Author name: Raju

CBSE Sample Papers for Class 10 Social Science Set 3

These Sample Papers are part of CBSE Sample Papers for Class 10 Social Science. Here we have given CBSE Sample Papers for Class 10 Social Science Set 3

Time allowed : 3 hours
Maximum Marks : 80

General Instructions

• The question paper has 26 questions in all. All questions are compulsory.
• Marks are indicated against each question.
• Questions from serial number 1 to 7 are Very Short Answer Type Questions. Each questions carries one mark.
• Questions from serial number 8 to 18 are 3 marks questions. Answers of these questions should not exceed 80 words each.
• Questions from serial number 19 to 25 are 5 marks questions. Answers of these questions should not exceed 100 words each.
• Question number 26 is a map question. It has two parts 26(A) and 26(B). 26(A) of 2 marks from History and 26(B) of 3 marks from Geography. After completion attach the map inside your answer book.
• There is no overall choice. However, internal choice has been provided in some questions. You have to attempt only one of the alternatives in all such-questions.

Question. 1.
What does the term ‘absolutist’ refer to ?
OR
How has the Maritime Silk Route useful for Vietnam ?

Question. 2.
Name the autobiography of Rassundari Debi.
OR
Mention two features of Devaki Nandan Khatri’s Chandrakanta’.

Question. 3.
What is open cast mining ?

Question. 4.
What are the basic elements of democracy.

Question. 5.
What would the lender do in case the borrower fails to repay the loan ?

Question. 6.
Ford motors, an American company, is one of the world’s largest automobile manufacturers with production spread over 26 countries of the world. The company wants to develop Ford India as a component supplying base for its other plants across the globe. Would you say Ford Motors is an MNC ? Why ?

Question. 7.
People make complaints about the lack of civic amenities such as bad roads, poor water supply and health facilities, but no one listens. Now the RTI Act gives you the power to question. Do you agree ? Discuss.

Question. 8.
“The most serious source of nationalist tension in Europe after 1871 was the area of Balkans.” Justify.
OR
Who was Paul Bernard ? Why did he believe in developing the economy of the colonies ?

Question. 9.
Why is ‘Godan’ considered an epic on Indian peasantry ? Explain.
OR
“Leading Indian novelists of the nineteenth century wrote for a national cause.” Do you agree with the statement ? Justify your answer.

Question. 10.
Explain any three reasons responsible for water scarcity in India.

Question. 11.
Ramlal is a farmer in poor state of Bihar. Due to uncertainties in farming, he does not want his son to become a farmer. There are hundreds of farmers like Ramlal who do not want their sons to become a farmer. Find out the reasons.

Question. 12.
Explain the meaning of decentralisation. Also discuss provisions that have been made towards decentralisation in India after the constitutional amendment in 1992.

Question. 13.
“Democracies lead to a peaceful and harmonious life among citizens.” Support the statement with suitable examples.

Question. 14.
What are public interest pressure groups ? Describe their functioning.

Question. 15.
The countries of the Middle-East have very high per capita income due to revenues from crude oil but they are otherwise not developed. Inspite of high per capita income why countries of Middle-East are not so called developed ? What factor other than income are important aspects of development ?

Question. 16.
Imagine that you are the head of your village. In that capacity, suggest some activities that you think should be taken up under MGNREGA that would increase the income of people. Discuss.

Question. 17.
What are Special Economic Zones (SEZs) ? Write two characteristics of Special Economic Zones (SEZs).

Question. 18.
What legal measures were taken by the government to empower the consumers in India ?

Question. 19.
‘India had a vibrant trade in cotton and silk till the mid of 18th century ? How did the network of Indian textile come to an end ? Give two reasons. Name the new ports which replaced the earlier ports.
OR
“By the first decade of the 20th century, a series of changes affected the patttern of industrialisation in India.” Support the statement with examples.
OR
How far is it correct to say that, ‘The First World War was the first modern industrial war’ ? Explain.

Question. 20.
“Nationalism spreads when people to believe that they are all part of the same nation”. Justify the statement.
OR
Analyse the role of merchants and the industrialists in the civil disobedience movement.

Question. 21.
Name the integrated steel plants of India. What are the problems faced by this industry ? What is India’s present position with regard to manufacturing and consumption of iron and steel ?

Question. 22.
“Roadways still have an edge over railways in India.” Support the statement with arguments.
OR
How has the distribution pattern of the railway network in the country been largely influenced by physiographic and economic factors ? Explain with examples.

Question. 23.
How does communalism take various forms in politics ? Explain any five.

Question. 24.
Why is it believed that political parties need to face and overcome the challenge of dynastic succession to remain effective instruments of democracy ? Explain.
OR
‘Modern democracies cannot exist without political parties’. Examine the statement.

