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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. 2. Russian Revolution. (a) The crises of Tzarism. 3. Rise of Nazism. (a) The growth of social democracy 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. 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). |
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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
Posters
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? |
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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
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Suggested Activities / Instructions :
Theme 1
Theme II :
Theme IV :
Unit - 5 : Disaster Management
25 Periods
PRESCRIBED TEXTBOOKS :
4. Is it important to increase the area under irrigation? Why?
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.
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
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
2. Modern farming methods require more inputs which are manufactured in industry. Do you agree?
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..
3. How did the spread of electricity help farmers in Palampur?
Ans:-The Electricity powers all the tube wells in the fields and is used in various types of small scale industry.
4. Is it important to increase the area under irrigation? Why?
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.
5. Construct a table on the distribution of land among the 450 families of Palampur.
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.
6. Why are the wages for farm labourers in Palampur less than minimum wages?
Ans:- There is heavy competition for work among the farm labourers in Palampur, so people agree to work for lower wages.
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?
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.
8. What are the different ways of increasing production on the same piece of land? Use examples to explain.
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.
9. Describe the work of a farmer with 1 hectare of land.
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.
10. How do the medium and large farmers obtain capital for farming? How is it different from the small farmers?
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.
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?
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
13. What are the non-farm production activities taking place in your region? Make a short list.
Ans:-Dairy, Small scale Industry , poultry.
14. What can be done so that more non-farm production activities can be started in villages?
Ans:-There are few Non farm activities like dairy, poultry, small factories can be started in the village.
1. What do you understand by 'people as a resource'?
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'.
2. How is human resource different from other resources like land and physical capital?
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.
3. What is the role of education in human capital formation?
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.
4. What is the role of health in human capital formation?
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.
5. What part does health play in the individual’s working life?
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 .
6. What are the various activities undertaken in the primary sector, secondary sector and tertiary sector?
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.
7. What is the difference between economic activities and non-economic activities
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.
8. Why are women employed in low paid work?
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.
9. How will you explain the term unemployment?
Ans:- Unemployment is said to exist when people who are willing to work at the going wages and cannot find jobs.
10. What is the difference between disguised unemployment and seasonal unemployment?
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.
11. Why is educated unemployed, a peculiar problem of India?
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.
12. In which field do you think India can build the maximum employment opportunity?
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.
13. Can you suggest some measures in the education system to mitigate the problem of the educated unemployed?
14. Can you imagine some village which initially had no job opportunities but later came up with many?
15. Which capital would you consider the best — land, labour, physical capital and human capital? Why?
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!
1. Describe how the poverty line is estimated in India.
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.
2. Do you think that present methodology of poverty estimation is appropriate?
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.
3. Describe poverty trends in India since 1973.
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.
4. Discuss the major reasons for poverty in India.
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.
5. Identify the social and economic groups which are most vulnerable to poverty in India.
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.
6. Give an account of interstate disparities in poverty in India.
7. Describe global poverty trends.
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.
8. Describe current government strategy of poverty alleviation.
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)
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?
(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.
1. How is food security ensured in India?
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.
2. Which are the people more prone to food insecurity?
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.
3. Which states are more food insecure in India?
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.
4. Do you believe that green revolution has made India self-sufficient in food grains? How?
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.
5. A section of people in India are still without food. Explain?
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.
6. What happens to the supply of food when there is a disaster or a calamity?
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.
7. Differentiate between seasonal hunger and chronic hunger?
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.
8. What has our government done to provide food security to the poor? Discuss any two schemes launched by the government?
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.
9. Why is a buffer stock created by the government?
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.
10. Write notes on:
(a) Minimum support price
(b) Buffer stock
(c) Issue price
(d) Fair price shops
(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.
11. What are the problems of the functioning of ration shops?
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.
12. Write a note on the role of cooperatives in providing food and related items.
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.
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?
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?
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?
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.
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
2. Now use these adverbs to fill in the blanks in the sentences below.
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?
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.
III. Answer the question in two or three paragraphs (100–150 words).
1. How does Evelyn hear music?
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.
