her our own family. Kalam describes himself as a short boy with rather undistinguished looks, born to tall and handsome parents. But this only shows his humble nature. A great personality who doesn’t believe in praising himself, even after all that he has achieved. 2. What characteristics does he say he inherited from his parents? Ans. Kalam says that he inherited honesty and self-discipline from his father and from his mother, he inherited faith in goodness and deep kindness.

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CBSE English - Chapter 6 - My Childhood - Page 75 - Q3

Question: 

Discuss these questions in class with your teacher and then write down your answers in two or three paragraphs each.

1. “On the whole, the small society of Rameswaram was very rigid in terms of the segregation of different social groups,” says the author.
(i) Which social groups does he mention? Were these groups easily identifiable (for example, by the way they dressed)?

(ii) Were they aware only of their differences or did they also naturally share friendships and experiences? (Think of the bedtime stories in Kalam’s house; of who his friends were; and of what used to take place in the pond near his house.)
(iii) The author speaks both of people who were very aware of the differences among them and those who tried to bridge these differences. Can you identify such people in the text?
2. (i) Why did Abdul Kalam want to leave Rameswaram?
ii) What did his father say to this?
(iii) What do you think his words mean? Why do you think he spoke those words?

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Answer: 

1. “On the whole, the small society of Rameswaram was very rigid in terms of the segregation of different social groups,” says the author.
(i) Which social groups does he mention? Were these groups easily identifiable (for example, by the way they dressed)?
Ans. Kalam has mentioned about two major social groups existing in Rameswaram – The Hindu Brahmins and the Muslims.
Yes these groups were easily identifiable from their appearances. The Hindu Brahmins wore a sacred thread and the Muslims wore a cap.

(ii) Were they aware only of their differences or did they also naturally share friendships and experiences? (Think of the bedtime stories in Kalam’s house; of who his friends were; and of what used to take place in the pond near his house.)
Ans. They were very well aware of their differences but they still naturally shared friendships and experiences. And that makes our India so special with people from different diversities living here in harmony.
The three close friends of Kalam were all from orthodox Hindu Brahmin family. But still all of them were inseparable. During the annual Shri Sita Rama Kalyanam ceremony, Kalam’s family used to arrange boats with a special platform for carrying idols of the Lord from the temple to the marriage site, situated in the middle of the pond called Rama Tirtha. Further, Kalam and his siblings were not only told the events from the life of the Prophet, but also from the Ramayana, as the bedtime stories from his mother and grandmother.

(iii) The author speaks both of people who were very aware of the differences among them and those who tried to bridge these differences. Can you identify such people in the text?
Ans. Such persons include Kalam’s own family members who helped the Hindus in the Shri Sita Rama Kalyanam. Further his mother and grandmother not only told their children the events from the life of the Prophet , but also from the Ramayana as their bedtime stories.
Then there was Pakshi Lakshmana Sastry, the high priest of the Rameswaram temple and his friend Ramanadha Sastry’s father who was against spreading the poison of social inequality and communal intolerance in the minds of innocent children.
There was his science teacher Sivasubramania Iyer as well, who although being an orthodox Brahmin, called Kalam to his home and fed him the food from his own hands.

2. (i) Why did Abdul Kalam want to leave Rameswaram?
Ans. Kalam wanted to leave Rameswaram to study at the district headquarters in Ramanathapuram. The Second World War had got over by then and the whole country was optimistic towards a free and self governed India. This optimism also got into Kalam and he thought of doing something for the nation by getting educated at a better place.

(ii) What did his father say to this?
Ans. His father readily agreed to it and said that he knew that one day Kalam had to go away. He gave the example of a seagull to him. He even consoled Kalam’s hesitant mother by quoting from the Khalil Gibran that our children are not actually ours but that of the Life’s longing for itself. They come to us but not from us. We can only give them our love but not our thoughts because they come with their own thoughts.

(iii) What do you think his words mean? Why do you think he spoke those words?
Ans. Kalam’s father may not be educated much but he possessed great innate wisdom and was a visionary. He could see that his son had something in him to do big. That’s why he gave him the example of a seagull who flies across the Sun alone and without a nest. He knew that Kalam had to leave home to grow. He also consoled Kalam’s mother, who was hesitant in sending Kalam away from her, by quoting the lines from Khalil Gibran which stated that no human being is bound to anyone. They have their own life and they owe to the Mother Nature for that. They come to their parents, not to serve them but to do something great in their life. So it’s the duty of the parents to love them and not impose their own thoughts over them. Everyone has got their own thinking and they should be left to lead their life, their own way.

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CBSE English - Chap 7 - Packing

CBSE English - Chapter 7 - Packing - Page 89 - Q1

Question: 

I. Discuss in pairs and answer each question below in a short paragraph (30 – 40 words).

1. How many characters are there in the narrative? Name them. (Don’t forget the dog!).
2. Why did the narrator (Jerome) volunteer to do the packing?
3. How did George and Harris react to this? Did Jerome like their reaction?
4. What was Jerome’s real intention when he offered to pack?
5. What did Harris say after the bag was shut and strapped? Why do you think he waited till then to ask?
6. What “horrible idea” occurred to Jerome a little later?
7. Where did Jerome finally find the toothbrush?
8. Why did Jerome have to reopen the packed bag?
9. What did George and Harris offer to pack and why?

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Answer: 

1. How many characters are there in the narrative? Name them. (Don’t forget the dog!).
Ans. There are four characters in the narrative. Jerome (the narrator), Harris, George and Montmorency (the dog).

2. Why did the narrator (Jerome) volunteer to do the packing?
Ans. The narrator volunteered to do the packing because he thought he was quite good at packing and could do the job better than anyone living on Earth. He also knew how bad Harris and George were at the work.

3. How did George and Harris react to this? Did Jerome like their reaction?
Ans. George and Harris fell into the suggestion with a readiness and left the entire job on Jerome. George put on a pipe and spread himself over the easy-chair, and Harris cocked his legs on the table and lit a cigar.
No Jerome didn’t like their reaction because he intended a little differently at his suggestion.

4. What was Jerome’s real intention when he offered to pack?
Ans. When Jerome offered to pack, he actually meant to boss the job. He thought of supervising and Harris & George pottering about under his directions.

5. What did Harris say after the bag was shut and strapped? Why do you think he waited till then to ask?
Ans. When the bag was shut and strapped, Harris asked Jerome if he was not going to put the boots in?
He waited till then to ask to make fun of Jerome. He knew that Jerome thought of himself as a great packer, so he enjoyed every mistake of his and made fun sarcastically.

6. What “horrible idea” occurred to Jerome a little later?
Ans. Jerome, though being a great person in the art of packing, often remained unsure if he had packed his toothbrush. So every time, even though he had taken his toothbrush, the very idea of it haunted him. And that’s why, he calls this worried feeling as an horrible idea.

7. Where did Jerome finally find the toothbrush?
Ans. He finally found it inside a boot.

8. Why did Jerome have to reopen the packed bag?
Ans. He had to reopen the packed bag to check whether he had taken the toothbrushes. He always had this feeling that he did not take his toothbrush along. So he wanted to make sure that he had taken it.

9. What did George and Harris offer to pack and why?
Ans. George and Harris offered to pack the hampers. It was getting late and they thought that Jerome had taken just too much of time packing the bag, so they wanted to show him how to do the work more efficiently.

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CBSE English - Chapter 7 - Packing - Page 89 - Q2

Question: 

II. What does Jerome say was Montmorency’s ambition in life? What do you think of Montmorency and why?

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Answer: 

Ans. As per Jerome, Montmorency’s ambition in life was to get in the way and be sworn at. If he could squirm in anywhere where he particularly was not wanted, and be a perfect nuisance, and make people mad, and things thrown at his head, then he felt his day had not been wasted. To get somebody to stumble over him, and curse him steadily for an hour, was his highest aim and object; and, when he had succeeded in accomplishing this, his conceit became quite unbearable.
The narrator has talked of Montmorency in a way that it seems, he was a mischievous little child who loved creating troubles for others. But we should not forget that he was just a dog sans much mind like the humans. All he wanted was a little attention from his masters. Whenever he found people busy with their work, he might feel bored and wanted to get involved. He meant no trouble intentionally. But when people shouted at him or threw things at his head, he got discouraged and then went away to sit silently, which the narrator calls as the fulfillment of his conceit. He might also be hungry because till the time Jerome was packing, he is seen nowhere but then suddenly his presence becomes so evident when the packing of hampers is started.
This story is actually written in a humorous way with irony over every instance and decisions. In this attempt, the author has also used Montmorency as a vivid character in the story. He has described him as one of the nuisances among all the idiotics that kept happening in that room.

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CBSE English - Chapter 7 - Packing - Page 89 - Q3

Question: 

III. Discuss in groups and answer the following questions in two or three paragraphs (100 –150 words)

1. Of the three, Jerome, George and Harris, who do you think is the best or worst packer? Support your answer with details from the text.
2. How did Montmorency ‘contribute’ to the packing?
3. Do you find this story funny? What are the humorous elements in it?
(Pick out at least three, think about what happens, as well as how it is described.)

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Answer: 

1. Of the three, Jerome, George and Harris, who do you think is the best or worst packer? Support your answer with details from the text.
Ans. Out of the three, Jerome was of course the best packer. He knew how to arrange things in order, while all that Harris and George could do was breaking a cup; placing hard things over the soft ones; fighting hard to adjust a pack of butter, and getting constantly irritated by Montmorency. Till the time Jerome packed, although he took his time, we can’t find Montmorency disturbing him though he was present there in the room. But then suddenly his presence is felt as a nuisance when Harris and George take up the job. They even kept things behind them and then kept searching for it. They made everything such a mess that they couldn’t even see what they tread on.

2. How did Montmorency ‘contribute’ to the packing?
Ans. Montmorency’s ambition in life was to get in the way and be sworn at. He squirmed in everywhere when he particularly was not wanted, and became a perfect nuisance. He made Harris and George go mad at him.
He came and sat down on things, just when they were wanted to be packed; and he labored under the fixed belief that, whenever Harris or George reached out their hand for anything, it was his cold damp nose that they wanted. He put his leg into the jam and worried the teaspoons. He also pretended that the lemons were rats. So he got into the hamper and killed three of them before Harris could land him with the frying-pan.

3. Do you find this story funny? What are the humorous elements in it?
(Pick out at least three, think about what happens, as well as how it is described.)
Ans. Yes this story is surely funny. The sarcastic approach that the author has used and also the irony about the incidences & decisions, makes it quite humorous.
Just for example, the way Harris reminds Jerome of the boots when the bag was shut and strapped; or the way in which Harris and George do their packing; even the plot of Montmorency are all very funny.

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CBSE English - Chap 8 - Reach for the Top

CBSE English - Chapter 8 - Reach For The Top - Page 102 - Q1

Question: 

I. Answer these questions in one or two sentences each. (The paragraph numbers within brackets provide clues to the answers.)

1. Why was the ‘holy man’ who gave Santosh’s mother his blessings surprised? (1)
2. Give an example to show that even as a young girl Santosh was not ready to accept anything unreasonable. (2)
3. Why was Santosh sent to the local school? (3)
4. When did she leave home for Delhi, and why? (4)
5. Why did Santosh’s parents agree to pay for her schooling in Delhi? What mental qualities of Santosh are brought into light by this incident? (4)

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Answer: 

1. Why was the ‘holy man’ who gave Santosh’s mother his blessings surprised? (1)
Ans. Santosh was born in a society where the birth of a son was regarded as a blessing, and a daughter, though not considered a curse, was not generally welcome. So the holy man, while giving the blessings to unborn child’s mother, assumed that she wanted a son. But, to everyone’s surprise, Santosh’s grandmother, who was standing close by, told him that they did not want a son. At this the holy man was surprised.

2. Give an example to show that even as a young girl Santosh was not ready to accept anything unreasonable. (2)
Ans. In her young age, Santosh preferred wearing shorts while the girls were supposed to wear traditional Indian dresses. This shows that she was not ready to accept anything unreasonable.

3. Why was Santosh sent to the local school? (3)
Ans. Being a girl, Santosh was not supposed to get higher education. Girls in her village were married at the age of sixteen. So, in line with the prevailing custom in the family, Santosh had to make do with the local village school

4. When did she leave home for Delhi, and why? (4)
Ans. She left home for Delhi at an age of sixteen. She did so in her urge to get higher education before getting married.

5. Why did Santosh’s parents agree to pay for her schooling in Delhi? What mental qualities of Santosh are brought into light by this incident? (4)
Ans. Santosh’s parents though that they could compel to agree to their wishes by threatening her not to pay fees for her higher studies..But when Santosh humbly told them that she still wishes to continue her studies, by earning money through some part time job, her parents finally, bowed down to her determination and firmness and they agreed to pay the school fees.
This the mental toughness of Santosh. She was very determined about what she wished to do.

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CBSE English - Chapter 8 - Reach For The Top - Page 103 - Q2

Question: 

II. Answer each of these questions in a short paragraph (about 30 words).
1. How did Santosh begin to climb mountains?
2. What incidents during the Everest expedition show Santosh’s concern for her team-mates?
3. What shows her concern for the environment?
4. How does she describe her feelings at the summit of the Everest?
5. Santosh Yadav got into the record books both times she scaled Mt. Everest. What were the reasons for this?

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Answer: 

1. How did Santosh begin to climb mountains?
Ans. In Jaipur, Santosh’s Hostel faced the Aravalli hills. She always saw a few peole going up the hills and then vanishing. So she decided to check the matter herself. At the hills she only saw a few mountaineers, whom she asked if she could join them. The Mountaineers agreed and thus she began to climb mountains.

2. What incidents during the Everest expedition show Santosh’s concern for her team-mates?
Ans. During the 1992 Everest mission, Santosh Yadav provided special care to a climber who lay dying at the South Col. She was unfortunately unsuccessful in saving him. However, she managed to save another climber, Mohan Singh, who would have met with the same fate had she not shared her oxygen with him.

3. What shows her concern for the environment?
Ans. As a fervent environmentalist, Santosh collected and brought down 500 kilograms of garbage from the Himalayas. This shows her concern for the environment.

4. How does she describe her feelings at the summit of the Everest?
Ans. Describing her feelings at the summit of the Everest, Santosh said that it took some time for the enormity of the moment to sink in... Then she unfurled the Indian tricolour and held it aloft on the roof of the world. It was a spiritual moment for her and she felt proud as an Indian.

5. Santosh Yadav got into the record books both times she scaled Mt. Everest. What were the reasons for this?
Ans. First time when Santosh scaled the Mt. Everest at the age of twenty, she became the youngest woman of the world to achieve that feat.
And when she scaled it the second time, she set a record as the only woman to have scaled the Everest twice.

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CBSE English - Chap 9 - The Bond of Love

CBSE English - Chap 10 - Kathmandu

CBSE English - Chap 11 - IF I were You

CBSE 9TH History

ICH helps the Class IX Students of CBSE History ( free online Guide) to go through the latest updates by the CBSE Board.Here you will find information on CBSE Class IX History Sample Papers, CBSE IX History Guess Papers, CBSE Class IX History Syllabus and NCERT Texbook Solutions

CBSE 9TH Maths

Maths Syllabus 2010 - CBSE IX

Course Structure

Class IX

One Paper Time : 3 Hours Marks : 80

UNITS MARKS

I. NUMBER SYSTEMS 06

II. ALGEBRA 20

III. COORDINATE GEOMETRY 06

IV. GEOMETRY 22

V. MENSURATION 14

VI. STATISTICS AND PROBABILITY 12

TOTAL 80

UNIT I : NUMBER SYSTEMS

1. REAL NUMBERS (20) Periods

Review of representation of natural numbers, integers, rational numbers on the number line. Representation of terminating / non-terminating recurring decimals, on the number line through successive magnification. Rational numbers as recurring/terminating decimals. Examples of nonrecurring / non terminating decimals such as etc. Existence of non-rational numbers (irrational numbers) such as and their representation on the number line. Explaining that every real number is represented by a unique point on the number line and conversely, every point on the number line represents a unique real number. Existence of √x for a given positive real number x (visual proof to be emphasized). Definition of nth root of a real number. Recall of laws of exponents with integral powers. Rational exponents with positive real bases (to be done by particular cases, allowing learner to arrive at the general laws.) Rationalization (with precise meaning) of real numbers of the type (& their combinations) where x and y are natural number and a, b are integers.

UNIT II : ALGEBRA

1. POLYNOMIALS (25) Periods

Definition of a polynomial in one variable, its coefficients, with examples and counter examples, its terms, zero polynomial. Degree of a polynomial. Constant, linear, quadratic, cubic polynomials; monomials, binomials, trinomials. Factors and multiples. Zeros/roots of a polynomial / equation. State and motivate the Remainder Theorem with examples and analogy to integers. Statement and proof of the Factor Theorem. Factorization of ax2 + bx + c, a ≠ 0 where a, b, c are real numbers, and of cubic polynomials using the Factor Theorem. Recall of algebraic expressions and identities. Further identities of the type (x + y + z)2 = x2 + y2 + z2 + 2xy + 2yz + 2zx, (x y)3 = x3 y3 3xy (x y). x3 + y3 + z3 - 3xyz = (x + y + z) (x2 + y2 + z2 - xy - yz - zx) and their use in factorization of polymonials. Simple expressions reducible to these polynomials.

2. LINEAR EQUATIONS IN TWO VARIABLES (12) Periods

Recall of linear equations in one variable. Introduction to the equation in two variables. Prove that a linear equation in two variables has infinitely many solutions and justify their being written as ordered pairs of real numbers, plotting them and showing that they seem to lie on a line. Examples, problems from real life, including problems on Ratio and Proportion and with algebraic and graphical solutions being done simultaneously.

UNIT III : COORDINATE GEOMETRY

1. COORDINATE GEOMETRY (9) Periods

The Cartesian plane, coordinates of a point, names and terms associated with the coordinate plane, notations, plotting points in the plane, graph of linear equations as examples; focus on linear equations of the type ax + by + c = 0 by writing it as y = mx + c and linking with the chapter on linear equations in two variables.

UNIT IV : GEOMETRY

1. INTRODUCTION TO EUCLID'S GEOMETRY (6) Periods

History - Euclid and geometry in India. Euclid's method of formalizing observed phenomenon into rigorous mathematics with definitions, common/obvious notions, axioms/postulates and theorems. The five postulates of Euclid. Equivalent versions of the fifth postulate. Showing the relationship between axiom and theorem.

1. Given two distinct points, there exists one and only one line through them.

2. (Prove) two distinct lines cannot have more than one point in common.

2. LINES AND ANGLES (10) Periods

1. (Motivate) If a ray stands on a line, then the sum of the two adjacent angles so formed is 180o and the converse.
2. (Prove) If two lines intersect, the vertically opposite angles are equal.
3. (Motivate) Results on corresponding angles, alternate angles, interior angles when a transversal intersectstwo parallel lines.
4. (Motivate) Lines, which are parallel to a given line, are parallel.
5. (Prove) The sum of the angles of a triangle is 180o.
6. (Motivate) If a side of a triangle is produced, the exterior angle so formed is equal to the sum of the twointeriors opposite angles.

3. TRIANGLES (20) Periods

1. (Motivate) Two triangles are congruent if any two sides and the included angle of one triangle is equalto any two sides and the included angle of the other triangle (SAS Congruence).
2. (Prove) Two triangles are congruent if any two angles and the included side of one triangle is equal toany two angles and the included side of the other triangle (ASA Congruence).
3. (Motivate) Two triangles are congruent if the three sides of one triangle are equal to three sides of theother triangle (SSS Congruene).
4. (Motivate) Two right triangles are congruent if the hypotenuse and a side of one triangle are equal(respectively) to the hypotenuse and a side of the other triangle.
5. (Prove) The angles opposite to equal sides of a triangle are equal.
6. (Motivate) The sides opposite to equal angles of a triangle are equal.
7. (Motivate) Triangle inequalities and relation between 'angle and facing side' inequalities in triangles.

4. QUADRILATERALS (10) Periods

1. (Prove) The diagonal divides a parallelogram into two congruent triangles.
2. (Motivate) In a parallelogram opposite sides are equal, and conversely.
3. (Motivate) In a parallelogram opposite angles are equal, and conversely.
4. (Motivate) A quadrilateral is a parallelogram if a pair of its opposite sides is parallel and equal.
5. (Motivate) In a parallelogram, the diagonals bisect each other and conversely.
6. (Motivate) In a triangle, the line segment joining the mid points of any two sides is parallel to the third side and (motivate) its converse.

5. AREA (4) Periods

Review concept of area, recall area of a rectangle.

1. (Prove) Parallelograms on the same base and between the same parallels have the same area.
2. (Motivate) Triangles on the same base and between the same parallels are equal in area and its converse.

6. CIRCLES (15) Periods

Through examples, arrive at definitions of circle related concepts, radius, circumference, diameter, chord,arc, subtended angle.

1. (Prove) Equal chords of a circle subtend equal angles at the center and (motivate) its converse.
2. (Motivate) The perpendicular from the center of a circle to a chord bisects the chord and conversely,the line drawn through the center of a circle to bisect a chord is perpendicular to the chord.
3. (Motivate) There is one and only one circle passing through three given non-collinear points.
4. (Motivate) Equal chords of a circle (or of congruent circles) are equidistant from the center(s) andconversely.
5. (Prove) The angle subtended by an arc at the center is double the angle subtended by it at any point on the remaining part of the circle.
6. (Motivate) Angles in the same segment of a circle are equal.
7. (Motivate) If a line segment joining two points subtendes equal angle at two other points lying on thesame side of the line containing the segment, the four points lie on a circle.
8. (Motivate) The sum of the either pair of the opposite angles of a cyclic quadrilateral is 180o and itsconverse

7. CONSTRUCTIONS (10) Periods

1. Construction of bisectors of line segments & angles, 60o, 90o, 45o angles etc., equilateral triangles.
2. Construction of a triangle given its base, sum/difference of the other two sides and one base angle.
3. Construction of a triangle of given perimeter and base angles.