Question. 25.
Sarita works in the agricultural fields, Ramesh works as a mechanic in Tata Motors, and Ritu works at a call centre located in Gurugram. How can the economic activities of Sarita, Ramesh and Ritu be classified ? Do you think this classfication is useful ?
OR
Rekha is engaged in fishing and selling them in the market. Name the sector in which Rekha is working. Though this is the largest employer in India why does it produce only a quarter of the GDP ?

Question. 26.
(A) Two features (a) and (b) are marked on the given political outline map of India.
Identify these features with the help of the following information and write their correct names on the lines marked near them.

(a) The place where move¬ment of Indigo Planters began.
(b) The place where cotton mill workers went in Satya- grah.
(B) Locate and label the following with appropriate symbols.
(i) A Dam on river Krishna.
(ii) Iron ore exporting port.
(iii) Tarapur nuclear power plant.

ANSWERS

Answer. 1.
The term ‘absolutist’ refers to the following points :

1. A government or a system of rule that has no restraints on power exercised.
2. A form of monarchical government that was centralised.
3. A form of government that is repressive.

OR
The Maritime Silk Route was useful for Vietnam as it:

1. helped import and export of goods.
2. business experties in diverse fields and more plentiful opportunities.

Answer. 2.
Amar Jiban was the autobiography written by Rassundari Debi. It was published in 1876. It was the first auto biography written by an Indian woman published in Bengali language.
OR
Following are the two features of Devaki Nandan Khatri’s Chandrakanta :

1. It is a romance with dazzling elements of fantasy.
2. It had contributed immensely in popularising the Hindi language and the Nagari script.

Answer. 3.
Open cast mining : It is a surface mining in which minerals are extracted from a shallow depth without a subsurface tunneling. In this process the minerals are extracted by removing the overlying materials from the surface. It is safe because there is no risk of gas explosion while extracting the minerals.

Answer. 4.
A formal constitution, regular elections, political parties and constitutional rights are the basic elements of democracy.

Answer. 5.
If the borrower fails to repay the loan, the lender has the right to sell the asset or collateral used for borrowing.

Answer. 6.
Yes, Ford Motors is an MNC because of the following reasons :

1. It owns or controls its production units in many countries, with its head office in USA.
2. It does different operations related to its business at different locations across the globe.

Answer. 7.
Yes, I agree that RTI gives us the power to find out how the government departments work so that we can approach the concerned administration agency which will repair the bad roads, ensure adequate and clean water supply or improve the health facilities. The RTI Act helps us to aproach the concerned department to get the work done.

Answer. 8.
The Balkan region became a source of nationalist tension in Europe after 1871 because of the following reasons :

1. The Balkans consisted of regions of modern day. Romania, Bulgaria, Albania, Greece, Macedonia, Croatia, Bosnia—Herzegovina, Slovenia and Montenegro and their inhabitants were broadly known as Slavs.
2. When the Ottoman Empire collapsed, it initiated nationalism in the Balkans states. Soon the feeling of nationalism spread and the situation became very unstable. The Ottoman empire tried to control the situation by strengthening itself through modernisation and internal reforms but all efforts went in vain.
3. Gradually, its European nations got separated and fought for independence and political rights. In the race of expanding their territories and to impose their supremacy on each other, Slavic nationalities quickly got into severe clashes. As a result, the Balkan area became an area of intense conflict. Matters were further worsened because, the Balkans also became the part of big power rivalry. During this period, there were intense rivalry among the European powers over trade and colonies as well as naval and military rights.

Thus, each power-Russia, Germany, England, Austria and Hungary was keen on countering the hold of other powers over the Balkans, and extending its own control over the area. This led to continued series of wars in the region and finally, the First World War broke out in 1914.
OR
Paul Bernard was a great French writer and policy-maker, who suggested a model to develop the French colonies. He was a believer of development of colonies and supported the idea that economic development of the colony was the only method which could help in serving the interests of the mother country.

Bernard’s ideas for the development of the economy were :

1. He strongly believed that the economy of the colonies needed to be developed and argued that the purpose of gaining control over colonies was to make profits.
2. If the economy was developed and the standard of living of the people improved, they would be able to buy more goods.
3. As a result, the market would expand which would lead to better profits for French business.

Answer. 9.
Godan is a Hindi novel by Munshi Premchand, translated into English as “The Gift of a Cow”. It was published in 1936 and remains Premchand’s best known work. The novel tells the moving story of Hori and his wife Dhania; a peasant couple. Landlords, money lenders, priests and colonial bureaucrats all those who hold power in society, form a network of oppression and rob their land making them landless labourers. Yet, Hori and Dhania retain their dignity to the end.