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.
7. When we come to terms with something, it is (still upsetting/no longer upsetting)
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
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
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?
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.
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?
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.
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.
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.
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?
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.
4. What did Einstein call his desk drawer at the patent office? Why?
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.
5. Why did Einstein write a letter to Franklin Roosevelt?
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.
6. How did Einstein react to the bombing of Hiroshima and Nagasaki?
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.
7. Why does the world remember Einstein as a “world citizen”?
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.
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?
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.
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?
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.
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?
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.
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?
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.
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?
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.
II. What does Jerome say was Montmorency’s ambition in life? What do you think of Montmorency and why?
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.
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.)
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.
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)
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.
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?
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.
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
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
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
| 1 (i) | (C) Orissa |
| 1 (iI) | (a) 97° 25' E |
| 1 (iii) | (c) Nepal |
| 1 (iv) | (c) Lakshadweep |
| 1 (v) | (c) Tajikistan |
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?
| 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 |
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?
|
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.
|
4 The central location of India at the head of the Indian Ocean is considered of great significance. Why?
| 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. |
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
| 1 (i) | (c) Peninsula |
| 1 (ii) | (c) Purvanchal |
| 1 (iii) | (c) Kannad |
| 1(iv) | (c) Mahadergiri |
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.
| 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 |
3. Distinguish between
(i) Converging and diverging tectonic plates
(ii) Bhangar and Khadar
(iii) Western Ghats and Eastern Ghats
| 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 b) The average Height of Eastern Ghats is 600 metres |
4. Describe how the Himalayas were formed.
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
5. Which are the major physiographic divisions of India? Contrast the relief of the Himalayan region with that of the Peninsular plateau.
|
The physical features of India can be grouped under the following physiographic divisions (i) The Himalayan Mountains |
6. Give an account of the Northern Plains of India.
|
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 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.
|
7. Write short notes on the following.
(i) The Indian Desert
(ii) The Central Highlands
(iii) The Island groups of India
| 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 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. |
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
| 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 |
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.
| 2 (i) |
Any elevated area, such as a mountain or an upland,separates two drainage basins. Such an upland 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 :
|
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
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
4. Discuss the significant difference between the Himalayan and the Peninsular rivers.
|
Himalayan Rivers
|
Peninsular Rivers
|
5. Compare the east flowing and the west flowing rivers of the Peninsular plateau.
| 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. |
Summarize the rules for writing of distribution of electrons in various shells for the first eighteen elements.
Define valency by taking examples of silicon and oxygen.
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
| 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 |
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?
| 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: |
| 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 |
| 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. |
3. Why does the rainfall decrease from the east to the west in Northern India.
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.
5. Describe the regional variations in the climatic conditions of India with the help of suitable examples.
6. Discuss the mechanism of monsoons.
7. Give an account of weather conditions and characteristics of the cold season.
What would happen to the life of a cell if there was no Golgi apparatus?
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
| 1 (i) | (d) Tropical Evergreen |
| 1 (ii) | |
| 1 (iii) | (c) Orissa |
| 1 (iv) | (b) Dihang-Dibang |
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.
3. Distinguish between
(i) Flora and Fauna
(ii) Tropical Evergreen and Deciduous forests
4. Name different types of Vegetation found in India and describe the vegetation oF high altitudes.
5. Quite a few species of plants and animals are endangered in India. Why?
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)
| 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 |
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?
3. Distinguish between population growth and population change.
4. What is the relation between occupational structure and development?
5. What are the advantages of having a healthy population?
Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, cold drink, smell of perfume.
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.
A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?
What are the characteristics of particles of matter?
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.
(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.
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.
Liquids generally have lower density as compared to solids. But you must have observed that ice floats on water. Find out why.
Convert the following temperature to Celsius scale:
(a) 300 K
(b) 573 K
What is the physical state of water at:
(a) 250°C
(b) 100°C
For any substance, why does the temperature remain constant during the change of state?
Suggest a method to liquefy atmospheric gases.
Why does a desert cooler cool better on a hot dry day?
How does water kept in an earthen pot (matka) become cool during summers?