UNIT V : MENSURATION

1. AREAS (4) Periods

Area of a triangle using Hero's formula (without proof) and its application in finding the area of a quadrilateral.

2. SURFACE AREAS AND VOLUMES (10) Periods
Surface areas and volumes of cubes, cuboids, spheres (including hemispheres) and right circular cylinders/cones.

UNIT VI : STATISTICS AND PROBABILITY

1. STATISTICS (13) Periods

Introduction to Statistics : Collection of data, presentation of data - tabular form, ungrouped / grouped,bar graphs, histograms (with varying base lengths), frequency polygons, qualitative analysis of data to choosethe correct form of presentation for the collected data. Mean, median, mode of ungrouped data.

2. PROBABILITY (12) Periods
History, Repeated experiments and observed frequency approach to probability. Focus is on empirical  probability. (A large amount of time to be devoted to group and to individual activities to motivate the concept; the experiments to be drawn from real - life situations, and from examples used in the chapter on statistics).

INTERNAL ASSESSMENT 20 Marks

Evaluation of activities 10 Marks Project Work 05 Marks   Continuous Evaluation 05 Marks

CBSE 9TH Maths - Chap 1 - Number Systems

CBSE 9TH Maths - Chap 2 - Polynomials

CBSE 9TH Maths - Chap 3 - Coordinate Geometry

CBSE 9TH Maths - Chap 4 - Linear Equations in Two Variables

CBSE 9TH Maths - Chap 5 - Intreduction to Euclid's Geometry

CBSE 9TH Maths - Chap 6 - Lines and Angles

CBSE 9TH Maths - Chap 7 - Triangles

CBSE 9TH Maths - Chap 8 - Quadrilaterals

CBSE 9TH Maths - Chap 9 - Areas of Parallelograms and Triangles

CBSE 9TH Maths - Chap 10 - Circles

CBSE 9TH Maths - Chap 11 - Constructions

CBSE 9TH Maths - Chap 12 - Heron's Formula

CBSE 9TH Maths - Chap 13 - Surface Areas and Volumes

CBSE 9TH Maths - Chap 14 - Statistics

CBSE 9TH Maths - Chap 15 - Probability

CBSE 9TH Geography

CBSE Geography - Chapter 1 - India - Size and Location

CBSE Geography - Chapter 1 - India - Size and Location - Page 6 - Q1

Question: 

1. Choose the right answer from the four alternatives given below.

(i) The Tropic of Cancer does not pass through
(a) Rajasthan (c) Chhattisgarh
(b) Orissa (d) Tripura

(ii) The easternmost longitude of India is
(a) 97° 25' E (c) 77° 6' E
(b) 68° 7' E (d) 82° 32' E

(iii) Uttaranchal, Uttar Pradesh, Bihar, West Bengal and Sikkim have common frontiers with
(a) China (c) Nepal
(b) Bhutan (d) Myanmar

(iv) If you intend to visit Kavarati during your summer vacations, which one of the following Union Territories of India you will be going to

(a) Pondicherry (c) Andaman and Nicobar
(b) Lakshadweep (d) Diu and Daman

(v) My friend hails from a country which does not share land boundary with India. Identify the country.
(a) Bhutan (c) Bangladesh
(b) Tajikistan (d) Nepal

Answer: 

1 (i)  (C) Orissa
1 (iI) (a)  97° 25' E
1 (iii) (c) Nepal
1 (iv) (c) Lakshadweep
1 (v) (c) Tajikistan
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CBSE Geography - Chapter 1 - India - Size and Location - Page 6 - Q2

Question: 

2 Answer the following questions briefly.

(i) Name the group of islands lying in the Arabian sea.
(ii) Name the countries which are larger than India.
(iii) Which island group of India lies to its south-east?
(iv) Which island countries are our southern neighbours?

Answer: 

2 (i) Lakshadweep lies in the Arabian Sea
2 (ii)

There are  6 Countries which are larger than India. The countries are as follows:

Russia , Canada , USA , China , Brazil , Australia

2 (iii) Anandaman and Nicobar islands
2 (iv) Sri Lanka and Maldives
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CBSE Geography - Chapter 1 - India - Size and Location - Page 6 - Q3

Question: 

3 The sun rises two hours earlier in Arunachal Pradesh as compared to Gujarat in the west but the watches show the same time. How does this happen?

Answer: 

The Earth takes 4 minutes to ratate through 10  of Longitute. The time taken to rotate 150 of longitutde difference is 1 hour. India has a longitudinal extent of 300 . And hence , there is a differnce between the sun rises of two hours in Eastern parts of Arunachal Pradesh as compared to Gujarat in the west because of this longitudinal extent of 300 .

But the watches are set at for all parts of India as per the indian standard time measured at  82 1/20 Longitude. Hence the watches show the same time both at Arunchalam Pradesh and Gujarat.

 

 

 

 

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CBSE Geography - Chapter 1 - India - Size and Location - Page 6 - Q4

Question: 

4 The central location of India at the head of the Indian Ocean is considered of great significance. Why?

Answer: 

The trans Indian Ocean routes which connect  the countries of Europe in the West and the countries of East Asia provide a strategic central location to India. The Deccan Peninsula protrudes into the Indian Ocean, thus helping India to close connect with West Asia, Africa and Europe from the western coast and with Southeast and East Asia from the eastern coast. It makes Indian Ocean encloses India from three directions East , West and South.No other country has a long coastline on the Indian Ocean as India has. And hence , India’s eminent position in the Indian Ocean  justifies the naming of Indian Ocean after India.
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CBSE Geography - Chapter 2 - Physical Features of India

CBSE Geography - Chap 2 - Physical Features of India - P15 - Q1

Question: 

1. Choose the right answer from the four alternatives given below.

(i) A landmass bounded by sea on three sides is referred to as
(a) Coast (c) Peninsula
(b) Island (d) none of the above

(ii) Mountain ranges in the eastern part of India forming its boundary with
Myanmar are collectively called as
(a) Himachal (c) Purvanchal
(b) Uttaranchal (d) none of the above

(iii) The western coastal strip, south of Goa is referred to as
(a) Coromandal (c) Kannad
(b) Konkan (d) Northern Circar

(iv) The highest peak in the Eastern Ghats is
(a) Anai Mudi (c) Mahendragiri
(b) Kanchenjunga (d) Khasi

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Answer: 

 

1 (i) (c) Peninsula
1 (ii) (c) Purvanchal
1 (iii) (c) Kannad
1(iv) (c) Mahadergiri

 

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CBSE Geography - Chap 2 - Physical Features of India - P15 - Q2

Question: 

2 Answer the following questions briefly.

(i) What are tectonic plates?
(ii) Which continents of today were part of the Gondwana land?

(iii) What is the bhabar?
(iv) Name the three major divisions of the Himalayas from north to south.
(v) Which plateau lies between the Aravali and the Vindhyan ranges?
(vi) Name the island group of India having coral origin.

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Answer: 

2 (i) Earth scientists have attempted to explain the formation of physical features with the help of Plate  tectonics theroy based on certain evidences.According to Plate Tectonics theory, the crust (upper part) of the earth has been formed out of seven major and some minor plates.The movement of the plates results in the building up of stresses within the plates and the continental rocks above, leading to folding, faulting and volcanic activity.
2 (ii) The Gondwanaland included India, Australia, South Africa and South America as one single land mass. It was located in the southern Hemisphere.
2 (iii) At the Northern plains ,the rivers, after descending from the mountains deposit pebbles in a narrow belt of about 8 to 16 km in width lying parallel to the slopes of the
Shiwaliks. It is known as bhabar. All the streams disappear in this bhabar belt.
2 (iv)

The three major divisions of the Himalayas from north to south are as follow

a) the Great or Inner Himalayas or the ‘Himadri’.

b) Himachal or lesser Himalaya.

c) Shiwaliks

2   ( v) Central Highlands
2 (vi) Lakshadweep Islands

 

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CBSE Geography - Chap 2 - Physical Features of India - P16 - Q3

Question: 

3. Distinguish between

(i) Converging and diverging tectonic plates
(ii) Bhangar and Khadar
(iii) Western Ghats and Eastern Ghats

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Answer: 
3 (i)

Converging tectonic plates

The plates that come towards each other and form convergent boundary are known as Converging tectonic plates 

Diverging tectonic plates

The plates that move away from each other and form divergent boundary are known as Diverging tectonic plates

 3 (ii)

 Bhangar

a) The largest part of the northern plain is formed of older alluvium. This part is known as bhangar.

b) They lie above the flood plains of the rivers and present a terrace like feature.

 Khandar

The soil in northern plains contain calcareous deposites locally known as kankar. The newer,younger deposits of the flood plains are called khadar.

They are renewed almost every yearand so are fertile, thus, ideal for intensiveagriculture.

 3 (iii)

 Western Ghats

a) Western ghats lie parallel to the western coast. They are continuous chain from Gulf of Cambay to Kanyakumari.

b) The Western Ghats are higher than the Eastern Ghats. Their average elevation is 900–1600 metres

 

 Eastern Ghats

a) The Eastern Ghats stretch from the Mahanadi Valley to the Nigiris in the south.The Eastern Ghats are discontinuous and irregular and dissected by rivers draining into
the Bay of Bengal.

b) The average Height of Eastern Ghats is 600 metres


 

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CBSE Geography - Chap 2 - Physical Features of India - P16 - Q4

Question: 

4. Describe how the Himalayas were formed.

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Answer: 

 The Gondwanaland included India, Australia, South Africa and South America as one single land mass. The convectional
currents split the crust into a number of pieces, thus leading to the drifting of the Indo-Australian plate after being separated from the Gondwana land, towards north. The northward drift resulted in the collision of the plate with the much larger Eurasian Plate. Due to this collision, the sedimentary rocks which were accumulated in the geosyncline known as the Tethys were folded
to form the mountain system of western Asia and Himalayas

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CBSE Geography - Chap 2 - Physical Features of India - P16 - Q5

Question: 

5. Which are the major physiographic divisions of India? Contrast the relief of the Himalayan region with that of the Peninsular plateau.

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Answer: 

 

The physical features of India can be grouped under the following physiographic divisions

(i) The Himalayan Mountains
(ii) The Northern Plains
(iii) The Peninsular Plateau
(iv) The Indian Desert
(v) The Coastal Plains
(vi) The Islands

 

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CBSE Geography - Chap 2 - Physical Features of India - P16 - Q6

Question: 

6. Give an account of the Northern Plains of India.

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Answer: 

 

The northern plain has been formed by the interplay of the three major river systems, namely– the Indus, the Ganga and the Brahmaputra along with their tributaries.  This plain is formed of alluvial soil. The deposition of alluvium in a vast basin lying at the foothills of the Himalaya over millions of years, formed this fertile plain. It spreads over an area of 7 lakh sq. km. The plain being about 2400 Km long and 240 to 320 Km broad, is a densely populated physiographic division. With a rich soil cover combined with adequate water supply and favourable climate it is agriculturally a very productive part of India.

The Northern Plain is broadly divided into three sections.

Punjab Plains - The Western part of the Northern Plain is referred to as the Punjab Plains.Formed by the Indus and its tributaries, the larger part of this plain lies in Pakistan. The Indus and its tributaries–the Jhelum, the
Chenab, the Ravi, the Beas and the Satluj originate in the Himalaya.This section of the plain is dominated by the doabs.

Ganga Plains - The Ganga plain extends between Ghaggar and Teesta rivers. It is spread over the states of North India, Haryana, Delhi, U.P., Bihar, partlyJharkhand and West Bengal to its East.

Brahmaputra plain - The Brahmaputra Plain lies in the eastern and is often kown as Assam Valley.

 

 

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CBSE Geography - Chap 2 - Physical Features of India - P16 - Q7

Question: 

7. Write short notes on the following.

(i) The Indian Desert
(ii) The Central Highlands
(iii) The Island groups of India

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Answer: 

 

7 (i) The Indian desest lies towards the western margins of the Aravali Hills. It is a sandy plain covered with sand dunes. Therainfall  is below 150 mm per year. It has arid climate with low vegetatin cover. Streams appear during the rainy season. Luni is the only large river in this region.
7 (ii)

The part of the Peninsular plateau lying to the north of the Narmada river covering a major area of the Malwa plateau is known as the Central Highlands.The Central Highlands are wider in the west but narrower in the east.
The eastward extensions of this plateau are locally known as the Bundelkhand ,Baghelkhand and The Chotanagpur plateau

The Western part consists of Vindhayas , Aravallis and Malwa Plateau

7 (iii)

Indai has two groups pf Island.

a) Lakshadweep Islands group - It is lying close to the Malabar coast of Kerala. This group of islands is composed of small coral isalnds.  It covers small area of 32 sq km. Kavaratti island is the administrative headquarters of Lakshadweep. This island group has great diversity of flora and fauna.

b)Andaman and Nicobar islands - The elongated chain of islands located in the Bay of Bengal extending from north to south are Andaman and Nicobar islands. They are bigger in size and are more numerous and scattered. The entire group of islands is divided into two broad categories – The Andaman in the north and the Nicobar in the south.

 

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CBSE Geography - Chapter 3 - Drainage

CBSE Geography - Chapter 3 - Drainage - P23 - Q1

Question: 

1. Choose the right answer from the four alternatives given below.

(i) Which one of the following describes the drainage patterns resembling the
branches of a tree?
(a) Radial (c) Centrifugal
(b) Dendritic (d) Trellis

(ii) In which of the following states is the Wular lake located?
(a) Rajasthan (c) Punjab
(b) Uttar Pradesh (d) Jammu and Kashmir

(iii) The river Narmada has its source at
(a) Satpura (c) Amarkantak
(b) Brahmagiri (d) Slopes of the Western ghats

(iv) Which one of the following lakes is a salt water lake?
(a) Sambhar (c) Wular
(b) Dal (d) Gobind Sagar

(v) Which one of the following is the longest river of the Peninsular India?
(a) Narmada (c) Godavari
(b) Krishma (d) Mahanadi

 (vi) Which one amongst the following rivers flows through a rift valley?
(a) Damodar (c) Krishna
(b) Tungabhadra (d) Tapi

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Answer: 

 

 1 (i)  (b) Dendritic
 1 (ii)  (d) Jammu and Kashmir
 1 (iii) (a) Amarkantak
 1 (iv) (a) Sambhar
 1(v)  (c) Godavari
 1 (vi)  (d) Tapi

 

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CBSE Geography - Chapter 3 - Drainage - P24 - Q2

Question: 

2. Answer the following questions briefly.

(i) What is meant by a water divide? Give an example.
(ii) Which is the largest river basin in India?
(iii) Where do the rivers Indus and Ganga have their origin?
(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
(vi) Which two Peninsular rivers flow through trough?
(vii) State some economic benefits of rivers and lakes.

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Answer: 

 

2 (i)

Any elevated area, such as a mountain or an upland,separates two drainage basins. Such an upland
is known as a water divide.

Ambala is located on the water divide between th Indus and the Ganga river systems.

2(ii) Ganga- Brahmaputra
2(iii) The river Indus rises in Tibet, near Lake Mansarowar.The headwaters of the Ganga originates at Gangotri Glacier.
2 (iv) The headwaters of the Ganga is fed by the Gangotri Glacier and joined by the Alaknanda at Devaprayag in Uttaranchal. Here the river gets it name 'Ganga'
2 (v)  In Tibet the river carries a smaller volume of water and less silt as Tibet is a cold and a dry area.
 2 (Vi)  Narmada and Tapi
 2 (vii)

 Roles and Economic Benefits of River and Lake are as follows :

  • Rivers have been of fundamental importance throughout the human history. Water from the rivers is a basic natural resource, essential for various human activities.
  • The river banks have attracted settlers from ancient times. These settlements have now become big cities.
  • Using rivers for irrigation, navigation, hydro-power generation is of special significance especially country like India
  •  
  • Lakes are of great value to human beings. A lake helps to regulate the flow of a river.During heavy rainfall, it prevents flooding and during the dry season, it helps to maintain an even flow of water.
  • Lakes can also be used for developing hydel power.
  • They moderate the climate of the surroundings; maintain the aquatic ecosystem, enhance natural beauty, help develop tourism and provide recreation.

 

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CBSE Geography - Chapter 3 - Drainage - P24 - Q3

Question: 

3. Below are given names of a few lakes of India. Group them under two categories – natural and created by human beings.

(a) Wular                             (b) Dal
(c) Nainital                          (d) Bhimtal
(e) Gobind Sagar              (f) Loktak
(g) Barapani                       (h) Chilika
(i) Sambhar                        (j) Rana Pratap Sagar
(k) Nizam Sagar                (l) Pulicat
(m) Nagarjuna Sagar       (n) Hirakund

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Answer: 

 Natural Lakes

(a) Wular ,  (b) Dal , (c) Nainital ,  (d) Bhimtal , (f) Loktak , (g) Barapani , (h) Chilika , (i) Sambhar  ,   (k) Nizam Sagar , (l) Pulicat
(m) Nagarjuna Sagar      

Man-made Lakes

(e) Gobind Sagar , (j) Rana Pratap Sagar ,  (n) Hirakund

 

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CBSE Geography - Chapter 3 - Drainage - P24 - Q4

Question: 

4. Discuss the significant difference between the Himalayan and the Peninsular rivers.

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Answer: 

 

Himalayan Rivers

  1. Most of the Himalayan rivers are perennial. It means that they have water throughout the year. These rivers receive water from rain as well as from melted snow from the lofty mountains.
  2. The Himalayan rivers have long courses from their source to the sea.
  3. The two major Himalayan rivers, the Indus and the Brahmaputra originate from the north of the mountain ranges.

Peninsular Rivers

  1. A large number of the Peninsular rivers are seasonal, as their flow is dependent on rainfall.
  2. The Peninsular rivers have shorter and shallower courses as compared to their Himalayan counterparts.
  3. Most of the rivers of peninsular India originate in the Western Ghats and flow towards the Bay of Bengal.
  1.  
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CBSE Geography - Chapter 3 - Drainage - P24 - Q5

Question: 

5. Compare the east flowing and the west flowing rivers of the Peninsular plateau.

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Answer: 
The east flowing rivers
The west flowing rivers
Mahanadi , Godavari , Krishna Cauvery ae east flowing rivers Narmada and Tapi are west flowing rives
These rivers form deltas on the east coast Deltas are not formed by these rivers
They flow into Bay of Bangal These rivers fall into Arabian Sea.

 

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CBSE Geography - Chapter 3 - Drainage - P24 - Q6

Question: 

6. Why are rivers important for the country’s economy?

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CBSE Geography - Chapter 4 - Climate

CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q6

Question: 

Summarize the rules for writing of distribution of electrons in various shells for the first eighteen elements.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q7

Question: 

Define valency by taking examples of silicon and oxygen.

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CBSE Geography - Chapter 4 - Climate - P39 - Q1

Question: 

1. Choose the correct answer from the four alternatives given below.

(i) Which one of the following places receives the highest rainfall in the world?
(a) Silchar (c) Cherrapunji
(b) Mawsynram (d) Guwahati

(ii) The wind blowing in the northern plains in summers is known as:
(a) Kaal Baisakhi (c) Trade Winds
(b) Loo (d) None of the above

(iii) Which one of the following causes rainfall during winters in north-western
part of India.
(a) Cyclonic depression (c) Western disturbances
(b) Retreating monsoon (d) Southwest monsoon

(iv) Monsoon arrives in India approximately in:
(a) Early May (c) Early June
(b) Early July (d) Early August

(v) Which one of the following characterises the cold weather season in India?
(a) Warm days and warm nights
(b) Warm days and cold nights
(c) Cool days and cold nights
(d) Cold days and warm nights

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Answer: 

 

1 (i) (b) Mawsynram
1 (ii) (b) Loo
1 (ii) (c) Western disturbances
1 (iv) (c) Early June
1 (v) (c) Cool days and cold nights

 

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CBSE Geography - Chapter 4 - Climate - P39 - Q2

Question: 

2. Answer the following questions briefly.

(i) What are the controls affecting the climate of India?
(ii) Why does India have a monsoon type of climate?
(iii) Which part of India does experience the highest diurnal range of temperature and why?
(iv) Which winds account for rainfall along the Malabar coast?
(v) What are Jet streams and how do they affect the climate of India?
(vi) Define monsoons. What do you understand by “break” in monsoon?
(vii) Why is the monsoon considered a unifying bond?

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Answer: 
2 (i)

 the controls affecting the climate of India are as follows ;

(a) Latitudes - Due to Extend of the Country , India’s climate has characteristics of tropical as well as subtropical climates

(b) Altitudes - India has mountains to the north and India also has a vast coastal area. Thus Altitude plays an important role in controlling the Climate.

(c) Pressure and Winds - The climate and associated weather conditions in India are governed by the following atmospheric conditions:
• Pressure and surface winds;
• Upper air circulation; and
• Western cyclonic disturbances and tropical cyclones.