Godan is considered an epic on Indian peasantry because of the following reasons :

1. This novel touched the soul of Indian peasantry of that time, filled with powerful characters drawn from all levels of society.
2. As a progressive writer, Premchand fights against social injustice in all forms. In Godan, he shows his deep sympathy for the poor labourers, peasants, woman and oppressed persons of the society.
3. In ‘Godan’ Premchand gives a realistic portrayal of the Indian peasantry and presents a portrait gallery of contemporary Indian society.

In ‘Godan’ Hori is such a victim of this cruel and heartless system. The novel tends to assume the form of an epic of a common man and his everyday life and expresses the rapid socio-cultural changes in modern society. Thus, ‘Godan’ deals with the epic struggle of the Indian peasantry.
OR
(i) Yes, I agree with the statement as many historical novels were written about India’s glorious past. They were written about Marathas and Rajputs which produced a sense of pan-Indian belonging. They imagined the nation to be full of adventure, heroism, romance and sacrifice. Bhudev Mukhopadhya’s Anguriya Binimoy (1857) was the first historical novel written in Bengal.

Bankimchandra’s Anandamath was about a Hindu militia that fought against the Muslims to establish a Hindu Kingdom. It was a novel that inspired many freedom fighters.

Writers like Premchand, wrote novels which included various classes. Premchand created characters who believed in a comihunity based on democratic values. He made us think of social issues like caste oppression. Thus, all the above writers wrote for a national cause.

Answer. 10.

1. India witnessed industrialisation after independence, the establishment of large industrial houses and an increasing number of industries has exerted tremendous pressure on the fresh water resources.
2. An increase in the number of Urban centres with dense population has also exerted pressure on water resources. Many houses and societies have independent water supply system which have lowered the water level.
3. The deterioration of the quality of water due to industrial and domestic wastes has resulted in the scarcity of water in India. The failure of people to realise the importance of rain water harvesting has also made water a scarce resource.

Answer. 11.
Indian farmers do not want their sons to become a farmer because of the following reasons:

1. The share of agriculture in India’s GDP has been declining since 1951 and so, farming has a bleak future in terms of income.
2. Land reform laws have been enacted more than 40 years ago, but their implementation is inadequate resulting in unimproved condition of small farmers. Also the exploitation by middlemen is continuously increasing resulting in farmers not getting a remunerative price for their produce.
3. Irrigation is still inadequate in many parts of the country which make the farmers depend on the monsoons. A bad monsoon can spell doom for the crop,

Answer. 12.
When power is taken away from Central and State government and given to local government, it is called decentralisation. A major step towards decentralisation was taken in 1992. The constitution was amended to make third-tier system of the government more powerful and effective. As a result, rural local self-government, i.e., Panchayati Raj came into existence. It was made for the following objectives :

1. To provide third-tier system of the Panchayati Raj for all the states having population of over 20 lakhs and to hold panchayat elections regularly at the lapse of every 5 years.
2. To provide reservation of seats for Scheduled castes (SCs), Scheduled Tribes (STs) and other Backward Classes (OBCs) and to appoint State Election Commission to conduct panchayats and municipal elections. Here at least one-third of all positions are reserved for women.

Answer. 13.
Democracy leads to a peaceful and harmonious life among citizens as it gives a sound political system based on social equality to its citizens.

We can prove the statement by citing the following instances :

1. Democracy provides a conducive political environment to citizens for their popular participation in policies. Every citizen has the right to vote and right to contest election.
2. Democracy stands for equal economic status to all citizens. It ensures that the rights of the people are protected by the state thereby, the government functions according to the law.
3. In democracy, government undertakes extensive social welfare schemes to achieve universal literacy rate. In the social sphere, democracy tries to help its citizens to lead a peaceful and harmonious life by accommodating various social divisions and providing social equality to its citizens.

The support for the idea of democracy is overwhelming all over the word and is evident from South Asia.

Answer. 14.
Public Interest Group : Public interest groups or public interest pressure groups are those groups which seek to promote the interests of the large section of society, not only for its members.

Functioning of public interest group :

1. Sometimes the members of a public interest group may undertake those activities that benefit them as well as others.
2. They represent some common or general interest that needs to be defended. Hence, they promote collective good rather than selective good.

For example : BAMCFF is an organisation largely made up of government employees who campaign against caste discrimination. But its main concern is with social justice and social equality for the entire nation.

Answer. 15.
The countries of the Middle-East have very high per capita income due to revenues from crude oil, but they are otherwise not developed in every sector (except Israel). Their literacy rate, life expectancy at birth and other similar parameters do not match with those of developed countries of the west.