Why does our palm feel cold when we put some acetone or petrol or perfume on it?
Why are we able to sip hot tea or milk faster from a saucer than a cup?
What type of clothes should we wear in summers?
Convert the following temperatures to Celsius scale.
(a) 300 K
(b) 573 K
Convert the following temperatures to Kelvin scale.
(a) 25°C
(b) 373°C
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.
Arrange the following substances in increasing order of forces of attraction between particles−− water, sugar, oxygen.
What is the physical state of water at−−
(a) 25°C
(b) 0°C
(c) 100°C
Give two reasons to justify−
(a) water at room temperature is a liquid.
(b) an iron almirah is a solid at room temperature.
Why is ice at 273 K more effective in cooling than water at the same temperature?
What produces more severe burns, boiling water or steam?
1. What is meant by a pure substance?
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.
2. List the points of differences between homogeneous and heterogeneous mixtures.
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.
1. Differentiate between homogeneous and heterogeneous mixtures with examples.
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.
2. How are sol, solution and suspension different from each other?
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.
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.
(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 %
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?
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.
2. Name the technique to separate
(i) butter from curd,
(ii) salt from sea-water,
(iii) camphor from salt.
(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
2. Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
3. What type of mixtures are separated by the technique of crystallisation?
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.
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.
• 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
2. Try segregating the things around you as pure substancesr or mixtures.
Pure substances -----------> salt , sugar , water
Mixtures -----------> milk , water, minerals, soil , lemonade
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.
(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
2. Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
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.
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?
(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.
4. Explain the following giving examples.
(a) saturated solution
(b) pure substance
(c) colloid
(d) suspension
(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.
5. Classify each of the following as a homogeneous or heterogeneous mixture.
soda water, wood, air, soil, vinegar, filtered tea.
Homogeneous mixture : soda water , air, vinegar
Heterogeneous mixture : wood, soil, filtered tea.
How would you confirm that a colourless liquid given to you is pure water?
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.
“pure substance” are as follows
(a) Ice
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury
8. Identify the solutions among the following mixtures.
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water.
The list of solutions among the following mixtures are
(b) Sea water
(c) Air
(e) Soda water.
9. Which of the following will show “Tyndall effect”?
(a) Salt solution
(b) Milk
(c) Copper sulphate solution
(d) Starch solution.
Milk and Starch Solution will show Tyndall Effect.
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
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
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.
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.
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
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.
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?
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
Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?
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.
Which postulate of Dalton’s atomic theory can explain the law of definite proportions?
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.
1. Define the atomic mass unit.
One atomic mass unit is a mass unit equal to exactly onetwelfth (1/12th) the mass of one atom of carbon-12.
2. Why is it not possible to see an atom with naked eyes?
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
1. Write down the formulae of
(i) sodium oxide
(ii) aluminium chloride
(iii) sodium suphide
(iv) magnesium hydroxide
The formulae of
(i) sodium oxide ---------------------------> Na2O
(ii) aluminium chloride----------------------> AlCl3
(iii) sodium suphide -------------------------> Na2S
(iv) magnesium hydroxide ------------------> Mg(OH)2
2. Write down the names of compounds represented by the following formulae:
(i) Al2(SO4)3
(ii) CaCl2
(iii) K2SO4
(iv) KNO3
(v) CaCO3
(i) Al2(SO4)3 → Aluminium sulphate
(ii) CaCl2 → Calcium chloride
(iii) K2SO4 → Potassium sulphate
(iv) KNO3 → Potassium nitrate
(v) CaCO3 → Calcium carbonate
What is meant by the term chemical formula?
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.
How many atoms are present in a
(i) H2S molecule and
(ii) PO43− ion?
(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.
Calculate the molecular masses of H2, O2, Cl2, CO2, CH4, C2H6, C2H4, NH3, CH3OH.
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
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.
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
If one mole of carbon atoms weighs 12 gram, what is the mass (in gram) of 1 atom of carbon?
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
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)?
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.
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.
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%
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?
What are polyatomic ions? Give examples?