2 (ii)  The climate of India is described as the ‘monsoon’ type.‘Monsoon’ refers to the seasonal reversal in the wind direction during a year.The Tropic of Cancer passes through the middle of the country from the Rann of Kuchchh in the west to Mizoram in the east. Almost half of the country, lying south of the Tropic of Cancer, belongs to the tropical area. All the remaining area, north of the Tropic, lies in the sub-tropics.
Therefore, India’s climate has characteristics of tropical as well as subtropical climates. And Hence , India has temperatures throughout the year and most of the rain occurs in summer.
2 (iii) The highest diurnal range of temperature is in the Thar desert Region. In the Thar Desert the day temperature may rise to 50°C, and drop down to near 15°C the same night.
2 (iv)  Malabar region lies on the west Coast.South West Mansoon winds reaches Malabar Coast which results in heavy rainfall.This is known as the ‘burst’ of the monsoon
2 (v)

Jet Streams are a narrow belt of high altitude (above 12,000 m) westerly winds in the troposphere. Their speed varies from about 110 km/h in summer to about 184 km/h in winter.

Over India, western jet streams blow south of the Himalayas, all through the year except in summer.The western cyclonic disturbances experienced in the north and north-western parts of the country are brought in by this westerly flow. Also an easterly jet stream, called the tropical easterly jet stream
blows over peninsular India, approximately over 14°N during the summer months.

2 (vi)

 The word monsoon is derived from the Arabic word ‘mausim’ which literally means season. ‘Monsoon’ refers to the seasonal reversal in the wind direction during a year.

The 'Break' in Mansoon means the monsoon rains take place only for a few days at a time. They are interspersed with rainless intervals.Thus, it has wet and dry spells. These breaks in monsoon are related to the movement of the monsoon trough.

2 (vii)  The Indian landscape, its animal and plant life, its entire agricultural calendar and the life of the people, including their festivities, revolve around Mansoon phenomenon. Year after year, people of India from north to south and from east to west, eagerly await the arrival of the monsoon. These monsoon winds bind the whole country by providing water to set the agricultural activities in motion. The river valleys which carry this water also unite as a single river valley unit. And hence ,the monsoon is considered a unifying bond.

 

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CBSE Geography - Chapter 4 - Climate - P39 - Q3

Question: 

3. Why does the rainfall decrease from the east to the west in Northern India.

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CBSE Geography - Chapter 4 - Climate - P39 - Q4

Question: 

4. Give reasons as to why.
(i) Seasonal reversal of wind direction takes place over the Indian subcontinent?
(ii) The bulk of rainfall in India is concentrated over a few months.
(iii) The Tamil Nadu coast receives winter rainfall.
(iv) The delta region of the eastern coast is frequently struck by cyclones.
(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone.

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CBSE Geography - Chapter 4 - Climate - P40 - Q5

Question: 

5. Describe the regional variations in the climatic conditions of India with the help of suitable examples.

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CBSE Geography - Chapter 4 - Climate - P40 - Q6

Question: 

6. Discuss the mechanism of monsoons.

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CBSE Geography - Chapter 4 - Climate - P40 - Q7

Question: 

7. Give an account of weather conditions and characteristics of the cold season.

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CBSE Geography - Chapter 4 - Climate - P40 - Q8

Question: 

8. Give the characteristics and effects of the monsoon rainfall in India.

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CBSE Geography - Chapter 5 - Natural Vegetation and Wild Life

CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P67 - Q4

Question: 

What would happen to the life of a cell if there was no Golgi apparatus?

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CBSE Geography - Chapter 5 - Natural Vegetation and Wild Life - P51 - Q1

Question: 

1. Choose the right answer from the four alternatives given below:

(i) To which one of the following types of vegetation does rubber belong to?
(a) Tundra (c) Himalayan
(b) Tidal (d) Tropical Evergreen

(ii) Cinchona trees are found in the areas of rainfall more than
(a) 100 cm (c) 70 cm
(b) 50 cm (d) less than 50 cm

(iii) In which of the following state is the Simlipal bio-reserve located?
(a) Punjab (b) Delhi
(c) Orissa (d) West Bengal

(iv) Which one of the following bio-reserves of India is not included in the world network of bioreserve?
(a) Manas (c) Gulf of Mannar
(b) Dihang-Dibang (d) Nanda devi

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Answer: 
1 (i) (d) Tropical Evergreen
1 (ii)  
1 (iii) (c) Orissa
1 (iv) (b) Dihang-Dibang

 

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CBSE Geography - Chapter 5 - Natural Vegetation and Wild Life - P52 - Q2

Question: 

2. Answer the following questions briefly.
(i) Define an ecosystem.
(ii) What factors are responsible for the distribution of plants and animals in India?
(iii) What is a bio-reserve? Give two examples.
(iv) Name two animals having habitat in tropical and montane type of vegetation.

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CBSE Geography - Chapter 5 - Natural Vegetation and Wild Life - P52 - Q3

Question: 

3. Distinguish between
(i) Flora and Fauna
(ii) Tropical Evergreen and Deciduous forests

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CBSE Geography - Chapter 5 - Natural Vegetation and Wild Life - P52 - Q4

Question: 

4. Name different types of Vegetation found in India and describe the vegetation oF high altitudes.

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CBSE Geography - Chapter 5 - Natural Vegetation and Wild Life - P52 - Q5

Question: 

5. Quite a few species of plants and animals are endangered in India. Why?

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CBSE Geography - Chapter 5 - Natural Vegetation and Wild Life - P52 - Q6

Question: 

6. Why has India a rich heritage of flora and fauna?

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CBSE Geography - Chapter 6 - Population

CBSE Geography - Chapter 6 - Population - P60 - Q1

Question: 

1. Choose the right answer from the four alternatives given below.

(i) Migrations change the number, distribution and composition of the population in
(a) the area of departure (c) both the area of departure and arrival
(b) the area of arrival (d) none of the above

(ii) A large proportion of children in a population is a result of
(a) high birth rates (c) high death rates
(b) high life expectancies (d) more married couples

(iii) The magnitude of population growth refers to
(a) the total population of an area
(b) the number of persons added each year
(c) the rate at which the population increases
(d) the number of females per thousand males

(iv) According to the Census 2001, a “literate” person is one who
(a) can read and write his/her name
(b) can read and write any language
(c) is 7 years old and can read and write any language with understanding
(d) knows the 3 ‘R’s (reading, writing, arithematic)

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Answer: 
1 (i) (c) both the area of departure and arrival
1 (ii) (a) high birth rates
1 (iii) (b) the number of persons added each year
1 (iv) (c) is 7 years old and can read and write any language with understanding

 

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CBSE Geography - Chapter 6 - Population - P60 - Q2

Question: 

2. Answer the following questions briefly.
(i) Why is the rate of population growth in India declining since 1981?
(ii) Discuss the major components of population growth.
(iii) Define age structure, death rate and birth rate.
(iv) How is migration a determinant factor of population change?

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CBSE Geography - Chapter 6 - Population - P60 - Q3

Question: 

3. Distinguish between population growth and population change.
 

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CBSE Geography - Chapter 6 - Population - P60 - Q4

Question: 

4. What is the relation between occupational structure and development?

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CBSE Geography - Chapter 6 - Population - P60 - Q5

Question: 

5. What are the advantages of having a healthy population?

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CBSE Geography - Chapter 6 - Population - P60 - Q6

Question: 

6. What are the significant features of the National Population Policy 2000?

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CBSE 9TH Science

CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS

CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P3 - Q1

Question: 

Which of the following are matter?

Chair, air, love, smell, hate, almonds, thought, cold, cold drink, smell of perfume.
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P3 - Q2

Question: 

Give reasons for the following observation:

The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close.
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P3 - Q3

Question: 

A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P3 - Q4

Question: 

What are the characteristics of particles of matter?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P6 - Q1

Question: 

The mass per unit volume of a substance is called density (density = mass/volume). Arrange the following in order of increasing density − air, exhaust from chimney, honey, water, chalk, cotton, and iron.

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P6 - Q2

Question: 

(a) Tabulate the differences in the characteristics of states of matter.

(b) Comment upon the following: rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy, and density.
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P6 - Q3

Question: 

Give reasons:

(a) A gas fills completely the vessel in which it is kept.

(b) A gas exerts pressure on the walls of the container.

(c) A wooden table should be called a solid.

(d) We can easily move our hand in air, but to do the same through a solid block of wood, we need a karate expert.
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P6 - Q4

Question: 

Liquids generally have lower density as compared to solids. But you must have observed that ice floats on water. Find out why.

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P9 - Q1

Question: 

Convert the following temperature to Celsius scale:

(a) 300 K

(b) 573 K
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P9 - Q2

Question: 

What is the physical state of water at:

(a) 250°C

(b) 100°C
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P9 - Q3

Question: 

For any substance, why does the temperature remain constant during the change of state?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P9 - Q4

Question: 

Suggest a method to liquefy atmospheric gases.

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P10 - Q1

Question: 

Why does a desert cooler cool better on a hot dry day?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P10 - Q2

Question: 

How does water kept in an earthen pot (matka) become cool during summers?
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P10 - Q3

Question: 

Why does our palm feel cold when we put some acetone or petrol or perfume on it?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P10 - Q4

Question: 

Why are we able to sip hot tea or milk faster from a saucer than a cup?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P10 - Q5

Question: 

What type of clothes should we wear in summers?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q1

Question: 

Convert the following temperatures to Celsius scale.

(a) 300 K

(b) 573 K
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q2

Question: 

Convert the following temperatures to Kelvin scale.

(a) 25°C

(b) 373°C
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q3

Question: 

Give reason for the following observations.

(a) Naphthalene balls disappear with time without leaving any solid.

(b) We can get the smell of perfume sitting several metres away.
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q4

Question: 

Arrange the following substances in increasing order of forces of attraction between particles−− water, sugar, oxygen.

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q5

Question: 

What is the physical state of water at−−

(a) 25°C

(b) 0°C

(c) 100°C
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q6

Question: 

Give two reasons to justify−

(a) water at room temperature is a liquid.

(b) an iron almirah is a solid at room temperature.
 

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q7

Question: 

Why is ice at 273 K more effective in cooling than water at the same temperature?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q8

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What produces more severe burns, boiling water or steam?

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CBSE 9TH Science - Chap 1 - MATTER IN OUR SURROUNDINGS - P12 - Q9

Question: 

Name A, B, C, D, E and F in the following diagram showing change in its state.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE

CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P15 - Q1

Question: 

1. What is meant by a pure substance?

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Answer: 

 A pure substance consists of a single type of particles and all the constituent particles of that substance are
the same in their chemical nature. 

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P15 - Q2

Question: 

2. List the points of differences between homogeneous and heterogeneous mixtures.

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Answer: 

Homogeneous  mixtures have a uniform composition throughout. Examples of such mixtures are: (i) salt in water and (ii) sugar in water.

Heterogeneous Mixtures are those mixtures which contain physically distinct parts and have non-uniform
compositions.Mixtures of sodium chloride and iron filings, salt and sulphur, and oil and water are
examples of heterogeneous mixtures.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P18 - Q1

Question: 

1. Differentiate between homogeneous  and heterogeneous mixtures with examples.

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Answer: 

 Homogeneous  mixtures have a uniform composition throughout. Examples of such mixtures are: (i) salt in water and (ii) sugar in water.

Heterogeneous Mixtures are those mixtures which contain physically distinct parts and have non-uniform
compositions.Mixtures of sodium chloride and iron filings, salt and sulphur, and oil and water are
examples of heterogeneous mixtures.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P18 - Q2

Question: 

2. How are sol, solution and suspension different from each other?

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Answer: 

 Sol : A Sol is a heterogeneous mixture. The size of particles of a colloid is too small to be individually seen by naked eyes. Colloids are big enough to scatter a beam of light passing through it and make its path visible.

Solution : A solution is a homogeneous mixture of two or more substances.In a solution there is homogeneity at the particle level. For example, lemonade tastes the same throughout. This shows that
particles of sugar or salt are evenly distributed in the solution.Because of very small particle size, they
do not scatter a beam of light passing through the solution. So, the path of light is not visible in a solution.

Suspension : A suspension is a heterogeneous mixture in which the solute particles do not dissolve but remain suspended throughout the bulk of the medium. Particles of a suspension are visible to the naked eye.The particles of a suspension scatter a beam of light passing through it and make its path visible.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P18 - Q3

Question: 

3. To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.

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Answer: 

 (i)    Mass of solute ( Sodium Chloride) = 36 g

        Mass of solvent ( water) = 100 g

       Mass of solution =  Mass of solute + Mass of solvent = 36 + 100 = 136 g

Mass by mass percentage of a solution ( Concentration of solution )

                  = (Mass of solute)/(Mass of solution)×100

                 = ( 36 g of sodium chloride) /( 136 g of water)×100

                 =  26.47 %
 
 

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P24 - Q1

Question: 

1. How will you separate a mixture containing kerosene and petrol (difference in their boiling points is more than 25ºC), which are miscible with each other?

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Answer: 

We can use distillation process to separate a mixture containing kerosene and petrol (difference in their boiling points is more than 25ºC), which are miscible with each other.

To separate kerosene and petrol from their mixture,take the mixture in a distillation flask. Fit it with a thermometer. Arrange the apparatus as shown in Fig. 2.9.(NCERT BOOK PAGE 21) Heat the mixture slowly keeping a close watch at the thermometer.  The kerosene vaporises, condenses in the condenser and can be collected from the condenser outlet.Petrol is left behind in the distillation flask.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P24 - Q2

Question: 

2. Name the technique to separate

(i) butter from curd,
(ii) salt from sea-water,
(iii) camphor from salt.

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Answer: 

 (i) butter from curd     - Seperation process is Centrifugation
(ii) salt from sea-water  - Seperation process is Evaporation
(iii) camphor from salt - Seperation process is Sumlimation

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P28 - Q2

Question: 

2. Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P24 - Q3

Question: 

3. What type of mixtures are separated by the technique of crystallisation?

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Answer: 

 Crystallisation is a process that separates a pure solid in the form of its crystals from a solution.The crystallisation method is used to purify solids. For example, the salt we get from sea water can have many impurities in it. To remove these impurities, the process of crystallisation is used.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P24a - Q1

Question: 

1. Classify the following as chemical or physical changes:
• cutting of trees,
• melting of butter in a pan,
• rusting of almirah,
• boiling of water to form steam,
• passing of electric current, through water and the water breaking down into hydrogen and oxygen gases,
• dissolving common salt in water
• making a fruit salad with raw fruits, and
• burning of paper and wood.

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Answer: 

 • cutting of trees                   ------------> Physical Changes
• melting of butter in a pan ------------> Physical Changes
• rusting of almirah              ------------> Chemical Changes
• boiling of water to form steam ------------> Physical Changes
• passing of electric current, through water and the water breaking down into hydrogen and oxygen gases ------------> Chemical Changes
• dissolving common salt in water   ------------> Physical Changes
• making a fruit salad with raw fruits ------------> Physical Changes
• burning of paper and wood  ------------> Chemical Changes

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P24a - Q2

Question: 

2. Try segregating the things around you as pure substancesr or mixtures.

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Answer: 

 Pure substances   -----------> salt , sugar , water

  Mixtures     -----------> milk , water, minerals, soil , lemonade

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P28 - Q1

Question: 

1. Which separation techniques will you apply for the separation of the following?
(a) Sodium chloride from its solution in water.
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride.
(c) Small pieces of metal in the engine oil of a car.
(d) Different pigments from an extract of flower petals.
(e) Butter from curd.
(f) Oil from water.
(g) Tea leaves from tea.
(h) Iron pins from sand.
(i) Wheat grains from husk.
(j) Fine mud particles suspended in water.

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Answer: 

(a) Sodium chloride from its solution in water.  -------------> Evaporation
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride. -------------> Sublimation
(c) Small pieces of metal in the engine oil of a car. -------------> Decantation
(d) Different pigments from an extract of flower petals. -------------> Chromotography
(e) Butter from curd. -------------> Centrifugation
(f) Oil from water. ------------->  Seperating Funnel
(g) Tea leaves from tea. -------------> Filtration
(h) Iron pins from sand. -------------> Magnetic Seperation
(i) Wheat grains from husk. ------------->Winnowing
(j) Fine mud particles suspended in water. -------------> Centrifugation

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P28 - Q2

Question: 

2. Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.

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Answer: 

 Water is a solvent  which is boiled in a saucer pan. Milk and tea are solutes that are added to water (solvent). They form a solution .  The solution is poured through a strainer. The insoluble part ,residue ,is left in the strainer and solution is collected in a teapot. Sugar is added to the filtrate and soluble sugar dissolves in the solution. And we get the tea.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P28 - Q3

Question: 

3. Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

 

See the Table in NCERT Book Page No 28

(a) What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K?
(b) Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.
(c) Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature?
(d) What is the effect of change of temperature on the solubility of a salt?

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Answer: 

 (a) At 313 K , 62 g of Potassium nitrate is required to be added in 100 g of Water  to make a saturated solution. ( As per the Table given)

 

To make saturated solution with 50 g of water =  (62/100)* 50 g  of potassium nitrate would be needed

                                                                                    = 31 g

(b) There will be precipitation of potassium chloride as the solution cools down to room temperature from 353. The solubility of  potassium cloride decreases as the temperature of water decreases.

(c) Ammonium Chloride has the highest solution at 293 K.

(d) As observed at the given table , the solubility of a salt increases with the increase of temperature and decreases as the temperature decreases.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P29 - Q4

Question: 

4. Explain the following giving examples.
(a) saturated solution
(b) pure substance
(c) colloid
(d) suspension

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Answer: 

 (a) Saturated Solution : At any particular temperature, a solution that has dissolved as much solute as it is capable of dissolving, is said to be a saturated solution. In other words, when no more solute can be dissolved in a solution at a given temperature, it is called a saturated solution.

 

(b) pure substance :  all the constituent particles of that substance are the same in their chemical nature. A pure substance consists of a single type of particles.Pure substances can be elements or compounds.

(c) colloid : Colloids are heterogeneous mixtures in which the particle size is too small to be seen with the naked eye, but is big enough to scatter light. Colloids are useful in industry and daily life. The particles are called the dispersed phase and the medium in which they are distributed is called the dispersion medium.

(d) suspension : Materials that are insoluble in a solvent and have particles that are visible to naked eyes, form a suspension. A suspension is a heterogeneous mixture.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P29 - Q5

Question: 

5. Classify each of the following as a homogeneous or heterogeneous mixture.
soda water, wood, air, soil, vinegar, filtered tea.

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Answer: 

 Homogeneous mixture : soda water , air, vinegar

Heterogeneous mixture :  wood, soil, filtered tea.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P29 - Q6

Question: 

How would you confirm that a colourless liquid given to you is pure water?

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Answer: 

 

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P29 - Q7

Question: 

7. Which of the following materials fall in the category of a “pure substance”?

(a) Ice
(b) Milk
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury
(g) Brick
(h) Wood
(i) Air.

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Answer: 

 “pure substance” are as follows

(a) Ice
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury
 

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P29 - Q8

Question: 

8. Identify the solutions among the following mixtures.
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water.

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Answer: 

The list of solutions among the following mixtures are

(b) Sea water
(c) Air
(e) Soda water.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P29 - Q9

Question: 

9. Which of the following will show “Tyndall effect”?
(a) Salt solution
(b) Milk
(c) Copper sulphate solution
(d) Starch solution.

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Answer: 

 Milk and Starch Solution will show Tyndall Effect.

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P29 - Q10

Question: 

10. Classify the following into elements, compounds and mixtures.
(a) Sodium
(b) Soil
(c) Sugar solution
(d) Silver
(e) Calcium carbonate
(f) Tin
(g) Silicon

(h) Coal
(i) Air
(j) Soap
(k) Methane
(l) Carbon dioxide
(m) Blood

 

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Answer: 

Elements :  (a) Sodium,(d) Silver,(f) Tin, (g) Silicon

Compounds : (e) Calcium carbonate , (k) Methane ,(l) Carbon dioxide

Mixtures : (b) Soil,(c) Sugar solution ,(h) Coal , (i) Air,(j) Soap,(m) Blood

 

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CBSE 9TH Science - Chap 2 - IS MATTER AROUND US PURE - P30 - Q11

Question: 

11. Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron filings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of a candle.

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Answer: 

 The list of Chemical Changes are

(a) Growth of a plant
(b) Rusting of iron
(d) Cooking of food
(e) Digestion of food
(g) Burning of a candle.

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES

CBSE Science - Chap 3 - Atom and molecules - P32 - Q1

Question: 

In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium
ethanoate. Show that these observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water

Answer: 

 Mass of sodium carbonate = 5.3 g (Given)

Mass of ethanoic acid = 6 g (Given)

Mass of sodium ethanoate = 8.2 g (Given)

Mass of carbon dioxide = 2.2 g (Given)

Mass of water = 0.9 g (Given)

Now, total mass before the reaction = (5.3 + 6) g = 11.3 g

And, total mass after the reaction = (8.2 + 2.2 + 0.9) g  = 11.3 g

∴Total mass before the reaction = Total mass after the reaction

Hence, the given observations are in agreement with the law of conservation of mass.

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CBSE Science - Chap 3 - Atom and molecules - P33 - Q2

Question: 

Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas  would be required to react completely with 3 g of hydrogen gas?

Answer: 

The ratio of hydrogen and oxygen by mass to form water is 1:8. ( Given )

Then, the mass of oxygen gas required to react completely with 1 g of hydrogen gas is 8 g.