The Middle-East countries are not so developed because of the following reasons :

(i) The probable reason is that they have become rich nations recently due to sharp increase in the price of oil, but their society has not developed accordingly. Most of the wealth is accumulated in few hands. So, the society has widespread inequality.
(ii) Though income is one of the most important aspects of our lives, but there are other important factor also. These are :

(a) People also seek equal treatment, freedom, security and respect.
(b) Women need safe and secure environment to take up a variety of jobs or run a business.
(c) People also need political rights and also seek a pollution-free environment.

(iii) These countries are not considered as developed because they lack other basic facilities such as health care and education, without these basic facilities people of a country cannot contribute much to the national income and thus, no development takes place.

Answer. 16.
Being a village head, I can suggest many activities that would increase the income of people under MGNREGA scheme. These are :

1. Water conservation and water harvesting.
2. Drought proofing by digging tube wells.
3. Making provision of irrigation facility on the lands of disadvantaged sections SCs, STs and others.
4. Constructing irrigation canals, renovation of traditional water bodies (e.g., tanks).
5. Additionally, Land development for agriculture, horticulture, etc., can be done.
6. Constructing check dams for flood control. Construction of roads for improving rural connectivity to provide all weather access to the villages. It can also be considered a beneficial activity to increase the income of people.

Answer. 17.
The goverment of India has set-up industrial zones to attract the foreign investment in India, which are known as Special Economic Zones.

The following are the two characteristics of Special Economic Zones :

1. These zones are expected to have world-class infrastructure such as electricity, water supply, roads, transport, storage, recreational and educational facilities.
2. Companies setting up their production units in the SEZs are exempted from the payment of taxes for the initial five years. Additionally, government has also allowed flexibility in the labour laws to attract foreign investment.

Answer. 18.
Legal measures taken by the government to empower the consumers in India are :

1. The Consumer Protection Act, 1986 : The major step taken by the government in this regard was the enactment of the Consumer Protection Act, 1986 under which a consumer can appeal in state and national courts, even if his case has been dismissed at the district level.
2. Consumer Courts : These courts have been set-up to provide justice to the people who were treated unfairly in the market place. The consumers have been given the right to represent themselves in consumer courts. ,
3. Right to Information Act : This Act was passed in 2005 to ensure citizens all information about the functioning of government departments.

Answer. 19.
India had a vibrant trade in cotton and silk till the mid-18th century. By the 1750s, this network was controlled by Indian merchants and was broke down because :

1. The European Companies Gradually Gained Power : These companies first secured a variety of concessions from local courts, then they acquired the monopoly rights to trade. This resulted in a decline of the old ports of Surat and Hoogly through which local merchants had operated. Exports from those ports fell dramatically, the credit that had financed the earlier trade began drying up and the local banker slowly went bankrupt.
2. Decaying of Surat and Hoogly Port : While Surat and Hoogly ports decayed, Bombay and Calcutta port started to grow. This shift from the old ports to the new ones was an indicator of the growth of colonial power. Trade through the new ports came to be controlled by European Companies and was carried in European ships. While many of the old trading houses collapsed, those wanted to survive had to now operate within a network shaped by the European trading companies.

New Ports : The new ports that took place in Surat and Hoogly were Bombay and Calcutta.
OR
By the first decade of twentieth century, a series of changes affected the pattern of industrialisation in India in the following ways :

1. As the Swadeshi movement gathered momentum in India, the nationalists mobilised the people to boycott foreign cloth and other goods. Industrial groups organised themselves to protect their collective interests and pressurised the r government to increase tariff protection and grant other concessions also.
2. In 1906, the export of Indian yarn to China declined. So, the Indian industrialists shifted their interest from yarn to cloth production leading to considerable production of cotton piece goods.
3. The beginning of First World War created a new situation. Since British mills were busy in producing war materials to meet their own war needs, export of goods to India declined. This gave an opportunity to Indian industries to thrive. Indian mills had a vast home market to supply.
4. As the war continued, Indian factories were called upon to supply war needs for example, jute, bags, saddles, etc. New factories were set-up and old ones ran in multiple shifts.
5. After the war, industries in Britain got a severe setback. However, in India local , industrialists gradually consolidated their position substituting foreign manufactures and capturing home market. Handicraft production also expanded in the 20th century.

OR
The First World War was said to be the first modem industrial war. For the first time, it saw the use of machine guns, tanks, aircraft, chemical weapons, etc., on a massive i scale. During this time, the world experienced an economic and political instability. The First World War was too horrible like none other before.