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–
Write the chemical formulae of the following:
(a) Magnesium chloride
(b) Calcium oxide
(c) Copper nitrate
(d) Aluminium chloride
(e) Calcium carbonate
(a) Magnesium chloride → MgCl2
(b) Calcium oxide ------> CaO
(c) Copper nitrate ------> Cu (NO3)2
(d) Aluminium chloride ------> AlCl3
(e) Calcium carbonate ------> CaCO3
Give the names of the elements present in the following compounds:
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate
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
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
(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
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)?
(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
Convert into mole.
(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide
(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
What is the mass of:
(a) 0.2 mole of oxygen atoms?
(b) 0.5 mole of water molecules?
(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
Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.
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)
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)
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
What are canal rays?
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.
If an atom contains one electron and one proton, will it carry any charge or not?
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.
On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole.
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.
Name the three sub-atomic particles of an atom.
The three sub-atomic particles of an atom are:
(i) Protons
(ii) Electrons, and
(iii) Neutrons
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
On the basis of Rutherford's model of an atom, protons (positively-charged particles) are present in the nucleus of an atom.
Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
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.
Draw a sketch of Bohr’s model of an atom with three shells.
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?
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.
Write the distribution of electrons in carbon and sodium atoms?
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.
K and L shells of an atom are full, then what would be the total number of electrons in the atom?
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.
How will you find the valency of chlorine, sulphur and magnesium?
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
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?
(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.
With the help of Table 4.1, find out the mass number of oxygen and sulphur atom.
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
For the symbol H, D and T tabulate three sub-atomic particles found in each of them.
| Symbol | Electrons | protons | Neutrons |
| H | 1 | 1 | 0 |
| D | 1 | 1 | 1 |
| T | 1 | 1 | 2 |
Write the electronic configuration of any one pair of isotopes and isobars.
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
Compare the properties of electrons, protons and neutrons.
What are the limitations of J.J. Thomson’s model of the atom?
What are the limitations of Rutherford’s model of the atom?
Describe Bohr’s model of the atom.
Compare all the proposed models of an atom given in this chapter.
Summarize the rules for writing of distribution of electrons in various shells for the first eighteen elements.
Define valency by taking examples of silicon and oxygen.
Explain with examples (i) Atomic number, (ii) Mass number, (iii) Isotopes and (iv) Isobars. Give any two uses of isotopes.
Na+ has completely filled K and L shells. Explain.
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.
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?
If Z = 3, what would be the valency of the element? Also, name the element.
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?
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.
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
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
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
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
|
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
|
−
|
Who discovered cells and how?
Why is the cell called the structural and functional unit of life?
How do substances like CO2 and water move in and out of the cell? Discuss.
Why is the plasma membrane called a selectively permeable membrane?
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. |
___________________________ |
Can you name the two organelles we have studied that contain their own genetic material?
If the organisation of a cell is destroyed due to some physical or chemical influence, what will happen?
Why are lysosomes known as suicide bags?
Where are proteins synthesized inside the cell?
Make a comparison and write down ways in which plant cells are different from animal cells.
How is a prokaryotic cell different from a eukaryotic cell?
What would happen if the plasma membrane ruptures or breaks down?
What would happen if the plasma membrane ruptures or breaks donwn?
Which organelle is known as the powerhouse of the cell? Why?
Where do the lipids and proteins constituting the cell membrane get synthesized?
How does an Amoeba obtain its food?
What is osmosis?
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.
What would happen to the life of a cell if there was no Golgi apparatus?
Which organelle is known as the powerhouse of the cell? Why?
Where do the lipids and proteins constituting the cell membrane get synthesized?
How does an Amoeba obtain its food?
What is osmosis?
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.
1. What is a tissue?
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.
2. What is the utility of tissues in multi-cellular organisms?
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.
1. Name types of simple tissues.
There are three types of simple tissues: (a) Parenchyma (b) Collenchyma and (c) Sclerenchyma.
2. Where is apical meristem found?
Apical meristem is present at the growing tips of stems and roots and increases the length of the stem and the root.