Therefore, the mass of oxygen gas required to react completely with 3 g of hydrogen gas is 8 × 3 g = 24 g

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CBSE Science - Chap 3 - Atoms and Molecules - P33 - Q3

Question: 

Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?

Answer: 

 The postulate of Dalton’s atomic theory which is a result of the law of conservation of mass is:

Atoms are indivisible particles, which can neither be created nor destroyed in a chemical reaction.

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CBSE Science - Chap 3 - Atoms and Molecules - P33 - Q4

Question: 

Which postulate of Dalton’s atomic theory can explain the law of definite proportions?

Answer: 

 The postulate of Dalton's atomic theory which can explain the law of definite proportion is:

The relative number and kind of atoms in a given compound remains constant.

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P35 - Q1

Question: 

1. Define the atomic mass unit.
 

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Answer: 

 One atomic mass unit is a mass unit equal to exactly onetwelfth (1/12th) the mass of one atom of carbon-12.

 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P35 - Q2

Question: 

2. Why is it not possible to see an atom with naked eyes?

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Answer: 

 Atoms of most elements are not able to exist independently. Atoms form molecules and ions. These molecules or ions aggregate in large numbers to form the matter that we can see, feel or touch. And hence it is not possible to see an atom with naked eyes

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P39 - Q1

Question: 

1. Write down the formulae of
(i) sodium oxide
(ii) aluminium chloride
(iii) sodium suphide
(iv) magnesium hydroxide
 

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Answer: 

 The formulae of

(i) sodium oxide    ---------------------------> Na2O
(ii) aluminium chloride----------------------> AlCl3
(iii) sodium suphide -------------------------> Na2S
(iv) magnesium hydroxide ------------------> Mg(OH)2
 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P39 - Q2

Question: 

2. Write down the names of compounds represented by the following formulae:
(i) Al2(SO4)3
(ii) CaCl2
(iii) K2SO4
(iv) KNO3
(v) CaCO3

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Answer: 

 (i) Al2(SO4)3 → Aluminium sulphate

(ii) CaCl2 → Calcium chloride

(iii) K2SO4 → Potassium sulphate

(iv) KNO3 → Potassium nitrate

(v) CaCO3 → Calcium carbonate

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P39 - Q3

Question: 

What is meant by the term chemical formula?

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Answer: 

 A chemical formula of a compound shows its constituent elements and the number of atoms of each combining element. It is a symbolic representation of its composition.

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P39 - Q4

Question: 

How many atoms are present in a

(i) H2S molecule and

(ii) PO43− ion?

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Answer: 

 (i) In an H2S molecule, three atoms are present; two of hydrogen and one of sulphur.

(ii) In a PO43− ion, five atoms are present; one of phosphorus and four of oxygen.

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P40 - Q1

Question: 

Calculate the molecular masses of H2, O2, Cl2, CO2, CH4, C2H6, C2H4, NH3, CH3OH.

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Answer: 

 Molecular mass of H2 = 2 × Atomic mass of H

= 2 × 1

= 2 u

Molecular mass of O2 = 2 × Atomic mass of O

= 2 × 16

= 32 u

Molecular mass of Cl2 = 2 × Atomic mass of Cl

= 2 × 35.5

= 71 u

Molecular mass of CO2 = Atomic mass of C + 2 × Atomic mass of O

= 12 + 2 × 16

= 44 u

Molecular mass of CH4 = Atomic mass of C + 4 × Atomic mass of H

= 12 + 4 × 1

= 16 u

Molecular mass of C2H6 = 2 × Atomic mass of C + 6 × Atomic mass of H

= 2 × 12 + 6 × 1

= 30 u

Molecular mass of C2H4 = 2 × Atomic mass of C + 4 × Atomic mass of H

= 2 × 12 + 4 × 1

= 28 u

Molecular mass of NH3 = Atomic mass of N + 3 × Atomic mass of H

= 14 + 3 × 1

= 17 u

Molecular mass of CH3OH = Atomic mass of C + 4 × Atomic mass of H + Atomic mass of O

= 12 + 4 × 1 + 16

= 32 u

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P40 - Q2

Question: 

Calculate the formula unit masses of ZnO, Na2O, K2CO3, given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, and O = 16 u.

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Answer: 

 Formula unit mass of ZnO = Atomic mass of Zn + Atomic mass of O

= 65 + 16

= 81 u

Formula unit mass of Na2O = 2 × Atomic mass of Na + Atomic mass of O

= 2 × 23 + 16

= 62 u

Formula unit mass of K2CO3 = 2 × Atomic mass of K + Atomic mass of C + 3 × Atomic mass of O

= 2 × 39 + 12 + 3 × 16

= 138 u

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P42 - Q1

Question: 

If one mole of carbon atoms weighs 12 gram, what is the mass (in gram) of 1 atom of carbon?

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Answer: 

 One mole of carbon atoms weighs 12 g (Given)

that is, mass of 1 mole of carbon atoms = 12 g

Then, mass of 6.022 * 1023 number of carbon atoms = 12 g

Therefore, mass of 1 atom of carbon  =  12/( 6.022 * 1023  )   = 1.9926 * 10-23 g

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P42 - Q2

Question: 

Which has more number of atoms, 100 grams of sodium or 100 grams of iron (given, atomic mass of Na = 23 u, Fe = 56 u)?

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Answer: 

 Atomic mass of Na = 23 u (Given)

Then, gram atomic mass of Na = 23 g

Now, 23 g of Na contains = 6.022 * 1023 number of atoms

Thus, 100 g of Na contains number of atoms

= ( 100 /23) * 6.022 * 1023 = 2.6182 * 1024 number of atoms

Again, atomic mass of Fe = 56 u(Given)

Then, gram atomic mass of Fe = 56 g

Hence, 56 g of Fe contains = 6.022 * 1023 number of atoms

Thus, 100 g of Fe contains number of atoms =  ( 100 /56) * 6.022 * 1023 =1.0753 * 1024 number of atoms

Therefore, 100 grams of sodium contain more number of atoms than 100 grams of iron.

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P43 - Q1

Question: 

A 0.24 g sample of compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.

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Answer: 

Mass of sample = 0.24 g (Given)

Mass of boron = 0.096 g (Given)

Mass of oxygen = 0.144 g (Given)

Therefore, percentage of boron by weight in the compound =  (0.096/0.24)*100  = 40%

And, percentage of oxygen by weight in the compound = (0.144/0.24)*100 = 60%

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P43 - Q2

Question: 

When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combinations will govern your answer?

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Answer: 

 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q3

Question: 

What are polyatomic ions? Give examples?

 

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Answer: 

 A group of atoms carrying a charge is known as a polyatomic ion. They carry a fixed charge on them.

For example,

Ammonium NH4+,  , Hydroxide OH ,Nitrate NO3 , carbonate HCO3 ,Carbonate CO32– ,Sulphite SO32–
 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q4

Question: 

Write the chemical formulae of the following:

(a) Magnesium chloride

(b) Calcium oxide

(c) Copper nitrate

(d) Aluminium chloride

(e) Calcium carbonate

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Answer: 

 (a) Magnesium chloride → MgCl2

(b) Calcium oxide ------>  CaO

(c) Copper nitrate ------>  Cu (NO3)2

(d) Aluminium chloride ------> AlCl3

(e) Calcium carbonate ------>  CaCO3

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q5

Question: 

Give the names of the elements present in the following compounds:

(a) Quick lime

(b) Hydrogen bromide

(c) Baking powder

(d) Potassium sulphate

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Answer: 

 Compound                                        Chemical formula                             Elements present

Quick lime                                            CaO                                                    Calcium, oxygen

Hydrogen bromide                             HBr                                                      Hydrogen, bromine

Baking powder                                    NaHCO3                                             Sodium, hydrogen, carbon, oxygen

Potassium sulphate                          K2SO4                                                  Potassium, sulphur, oxygen

 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q6

Question: 

Calculate the molar mass of the following substances:

(a) Ethyne, C2H2

(b) Sulphur molecule, S8

(c) Phosphorus molecule, P4 (atomic mass of phosphorus = 31)

(d) Hydrochloric acid, HCl

(e) Nitric acid, HNO3

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Answer: 

 (a) Molar mass of ethyne, C2H2 = 2 × 12 + 2 × 1 = 28 g

(b) Molar mass of sulphur molecule, S8 = 8 × 32 = 256 g

(c) Molar mass of phosphorus molecule, P4 = 4 × 31 = 124 g

(d) Molar mass of hydrochloric acid, HCl = 1 + 35.5 = 36.5 g

(e) Molar mass of nitric acid, HNO3 = 1 + 14 + 3 × 16 = 63 g
 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q7

Question: 

What is the mass of−−

(a) 1 mole of nitrogen atoms?

(b) 4 moles of aluminium atoms (Atomic mass of aluminium = 27)?

(c) 10 moles of sodium sulphite (Na2SO3)?

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Answer: 

 (a) The mass of 1 mole of nitrogen atoms is 14 g.

(b) The mass of 4 moles of aluminium atoms is (4 × 27) g = 108 g

(c) The mass of 10 moles of sodium sulphite (Na2SO3) is 10 × [2 × 23 + 32 + 3 × 16] g = 10 × 126 g = 1260 g
 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q8

Question: 

Convert into mole.

(a) 12 g of oxygen gas

(b) 20 g of water

(c) 22 g of carbon dioxide
 

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Answer: 

 (a) 32 g of oxygen gas = 1 mole

Then, 12 g of oxygen gas =12/32 mole= 0.375 mole

(b) 18 g of water = 1 mole

Then, 20 g of water = 20/18 mole= 1.11 moles (approx)

(c) 44 g of carbon dioxide = 1 mole

Then, 22 g of carbon dioxide = 22/44 mole = 0.5 mole
 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q9

Question: 

What is the mass of:

(a) 0.2 mole of oxygen atoms?

(b) 0.5 mole of water molecules?

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Answer: 

 (a) Mass of one mole of oxygen atoms = 16 g

Therefore, mass of 0.2 mole of oxygen atoms = 0.2 × 16g = 3.2 g

(b) Mass of one mole of water molecule = 18 g

Therefore , mass of 0.5 mole of water molecules = 0.5 × 18 g = 9 g
 

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q10

Question: 

Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.

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Answer: 

 1 mole of solid sulphur (S8) = 8 × 32 g = 256 g

that is, 256 g of solid sulphur contains = 6.022 × 1023 molecules

Then, 16 g of solid sulphur contains =  (16/256)*6.022 × 1023

                                                                  = 3.76 × 1022 molecules (approx)

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CBSE 9TH Science - Chap 3 - ATOMS AND MOLECULES - P44 - Q11

Question: 

Calculate the number of aluminium ions present in 0.051 g of aluminium oxide.

(Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27 u)
 

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Answer: 

 1 mole of aluminium oxide (Al2O3) = 2 × 27 + 3 × 16 = 102 g

i.e., 102 g of Al2O3 = 6.022 × 1023 molecules of Al2O3

Then, 0.051 g of Al2O3 contains = (0.051/102)*  6.022 × 1023 = 3.011 × 1020 molecules of Al2O3

The number of aluminium ions (Al3+) present in one molecule of aluminium oxide is 2.

Therefore, the number of aluminium ions (Al3+) present in 0.051 g  of aluminium oxide (Al2O3) = 2 × 3.011 × 1020 = 6.022 × 1020

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CBSE 9TH Science - Chap 4 - STRUCTURE OF THE ATOM

CBSE 9TH Science - Chap 4 - Structure of the Atom - P47 - Q1

Question: 

What are canal rays?

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Answer: 

Canal rays are positively charged radiations. These rays consist of positively charged particles (equal in magnitude but opposite in sign to that of the electron) called as protons. They were discovered by Goldstein in 1886.
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P47 - Q2

Question: 

If an atom contains one electron and one proton, will it carry any charge or not?

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Answer: 

A proton has equal charge in magnitude but opposite in sign to that of the electron. And hence If an atom contains one electron and one proton, it will not  carry any charge.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P49 - Q1

Question: 

On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole.
 

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Answer: 

 Thomson proposed that:
(i) An atom consists of a positively charged sphere and the electrons are embedded in it.
(ii) The negative and positive charges are equal in magnitude.

And hence , the atom as a whole is electrically neutral.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P49 - Q1 b

Question: 

Name the three sub-atomic particles of an atom.

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Answer: 

 The three sub-atomic particles of an atom are:

(i) Protons

(ii) Electrons, and

(iii) Neutrons

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P49 - Q2

Question: 

On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?

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Answer: 

 On the basis of Rutherford's model of an atom, protons (positively-charged particles) are present in the nucleus of an atom.
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P49 - Q2 b

Question: 

Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?

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Answer: 

The mass of an atom is the sum of the masses of protons and neutrons present in its nucleus.

Since helium atom has two protons, mass contributed by the two protons is (2 × 1) u = 2 u. Then, the remaining mass 2 u is contributed by neutrons.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P49 - Q3

Question: 

Draw a sketch of Bohr’s model of an atom with three shells.

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P49 - Q4

Question: 

What do you think would be the observation if the α-particle scattering experiment is carried out using a foil of a metal other than gold?

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Answer: 

 Gold is malleable and a thin foil of gold can be easily made. It is difficult to make such foils from other metals. So if the α-scattering experiment is carried out using a foil of a metal rather than gold, there would be no change in the observation.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P50 - Q1

Question: 

Write the distribution of electrons in carbon and sodium atoms?

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Answer: 

 The total number of electrons in a carbon atom is 6. The distribution of electrons in carbon atom is given by:

First orbit or K-shell = 2 electrons

Second orbit or L-shell = 4 electrons

Hence , the distribution of electrons in a carbon atom as 2, 4.

The total number of electrons in a sodium atom is 11. The distribution of electrons in sodium atom is given by:

First orbit or K-shell = 2 electrons

Second orbit or L-shell = 8 electrons

Third orbit or M-shell = 1 electron
Hence , distribution of electrons in a sodium atom as 2, 8, 1.
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P50 - Q2

Question: 

K and L shells of an atom are full, then what would be the total number of electrons in the atom?

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Answer: 

 The maximum number of electrons in different shells are as follows:
first orbit or K-shell will be = 2 × 12 = 2,
second orbit or L-shell will be = 2 × 22 = 8,

Hence , if K and L shells of an atom are full, then the total number of electrons in the atom would be 2+8 = 10 electrons.

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P52 - Q1

Question: 

How will you find the valency of chlorine, sulphur and magnesium?

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Answer: 

If atoms contain 4 or less electrons in their outermost shell, then atom can lose those electron. So, they are said to have valency of number of electrons present in the outermost shell.If atoms contain more than 4 electrons in their outermost shell, then atom can gain (8-n) electron where n = number of electrons in the outermost shell. So, they are said to have valency of ( 8 - n) where n = number of electrons present in the outermost shell.

The distribution of electrons in chlorine, sulphur, and magnesium atoms are 2, 8, 7; 2, 8, 6 and 2, 8, 2 respectively.

The outer most shell of chlorine, sulphur, and magnesium atoms has 7, 6, and 2 respectively.

Thus, the valency of chlorine = 8 −7 = 1

The valency of sulphur = 8 − 6 = 2

The valency of magnesium = 2

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P52 - Q1 b

Question: 

If number of electrons in an atom is 8 and number of protons is also 8, then

(i) what is the atomic number of the atom

and (ii) what is the charge on the atom?

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Answer: 

 (i) The atomic number is equal to the number of protons. Therefore, the atomic number of the atom is 8.

(ii) Since the number of both electrons and protons is equal, therefore, the charge on the atom is 0.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P52 - Q2

Question: 

With the help of Table 4.1, find out the mass number of oxygen and sulphur atom.

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Answer: 

 Mass number of oxygen = Number of protons + Number of neutrons = 8 u + 8 u = 16 u

Mass number of sulphur = Number of protons + Number of neutrons = 16 u +16 u = 32 u
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P53 - Q1

Question: 

For the symbol H, D and T tabulate three sub-atomic particles found in each of them.

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Answer: 

 

Symbol Electrons protons Neutrons
H 1 1 0
D 1 1 1
T 1 1 2

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P53 - Q2

Question: 

Write the electronic configuration of any one pair of isotopes and isobars.

 

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Answer: 

 Two isotopes of chlorine are  chlorine, 3517 Cl and and 3717 Cl .

The electronic configuration for both chlorine isotpes are 2 , 8 , 7 . ( isotopes have same electronic isotopes)

Calcium and Argon are isobars.

The electronic configuration for Calcium is 2 , 8, 8 , 2

The electronic configuration for Argon is 2,8,8
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q1

Question: 

Compare the properties of electrons, protons and neutrons.

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q2

Question: 

What are the limitations of J.J. Thomson’s model of the atom?

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q3

Question: 

What are the limitations of Rutherford’s model of the atom?

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q4

Question: 

Describe Bohr’s model of the atom.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q5

Question: 

Compare all the proposed models of an atom given in this chapter.

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q6

Question: 

Summarize the rules for writing of distribution of electrons in various shells for the first eighteen elements.

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P54 - Q7

Question: 

Define valency by taking examples of silicon and oxygen.

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q8

Question: 

Explain with examples (i) Atomic number, (ii) Mass number, (iii) Isotopes and (iv) Isobars. Give any two uses of isotopes.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q9

Question: 

Na+ has completely filled K and L shells. Explain.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q10

Question: 

If bromine atom is available in the form of, say, two isotopes (IMAGES) (49.7%) and IMAGES(50.3%), calculate the average atomic mass of bromine atom.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q11

Question: 

The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes IMAGES and  IMAGES in the sample?

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q12

Question: 

If Z = 3, what would be the valency of the element? Also, name the element.

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q13

Question: 

Composition of the nuclei of two atomic species X and Y are given as under
X Y
Protons = 6 6
Neutrons = 6 8
Give the mass numbers of X and Y. What is the relation between the two species?
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q14

Question: 

For the following statements, write T for ‘True’ and F for ‘False’.
(a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons.
(b) A neutron is formed by an electron and a proton combining together. Therefore, it is neutral.
(c) The mass of an electron is about  times that of proton.
(d) An isotope of iodine is used for making tincture iodine, which is used as a medicine.
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q15

Question: 

Put tick (IMAGES) against correct choice and cross (IMAGES) against wrong choice in the following question:
Rutherford’s alpha-particle scattering experiment was responsible for the discovery of
(a) Atomic nucleus
(b) Electron
(c) Proton
(d) Neutron
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q16

Question: 

Put tick (IMAGES) against correct choice and cross (IMAGES) against wrong choice in the following question:
Isotopes of an element have
(a) the same physical properties
(b) different chemical properties
(c) different number of neutrons
(d) different atomic numbers
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P55 - Q17

Question: 

Put tick (IMAGES) against correct choice and cross (IMAGES) against wrong choice in the following question:

Number of valence electrons in Cl− ion are:

(a) 16

(b) 8

(c) 17

(d) 18
 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P56 - Q18

Question: 

Which one of the following is a correct electronic configuration of sodium?
(a) 2, 8
(b) 8, 2, 1
(c) 2, 1, 8
(d) 2, 8, 1
 

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Answer: 

 

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CBSE 9TH Science - Chap 4 - Structure of the Atom - P56 - Q19

Question: 
Complete the following table.
 
Atomic number
Mass number
Number of Neutrons
Number of protons
Number of electrons
Name of the Atomic species
9
10
16
32
Sulphur
24
12
2
1
1
0
1
1
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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE

CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P59 - Q1

Question: 

Who discovered cells and how?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P59 - Q2

Question: 

Why is the cell called the structural and functional unit of life?

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Answer: 

 

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P61 - Q1

Question: 

How do substances like CO2 and water move in and out of the cell? Discuss.

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P61 - Q2

Question: 

Why is the plasma membrane called a selectively permeable membrane?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P63 - Q1

Question: 

Fill in the gaps in the following table illustrating differences between prokaryotic and eukaryotic cells.

 

Prokaryotic cell

 

Eukaryotic cell

1.

Size: generally small ( 1-10 µm) 1 µm== 10-6 m

1.

Size: generally large (5-100 µm)

2.

Nuclear region: _____________________________ and is known as ________.

2.

Nuclear region: well-defined and surrounded by a nuclear membrane

3.

Chromosome: single

3.

More than one chromosome

4.

Membrane-bound cell organelles are absent

4.

___________________________




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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P65 - Q1

Question: 

Can you name the two organelles we have studied that contain their own genetic material?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P65 - Q2

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If the organisation of a cell is destroyed due to some physical or chemical influence, what will happen?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P65 - Q3

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Why are lysosomes known as suicide bags?
 

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P65 - Q4

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Where are proteins synthesized inside the cell?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q1

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Make a comparison and write down ways in which plant cells are different from animal cells.

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q2

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How is a prokaryotic cell different from a eukaryotic cell?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q3

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What would happen if the plasma membrane ruptures or breaks down?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q4

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What would happen if the plasma membrane ruptures or breaks donwn?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q5

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Which organelle is known as the powerhouse of the cell? Why?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q6

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Where do the lipids and proteins constituting the cell membrane get synthesized?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q7

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How does an Amoeba obtain its food?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q8

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What is osmosis?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P66 - Q9

Question: 

Carry out the following osmosis experiment:
Take four peeled potato halves and scoos each one out to make potato cups. One of the potato should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
(a) Keep cup A empty
(b) put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.

Keep these for two hours. Then observe the four potato cups and answer the following:

(i) Expalin why water gathers in the hollowed portion of B and C.

(ii) Why is potato A necessar for this experiment?