Two main characteristics of this war were :

1. To fight the war, millions of soldiers had to be recruited from around the world and moved to the front lines on large ships and trains.
2. The scale of death and destruction was devastating, 9 million people were dead and 20 millions were injured, which was not possible without the use of industrial arms.

The first world war was called the first modern industrial war due to the following reasons:

1. The end of the First World War led to a profilic growth in the industry sector, mass production took place to feed and clothe the soldiers at war.
2. It led to many technological breakthroughs in terms of weapons and other warfare, that boosted the steel and iron industry around the world.
3. At the end of this war, many new companies and industries were established for sustainable recovery, thus, the First World War was also called the first modern industrial war.

Answer. 20.
The spreading of nationalism took place due to following factors :

1. United Stmggle : Different religious groups and communities unitedly struggled against the British rule.
2. Cultural Processes : Unity spread through various cultural processes like history, folklore, songs and symbols that helped in spread of nationalism.
3. Common Identity : The painting of ‘Bharat Mata’ was commonly identified as motherland and affected the people equally.
4. Revival of India Folklore : Reviving the folklore through folk songs, legends helped in promoting traditional culture and restore a sense of pride in the past history and culture.
5. Role of the Leaders : Leaders like Mahatma Gandhi, Jawaharlal Nehru aroused the feelings of nationalism through their motivational speeches and political activities. Thus, it can be concluded that nationalism spread, when people began to believe that they were all part of the same nation.

OR
Indian merchants and industrialists made huge profits during the First World War.

The following points analyse the role of merchants and the industrialists in the Civil Disobedience Movement:

1. They became powerful in the society and wanted to expand their business. So, they started opposing colonial policies that restricted their business.
2. They wanted protection against imports of foreign goods and rupee sterling foreign exchange ratio that would discourage imports.
3. These indsutrialists criticised colonial control over the Indian economy and supported the Civil Disobedience Movement at its first stage.
4. They gave financial assistance and refused to buy or sell imported goods.
5. Most industrialists thought ‘Swaraj’ as a time when colonial restriction did not exist on business world, as a result trade and business would flourish without constraints.

Answer. 21.
An integrated steel plant at large level handles everything in one complex from assembling of raw material and melting of iron ore in the blast furnace to steel making, rolling and shaping. Steel plants are usually concentrated near the sources of raw materials and market.

Four major steel plants in India are :

1. Indian Iron and Steel Company, IISCO located at Bumpur, West Bengal.
2. Tata Iron and Steel Company, TISCO at Jamshedpur, Jharkhand.
3. Bhilai Steel Plant, located at Bhilai in Chhattisgarh.
4. Bokaro Steel Plant, at Bokaro, Jharkhand.

Though India is an important iron and steel producing country in the world, we are not able to perform to our full potential.

Following challenges can be attributed to this :

1. Capital : Iron and Steel Industry requires large capital investment which developing country like India cannot afford.
2. Lack of Technology : Indian Steel Industry was characterised by a high degree of technological deficiency. This resulted in lower levels of investment in technological developments.
3. Shortage of Metallurgical Coal : Although India has huge deposits of high grade iron ore, many steel plants are forced to import metallurgical coal. For example, steel plant at Visakhapatnam has to import coal from Australia.
4. Inferior Quality of Products : Lack of modern technological and capital inputs and weak infrastructural facilities lead to the process of steel making extra time consuming, expensive and yields inferior variety of goods. Such a situation forces us to import better quality steel from abroad.

Thus, there is an urgent need to improve the situation and take the country out of desperate position.

Today, India ranks ninth among the world crude steel producers with 32-8 million tonnes of steel production. It is the largest producer of sponge iron. In spite of a large quantity of production of steel, per capita consumption of steel per annum in India is very low.

Answer. 22.
Roadways are the most important means of transport in India. India has one of the largest networks of roadways in the world, aggregating about 2-3 million km. Road transport has preceded railways and still have an edge over it in view of the ease with which it can be built and maintained.

Road transport is more useful than railway on account of the following merits :

1. Construction and maintenance cost of roads is much lower than the railways. Also roads can traverse comparatively more dissected and undulating topography.
2. Roads can negotiate higher gradient of slope and can traverse mountainous regions such as the Himalayas. They can reach remote villages and hilly regions where railway tracks cannot be laid.
3. Roads provide door to door service. Thus the cost of loading and unloading is much lower.
4. Road transport is also used as a feeder to other modes of transportation. For example, they provide a link between railway stations, airports and sea ports.
5. They link the villages, towns and cities with the railways. They provide linkage between ports and markets and trading centres.