4. What are the constituents of phloem?
Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and the phloem parenchyma.
1. Name the tissue responsible for movement in our body.
Muscular tissue is responsible for movement in human body.
2. What does a neuron look like?
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.
3. Give three features of cardiac muscles.
The three features of cardiac muscles are
4. What are the functions of areolar tissue?
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.
1. Define the term “tissue”.
Tissue is a group of cells similar in structure and function.
2. How many types of elements together make up the xylem tissue? Name them.
Xylem consists of four elments . They are tracheids, vessels, xylem parenchyma and xylem fibres.
3. How are simple tissues different from complex tissues in plants?
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.
4. Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall.
| 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. |
5. What are the functions of the stomata?
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.
7. What is the specific function of the cardiac muscle?
Cardiac muscles of the heart are responsible for the rhythmiccontraction and relaxation throughout life.
8. Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.
| 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 | |||
|
|||||
| 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 | |||
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.
(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
11. Identify the type of tissue in the following: skin, bark of tree, bone, lining of kidney tubule, vascular bundle.
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
12. Name the regions in which parenchyma tissue is present.
stems roots , fruit , leaves ,and flowers are the resion where parenchyma tissue is present.
13. What is the role of epidermis in plants?
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.
14. How does the cork act as a protective tissue?
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
Why do we classify organisms?
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.
Give three examples of the range of variations that you see in life-forms around you.
Three examples of the range of variations that you see in life-forms around us are as follows :
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?
What is the primary characteristic on which the first division of organisms is made?
On what basis are plants and animals put into different categories?
Which organisms are called primitive and how are they different from the so-called advanced organisms?
Will advanced organisms be the same as complex organisms? Why?
What is the criterion for classification of organisms as belonging to kingdom Monera or Protista?
In which kingdom will you place an organism which is single-celled, eukaryotic and photosynthetic?
An organism which is single-celled, eukaryotic and photosynthetic will be placed in Kingdom Protista.
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?
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.
Which division among plants has the simplest organisms?
Thallophyta is the division of plants that has the simplest organisms. This group includes plants, which do not contain a well differentiated plant body.
How are pteridophytes different from the phanerogams?
How do gymnosperms and angiosperms differ from each other?
How do poriferan animals differ from coelenterate animals?
How do annelid animals differ from arthropods?
What are the differences between amphibians and reptiles?
What are the differences between animals belonging to the Aves group and those in the mammalia group?
What are the advantages of classifying organisms?
How would you choose between two characteristics to be used for developing a hierarchy in classification?
Explain the basis for grouping organisms into five kingdoms.
What are the major divisions in the Plantae? What is the basis for these divisions?
How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?
An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.
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.
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?
Distinguish between speed and velocity.
Under what condition(s) is the magnitude of average velocity of an object equal to its average speed?
What does the odometer of an automobile measure?
What does the path of an object look like when it is in uniform motion?
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.
When will you say a body is in (i) uniform acceleration? (ii) non-uniform acceleration?
A bus decreases its speed from 80 km h−1 to 60 km h−1 in 5 s. Find the acceleration of the bus.
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.
What is the nature of the distance−time graphs for uniform and non-uniform motion of an object?
What can you say about the motion of an object whose distance−time graph is a straight line parallel to the time axis?
What can you say about the motion of an object if its speed−time graph is a straight line parallel to the time axis?
What is the quantity which is measured by the area occupied below the velocity−time graph?
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.
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.
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?
A racing car has a uniform acceleration of 4 m s−2. What distance will it cover in 10 s after start?
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?
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?
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?
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?
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?
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?
Fig 8.11 shows the distance-time graph of three objects A, B and C. Study the graph and answer the following questions:
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?
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?
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.
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?
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.
Explain why some of the leaves may get detached from a tree if we vigorously shake its branch.
Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest?
If action is always equal to the reaction, explain how a horse can pull a cart.
Explain, why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.
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.
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.
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.
When a carpet is beaten with a stick, dust comes out of it. Explain.
When a carpet is beaten with a stick, dust comes out of it. Explain.
Why is it advised to tie any luggage kept on the roof of a bus with a rope?