(iii) Explain why water does not gather in the hollowed out portions of A and d.

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P67 - Q4

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What would happen to the life of a cell if there was no Golgi apparatus?
 

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P67 - Q5

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Which organelle is known as the powerhouse of the cell? Why?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P67 - Q6

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Where do the lipids and proteins constituting the cell membrane get synthesized?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P67 - Q7

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How does an Amoeba obtain its food?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P67 - Q8

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What is osmosis?

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CBSE 9TH Science - Chap 5 - THE FUNDAMENTAL UNIT OF LIFE - P67 - Q9

Question: 

Carry out the following osmosis experiment:
Take four peeled potato halves and scoop each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.
Keep these for two hours. Then observe the four potato cups and answer the following:
(i) Explain why water gathers in the hollowed portion of B and C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed out portions of A and D.
 

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CBSE 9TH Science - Chap 6 - TISSUES

CBSE 9TH Science - Chap 6 - TISSUES - P69 - Q1

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1. What is a tissue?

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 A group of cells that are similar in structure and/or work together to achieve a particular function forms a tissue. This cluster of cells, tissue, is arranged and designed so as to give the highest possible efficiency of
function. Blood, phloem and muscle are all examples of tissues.

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CBSE 9TH Science - Chap 6 - TISSUES - P69 - Q2

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2. What is the utility of tissues in multi-cellular organisms?

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In multi-cellular organisms there are millions of cells. Most of these cells are specialised to carry out a few functions. Each specialised function is taken up by a different group of cells. Cells specialising in one function are often grouped together in the body.This cluster of cells, called a tissue, is arranged and designed so as to give the highest possible efficiency of function.

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CBSE 9TH Science - Chap 6 - TISSUES - P74 - Q1

Question: 

1. Name types of simple tissues.

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There are three types of simple tissues: (a) Parenchyma (b) Collenchyma and (c) Sclerenchyma.

 

 

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CBSE 9TH Science - Chap 6 - TISSUES - P74 - Q2

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2. Where is apical meristem found?
 

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 Apical meristem is present at the growing tips of stems and roots and increases the length of the stem and the root.

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CBSE 9TH Science - Chap 6 - TISSUES - P74 - Q4

Question: 

4. What are the constituents of phloem?

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 Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and the phloem parenchyma.

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CBSE 9TH Science - Chap 6 - TISSUES - P78 - Q1

Question: 

1. Name the tissue responsible for movement in our body.
 

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 Muscular tissue  is responsible for movement in human body.

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CBSE 9TH Science - Chap 6 - TISSUES - P78 - Q2

Question: 

2. What does a neuron look like?

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 Nervous tissue are called nerve cells or neurons.A neuron consists of a cell body with a nucleus and cytoplasm, from which long thin hair-like parts arise. Usually each neuron has a single long part, called the axon, and many short, branched parts called dendrites. An individual nerve cell may be up to a metre long.

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CBSE 9TH Science - Chap 6 - TISSUES - P78 - Q3

Question: 

3. Give three features of cardiac muscles.

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Answer: 

The three features of cardiac muscles are

  1. The muscles of the heart show rhythmic contraction and relaxation throughout life.
  2. Heart muscle cells are cylindrical, branched and uninucleate.
  3. Cardiac muscles are involuntary muscles.
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CBSE 9TH Science - Chap 6 - TISSUES - P78 - Q4

Question: 

4. What are the functions of areolar tissue?

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 Areolar connective tissue is found between the skin and muscles, around blood vessels and nerves and in the bone marrow. It fills the space inside the organs, supports internal organs and helps in repair of tissues.

 

 

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CBSE 9TH Science - Chap 6 - TISSUES - P79 - Q1

Question: 

1. Define the term “tissue”.
 

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 Tissue is a group of cells similar in structure and function.

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CBSE 9TH Science - Chap 6 - TISSUES - P79 - Q2

Question: 

2. How many types of elements together make up the xylem tissue? Name them.

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Answer: 

 Xylem consists of four elments . They are tracheids, vessels, xylem parenchyma and xylem fibres.

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CBSE 9TH Science - Chap 6 - TISSUES - P79 - Q3

Question: 

3. How are simple tissues different from complex tissues in plants?

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The difference between simple and Complex tissues are as follows:

a) Simple Cells are all made of one type of cells, which look like each other.  Whereas Complex tissues are made of more than one type of cells. All these cells coordinate to perform a common function.

b) Parenchyma, collenchyma and sclerenchyma are three types of simple tissues.whereas Xylem and phloem are types of complex tissues.

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CBSE 9TH Science - Chap 6 - TISSUES - P79 - Q4

Question: 

4. Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall.
 

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Answer: 

 

Parenchyma collenchyma sclerenchyma
Parenchyma consists of relatively unspecialised cells with thin cell walls. They are usually loosely packed,so that large spaces between cells (intercellular spaces) are found in this tissue. The cells of collenchyma tissue are living, elongated and irregularly thickened at the corners. There is very little intercellular space The cells of this
tissue are dead. They are long and narrow as the walls are thickened due to lignin (a chemical substance which acts as cement and hardens them). Often these walls are so thick that there is no internal space inside the cell.

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CBSE 9TH Science - Chap 6 - TISSUES - P79 - Q5

Question: 

 

 5. What are the functions of the stomata?

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The function of stomata are as follows :

a)Stomata are necessary for exchanging gases with the atmosphere.

b)Transpiration (loss of water in the form of water vapour) also takes place through stomata.

 

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CBSE 9TH Science - Chap 6 - TISSUES - P79 - Q7

Question: 

7. What is the specific function of the cardiac muscle?
 

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Cardiac muscles of the heart are responsible for the rhythmiccontraction and relaxation throughout life.
 

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CBSE 9TH Science - Chap 6 - TISSUES - P79 - Q8

Question: 

8. Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.

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Answer: 
striated muscles unstriated muscles Cardiac muscles
On the basis of their structure
The cells of this tissue are long, cylindrical, unbranched and multinucleate (having many nuclei). The cells are long with pointed ends(spindle-shaped) and uninucleate (having asingle nucleus). Heart muscle cells are cylindrical, branched and uninucleate
On the basis of site/location in the body.
  They are mostly attached to bones and help in body movement. The movement of food in the alimentary
canal or the contraction and relaxation of blood vessels are because of unstriated muscles.They are  found in the iris of the eye, in ureters and in the bronchi of the lungs.
The muscles of the heart show rhythmic contraction and relaxation
     
     
     
     

 

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CBSE 9TH Science - Chap 6 - TISSUES - P79a - Q10

Question: 

10. Name the following.
(a) Tissue that forms the inner lining of our mouth.
(b) Tissue that connects muscle to bone in humans.
(c) Tissue that transports food in plants.
(d) Tissue that stores fat in our body.
(e) Connective tissue with a fluid matrix.
(f) Tissue present in the brain.
 

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Answer: 

 (a) Tissue that forms the inner lining of our mouth. -----------------> Epithelial Tissue
(b) Tissue that connects muscle to bone in humans. -----------------> Tendons
(c) Tissue that transports food in plants. -----------------> Phloem
(d) Tissue that stores fat in our body. -----------------> Adipose
(e) Connective tissue with a fluid matrix. -----------------> Blood
(f) Tissue present in the brain.-----------------> Nervous

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CBSE 9TH Science - Chap 6 - TISSUES - P74 - Q3

Question: 

3. Which tissue makes up the husk of coconut?

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Answer: 

 The husk of a coconut is made of sclerenchymatous tissue.

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CBSE 9TH Science - Chap 6 - TISSUES - P79a - Q11

Question: 

11. Identify the type of tissue in the following: skin, bark of tree, bone, lining of kidney tubule, vascular bundle.

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Answer: 

Skin: Stratified squamous epithelial tissue

 

Bark of tree: Simple permanent tissue

 

Bone: Connective tissue

 

Lining of kidney tubule: Cuboidal epithelial tissue

 

Vascular bundle: Complex permanent tissue

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CBSE 9TH Science - Chap 6 - TISSUES - P79a - Q12

Question: 

12. Name the regions in which parenchyma tissue is present.

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Answer: 

 stems roots , fruit , leaves ,and flowers are the resion where parenchyma tissue is present.

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CBSE 9TH Science - Chap 6 - TISSUES - P79a - Q13

Question: 

13. What is the role of epidermis in plants?

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Answer: 

Epidermis has a protective role to play, cells of epidermal tissue form a continuous layer without intercellular spaces.The entire surface of a plant has this outer covering of epidermis. It protects all the parts of the plant.
Epidermal cells on the aerial parts of the plant often secrete a waxy, water-resistant layer on their outer surface. This aids in protection against loss of water, mechanical injury andinvasion by parasitic fungi.  Stomata present in epidermis are necessary for exchanging gases with the atmosphere.

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CBSE 9TH Science - Chap 6 - TISSUES - P79a - Q14

Question: 

14. How does the cork act as a protective tissue?

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Answer: 

The outer protective tissue forms the several-layer thick cork or the bark of the tree. Cells of cork are dead and compactly arranged without intercellular spaces . They also have a chemical called suberin in their walls that makes them impervious to gases and water. And hence cork plays a role of protective tissue

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CBSE 9TH Science - Chap 6 - TISSUES - P79a - Q15

Question: 

15. Complete the table:

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Answer: 

 Simple --------> Parenchyma, collenchyma and sclerenchyma

Complex ------------> Xylem ,phloem

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CBSE 9TH Science - Chap 7 - DIVERSITY IN LIVING ORGANISMS

CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P80 - Q1

Question: 

Why do we classify organisms?
 

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The wide  variety of life (10-13 millions of life forms  ) around us has evolved on the earth over millions of years. However, we do not have more than a
tiny fraction of this time to try and   understand all these living organisms, so we cannot look at them one by one. Instead, we look for similarities among the organisms, which will allow us to put them into different classes and then study different classes or groups as a whole.And Hence the need to classify Organisms.

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P80 - Q2

Question: 

Give three examples of the range of variations that you see in life-forms around you.

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Answer: 

Three examples of the range of variations that you see in life-forms around us are as follows :

  1. The size of organisms is of great variety. On one hand there are microscopic bacteria of a few micrometre in size. While on the other hand we have blue whale and red wood trees of california of approximate sizes of 30 metres and  100 metres repectively.
  2. The Life Span varies a lot. Some pine trees livefor thousands of years while insects like mosquitoes die within a few days.
  3. Life also ranges from colourless or even transparent worms to brightly coloured birds and flowers.
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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P82 - Q1

Question: 

Which do you think is a more basic characteristic for classifying organisms?

(a) The place where they live.

(b) The kind of cells they are made of. Why?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P82 - Q2

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What is the primary characteristic on which the first division of organisms is made?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P82 - Q3

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On what basis are plants and animals put into different categories?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P83 - Q1

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Which organisms are called primitive and how are they different from the so-called advanced organisms?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P83 - Q2

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Will advanced organisms be the same as complex organisms? Why?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P85 - Q1

Question: 

What is the criterion for classification of organisms as belonging to kingdom Monera or Protista?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P85 - Q2

Question: 

In which kingdom will you place an organism which is single-celled, eukaryotic and photosynthetic?

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Answer: 

 An organism which is single-celled, eukaryotic and photosynthetic will be placed in Kingdom Protista.

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P85 - Q3

Question: 

In the hierarchy of classification, which grouping will have the smallest number of organisms with a maximum of characteristics in common and which will have the largest number of organisms?

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In the hierarchy of classification,a species will have the smallest number of organisms with a maximum of characteristics in common, whereas the kingdom will have the largest number of organisms.

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P88 - Q1

Question: 

Which division among plants has the simplest organisms?

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Answer: 

 Thallophyta is the division of plants that has the simplest organisms. This group includes plants, which do not contain a well differentiated plant body.

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P88 - Q2

Question: 

How are pteridophytes different from the phanerogams?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P88 - Q3

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How do gymnosperms and angiosperms differ from each other?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P94 - Q1

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How do poriferan animals differ from coelenterate animals?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P94 - Q2

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How do annelid animals differ from arthropods?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P94 - Q3

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What are the differences between amphibians and reptiles?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P94 - Q4

Question: 

What are the differences between animals belonging to the Aves group and those in the mammalia group?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P97 - Q1

Question: 

What are the advantages of classifying organisms?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P97 - Q2

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How would you choose between two characteristics to be used for developing a hierarchy in classification?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P97 - Q3

Question: 

Explain the basis for grouping organisms into five kingdoms.

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P97 - Q4

Question: 

What are the major divisions in the Plantae? What is the basis for these divisions?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P97 - Q5

Question: 

How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

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CBSE 9TH Science - Chap 7 - Diversity of Living Organisms - P97 - Q6

Question: 

Explain how animals in Vertebrata are classified into further subgroups.

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CBSE 9TH Science - Chap 8 - MOTION

CBSE 9TH Science - Chap 8 - MOTION - P100 - Q1

Question: 

An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.

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CBSE 9TH Science - Chap 8 - MOTION - P100 - Q3

Question: 

Which of the following is true for displacement?

(a) It cannot be zero.

(b) Its magnitude is greater than the distance travelled by the object.
 

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CBSE 9TH Science - Chap 8 - MOTION - P100 - Q10

Question: 

An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the earth?

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CBSE 9TH Science - Chap 8 - MOTION - P102 - Q1

Question: 

Distinguish between speed and velocity.

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CBSE 9TH Science - Chap 8 - MOTION - P102 - Q2

Question: 

Under what condition(s) is the magnitude of average velocity of an object equal to its average speed?

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CBSE 9TH Science - Chap 8 - MOTION - P102 - Q3

Question: 

What does the odometer of an automobile measure?

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CBSE 9TH Science - Chap 8 - MOTION - P102 - Q4

Question: 

What does the path of an object look like when it is in uniform motion?

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CBSE 9TH Science - Chap 8 - MOTION - P102 - Q5

Question: 

During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3 × 108 m s−1.
 

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CBSE 9TH Science - Chap 8 - MOTION - P103 - Q1

Question: 

When will you say a body is in (i) uniform acceleration? (ii) non-uniform acceleration?
 

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CBSE 9TH Science - Chap 8 - MOTION - P103 - Q2

Question: 

A bus decreases its speed from 80 km h−1 to 60 km h−1 in 5 s. Find the acceleration of the bus.

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CBSE 9TH Science - Chap 8 - MOTION - P103 - Q3

Question: 

A train starting from a railway station and moving with uniform acceleration attains a speed 40 km h−1 in 10 minutes. Find its acceleration.

 

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CBSE 9TH Science - Chap 8 - MOTION - P107 - Q1

Question: 

What is the nature of the distance−time graphs for uniform and non-uniform motion of an object?
 

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CBSE 9TH Science - Chap 8 - MOTION - P107 - Q2

Question: 

What can you say about the motion of an object whose distance−time graph is a straight line parallel to the time axis?
 

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CBSE 9TH Science - Chap 8 - MOTION - P107 - Q3

Question: 

What can you say about the motion of an object if its speed−time graph is a straight line parallel to the time axis?
 

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CBSE 9TH Science - Chap 8 - MOTION - P107 - Q4

Question: 

What is the quantity which is measured by the area occupied below the velocity−time graph?
 

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CBSE 9TH Science - Chap 8 - MOTION - P109 - Q1

Question: 

A bus starting from rest moves with a uniform acceleration of 0.1 m s−2 for 2 minutes. Find (a) the speed acquired, (b) the distance travelled.
 

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CBSE 9TH Science - Chap 8 - MOTION - P110 - Q2

Question: 

A train is travelling at a speed of 90 km h−1. Brakes are applied so as to produce a uniform acceleration of −0.5 m s−2. Find how far the train will go before it is brought to rest.
 

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CBSE 9TH Science - Chap 8 - MOTION - P110 - Q3

Question: 

A trolley, while going down an inclined plane, has an acceleration of 2 cm s−2. What will be its velocity 3 s after the start?
 

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CBSE 9TH Science - Chap 8 - MOTION - P110 - Q4

Question: 

A racing car has a uniform acceleration of 4 m s−2. What distance will it cover in 10 s after start?
 

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CBSE 9TH Science - Chap 8 - MOTION - P110 - Q5

Question: 

A stone is thrown in a vertically upward direction with a velocity of 5 m s−1. If the acceleration of the stone during its motion is 10 m s−2 in the downward direction, what will be the height attained by the stone and how much time will it take to reach there?
 

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CBSE 9TH Science - Chap 8 - MOTION - P112 - Q1

Question: 

An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s?

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CBSE 9TH Science - Chap 8 - MOTION - P112 - Q2

Question: 

Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging (a) from A to B and (b) from A to C?

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CBSE 9TH Science - Chap 8 - MOTION - P112 - Q3

Question: 

Abdul, while driving to school, computes the average speed for his trip to be 20 km h−1. On his return trip along the same route, there is less traffic and the average speed is 40 km h−1. What is the average speed for Abdul’s trip?

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CBSE 9TH Science - Chap 8 - MOTION - P112 - Q4

Question: 

A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of 3.0 m s−2 for 8.0 s. How far does the boat travel during this time?

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CBSE 9TH Science - Chap 8 - MOTION - P112 - Q5

Question: 

A driver of a car travelling at 52 km h−1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h−1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?

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CBSE 9TH Science - Chap 8 - MOTION - P112 - Q6

Question: 

Fig 8.11 shows the distance-time graph of three objects A, B and C. Study the graph and answer the following questions:

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CBSE 9TH Science - Chap 8 - MOTION - P113 - Q7

Question: 

A ball is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate of 10 m s−2, with what velocity will it strike the ground? After what time will it strike the ground?
 

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CBSE 9TH Science - Chap 8 - MOTION - P113 - Q8

Question: 

The speed-time graph for a car is shown is Fig. 8.12.
(a) Find out how far the car travels in the first 4 seconds. Shade the area on the graph that represents the distance travelled by the car during the period.

(b) Which part of the graph represents uniform motion of the car?

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CBSE 9TH Science - Chap 8 - MOTION - P113 - Q9

Question: 

State which of the following situations are possible and give an example for each of these:

(a) an object with a constant acceleration but with zero velocity.

(b) an object moving in a certain direction with an acceleration in the perpendicular direction.

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CBSE 9TH Science - Chap 8 - MOTION - P113 - Q10

Question: 

An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the earth?
 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION

CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P118 - Q1

Question: 

Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P118 - Q2

Question: 

In the following example, try to identify the number of times the velocity of the ball changes:
“A football player kicks a football to another player of his team who kicks the football towards the goal. The goalkeeper of the opposite team collects the football and kicks it towards a player of his own team”.
Also identify the agent supplying the force in each case.

 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P118 - Q3

Question: 

Explain why some of the leaves may get detached from a tree if we vigorously shake its branch.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION Q1

Question: 

If action is always equal to the reaction, explain how a horse can pull a cart.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P118 - Q4

Question: 

Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P126 - Q1

Question: 

If action is always equal to the reaction, explain how a horse can pull a cart.

 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P126 - Q2

Question: 

Explain, why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P126 - Q3

Question: 

From a rifle of mass 4 kg, a bullet of mass 50 g is fired with an initial velocity of 35 m s−1. Calculate the initial recoil velocity of the rifle.

 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P127 - Q4

Question: 

Two objects of masses 100 g and 200 g are moving along the same line and direction with velocities of 2 m s−1 and 1 m s−1, respectively. They collide and after the collision, the first object moves at a velocity of 1.67 m s−1. Determine the velocity of the second object.

 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q1

Question: 

An object experiences a net zero external unbalanced force. Is it possible for the object to be traveling with a non-zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q2

Question: 

When a carpet is beaten with a stick, dust comes out of it. Explain.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q2

Question: 

When a carpet is beaten with a stick, dust comes out of it. Explain.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q3

Question: 

Why is it advised to tie any luggage kept on the roof of a bus with a rope?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q4

Question: 

A batsman hits a cricket ball which then rolls on a level ground. After covering a short distance, the ball comes to rest. The ball slows to a stop because

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q10

Question: 

Using a horizontal force of 200 N, we intend to move a wooden cabinet across a floor at a constant velocity. What is the friction force that will be exerted on the cabinet?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q5

Question: 

A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it if its mass is 7 metric tonnes (Hint: 1 metric tonne = 1000 kg).

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q6

Question: 

A stone of 1 kg is thrown with a velocity of 20 m s−1 across the frozen surface of a lake and comes to rest after travelling a distance of 50 m. What is the force of friction between the stone and the ice?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q7

Question: 

A 8000 kg engine pulls a train of 5 wagons, each of 2000 kg, along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate:

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q8

Question: 

An automobile vehicle has a mass of 1500 kg. What must be the force between the vehicle and road if the vehicle is to be stopped with a negative acceleration of 1.7 m s−2?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q9

Question: 

What is the momentum of an object of mass m, moving with a velocity v?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P128 - Q11

Question: 

Two objects, each of mass 1.5 kg are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 m s−1 before the collision during which they stick together. What will be the velocity of the combined object after collision?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P129 - Q12

Question: 

According to the third law of motion when we push on an object, the object pushes back on us with an equal and opposite force. If the object is a massive truck parked along the roadside, it will probably not move. A student justifies this by answering that the two opposite and equal forces cancel each other. Comment on this logic and explain why the truck does not move.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P129 - Q13

Question: 

A hockey ball of mass 200 g travelling at 10 m s−1 is struck by a hockey stick so as to return it along its original path with a velocity at 5 m s−1. Calculate the change of momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.
 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P129 - Q14

Question: 

A bullet of mass 10 g travelling horizontally with a velocity of 150 m s−1 strikes a stationary wooden block and comes to rest in 0.03 s. Calculate the distance of penetration of the bullet into the block. Also calculate the magnitude of the force exerted by the wooden block on the bullet.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P129 - Q15

Question: 

An object of mass 1 kg travelling in a straight line with a velocity of 10 m s−1 collides with, and sticks to, a stationary wooden block of mass 5 kg. Then they both move off together in the same straight line. Calculate the total momentum just before the impact and just after the impact. Also, calculate the velocity of the combined object.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P129 - Q16

Question: 

An object of mass 100 kg is accelerated uniformly from a velocity of 5 m s−1 to 8 m
s−1 in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.