OR

1. Physiographic factors : Level lands of the Northern plains of India with high density of population, rich agricultural resources and greater industrial activities have favoured the development of railways in this region. The regions, therefore, have the densest network of railway in India.
2. The rugged terrain of the Himalayan mountain region in the north and north¬eastern states with sparse population and lack of economic opportunities is unfavourable for the construction of railway lines thereby, railway network is lacking in these regions.
3. Sparsely populated sandy deserts of Rajasthan, hilly contiguous stretch of the Sahyadri, swamps of Gujarat, forested tracks of Madhya Pradesh, Chhattisgarh, Odisha and Jharkhand, the Flood plains of Bihar and Assam have posed great difficulty in laying of railway lines.

Economic Factors :

1. State funding plays a vital role in the development of railways.
2. The places that are highly industrialised attract the development of railways.

Answer. 23.
Communal politics is based on the idea that religion is the principal basis of social community. It can take various forms in politics :

1. Communalism in Everyday Beliefs : The most common expression of communalism is in everyday beliefs. Communalism routinely involve religious prejudices, stereotypes of religious communities and belief in the superiority of one’s religion over other religions.
2. Communalism as Majoritarian Dominance and Political Dominance : A communal mind often leads to a quest for political dominance of one’s own religious community for those belonging to majority community, this takes the form of majoritarian dominance. For those belonging to the minority community, it can take the form of a desire to form a separate political unit.
3. Communalism as Political Mobilisation : Political mobilisation on religious lines is another frequent form of communalism. This involves the use of sacred symbols, religious leaders, emotional appeals and plain fear in order to bring the followers of one religion together in the political arena.
4. Communalism in the Form of Communal Violence : Sometimes communalism takes its most ugly form of communal violence, riots, and massacre. For instance, India and Pakistan suffered some of the worst communal riots at the time of partition in 1947.
5. To sum up, communalism leads to the belief that people belonging to different religions cannot live as equal citizens within one nation. Either, one of them has to dominate the rest or they have to form different nations.

Answer. 24.
All over the world, people express strong dissatisfaction about the performance of the political parties. In order to remain effective instrument of democracy, political parties need to overcome some challenges. These are :

1. The first challenge is the lack of democracy within parties. All over the world, there is a tendency in political parties towards the concentration of powers in the hands of one or few leaders at the top. Parties do not keep membership registers, do not hold organisational meetings and do not conduct internal elections regularly.
2. The second challenge is dynastic succession where the top positions of a party are always enjoyed by members of one particular family. This trend is harmful for other members of the party as well as for democracy. This tendency is present in some political parties all over the world.
3. The third challenge is about the growing role of money and muscle power in parties which is specially observed during elections. Rich people and companies who give funds to the parties always have say on the policies and decisions of the party.
4. The fourth challenge is that parties do not seem to offer a meaningful choice to the voters. In our country, the differences among all the major parties on the economic policies have reduced. Sometimes, the same set of leaders keep shifting from one party to another, thus people have no option available to them.
5. When the political parties will be able to overcome these challenges only then the people of a country will lead a peaceful life.

OR

1. Modern form of democracies also need representatives from various political parties to form the government and to keep a check on the ruling party by being in opposition.
2. Without political parties, there would be chaos and turmoil in the society.
3. Existence of political parties in a representative democracy ensures that the country runs as per its policies and ideologies and has a responsive and accountable government that is answerable to the people.
4. Without political parties, elected candidates will be independent and accountable to their constituency for what they do in the locality.
5. Political parties are required so that a country is governed as per set ideologies and will be responsible for how the country will run.

Answer. 25.
The economic activities of Sarita, Ramesh and Ritu can be classified into primary, secondary and tertiary activities respectively.

The classification is useful due to following reasons :

1. The classification of economic activities into primary, secondary and tertiary sectors is useful as it provides information on how and where the people of a country are employed.
2. Also, this helps in ascertaining as to which sector of economic activity contributes more or less to the country’s GDP and per capita income.
3. If the tertiary sector is developing much faster than the primary sector, it implies that more measures should be taken to increase productivity in agriculture sector.
4. The knowledge that the agriculture as a profession is becoming unpopular or regressive can only come through the classification of economic activities.