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
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?
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).
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?
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:
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?
What is the momentum of an object of mass m, moving with a velocity v?
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?
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.
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.
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.
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.
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.
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.
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.
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?
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)
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?
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.
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?
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
State the universal law of gravitation
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.
Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.
What do you mean by free fall?
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.
What do you mean by acceleration due to gravity?
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.
What are the differences between the mass of an object and its weight?
|
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). |
Why is the weight of an object on the moon 1/6 th its weight on the earth?
Let and
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:
Therefore, weight of an object on the moon is of its weight on the Earth.
Why is it difficult to hold a school bag having a strap made of a thin and strong string?
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.
What do you mean by buoyancy?
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.
Why does an object float or sink when placed on the surface of water?
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.
You find your mass to be 42 kg on a weighing machine. Is your mass more or less than 42 kg?
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.
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?
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.
How does the force of gravitation between two objects change when the distance between them is reduced to half?
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.,
If distance r becomes r/2, then the gravitational force will be proportional to
Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?
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.
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).
Since the object is on the surface of the Earth, r = radius of the Earth (R)
r = R = 6.4 × 106 m
Gravitational force,
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?
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.
If the moon attracts the earth, why does the earth not move towards the moon?
(i) Doubled
(ii) One-fourth and one-ninth
(iii) four times
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?
(i)
Doubled
(ii) One-fourth and one-ninth
(iii our times
What is the importance of universal law of gravitation?
Every object in the universe attracts every other object.
What is the acceleration of free fall?
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).
What do we call the gravitational force between the Earth and an object?
Gravitational force between the earth and an object is known as the weight of the object.
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].
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.
Why will a sheet of paper fall slower than one that is crumpled into a ball?
When a sheet of paper is crumbled into a ball, then its density increases.
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?
Weight of an object on the moon= 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
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.
(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,
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,
But,
Time of ascent = Time of descent
Therefore, total time taken by the ball to return = 5 + 5 = 10 s
A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.
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.
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?
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.
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
the force of attraction between the Earth and the Sun is given by:
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
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.
(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,
(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,
The combined displacement of both the stones at the meeting point is equal to the height of the tower 100 m.
In 4 s, the falling stone has covered a distance given by equation (1) as
Therefore, the stones will meet after 4 s at a height (100 − 80) = 20 m from the ground
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.
(a) 29.4 m/s
(b) 44.1 m
(c) 39.2 m above the ground
In what direction does the buoyant force on an object immersed in a liquid act?
An object immersed in a liquid experiences buoyant force in the upward direction.
Why does a block of plastic released under water come up to the surface of water?
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.
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?
density of the substance =
The density of the substance is more than the density of water (1 g cm−3). Hence, the substance will sink in water.
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?
Density of the 500 g sealed packet
The density of the substance is more than the density of water (). 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.
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?
Work done = Force × Displacement
W = F × S
Where,
F = 7 N
S = 8 m
Therefore, work done, W = 7 × 8
= 56 Nm
= 56 J
When do we say that work is done?
(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.
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
Work done = Force × Displacement
W = F × s
Define 1 J of work.
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.
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
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.
What is the kinetic energy of an object?
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.
Write an expression for the kinetic energy of an object.
Its SI unit is Joule (J).
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?
(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.
What is power?
Power is the rate of doing work or the rate of transfer of energy.
Define 1 watt of power:
A lamp consumes 1000 J of electrical energy in 10 s. What is its power?
A body is said to have power of 1 watt if it does work at the rate of 1 joule in 1 s
Define average power.
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.
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.
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.
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?
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.
A battery lights a bulb. Describe the energy changes involved in the process.
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.
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.
Work done by force is equal to the change in kinetic energy.
Therefore, work done by force =
= 40 − 250 = −210 J
The negative sign indicates that the force is acting in the direction opposite to the motion of the object
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.
W = mgh
Where,
Vertical displacement, h = 0
∴W = mg × 0 = 0
Hence, the work done by gravity on the body is zero.
The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?
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.
What are the various energy transformations that occur when you are riding a bicycle?