 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P129 - Q17

Question: 

Akhtar, Kiran and Rahul were riding in a motorocar that was moving with a high velocity on an expressway when an insect hit the windshield and got stuck on the windscreen. Akhtar and Kiran started pondering over the situation. Kiran suggested that the insect suffered a greater change in momentum as compared to the change in momentum of the motorcar (because the change in the velocity of the insect was much more than that of the motorcar). Akhtar said that since the motorcar was moving with a larger velocity, it exerted a larger force on the insect. And as a result the insect died. Rahul while putting an entirely new explanation said that both the motorcar and the insect experienced the same force and a change in their momentum. Comment on these suggestions.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P129 - Q18

Question: 

How much momentum will a dumbbell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10 m s−2.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P130 - Q1

Question: 

The following is the distance-time table of an object in motion:
Time in seconds    Distance in metres
0    0
1    1
2    8
3    27
4    64
5    125
6    216
7    343
(a) What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?
(b)What do you infer about the forces acting on the object?

 

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P130 - Q2

Question: 

Two persons manage to push a motorcar of mass 1200 kg at a uniform velocity along a level road. The same motorcar can be pushed by three persons to produce an acceleration of 0.2 m s−2. With what force does each person push the motorcar? (Assume that all persons push the motorcar with the same muscular effort)

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P130 - Q3

Question: 

A hammer of mass 500 g, moving at 50 m s−1, strikes a nail. The nail stops the hammer in a very short time of 0.01 s. What is the force of the nail on the hammer?

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P130 - Q4

Question: 

A motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km/h. Its velocity is slowed down to 18 km/h in 4 s by an unbalanced external force. Calculate the acceleration and change in momentum. Also calculate the magnitude of the force required.

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CBSE 9TH Science - Chap 9 - FORCE AND LAWS OF MOTION - P130 - Q5

Question: 

A large truck and a car, both moving with a velocity of magnitude v, have a head-on collision and both of them come to a halt after that. If the collision lasts for 1 s:
(a) Which vehicle experiences the greater force of impact?
(b) Which vehicle experiences the greater change in momentum?
(c) Which vehicle experiences the greater acceleration?
(d)Why is the car likely to suffer more damage than the truck?

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Science (Chemistry , Physics , Biology ) with Practicals Syllabus 2010 - CBSE Class IX

COURSE STRUCTURE

CLASS IX (THEORY)

One Paper Time : 21/2 hours. Marks : 60

Unit Marks

I. Food 05

II. Matter - Its nature and behaviour 15

III. Organisation in living world 13

IV. Motion, Force and Work 20

V. Our Environment 07

Total 60

Theme : Food (10 Periods)

Unit 1 : Food

Plant and animal breeding and selection for quality improvement and management ; use of fertilizers, manures; protection from pests and diseases; organic farming.

Theme : Materials (50 Periods)

Unit 2 : Matter - Nature and behaviour

Definition of matter; solid, liquid and gas; characteristics - shape, volume, density; change of state-melting(absorption of heat), freezing, evaporation (Cooling by evaporation), condensation, sublimation.

Nature of matter : Elements, compounds and mixtures. Heterogenous and homogenous mixtures, colloids and suspensions.

Particle nature, basic units : atoms and molecules. Law of constant proportions. Atomic and molecular masses.

Mole Concept : Relationship of mole to mass of the particles and numbers. Valency. Chemical formula of common  compounds.

Structure of atom : Electrons, protons and neutrons; Isotopes and isobars.

Theme : The World of the living (45 Periods)

Unit 3 : Organization in the living world.

Biological Diversity : Diversity of plants and animals - basic issues in scientific naming, basis of classification.Hierarchy of categories / groups, Major groups of plants (salient features) (Bacteria, Thalophyta, Bryo phyta,Pteridophyta, gymnosperms and Angiosperms). Major groups of animals (salient features) (Non-chordates upto
phyla and chordates upto classes).

Cell - Basic Unit of life : Cell as a basic unit of life; prokaryotic and eukaryotic cells, multicellular organisms; cellmembrane and cell wall, cell organelles; chloroplast, mitochondria, vacuoles, ER, golgi apparatus; nucleus,chromosomes - basic structure, number.Tissues, organs, organ systems, organism. Structure and functions of animal and plant tissues (four types in animals; merismatic and permanent tissues inplants).

Health and diseases : Health and its failure. Infectious and Non-infectious diseases, their causes and manifestation.Diseases caused by microbes (Virus, Bacteria and protozoans) and their prevention, Principles of treatment andprevention. Pulse polio programmes.

Theme : Moving things, people and ideas (60 Periods)

Unit 4 : Motion, Force and Work

Motion : Distance and displacement, velocity; uniform and non-uniform motion along a straight line; acceleration,distance-time and velocity-time graphs for uniform and uniformly accelerated motion, equations of motion by graphicalmethod; elementary idea of uniform circular motion.

Force and Newton's laws : Force and motion, Newton's laws of motion, inertia of a body, inertia and mass,momentum, force and acceleration. Elementary idea of conservation of momentum, action and reaction forces.

Gravitation : Gravitation; universal law of gravitation, force of gravitation of the earth (gravity), acceleration due togravity; mass and weight; free fall.

Work, Energy and Power : Work done by a force, energy, power; kinetic and potential energy; law of conservationof energy.

Floatation : Thrust and pressure. Archimedes' principle, buoyancy, elementary idea of relative density.

Work, Energy and Power : Work done by a force, energy, power; kinetic and potential energy; law of conservationof energy.

Sound : Nature of sound and its propagation in various media, speed of sound, range of hearing in humans; ultrasound;reflection of sound; echo and SONAR.
Structure of the human ear (auditory aspect only).

Theme : Natural Resources (15 Periods)

Unit 5 : Our Environment

Physical resources : Air, Water, Soil.Air for respiration, for combustion, for moderating temperatures, movements of air and its role in bringing rains
across India.Air, water and soil pollution ( brief introduction). Holes in ozone layer and the probable damages.

Bio-geo chemical cycles in nature : water, oxygen, carbon, nitrogen

PRACTICALS

LIST OF EXPERIMENTS

Marks : 40 (20 + 20)

1. To prepare

a) a true solution of common salt, sugar and alum
b) a suspension of soil, chalk powder and fine sand in water
c) a colloidal of starch in water and egg albumin in water and distinguish between these on the basis of

i) transparency

ii) filtration criterion

iii) stability

2. To prepare

a) a mixture

b) a compoundusing iron filings and sulphur powder and distinguish between these on the basis of :

i) appearance i.e., homogeneity and heterogeneity

ii) behaviour towards a magnet

iii) behaviour towards carbon disulphide as a solvant.

iv) effect of heat.

3. To carry out the following chemical reactions and record observations. Also identify the type of reaction

involved in each case.

i) Iron with copper sulphate solution in water.

ii) Burning of Magnesium in air.

iii) Zinc with dilute sulphuric acid

iv) Heating of Lead Nitrate

v) Sodium sulphate with Barium chloride in the form of their solutions in water.

4. To verify laws of reflection of sound.

5. To determine the density of solid (denser than water) by using a spring balance and a measuring cylinder.

6. To establish the relation between the loss in weight of a solid when fully immersed in

i) tap water

ii) strongly salty water, with the weight of water displaced by it by taking at least two different solids.

7. To measure the temperature of hot water as it cools and plot a temperature-time graph.

8. To determine the velocity of a pulse propagated through a stretched string/slinky.

9. To prepare stained temporary mounts of (a) onion peel and (b) human cheek cells and to record observations

and draw their labeled diagrams.

10. To identify parenchyma and sclerenchyma tissues in plants, striped muscle fibers and nerve cells in animals,

from prepared slides and to draw their labeled diagrams.

11. To separate the components of a mixture of sand, common salt and ammonium chloride (or camphor) by

sublimation.

12. To determine the melting point of ice and the boiling point of water.

69

13. To test (a) the presence of starch in the given food sample (b) the presence of the adulterant metanil yellow in

dal.

14. To study the characteristic of spirogyra/Agaricus, Moss/Fern, Pinus ( either with male or female conre) and an

Angiospermic plant. Draw and give two identifying features of groups they belong to.

15. To observe and draw the given specimens-earthworm, cockroach, bony fish and bird. For each specimen

record

(a) one specific feature of its phylum

(b) one adaptive feature with reference to its habitat.

SCHEME OF EVALUATION

Multiple choice type question written test (School based) : 20 Marks

 
Hands-on practicals examination (school based) : 20 Marks

CBSE 9TH Science - Chap 10 - GRAVITATION

CBSE 9TH Science - Chap 10 - GRAVITATION - P134 - Q1

Question: 

State the universal law of gravitation

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Answer: 

The force acting between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P134 - Q2

Question: 

Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.

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Answer: 

 \f$F=\frac{Gm_{1}}m_{2}{r^{2}}\f$

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CBSE 9TH Science - Chap 10 - GRAVITATION - P136 - Q1

Question: 

What do you mean by free fall?

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Answer: 

 When an object is released from a height, it falls towards the surface of the Earth under the influence of gravitational force. The motion of the object is said to have free fall.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P136 - Q2

Question: 

What do you mean by acceleration due to gravity?

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Answer: 

 changing velocity produces acceleration in the object. This acceleration is known as acceleration due to gravity (g). Its value is given by 9.8 m/s2.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P138 - Q1

Question: 

What are the differences between the mass of an object and its weight?

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Answer: 

 

S. No.

Mass

Weight

I.

Mass is the quantity of matter contained in the body.

Weight is the force of gravity acting on the body.

II.

It is the measure of inertia of the body.

It is the measure of gravity.

III.

Mass is a constant quantity.

Weight is not a constant quantity. It is different at different places.

IV.

It only has magnitude.

It has magnitude as well as direction.

V.

Its SI unit is kilogram (kg).

Its SI unit is the same as the SI unit of force, i.e., Newton (N).

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CBSE 9TH Science - Chap 10 - GRAVITATION - P138 - Q2

Question: 

Why is the weight of an object on the moon 1/6 th its weight on the earth?

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Answer: 

\f$W_{E}=\frac{GM_{E}m}{R_{E}}\f$

 Let \f$M_{M}\f$ and \f$R_{M}\f$ be the mass and radius of the moon. Then, according to the universal law of gravitation, weight WM of the object on the surface of the moon is given by:
\f$W_{M}=\frac{M_{M}R^{2}}{M_{E}R^{2}}\f$

\f$\frac{W_{M}}{W_{E}}=\frac{7.36X10^{22}X(6.37X10^{6}^)^{2}}{5.98X10^{24}X(1.74X10^{6})^{2}}\f$

\f$=0.165 = \frac{1}{6}\f$

Therefore, weight of an object on the moon is  of \f$\frac{1}{6}\f$ its weight on the Earth.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P141 - Q1

Question: 

Why is it difficult to hold a school bag having a strap made of a thin and strong string?

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Answer: 

 Because the pressure on the shoulders is quite large. This is because the pressure is inversely proportional to the surface area on which the force acts. The smaller is the surface area; the larger will be the pressure on the surface. In the case of a thin strap, the contact surface area is very small. Hence, the pressure exerted on the shoulder is very large.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P141 - Q2

Question: 

What do you mean by buoyancy?

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Answer: 

 When you try to immerse an object in water, then you can feel an upward force exerted on the object, which increases as you push the object deeper into water.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P141 - Q3

Question: 

Why does an object float or sink when placed on the surface of water?

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Answer: 

 Because the buoyant force acting on the object is less than the force of gravity. On the other hand, if the density of the object is less than the density of the liquid, then it floats on the surface of the liquid. This is because the buoyant force acting on the object is greater than the force of gravity.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P142 - Q1

Question: 

You find your mass to be 42 kg on a weighing machine. Is your mass more or less than 42 kg?

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Answer: 

 When you weigh your body, an upward force acts on it. This upward force is the buoyant force. As a result, the body gets pushed slightly upwards, causing the weighing machine to show a reading less than the actual value.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P142 - Q2

Question: 

You have a bag of cotton and an iron bar, each indicating a mass of 100 kg when measured on a weighing machine. In reality, one is heavier than other. Can you say which one is heavier and why?

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Answer: 

 This makes the cotton bag lighter than its actual value. For this reason, the iron bar and the bag of cotton show the same mass on the weighing machine, but actually the mass of the iron bar is more that that of the cotton bag.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P143 - Q1

Question: 

How does the force of gravitation between two objects change when the distance between them is reduced to half?

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Answer: 

 According to the universal law of gravitation, gravitational force (F) acting between two objects is inversely proportional to the square of the distance (r) between them, i.e.,
\f$F\alpha \frac{1}{r^{2}}\f$
If distance r becomes r/2, then the gravitational force will be proportional to \f$\frac{1}{\left(\frac{r}{2} \right)^{2}}=\frac{4}{r^{2}}\f$

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CBSE 9TH Science - Chap 10 - GRAVITATION - P143 - Q2

Question: 

Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?

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Answer: 

 Due to gravity (in the absence of air resistances). It is constant and does not depend upon the mass of an object. Hence, heavy objects do not fall faster than light objects.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P143 - Q3

Question: 

What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (Mass of the earth is 6 × 1024 kg and radius of the earth is 6.4 × 106 m).

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Answer: 

 Since the object is on the surface of the Earth, r = radius of the Earth (R)

r = R = 6.4 × 106 m

Gravitational force, \f$F=\frac{GMm}{R^{}}\f$

\f$=\frac{6.7X10^{-11X6X10^{24X1}}}{(6.4X10^{6})^{2}}=9.8N\f$
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P143 - Q4

Question: 

The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with a force that is greater or smaller or the same as the force with which the moon attracts the earth? Why?

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Answer: 

 Two objects attract each other with equal force, but in opposite directions. The Earth attracts the moon with an equal force with which the moon attracts the earth.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P143 - Q5

Question: 

If the moon attracts the earth, why does the earth not move towards the moon?

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Answer: 

 (i) Doubled
    
(ii) One-fourth and one-ninth
    
(iii)  four times

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q6

Question: 

What happens to the force between two objects, if (i) the mass of one object is doubled? (ii) the distance between the objects is doubled and tripled? (iii) the masses of both objects are doubled?

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Answer: 

 (i)
Doubled
    

(ii)    One-fourth and one-ninth
    

(iii    our times

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q7

Question: 

What is the importance of universal law of gravitation?

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Answer: 

 Every object in the universe attracts every other object.
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q8

Question: 

What is the acceleration of free fall?

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Answer: 

 When objects fall towards the Earth under the effect of gravitational force alone, then they are said to be in free fall. Acceleration of free fall is 9.8 m s−2, which is constant for all objects (irrespective of their masses).
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q9

Question: 

What do we call the gravitational force between the Earth and an object?

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Answer: 

Gravitational force between the earth and an object is known as the weight of the object.

 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q10

Question: 

Amit buys few grams of gold at the poles as per the instruction of one of his friends. He hands over the same when he meets him at the equator. Will the friend agree with the weight of gold bought? If not, why? [Hint: The value of g is greater at the poles than at the equator].

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Answer: 

 The value of g is greater at poles than at the equator. Therefore, gold at the equator weighs less than at the poles. Hence, Amit’s friend will not agree with the weight of the gold bought.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q11

Question: 

Why will a sheet of paper fall slower than one that is crumpled into a ball?

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Answer: 

 When a sheet of paper is crumbled into a ball, then its density increases.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q12

Question: 

Gravitational force on the surface of the moon is only 1/6 as strong as gravitational force on the Earth. What is the weight in newtons of a 10 kg object on the moon and on the Earth?

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Answer: 

 Weight of an object on the moon=\f$\frac{1}{6}X\f$ Weight of an object on the Earth

Also,

Weight = Mass × Acceleration

Acceleration due to gravity, g = 9.8 m/s2

Therefore, weight of a 10 kg object on the Earth = 10 × 9.8 = 98 N

And, weight of the same object on the moon \f$=\frac{1}{6}X98=16.3 N\f$
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q13

Question: 

A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate (i) the maximum height to which it rises. (ii)the total time it takes to return to the surface of the earth.

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Answer: 

 (i) 122.5 m  (ii) 10 s

According to the equation of motion under gravity:

v2 − u2 = 2 gs

Where,

u = Initial velocity of the ball

v = Final velocity of the ball

s = Height achieved by the ball

g = Acceleration due to gravity

At maximum height, final velocity of the ball is zero, i.e., v = 0

u = 49 m/s

During upward motion, g = − 9.8 m s−2

Let h be the maximum height attained by the ball.

Hence,
\f$0-(49)^{2}=2X(-9.8)Xh\f$

\f$h=\frac{49X49}{2X9.8}=122.5 m\f$
Let t be the time taken by the ball to reach the height 122.5 m, then according to the equation of motion:

v = u + gt

We get,
\f$0=(49)+t X(-9.8)\f$

\f$9.8t=49\f$

\f$t=\frac{49}{9.8}=5 s\f$
But,

Time of ascent = Time of descent

Therefore, total time taken by the ball to return = 5 + 5 = 10 s
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q14

Question: 

A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.

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Answer: 

 According to the equation of motion under gravity:

v2 − u2 = 2 gs

Where,

u = Initial velocity of the stone = 0

v = Final velocity of the stone

s = Height of the stone = 19.6 m

g = Acceleration due to gravity = 9.8 m s−2

∴ v2 − 02 = 2 × 9.8 × 19.6

v2 = 2 × 9.8 × 19.6 = (19.6)-2

v = 19.6 m s− 1

Hence, the velocity of the stone just before touching the ground is 19.6 m s−1.
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q15

Question: 

A stone is thrown vertically upward with an initial velocity of 40 m/s. Taking g = 10 m/s2, find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?

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Answer: 

 According to the equation of motion under gravity:

v2 − u2 = 2 gs

Where,

u = Initial velocity of the stone = 0

v = Final velocity of the stone

s = Height of the stone = 19.6 m

g = Acceleration due to gravity = 9.8 m s−2

∴ v2 − 02 = 2 × 9.8 × 19.6

v2 = 2 × 9.8 × 19.6 = (19.6)2

v = 19.6 m s− 1

Hence, the velocity of the stone just before touching the ground is 19.6 m s−1.
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q16

Question: 

Calculate the force of gravitation between the earth and the Sun, given that the mass of the earth = 6 × 1024 kg and of the Sun = 2 × 1030 kg. The average distance between the two is 1.5 × 1011 m

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Answer: 

 the force of attraction between the Earth and the Sun is given by:

\f$F=\frac{GM_{sun}M_{earth}}{R^{2}}\f$

Where,

MSun = Mass of the Sun = 2 × 1030 kg

MEarth = Mass of the Earth = 6 × 1024 kg

R = Average distance between the Earth and the Sun = 1.5 × 1011 m

G = Universal gravitational constant = 6.7 × 10−11 Nm2 kg−2
 

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q17

Question: 

A stone is allowed to fall from the top of a tower 100 m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 m/s. Calculate when and where the two stones will meet.

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Answer: 

 (i) For the stone dropped from the tower:

Initial velocity, u = 0

Let the displacement of the stone in time t from the top of the tower be s.

Acceleration due to gravity, g = 9.8 m s−2

From the equation of motion,
\f$s=ut+\frac{1}{2}gt^{2}\f$

\f$=0Xt+\frac{1}{2}X9.8Xt^{2}\f$

\f$s=4.9t^{2}\f$
(ii) For the stone thrown upwards:

Initial velocity, u = 25 m s−1

Let the displacement of the stone from the ground in time t be s'.

Acceleration due to gravity, g = −9.8 m s−2

Equation of motion,
\f$s^{t}=ut+\frac{1}{2}gt^{2}\f$

\f$=25t-\frac{1}{2}X9.8Xt^{2}\f$

\f$s=25t-4.9t^{^{2}}\f$
The combined displacement of both the stones at the meeting point is equal to the height of the tower 100 m.
\f$s+s^{t}=100\f$

\f$\frac{1}{2}gt^{2}+25t-\frac{1}{2}gt^{2}=100\f$

\f$t=\frac{100}{25}=4s\f$
In 4 s, the falling stone has covered a distance given by equation (1) as
\f$s=\frac{1}{2}X10X4^{2}=80m\f$
Therefore, the stones will meet after 4 s at a height (100 − 80) = 20 m from the ground

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CBSE 9TH Science - Chap 10 - GRAVITATION - P144 - Q18

Question: 

A ball thrown up vertically returns to the thrower after 6 s. Find (a) the velocity with which it was thrown up, (b) the maximum height it reaches, and (c) its position after 4 s.

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Answer: 

 (a) 29.4 m/s
    

(b) 44.1 m
    

(c) 39.2 m above the ground

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CBSE 9TH Science - Chap 10 - GRAVITATION - P145 - Q19

Question: 

In what direction does the buoyant force on an object immersed in a liquid act?