Hence, it is necessary to classify economic activities into these three sectors for smooth economic administration and development.
OR
Rekha is engaged in primary sector of economy. It is the largest employer in India. About 51% of the total population is engaged in primary sector in one way or the other. It contributes to only 17% of the country’s GDP. At the time of Indian independence this sector had the biggest share in the Gross Domestic Product. But by » years its contribution goes on declining and currently it contributes only 17% of the total GDP. This sector produces

only a quarter of the GDP because of the following reasons:

1. Productivity in the primary sector is very low because of the use of outdated means of production.
2. Since many people are engaged in agriculture, and land being very limited resource, the average holdings of a farmer is less. Thereby, it cannot produce the desired output.
3. Primary sector lacks modern irrigational facilities. Dependence on monsoons adds to the problem.
4. The govenment has not been able to provide an effective system of financing and transportation in the rural areas.
5. Getting credit/insurance for farmer is very difficult. The risk factor associated with giving loan to a farmer is very high. This makes farmers dependence on local money lenders for credit who charge exorbitant interest rates. So there comes the problem in accessing the market facilities.
6. All these factors result in the backwardness of Indian agriculture, hence, its contribution in India’s GDP is very less,

Answer. 26.
The answer map is given below.

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CBSE Sample Papers for Class 10 Science Paper 9

These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 9.

Time allowed : 3 hours
Maximum marks : 80

General Instructions

• The question paper comprises two sections, A and B. You are to attempt both the sections.
• All questions are compulsory.
• All questions of Section-A and B are to be attempted separately.
• There is an internal choice in two questions of three marks each and one question of five marks.
• Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
• Question numbers 3 to 5 in Section-A are two marks questions. These are to be answered in 30 words each.
• Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
• Question numbers 16 to 21 in Section-A are 5 mark questions. These are to be answered in 70 words each.
• Question numbers 22 to 27 in Section-B are based on practical skills. Each question is a two marks question. These are to be answered in brief.

SECTION – A

Question. 1.
Why do we feel tired and have pain in muscles and sometimes get cramps after strenous physical work?

Question. 2.
What will happen if intake of Iodine in our diet is low ?

Question. 3.
What is anode mud ?

Question. 4.
Why are ‘danger’ signal lights red in colour ?

Question. 5.
Quote three instances where human intervention saved the forests from destruction.

Question. 6.
On what does the strength of an electromagnet depend ?
OR
Why does a domestic electric circuit have an earth wire ?

Question. 7.
Calculate the amount of heat generated while transferring 90000 coulomb of charge between the two terminals of a battery of 40 V in one hour. Also determine the power expended in the process.

Question. 8.
How does the electronic configuration of an element is related to its position in the periodic table ?

Question. 9.
What is the significance of the word ‘potenz’ in chemistry ? What does it indicate ?

Question. 10.
While cleaning a garden, the gardener gets rid of all insects including earthworms from the soil. Will it have any effect on the soil in the garden ?
OR
Is it sensible to go back to the lifestyle of our grandparents in taking a cloth bag to the shop and purchasing provisions from the nearby grocer shop where he would pack the provisions in paper ?

Question. 11.
After fertilisation, what are the changes inside and outside the ovule ? Is there any part of the flower that remains in the fruit ? If yes, which part and in which fruit ?

Question. 12.
Three students were on the way from Agra to Delhi. Rishi, the one of the student among them who was driving the car saw from his side mirror that the car which was behind their car had met with an accident. He suddenly applied brakes even after his friends asked him to leave the situation as it was. But Rishi didn’t agree and got down of car and was also able to pursuade his friends to help the injured. The three students took the injured person to the nearest hospital. After getting conciousness, the victims please them with thanks for saving their life.
(a) Name the type of mirror from which Rishi saw the accident :
(b) Why this mirror is used as a side mirror in the vehicle ? Show it with the help of ray diagram.

Question. 13.
Is it necessary to mention the physical states of the reactants and products in a chemical equation. Explain with an example.
OR
(a) A dry pallet of common base ‘X’, when kept in open air absorbs moisture and turns sticky. The compound is also a by-product of chlor-alkali process. Identify ‘X’. What type of reaction occurs when ‘X’ is treated with strong acid ? Write a balanced chemical equation for such reaction.
(b) Can we store the base ‘X’ in an aluminium container ? Give reason in support of your answer.

Question. 14.
What is regeneration ? Where do you see it ? Is it similar to reproduction ?

Question. 15.
Compare natural and artificial ecosystem.

Question. 16.
Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes ?

Question. 17.
Ethanol is a liquid at room temperature. Discuss its physical and chemical properties.
OR
Write the balanced chemical equation for the following :
(a) Methane is burned in sufficient air.
(b) Ethanol is treated with sodium.
(c) Ethanoic acid is reacted with sodium Hydroxide.
(d) Ethanoic acid is treated with sodium carbonate.
(e) Ethanol is mixed with ethanoic acid in the presence of an acid.

Question. 18.
What is meant by double circulation and why is it seen only in birds and mammals ?

Question. 19.
(a) Rohit claims to have obtained an image twice the size of an object with a concave lens. Is he correct ? Give reason for your answer.
(b) Where should an object be placed in case of a convex lens to form an image of same size as of the object ? Show with the help of ray diagram the position and the nature of the image formed.
(c) With the help of ray diagram, illustrate the change in position, nature and size of the image formed if the convex lens in case of (ii) is replaced by concave lens of same focal length.