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.
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?
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.
A certain household has consumed 250 units of energy during a month. How much energy is this in joules?
1 unit = 1 kWh
1 kWh = 3.6 × 106 J
Therefore, 250 units of energy = 250 × 3.6 × 106 = 9 × 108 J
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.
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.
What is the work done by the force of gravity on a satellite moving round the earth? Justify your 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.
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.
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.
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.
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.
An electric heater is rated 1500 W. How much energy does it use in 10 hours?
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.
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?
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.
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?
To bring the object to rest, amount of work is required to be done on the object.
Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of 60 km/h?
Hence, 20.8 × 104 J of work is required to stop the car.
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
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.
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?
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.
Find the energy in kW h consumed in 10 hours by four devices of power 500 W each.
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.
A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy?
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.
How does the sound produced by a vibrating object in a medium reach your ear?
It forces the neighbouring particles of the medium to vibrate. These vibrating particles then force the particles adjacent to them to vibrate.
Explain how sound is produced by your school bell.
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.
Why are sound waves called mechanical waves?
Sound waves force the medium particles to vibrate. because of the interaction of the particles present in that medium.
Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend?
Sound needs a medium to propagate. Since the moon is devoid of any atmosphere, you cannot hear any sound on the moon.
Which wave property determines (a) loudness, (b) pitch?
(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.
What are wavelength, frequency, time period and amplitude of a sound wave?
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.
Distinguish between loudness and intensity of sound.
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
Guess which sound has a higher pitch: guitar or car horn?
the guitar has a higher pitch than a car horn.
How are the wavelength and frequency of a sound wave related to its speed?
Speed, wavelength, and frequency of a sound wave are related by the following equation:
Speed (v) = Wavelength () × Frequency (
)
Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.
Speed = Wavelength × Frequency
Hence, the wavelength of the sound wave is 2 m.
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?
period is reciprocal of the frequency of the wave and is given by the relation:
In which of the three media, air, water or iron, does sound travel the fastest at a particular temperature?
Sound travels the fastest in solids. Its speed decreases in liquids and it is the slowest in gases.
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?
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
Why are the ceilings of concert halls curved?
sound after reflection (from the walls) spreads uniformly in all directions.
What is the audible range of the average human ear?
The audible range of an average human ear lies between 20 Hz to 20,000 Hz.
What is the range of frequencies associated with
(a) Infrasound?
(b) Ultrasound?
(a) Infrasound has frequencies less than 20 Hz.
(b) Ultrasound has frequencies more than 20,000 Hz.
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?
Distance travelled by the sonar pulse during its transmission and reception in water = 2 × Actual distance = 2d
What is sound and how is it produced?
Sound is produced by vibration. When a body vibrates, it forces the neighbouring particles of the medium to vibrate.
Describe with the help of a diagram, how compressions and rarefactions are produced in air near a source of sound.
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 .
Cite an experiment to show that sound needs a material medium for its propagation.
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.
Why is sound wave called a longitudinal wave?
In a sound wave, the particles of the medium vibrate in the direction parallel to the direction of the propagation of disturbance.
Which characteristics of the sound helps you to identify your friend by his voice while sitting with others in a dark room?
Sound produced by two persons may have the same pitch and loudness, but the quality of the two sounds will be different.
Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why?
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.
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.
Given that the speed of sound in air = 344 m/s
(i) For, = 20 Hz
(ii) For,
Hence, for humans, the wavelength range for hearing is 0.0172 m to 17.2 m.
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.
Therefore, time taken by the sound wave to reach the other end,
Speed of sound wave in air at 25°C,
Therefore, time taken by sound wave to reach the other end,
The ratio of time taken by the sound wave in air and aluminium:
The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?
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.
Does sound follow the same laws of reflection as light does? Explain.
The incident sound wave and the reflected sound wave make the same angle with the normal to the surface at the point of incidence.
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?
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.
Give two practical applications of reflection of sound waves.
(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.
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.
According to the second equation of motion:
Now, time taken by the sound to reach the top from the base of the tower,
Therefore, the splash is heard at the top after time, t
Where,
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?