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Answer: 

 An object immersed in a liquid experiences buoyant force in the upward direction.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P145 - Q20

Question: 

Why does a block of plastic released under water come up to the surface of water?

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Answer: 

 One is the gravitational force, which pulls the object downwards, and the other is the buoyant force, which pushes the object upwards. If the upward buoyant force is greater than the downward gravitational force, then the object comes up to the surface of the water as soon as it is released within water. Due to this reason, a block of plastic released under water comes up to the surface of the water.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P145 - Q21

Question: 

The volume of 50 g of a substance is 20 cm3. If the density of water is 1 g cm−3, will the substance float or sink?

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Answer: 

 density of the substance =\f$\frac{Mass of the substance}{volume of the substance}=\frac{50}{50}=2.5 g cm^{-3}\f$

The density of the substance is more than the density of water (1 g cm−3). Hence, the substance will sink in water.

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CBSE 9TH Science - Chap 10 - GRAVITATION - P145 - Q22

Question: 

The volume of a 500 g sealed packet is 350 cm3. Will the packet float or sink in water if the density of water is 1 g cm−3? What will be the mass of the water displaced by this packet?

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Answer: 

 Density of the 500 g sealed packet\f$=\frac{Mass of the packet}{Volume of the packet}=\frac{500}{350}=1.428g cm^{-3}\f$

The density of the substance is more than the density of water (\f$1g cm^{-3}\f$ ). Hence, it will sink in water.

The mass of water displaced by the packet is equal to the volume of the packet, i.e., 350 g.
 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY

CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P148 - Q1

Question: 

A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?

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Answer: 

 Work done = Force × Displacement

W = F × S

Where,

F = 7 N

S = 8 m

Therefore, work done, W = 7 × 8

= 56 Nm

= 56 J

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P149 - Q1

Question: 

When do we say that work is done?

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Answer: 

(i) A force acts on the body.

(ii) There is a displacement of the body caused by the applied force along the direction of the applied force.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P149 - Q3

Question: 




Define 1 J of work


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Answer: 

 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P149 - Q2

Question: 

Write an expression for the work done when a force is acting on an object in the direction of its displacement.

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Answer: 

 Work done = Force × Displacement

W = F × s

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P149 - Q3

Question: 

Define 1 J of work.
 
 

 

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Answer: 

 1 J is the amount of work done by a force of 1 N on an object that displaces it through a distance of 1 m in the direction of the applied force.
 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P149 - Q4

Question: 

A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field

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Answer: 

 Work done = Force × Displacement

W = F × d

Where,

Applied force, F = 140 N

Displacement, d = 15 m

W = 140 × 15 = 2100 J

Hence, 2100 J of work is done in ploughing the length of the field.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P152 - Q1

Question: 

What is the kinetic energy of an object?

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Answer: 

 Kinetic energy is the energy possessed by a body by the virtue of its motion. Every moving object possesses kinetic energy. A body uses kinetic energy to do work.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P152 - Q2

Question: 

Write an expression for the kinetic energy of an object.

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Answer: 

 \f$E_{k}=\frac{1}{2}mv^{2}\f$

Its SI unit is Joule (J).

 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P152 - Q3

Question: 

The kinetic energy of an object of mass, m moving with a velocity of 5 m s−1 is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?

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Answer: 

 (i) If the velocity of an object is doubled, then v = 5 × 2 = 10 m s−1.

Therefore, its kinetic energy becomes 4 times its original value, because it is proportional to the square of the velocity. Hence, kinetic energy = 25 × 4 = 100 J.

(ii) If velocity is increased three times, then its kinetic energy becomes 9 times its original value, because it is proportional to the square of the velocity. Hence, kinetic energy = 25 × 9 = 225 J.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P156 - Q1

Question: 

What is power?

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Answer: 

 Power is the rate of doing work or the rate of transfer of energy.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P156 - Q2

Question: 

Define 1 watt of power:

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Answer: 

 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P156 - Q3

Question: 

A lamp consumes 1000 J of electrical energy in 10 s. What is its power?

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Answer: 

 A body is said to have power of 1 watt if it does work at the rate of 1 joule in 1 s

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P156 - Q4

Question: 

Define average power.

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Answer: 

 A body can do different amount of work in different time intervals. Hence, it is better to define average power. Average power is obtained by dividing the total amount of work done in the total time taken to do this work.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q1

Question: 

Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
•Suma is swimming in a pond.
•A donkey is carrying a load on its back.
•A wind mill is lifting water from a well.
•A green plant is carrying out photosynthesis.
•An engine is pulling a train.
•Food grains are getting dried in the sun.
•A sailboat is moving due to wind energy.

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Answer: 

 Work is done whenever the given two conditions are satisfied:

(i) A force acts on the body.

(ii) There is a displacement of the body by the application of force in or opposite to the direction of force.

(a) While swimming, Suma applies a force to push the water backwards. Therefore, Suma swims in the forward direction caused by the forward reaction of water. Here, the force causes a displacement. Hence, work is done by Seema while swimming.

(b) While carrying a load, the donkey has to apply a force in the upward direction. But, displacement of the load is in the forward direction. Since, displacement is perpendicular to force, the work done is zero.

(c) A wind mill works against the gravitational force to lift water. Hence, work is done by the wind mill in lifting water from the well.

(d) In this case, there is no displacement of the leaves of the plant. Therefore, the work done is zero.

(e) An engine applies force to pull the train. This allows the train to move in the direction of force. Therefore, there is a displacement in the train in the same direction. Hence, work is done by the engine on the train.

(f) Food grains do not move in the presence of solar energy. Hence, the work done is zero during the process of food grains getting dried in the Sun.

(g)Wind energy applies a force on the sailboat to push it in the forward direction. Therefore, there is a displacement in the boat in the direction of force. Hence, work is done by wind on the boat.
 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q2

Question: 

An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?

 

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Answer: 

 Work done by gravity is given by the expression,

W = mgh

Where,

h = Vertical displacement = 0

W = mg × 0 = 0 J

Therefore, the work done by gravity on the given object is zero joule.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q3

Question: 

A battery lights a bulb. Describe the energy changes involved in the process.

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Answer: 

 When a bulb is connected to a battery, then the chemical energy of the battery is transferred into electrical energy. When the bulb receives this electrical energy, then it converts it into light and heat energy.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q4

Question: 

Certain force acting on a 20 kg mass changes its velocity from 5 m s−1 to 2 m s−1. Calculate the work done by the force.

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Answer: 

 Work done by force is equal to the change in kinetic energy.

Therefore, work done by force =\f$(E_{k})_{2}-(E_{k})_{5}\f$

= 40 − 250 = −210 J

The negative sign indicates that the force is acting in the direction opposite to the motion of the object

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q5

Question: 

A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer.

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Answer: 

 

W = mgh

Where,

Vertical displacement, h = 0

W = mg × 0 = 0

Hence, the work done by gravity on the body is zero.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q6

Question: 

The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

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Answer: 

 No. The process does not violate the law of conservation of energy. This is because when the body falls from a height, then its potential energy changes into kinetic energy progressively. A decrease in the potential energy is equal to an increase in the kinetic energy of the body.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q7

Question: 

What are the various energy transformations that occur when you are riding a bicycle?

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Answer: 

 While riding a bicycle, the muscular energy of the rider gets transferred into heat energy and kinetic energy of the bicycle. Heat energy heats the rider’s body. Kinetic energy provides a velocity to the bicycle. The transformation can be shown as:

During the transformation, the total energy remains conserved.
 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q8

Question: 

Does the transfer of energy take place when you push a huge rock with all your might and fail to move it? Where is the energy you spend going?

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Answer: 

 When we push a huge rock, there is no transfer of muscular energy to the stationary rock. Also, there is no loss of energy because muscular energy is transferred into heat energy, which causes our body to become hot.
 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q9

Question: 

A certain household has consumed 250 units of energy during a month. How much energy is this in joules?

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Answer: 

 1 unit = 1 kWh

1 kWh = 3.6 × 106 J

Therefore, 250 units of energy = 250 × 3.6 × 106 = 9 × 108 J

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q10

Question: 

An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when it is half-way down.

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Answer: 

W = mgh

Where,

h = Vertical displacement = 5 m

m = Mass of the object = 40 kg

g = Acceleration due to gravity = 9.8 m s−2

∴ W = 40 × 5 × 9.8 = 1960 J.

At half-way down, the potential energy of the object will be = 980 J.

At this point, the object has an equal amount of potential and kinetic energy. This is due to the law of conservation of energy. Hence, half-way down, the kinetic energy of the object will be 1960/2 = 980 J.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q11

Question: 

What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.

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Answer: 

 If the direction of force is perpendicular to displacement, then the work done is zero.

When a satellite moves around the Earth, then the direction of force of gravity on the satellite is perpendicular to its displacement. Hence, the work done on the satellite by the Earth is zero.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P158 - Q12

Question: 

Can there be displacement of an object in the absence of any force acting on it? Think. Discuss this question with your friends and teacher.

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Answer: 

 Yes. For a uniformly moving object

Suppose an object is moving with constant velocity. The net force acting on it is zero. But, there is a displacement along the motion of the object.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q13

Question: 

A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not? Justify your answer.

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Answer: 

 When a person holds a bundle of hay over his head, then there is no displacement in the bundle of hay. Although, force of gravity is acting on the bundle, the person is not applying any force on it. Hence, in the absence of force, work done by the person on the bundle is zero.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q14

Question: 

An electric heater is rated 1500 W. How much energy does it use in 10 hours?

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Answer: 

 Where,

Power rating of the heater, P = 1500 W = 1.5 kW

Time for which the heater has operated, T = 10 h

Work done = Energy consumed by the heater

Therefore, energy consumed = Power × Time

= 1.5 × 10 = 15 kWh

Hence, the energy consumed by the heater in 10 h is 15 kWh.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q15

Question: 

Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest? What happens to its energy eventually? Is it a violation of the law of conservation of energy?

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Answer: 

 When a pendulum moves from its mean position P to either of its extreme positions A or B, it rises through a height h above the mean level P. At this point, the kinetic energy of the bob changes completely into potential energy. The kinetic energy becomes zero, and the bob possesses only potential energy. As it moves towards point P, its potential energy decreases progressively. Accordingly, the kinetic energy increases. As the bob reaches point P, its potential energy becomes zero and the bob possesses only kinetic energy. This process is repeated as long as the pendulum oscillates.

The bob does not oscillate forever. It comes to rest because air resistance resists its motion. The pendulum loses its kinetic energy to overcome this friction and stops after some time.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q16

Question: 

An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest?

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Answer: 

 To bring the object to rest, amount of work is required to be done on the object.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q17

Question: 

Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of 60 km/h?

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Answer: 

 \f$60X\frac{5}{18} ms^{-1}\f$ \f$E_{k}=\frac{1}{2}X1500X\left(60X\frac{5}{18} \right)^{2}=20.8X10^{4}j\f$

Hence, 20.8 × 104 J of work is required to stop the car.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q18

Question: 

In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero

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Answer: 

Work is done whenever the given two conditions are satisfied:

(i) A force acts on the body.

(ii) There is a displacement of the body by the application of force in or opposite to the direction of force.

Case I

In this case, the direction of force acting on the block is perpendicular to the displacement. Therefore, work done by force on the block will be zero.

Case II

In this case, the direction of force acting on the block is in the direction of displacement. Therefore, work done by force on the block will be positive.

Case III

In this case, the direction of force acting on the block is opposite to the direction of displacement. Therefore, work done by force on the block will be negative.
 

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q19

Question: 

Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?

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Answer: 

 This happens when all the forces cancel out each other i.e., the net force acting on the object is zero. For a uniformly moving object, the net force acting on the object is zero. Hence, the acceleration of the object is zero. Hence, Soni is right.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q20

Question: 

Find the energy in kW h consumed in 10 hours by four devices of power 500 W each.

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Answer: 

 Power rating of the device, P = 500 W = 0.50 kW

Time for which the device runs, T = 10 h

Work done = Energy consumed by the device

Therefore, energy consumed = Power × Time

= 0.50 × 10 = 5 kWh

Hence, the energy consumed by four equal rating devices in 10 h will be 4 × 5 kWh = 20 kWh = 20 Units.

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CBSE 9TH Science - Chap 11 - WORK AND ENERGY - P159 - Q21

Question: 

A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy?

Answer: 

 As the object touches the ground, all its potential energy gets converted into kinetic energy. As the object hits the hard ground, all its kinetic energy gets converted into heat energy and sound energy. It can also deform the ground depending upon the nature of the ground and the amount of kinetic energy possessed by the object.

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CBSE 9TH Science - Chap 12 - SOUND

CBSE 9TH Science - Chap 12 - SOUND - P162 - Q1

Question: 

How does the sound produced by a vibrating object in a medium reach your ear?

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Answer: 

 It forces the neighbouring particles of the medium to vibrate. These vibrating particles then force the particles adjacent to them to vibrate.

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CBSE 9TH Science - Chap 12 - SOUND - P163 - Q1

Question: 

Explain how sound is produced by your school bell.

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Answer: 

 When the bell moves backwards, it creates a region of low pressure know as rarefaction. As the bell continues to move forward and backward, it produces a series of compressions and rarefactions. This makes the sound of a bell propagate through air.

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CBSE 9TH Science - Chap 12 - SOUND - P163 - Q2

Question: 

Why are sound waves called mechanical waves?

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Answer: 

 Sound waves force the medium particles to vibrate. because of the interaction of the particles present in that medium.

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CBSE 9TH Science - Chap 12 - SOUND - P163 - Q3

Question: 

Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend?

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Answer: 

 Sound needs a medium to propagate. Since the moon is devoid of any atmosphere, you cannot hear any sound on the moon.
 

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CBSE 9TH Science - Chap 12 - SOUND - P166 - Q1

Question: 

Which wave property determines (a) loudness, (b) pitch?

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Answer: 

 (a) Amplitude (b) Frequency

(a) The loudness of a sound depends on its amplitude. If the amplitude of a sound is large, then the sound produced will also be loud.

(b) The pitch of a sound depends on its frequency. A sound will be considered a high pitched sound, if its frequency is high.
 

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CBSE 9TH Science - Chap 12 - SOUND - P166 - Q1

Question: 

What are wavelength, frequency, time period and amplitude of a sound wave?

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Answer: 

 Wavelength: The distance between two consecutive compressions or two consecutive rarefactions is known as the wavelength. Its SI unit is metre (m).

Frequency: The number of complete oscillations per second is known as the frequency of a sound wave. It is measured in hertz (Hz).

Amplitude: The maximum height reached by the crest or trough of a sound wave is called its amplitude.
 

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CBSE 9TH Science - Chap 12 - SOUND - P166 - Q1

Question: 

Distinguish between loudness and intensity of sound.

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Answer: 

 Intensity of a sound wave is defined as the amount of sound energy passing through a unit area per second. Loudness is a measure of the response of the ear to the sound. The loudness of a sound is defined by its amplitude. T

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CBSE 9TH Science - Chap 12 - SOUND - P166 - Q2

Question: 

Guess which sound has a higher pitch: guitar or car horn?

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Answer: 

 the guitar has a higher pitch than a car horn.

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CBSE 9TH Science - Chap 12 - SOUND - P166 - Q2

Question: 

How are the wavelength and frequency of a sound wave related to its speed?

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Answer: 

 Speed, wavelength, and frequency of a sound wave are related by the following equation:

Speed (v) = Wavelength (\f$\lambda \f$ ) × Frequency (\f$ \nu \f$ )
\f$v=\lambda  X \nu \f$

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CBSE 9TH Science - Chap 12 - SOUND - P166 - Q3

Question: 

Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.

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Answer: 

 Speed = Wavelength × Frequency
\f$\lambda =\frac{v}{\upsilon }=\frac{440}{220}=2 m\f$
Hence, the wavelength of the sound wave is 2 m.

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CBSE 9TH Science - Chap 12 - SOUND - P166 - Q4

Question: 

A person is listening to a tone of 500 Hz sitting at a distance of 450 m from the source of the sound. What is the time interval between successive compressions from the source?

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Answer: 

 period is reciprocal of the frequency of the wave and is given by the relation:

\f$t=\frac{1}{Frequency}=\frac{1}{500}=0.002 s\f$

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CBSE 9TH Science - Chap 12 - SOUND - P167 - Q1

Question: 

In which of the three media, air, water or iron, does sound travel the fastest at a particular temperature?

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Answer: 

 Sound travels the fastest in solids. Its speed decreases in liquids and it is the slowest in gases.

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CBSE 9TH Science - Chap 12 - SOUND - P168 - Q1

Question: 

An echo returned in 3 s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 m s−1?

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Answer: 

 In the given time interval, sound has to travel a distance that is twice the distance of the reflecting surface and the source.

Hence, the distance of the reflecting surface from the source \f$\frac{1026}{2}m=513 m\f$

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CBSE 9TH Science - Chap 12 - SOUND - P169 - Q1

Question: 

Why are the ceilings of concert halls curved?

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Answer: 

 sound after reflection (from the walls) spreads uniformly in all directions.

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CBSE 9TH Science - Chap 12 - SOUND - P170 - Q1

Question: 

What is the audible range of the average human ear?

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Answer: 

 The audible range of an average human ear lies between 20 Hz to 20,000 Hz.

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CBSE 9TH Science - Chap 12 - SOUND - P170 - Q2

Question: 

What is the range of frequencies associated with
(a) Infrasound?
(b) Ultrasound?

 

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Answer: 

 (a) Infrasound has frequencies less than 20 Hz.

(b) Ultrasound has frequencies more than 20,000 Hz.
 

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CBSE 9TH Science - Chap 12 - SOUND - P172 - Q1

Question: 

A submarine emits a sonar pulse, which returns from an underwater cliff in 1.02 s. If the speed of sound in salt water is 1531 m/s, how far away is the cliff?

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Answer: 

 Distance travelled by the sonar pulse during its transmission and reception in water = 2 × Actual distance = 2d

\f$Actual distance d=\frac{Distance of the cliff from the submarine}{2}\f$

\f$=\frac{1561.62}{2}=780.31 m\f$

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q1

Question: 

What is sound and how is it produced?

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Answer: 

 Sound is produced by vibration. When a body vibrates, it forces the neighbouring particles of the medium to vibrate.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q2

Question: 

Describe with the help of a diagram, how compressions and rarefactions are produced in air near a source of sound.

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Answer: 

 This region of high pressure is known as compressions. When it moves backward, it creates a region of low pressure in its vicinity. This region is known as a rarefaction. As the body continues to move forward and backwards, it produces a series of compressions and rarefactions .

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q3

Question: 

Cite an experiment to show that sound needs a material medium for its propagation.

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Answer: 

 Initially, one can hear the sound of the ringing bell. Now, pump out some air from the bell-jar using the vacuum pump. It will be observed that the sound of the ringing bell decreases. If one keeps on pumping the air out of the bell-jar, then at one point, the glass-jar will be devoid of any air. At this moment, no sound can be heard from the ringing bell although one can see that the prong of the bell is still vibrating. When there is no air present inside, we can say that a vacuum is produced. Sound cannot travel through vacuum. This shows that sound needs a material medium for its propagation.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q4

Question: 

Why is sound wave called a longitudinal wave?

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Answer: 

 In a sound wave, the particles of the medium vibrate in the direction parallel to the direction of the propagation of disturbance.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q5

Question: 

Which characteristics of the sound helps you to identify your friend by his voice while sitting with others in a dark room?

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Answer: 

 Sound produced by two persons may have the same pitch and loudness, but the quality of the two sounds will be different.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q6

Question: 

Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why?

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Answer: 

 The speed of sound (344 m/s) is less than the speed of light.(3X108 m/s) Sound of thunder takes more time to reach the Earth as compared to light.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q7

Question: 

A person has a hearing range from 20 Hz to 20 kHz. What are the typical wavelengths of sound waves in air corresponding to these two frequencies? Take the speed of sound in air as 344 m s−1.

 

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Answer: 

 Given that the speed of sound in air = 344 m/s

(i) For, = 20 Hz
\f$\lambda _{1}=\frac{344}{20}=17.2 m\f$
(ii) For,
\f$\lambda _{2}=\frac{v}{\upsilon _{2}}=\frac{344}{20000}=0.0172 m\f$
Hence, for humans, the wavelength range for hearing is 0.0172 m to 17.2 m.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q8

Question: 

Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.

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Answer: 

 Therefore, time taken by the sound wave to reach the other end,
\f$t_{AL}=\frac{d}{V_{AL}}=\frac{d}{6420}\f$
Speed of sound wave in air at 25°C, \f$v_{Air}=346 ms^{-1}\f$

Therefore, time taken by sound wave to reach the other end,
\f$t_{Air}=\frac{d}{v_{Air}}=\frac{d}{346}\f$
The ratio of time taken by the sound wave in air and aluminium: \f$\frac{t_{Air}}{t_{AL}}=\frac{\frac{d}{346}}{\frac{d}{6420}}=\frac{6420}{346}=18.55\f$

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q9

Question: 

The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?

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Answer: 

 Number of oscillations = Frequency × Total time

Given, Frequency of sound = 100 Hz

Total time = 1 min = 60 s

Number of oscillations/Vibrations = 100 × 60 = 6000

Hence, the source vibrates 6000 times in a minute, producing a frequency of 100 Hz.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q10

Question: 

Does sound follow the same laws of reflection as light does? Explain.

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Answer: 

 The incident sound wave and the reflected sound wave make the same angle with the normal to the surface at the point of incidence.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q11

Question: 

When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same. Do you hear echo sound on a hotter day?