Speed of sound = Wavelength × Frequency
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.
What is reverberation? How can it be reduced?
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.
What is loudness of sound? What factors does it depend on?
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.
Explain how bats use ultrasound to catch a prey.
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.
How is ultrasound used for cleaning?
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.
Explain the working and application of a sonar.
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’.
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.
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,![]()
Explain how defects in a metal block can be detected using ultrasound.
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.
Explain how the human ear works.
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.
State any two conditions essential for good health.
(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.
State any two conditions essential for being free of disease.
(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.
Are the answers to the above questions necessarily the same or different? Why?
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.
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?
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.
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?
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.
Why are we normally advised to take bland and nourishing food when we are sick?
we can get the nutrients and energy quickly to fight off the foreign disease- causing agents.
What are the different means by which infectious diseases are spread?
(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.
What precautions can you take in your school to reduce the incidence of infectious diseases?
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.
What is immunization?
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.
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?
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.
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.
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.
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.
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.
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.
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.
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?
(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.
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?
(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.
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?
(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.
How is our atmosphere different from the atmospheres on Venus and Mars?
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%.
How is our atmosphere different from the atmospheres on Venus and Mars ?
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.
How does the atmosphere act as a blanket?
(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.
What causes winds?
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.
How are clouds formed?
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.
List any three human activities that you think would lead to air pollution
(i) Burning of fossil fuels such as coal and petroleum
(ii) Industrialization
(iii) Deforestation
Why do organisms need water?
(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.
What is the major source of fresh water in the city/town/village where you live?
River is a major source of fresh water.
Do you know of any activity which may be polluting this water source?
The discharge of waste water from homes, industries, hospitals, etc. into the river pollutes this fresh water source.
How is soil formed?
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.
What is soil erosion?
The blowing away or washing away of land surface by wind or water is known as soil erosion.
What is soil erosion?
What are the methods of preventing or reducing soil erosion?
The methods of preventing or reducing soil erosion are:
(i) Prevention of deforestation
(ii) Plantation of trees
What are the different states in which water is found during the water cycle?
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).
Why is the atmosphere essential for life?
(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.
Name two biologically important compounds that contain both oxygen and nitrogen.
Two biologically important compounds that contain both oxygen and nitrogen are:
(i) Amino acids
(ii) Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)
Why is water essential for life?
(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...
List any three human activities which would lead to an increase in the carbon dioxide content of air.
(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.
How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource?
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.
What is the greenhouse effect?
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.
You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?
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.
What are the two forms of oxygen found in the atmosphere?
(i) Diatomic molecular form with chemical formula O2.
(ii) Triatomic molecular form with chemical formula O3 known as ozone.
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?
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.
Write a note on how forests influence the quality of our air, soil and water resources.
(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.
What do we get from cereals, pulses, fruits and vegetables?
How do biotic and abiotic factors affect crop production?
What are the desirable agronomic characteristics for crop improvements?
What are the desirable agronomic characteristics for crop improvements?
What are macro-nutrients and why are they called macro-nutrients?
How do plants get nutrients?
Compare the use of manure and fertilizers in maintaining soil fertility
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.
Why should preventive measures and biological control methods be preferred for protecting crops?
What factors may be responsible for losses of grains during storage?
Which method is commonly used for improving cattle breeds and why?
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.”
What management practices are common in dairy and poultry farming?
What are the differences between broilers and layers and in their management?
How are fish obtained?
What are the desirable characters of bee varieties suitable for honey production?
What are the advantages of composite fish culture?
What is pasturage and how is it related to honey production?
Explain any one method of crop production which ensures high yield.
Why are manures and fertilizers used in fields?
What are the advantages of inter-croping and crop rotation?
What are the advantages of inter-cropping and crop rotation?
What is genetic manipulation? How is it useful in agricultural practices?
How do storage grain losses occur?
How do storage grain losses occur?
How do good animal husbandry practices benefit farmers?
What are the benefits of cattle farming?
For increasing production, what is common in poultry, fisheries and bee-keeping?