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Answer: 

 An echo is heard when the time interval between the original sound and the reflected sound is at least 0.1 s. The speed of sound in a medium increases with an increase in temperature. Hence, on a hotter day, the time interval between the original sound and the reflected sound will decrease. Therefore, an echo can be heard only if the time interval between the original sound and the reflected sound is greater than 0.1 s.

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q12

Question: 

Give two practical applications of reflection of sound waves.

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Answer: 

 (i)Measure the distance and speed of underwater objects. This method is known as SONAR.

(ii) Working of a stethoscope is also based on reflection of sound. In a stethoscope, the sound of the patient’s heartbeat reaches the doctor’s ear by multiple reflection of sound.
 

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q13

Question: 

A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? Given, g = 10 m s−2 and speed of sound = 340 m s−1.
 

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Answer: 

 According to the second equation of motion:
\f$s=ut_{1}+\frac{1}{2}gt^{2}\f$

\f$500=0Xt_{1}+\frac{1}{2}X10Xt^{2}\f$

\f$t^{2}=100\f$

\f$t_{1}=10 s\f$
Now, time taken by the sound to reach the top from the base of the tower, \f$t_{2}=\frac{500}{340}=1.47 s\f$

Therefore, the splash is heard at the top after time, t

Where, \f$t=t_{1}+t_{2}=10+1.47=11.47 s\f$

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CBSE 9TH Science - Chap 12 - SOUND - P174 - Q14

Question: 

A sound wave travels at a speed of 339 m s−1. If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?
 

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Answer: 

 Speed of sound = Wavelength × Frequency
\f$v = \lambda X \upsilon \f$

\f$v=\frac{\upsilon }{\lambda }=\frac{339}{0.015}=22600 Hz\f$
The frequency range of audible sound for humans lies between 20 Hz to 20,000 Hz. Since the frequency of the given sound is more than 20,000 Hz, it is not audible.

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q15

Question: 

What is reverberation? How can it be reduced?

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Answer: 

 To reduce reverberations, sound must be absorbed as it reaches the walls and the ceiling of a room. Sound absorbing materials like fibreboard, rough plastic, heavy curtains, and cushioned seats can be used to reduce reverberation.

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q16

Question: 

What is loudness of sound? What factors does it depend on?

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Answer: 

 A loud sound has high energy. Loudness depends on the amplitude of vibrations. In fact, loudness is proportional to the square of the amplitude of vibrations.
 

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q17

Question: 

Explain how bats use ultrasound to catch a prey.

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Answer: 

 Bats produce high-pitched ultrasonic squeaks. These high-pitched squeaks are reflected by objects such as preys and returned to the bat’s ear. This allows a bat to know the distance of his prey.
 

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q18

Question: 

How is ultrasound used for cleaning?

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Answer: 

 Objects to be cleansed are put in a cleaning solution and ultrasonic sound waves are passed through that solution. The high frequency of these ultrasound waves detaches the dirt from the objects.
 

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q19

Question: 

Explain the working and application of a sonar.

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Answer: 

 SONAR is an acronym for Sound Navigation And Ranging. It is an acoustic device used to measure the depth, direction, and speed of under-water objects such as submarines and ship wrecks with the help of ultrasounds. It is also used to measure the depth of seas and oceans.

A beam of ultrasonic sound is produced and transmitted by the transducer (it is a device that produces ultrasonic sound) of the SONAR, which travels through sea water. The echo produced by the reflection of this ultrasonic sound is detected and recorded by the detector, which is converted into electrical signals. The distance (d) of the under-water object is calculated from the time (t) taken by the echo to return with speed (v) is given by 2d = v × t. This method of measuring distance is also known as ‘echo-ranging’.
 

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q20

Question: 

A sonar device on a submarine sends out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is 3625 m.

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Answer: 

 

Time taken to hear the echo, t = 5 s

Distance of the object from the submarine, d = 3625 m

Total distance travelled by the sonar waves during the transmission and reception in water = 2d

Velocity of sound in water,

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q21

Question: 

Explain how defects in a metal block can be detected using ultrasound.

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Answer: 

 Defects in metal blocks do not allow ultrasound to pass through them and they are reflected back. This fact is used to detect defects in metal blocks. Ultrasound is passed through one end of a metal block and detectors are placed on the other end. The defective part of the metal block does not allow ultrasound to pass through it. As a result, it will not be detected by the detector. Hence, defects in metal blocks can be detected using ultrasound.

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CBSE 9TH Science - Chap 12 - SOUND - P175 - Q22

Question: 

Explain how the human ear works.

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Answer: 

 Different sounds produced in our surroundings are collected by pinna that sends these sounds to the ear drum via the ear canal. The ear drum starts vibrating back and forth rapidly when the sound waves fall on it. The vibrating eardrum sets the small bone hammer into vibration. The vibrations are passed from the hammer to the second bone anvil, and finally to the third bone stirrup. The vibrating stirrup strikes on the membrane of the oval window and passes its vibration to the liquid in the cochlea. This produces electrical impulses in nerve cells. The auditory nerve carries these electrical impulses to the brain. These electrical impulses are interpreted by the brain as sound and we get a sensation of hearing.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL

CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P178 - Q1

Question: 

State any two conditions essential for good health.

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Answer: 

 (i) An individual must have better health facilities and more professionals to deal with health problems.

(ii) All basic necessary conditions to prevent diseases must be present. For example, proper garbage collection and disposal, clearing of drains, supply of healthy drinking water, etc.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P178 - Q2

Question: 

State any two conditions essential for being free of disease.

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Answer: 

 (i) Personal hygiene and cleanliness are necessary to stay away from diseases.

(ii) Individuals should take a balanced diet that contains carbohydrates, fats, proteins, vitamins, fibres, and proper quantity of water.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P178 - Q3

Question: 

Are the answers to the above questions necessarily the same or different? Why?

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Answer: 

 No. The answers to the above questions may not necessarily be the same. This is because a disease free state is not the same as being healthy. Good health is the ability of an individual to realise his or her full potential. Individuals can have poor health without having any identifiable disease.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P180 - Q1

Question: 

List any three reasons why you would think that you are sick and ought to see a doctor. If only one of these symptoms were present, would you still go to the doctor? Why or why not?

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Answer: 

 Therefore, it becomes necessary to visit a doctor so that the disease can be identified and can be treated with proper medication.

However, if only one of these symptoms is present, we usually do not visit a doctor. This is because such symptoms do not have much effect on our general health and ability to work. However, if a person is experiencing these symptoms for quite sometime, then he needs to visit a doctor for proper treatment.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P180 - Q2

Question: 

In which of the following case do you think the long-term effects on your health are likely to be most unpleasant?

• If you get jaundice,

• if you get lice,

• If you get acne.

Why?
 

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Answer: 

 Jaundice is a disease that can cause long-term effects on our health. It is a chronic disease that lasts for a long period of time.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P187 - Q1

Question: 

Why are we normally advised to take bland and nourishing food when we are sick?

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Answer: 

 we can get the nutrients and energy quickly to fight off the foreign disease- causing agents.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P187 - Q2

Question: 

What are the different means by which infectious diseases are spread?

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Answer: 

 (i) Sexual act between two people can lead to the transfer of diseases such as syphilis, gonorrhoea, AIDS, etc.

(ii) Certain diseases such as AIDS can spread via blood to blood contact during blood transfusion or pregnancy.

(iii) Certain diseases spread by animals called vectors. For example mosquitoes spread malaria.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P187 - Q3

Question: 

What precautions can you take in your school to reduce the incidence of infectious diseases?

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Answer: 

 Precautions to reduce incidence of infectious diseases are:

(i) Stay away from the diseased person.

(ii) Cover your mouth or nose while coughing or sneezing to prevent the spread of disease.

(iii) Drink safe water.

(iv) Keep the environment clean to prevent mosquitoes from breeding.
 

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P187 - Q4

Question: 

What is immunization?

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Answer: 

 communicable diseases by administration of some agent that mimics the microbe. This suspension of killed microbes that mimics the disease-causing microbes is known as vaccine.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P187 - Q5

Question: 

What are the immunization programmes available at the nearest health centre in your locality? Which of these diseases are the major health problems in your area?

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Answer: 

 The immunization programmes available at the nearest health centre are DPT (Diphtheria, Pertusis, and Tetanus), polio vaccine, hepatitis B, MMR (Measles, Mumps, and Rubella), jaundice, typhoid, etc.

Of all these diseases, jaundice and typhoid are major health problems.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P188 - Q1

Question: 

How many times did you fall ill in the last one year? What were the illnesses?

(a) Think of one change you could make in your habits in order to avoid any of /most of the above illnesses.

(b) Think of one change you would wish for in your surroundings in order to avoid any of/most of the above illnesses.
 

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Answer: 

 This varies from person to person. Some people fall ill several times in a year, while others do not fall ill at all. A person’s immune system and hygiene-related habits play a major role in determining the person’s health.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P188 - Q2

Question: 

A doctor/nurse/health-worker is exposed to more sick people than others in the community. Find out how she/he avoids getting sick herself/himself.

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Answer: 

 The following precautions must be taken by a doctor/ nurse/ health-worker:

(i) Wearing a mask when in contact with a diseased person.

(ii) Keeping yourself covered while moving around an infected place.

(iii) Drinking safe water.

(iv) Eating healthy and nutritious food.

(v) Ensuring proper cleanliness and personal hygiene.
 

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P188 - Q3

Question: 

Conduct a survey in your neighbourhood to find out what the three most common diseases are. Suggest three steps that could be taken by your local authorities to bring down the incidence of these diseases.

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Answer: 

 Three most common diseases are:

(i) Tuberculosis

(ii) Typhoid

(iii) Jaundice

Steps to be taken to bring down the incidence of these diseases are:

(i) Proper disposal of sewage.

(ii) Ensuring supply of safe drinking water.

(iii) Providing a clean environment and preventing mosquitoes from breeding.
 

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P188 - Q4

Question: 

A baby is not able to tell her/his caretakers that she/he is sick. What would help us to find out

(a) that the baby is sick?

(b) what is the sickness?
 

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Answer: 

 (a) The baby is sick can be determined by his/her behavioural changes such as constant crying of baby, improper intake of food, frequent mood changes, etc.

(b) The sickness is determined by symptoms or indications that can be seen in the baby. The symptoms include vomiting, fever, loose motion, paleness in the body, etc.
 

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P188 - Q5

Question: 

Under which of the following conditions is a person most likely to fall sick?

(a) when she is recovering from malaria.

(b) when she has recovered from malaria and is taking care of someone suffering from chicken-pox.

(c) when she is on a four-day fast after recovering from malaria and is taking care of someone suffering from chicken-pox.

Why?
 

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Answer: 

 (c)A person is more likely to fall sick when she is on a four day fast after recovering from malaria and is taking care of someone who is suffering from chicken pox. This is because she is fasting during recovery, and her immune system is so weak that it is not able to protect its own body from any foreign infection. If she is taking care of someone suffering from chicken pox, then she has more chances of getting infected from chicken pox virus and will get sick again with this disease.

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CBSE 9TH Science - Chap 13 - WHY DO WE FALL ILL - P188 - Q6

Question: 

Under which of the following conditions are you most likely to fall sick?

(a) when you are taking examinations.

(b) when you have travelled by bus and train for two days.

(c) when your friend is suffering from measles.

Why?
 

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Answer: 

 (c)You are more likely to fall sick when your friend is suffering from measles. This is because measles is highly contagious and can easily spread through respiration i.e., through air. Thus, if your friend is suffering from measles, stay away from him otherwise you might easily get infected with the disease.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES

CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P193 - Q1

Question: 

How is our atmosphere different from the atmospheres on Venus and Mars?

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Answer: 

 This difference lies essentially in their compositions. Earth’s atmosphere is a mixture of nitrogen (79%), oxygen (20%), and a small fraction of carbon dioxide, water vapours and other gases. This makes the existence of life possible on Earth. However, the atmospheres on Venus and Mars mainly consist of carbon dioxide. The amount of carbon dioxide on these planets can range from 95% to 97%.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P193 - Q1

Question: 

How is our atmosphere different from the atmospheres on Venus and Mars ?

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Answer: 

 our atmosphere is different from the atmospheres on vernus and mars in its composition.The Earth's atmosphere is a

mixture of nitrogen, oxygen and small comppounds of carbon dioxide and water vapours and its gases.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P193 - Q2

Question: 

How does the atmosphere act as a blanket?

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Answer: 

 (a) It prevents a sudden increase in the temperature during day time.

(b) It slows down the escape of heat from the surface of the Earth into outer space during night time.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P193 - Q3

Question: 

What causes winds?

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Answer: 

 On being heated, air becomes lighter and rises up. As a result, a region of low pressure is created. Then, air from a high pressure region moves to a low pressure region, causing wind.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P193 - Q4

Question: 

How are clouds formed?

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Answer: 

 A part of this water vapour also reaches the atmosphere through biological activities such as transpiration and respiration. This causes the air in the atmosphere to heat up. When this heated air rises, it expands and cools, which results in the condensation of water vapour forming water droplets. The presence of dust and other suspended particles in air also facilitates the process of condensation. The formation of water droplets leads to the formation of clouds.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P193 - Q5

Question: 

List any three human activities that you think would lead to air pollution

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Answer: 

 (i) Burning of fossil fuels such as coal and petroleum
(ii) Industrialization
(iii) Deforestation

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P194 - Q1

Question: 

Why do organisms need water?

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Answer: 

 (i) All cellular processes need water as a medium. Usually, the reactions that take place in our body or within the cells occur between substances that are dissolved in water.

(ii) Since most of the substances are transported in a dissolved form, water is necessary.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P194 - Q2

Question: 

What is the major source of fresh water in the city/town/village where you live?

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Answer: 

 River is a major source of fresh water.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P194 - Q3

Question: 

Do you know of any activity which may be polluting this water source?

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Answer: 

 The discharge of waste water from homes, industries, hospitals, etc. into the river pollutes this fresh water source.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P196 - Q1

Question: 

How is soil formed?

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Answer: 

 Soil is formed by breaking down of rocks at or near the surface of the Earth through various physical, chemical, and biological processes by various factors such as the sun, water, wind, and living organisms.

(i) Sun:

During day time, the rocks are heated. This causes the rocks to expand. During night time, these rocks cool down and contract. Since all parts of the rock do not undergo expansion and contraction at the same rate, this causes the formation of cracks in these rocks. These cracks lead to the breaking up of huge rocks into smaller pieces.

(ii) Water:

Water catalyses the process of formation of soil in two ways.

(a) Water goes into the cracks and crevices formed in the rocks. When this water freezes, its volume increases. As a result, the size of the cracks also increases. This helps in the weathering of rocks.

(b) Running water wears away hard rocks over long periods of time. Water moving in fast speed carries big and small particles of rock downstream. These rocks rub against each other, resulting in breaking down of rocks. These smaller particles are carried away by running water and deposited down its path.

(iii) Wind:

Strong winds carry away rocks, which causes rubbing of rocks. This results in the breaking down of rocks into smaller and smaller particles.

(iv) Living organisms:

Some living organisms like lichens help in the formation of soil. Lichens also grow on rocks. During their growth, lichens release certain substances, which cause the rock surface to powder down forming a thin layer of soil. On this thin layer of soil, some small plants like moss also grow. They further cause the breaking down of the rock particles.
 

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P196 - Q2

Question: 

What is soil erosion?

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Answer: 

 The blowing away or washing away of land surface by wind or water is known as soil erosion.
 

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P196 - Q2

Question: 

What is soil erosion?

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Answer: 

 

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P196 - Q3

Question: 

What are the methods of preventing or reducing soil erosion?

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Answer: 

 The methods of preventing or reducing soil erosion are:
(i) Prevention of deforestation
(ii) Plantation of trees
 

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q1

Question: 

What are the different states in which water is found during the water cycle?

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Answer: 

 During the water cycle, water is found in solid state (snow, ice, etc.), liquid state (ground water, river water, etc.), and gaseous state (water vapours).

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q1

Question: 

Why is the atmosphere essential for life?

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Answer: 

 (i) Atmosphere keeps the average temperature of the Earth fairly constant during day time.

(ii) It prevents a sudden increase in temperature during day time.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q2

Question: 

Name two biologically important compounds that contain both oxygen and nitrogen.

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Answer: 

 Two biologically important compounds that contain both oxygen and nitrogen are:

(i) Amino acids

(ii) Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)
 

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q2

Question: 

Why is water essential for life?

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Answer: 

 (i) Most biological reactions occur when substances are dissolved in water. Thus, all cellular processes need water as a medium to take place.

(ii) Transportation of biological substances needs water as a medium.
Working...
 

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q3

Question: 

List any three human activities which would lead to an increase in the carbon dioxide content of air.

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Answer: 

 (i) Burning of fuels in various processes like heating, cooking, transportation, and industry.

(ii) Human induced forest fires

(iii) The process of deforestation includes the cutting down of trees. This decreases the uptake of carbon dioxide for photosynthesis. Eventually, the content of carbon dioxide increases.
 

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q3

Question: 

How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource?

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Answer: 

 Organisms that live in water are not totally independent of soil as a resource. These organisms depend on aquatic plants for food and other substances. These aquatic plants in turn require minerals for their sustenance. These minerals are carried to water bodies from soil by rivers, rain water, etc. Without the supply of minerals from the soil to the water bodies, it is impossible to imagine aquatic life.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q4

Question: 

What is the greenhouse effect?

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Answer: 

 Some gases like carbon dioxide, methane, nitrous oxide prevent the escape of heat from the Earth’s surface by trapping it. This increases the average temperature of the Earth. This is called the green house effect. An increase in the content of such gases would lead to a situation of global warming.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q4

Question: 

You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?

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Answer: 

They are able to study these elements using various instruments. The maximum and minimum temperature of a day is measured by a thermometer known as the maximum−minimum thermometer. Rain fall is measured by an instrument known as the rain gauge. Wind speed is measured by anemometers. There are various instruments used to measure humidity.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P201 - Q5

Question: 

What are the two forms of oxygen found in the atmosphere?

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Answer: 

 (i) Diatomic molecular form with chemical formula O2.

(ii) Triatomic molecular form with chemical formula O3 known as ozone.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P202 - Q5

Question: 

We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution?

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 Yes. Isolating human activities to specific areas would help in reducing levels of pollution. For example, setting up of industries in isolated regions will control pollution to some extent.

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CBSE 9TH Science - Chap 14 - NATURAL RESOURCES - P202 - Q6

Question: 

Write a note on how forests influence the quality of our air, soil and water resources.

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 (i) Forests balance the percentages of carbon dioxide and oxygen in the atmosphere. The increasing amount of carbon dioxide caused by human activities is balanced by a larger intake of carbon dioxide by plants during the process of photosynthesis. Simultaneously, a large amount of oxygen is released.

(ii) Forests prevent soil erosion. Roots of plants bind the soil tightly in a way that the surface of the soil cannot be eroded away by wind, water, etc.

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES

CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P204 - Q1

Question: 

What do we get from cereals, pulses, fruits and vegetables?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P205 - Q1

Question: 

How do biotic and abiotic factors affect crop production?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P205 - Q2

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What are the desirable agronomic characteristics for crop improvements?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P205 - Q2

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What are the desirable agronomic characteristics for crop improvements?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P206 - Q1

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What are macro-nutrients and why are they called macro-nutrients?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P206 - Q2

Question: 

How do plants get nutrients?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P207 - Q1

Question: 

Compare the use of manure and fertilizers in maintaining soil fertility

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P208 - Q1

Question: 

Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertilizer.
(c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.
 

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P209 - Q1

Question: 

Why should preventive measures and biological control methods be preferred for protecting crops?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P209 - Q2

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What factors may be responsible for losses of grains during storage?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P210 - Q1

Question: 

Which method is commonly used for improving cattle breeds and why?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P211 - Q1

Question: 

Discuss the implications of the following statement:
“It is interesting to note that poultry is India’s most efficient converter of low fibre food stuff (which is unfit for human consumption) into highly nutritious animal protein food.”
 

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P211 - Q1

Question: 

What management practices are common in dairy and poultry farming?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P211 - Q2

Question: 

What are the differences between broilers and layers and in their management?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P213 - Q1

Question: 

How are fish obtained?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P213 - Q1

Question: 

What are the desirable characters of bee varieties suitable for honey production?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P213 - Q2

Question: 

What are the advantages of composite fish culture?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P213 - Q2

Question: 

What is pasturage and how is it related to honey production?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P214 - Q1

Question: 

Explain any one method of crop production which ensures high yield.

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P214 - Q2

Question: 

Why are manures and fertilizers used in fields?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P214 - Q3

Question: 

What are the advantages of inter-croping and crop rotation?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P214 - Q3

Question: 

What are the advantages of inter-cropping and crop rotation?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P214 - Q4

Question: 

What is genetic manipulation? How is it useful in agricultural practices?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P215 - Q5

Question: 

How do storage grain losses occur?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P215 - Q5

Question: 

How do storage grain losses occur?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P215 - Q6

Question: 

How do good animal husbandry practices benefit farmers?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P215 - Q7

Question: 

What are the benefits of cattle farming?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P215 - Q8

Question: 

For increasing production, what is common in poultry, fisheries and bee-keeping?

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CBSE 9TH Science - Chap 15 - IMPROVEMENT IN FOOD RESOURCES - P215 - Q9

Question: 

How do you differentiate between capture fishing, mariculture and aquaculture?

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