Question. 20.
How did the Modem periodic table answer many of the queries raised in Mendeleev’s periodic table ?

Question. 21.
What is the importance of wildlife ? Give some measures to conserve our wildlife ? Give some examples of endangered plant and animal species ?
OR
Discuss the role of a food chain in an ecosystem with an example. Comment on the energy flow through a food chain.

SECTION – B

Question. 22.
When an iron rod is dipped into a solution of copper sulphate, copper is displaced. Why is it so ?

Question. 23.
Iron filings were added to a solution of copper sulphate. After 10 minutes, it was observed that the blue colour of the solution changes and a layer gets deposited on iron filings. What is the colour of the solution and the layer deposited ?

Question. 24.
While preparing a temporary stained mount of a leaf epidermal peel, how is the extra stain removed ?

Question. 25.
The given slides A and B were identified by four students I, II, III and IV as stated below :

Question. 26.
A student did the experiment to find the equivalent resistance of two given resistors, Rj and R2 first when they are connected in series and next when they are connected in parallel. The two values of the equivalent resistance obtained by him were Rs and Rp respectively. Compare Rg and RP.
OR
Which of the circuit components in the following circuit diagram are connected in parallel ?

Question. 27.
An identical prism is stuck to the first prism using a transparent adhesive with the same refractive index as the glass. This is shown in figure. In this figure, draw the path of the ray after it has reached B and until it has passed into the air again.

ANSWERS

SECTION – A

Answer. 1.
This is due to accumulation of lactic acid in the muscles.

Answer. 2.

1. When iodine intake is low, release of thyroxine from thyroid gland will be less by which protein, carbohydrate and fat metabolisms will be affected.
2. A person might suffer from goitre in case of iodine deficiency in the body.

Answer. 3.
Anode mud is a deposit of insoluble residue or mixture that collects at the anode in an electrolytic refining process and is formed by the dissolution of the anode in commercial electrolysis or plating process. The soluble impurities go into solution. It is also referred to as the anode slime. Some of the elements present in anode mud are Tellurium, Selenium, Antimony, Gold, Silver, Platinum and copper which are recovered later.

Answer. 4.
Danger signal lights are red in colour because the red coloured light having longer wavelength is scattered the least by fog or smoke. Therefore, it can be seen clearly from a distance.

Answer. 5.
The human intervention that saved the forests from destruction are the following :

1. The ‘Chipko Andolan’ (‘Hug the Trees Movement’) in a remote village called Reni in Garhwal, during the early 1970s.
2. The sal forsts of Arabari (in West Bengal) were saved from the degradation with the active and willing participation of the local community.
3. Amrita Devi Bishnoi, who in 1731 sacrificed her life along with 363 others for the protection of ‘khejri’ trees in Khejrali village near Jodhpur in Rajasthan.

Answer. 6.
The strength of an electromagnet depends on the following factors :

1. Number of turns in the coil : If we increase the number of turns in the coil, the strength of electromagnet increases.
2. Current flowing in the coil: If the current in the coil is increased, the strength of electromagnet increases.
3. Length of air gap between its poles : If we reduce the length of air gap between the poles of an electromagnet, then its strength increass.

OR
Domestic circuits generally have an earth wire which has an insulation of green colour. It is usually connected .to a metal plate deep in the earth near the house. This is a safety measure especially for those appliances that have a metallic body, for example, table fan, toaster, refrigerator etc. The metallic body is connected to the earth-wire which provides a low-resistance conducting path for the current. Thus, it ensures that any leakage of current to the metallic body of the appliance keeps its potential to that of the earth, and the user may not get a severe shock.

Answer. 7.
Here charge transferred Q = 90000 C, potential difference between the terminals of battery V = 40 V and time t – 1 h = 3600 s.
∴ Current, I = \(\frac { Q }{ t } \) = \(\frac { 90000 }{ 3600 } \) = 25A
∵ Amount of heat generated, H = VIt = 40 × 25 × 3600 = 3600000 J = 3.6 × 106 J
and power expended, P = \(\frac { H }{ t } \) = VI = 40 × 25 = 1000 W

Answer. 8.
The electronic configuration of an atom gives us the atomic number of an element as the number of electrons is equal to the number of protons in the atom. The atomic number of an element is a more fundamental property than its atomic mass. The Modem Periodic Table has 18 vertical columns known as groups and 7 horizontal rows known as periods. The elements present in a group have the same number of valence electrons. In other words groups in the Modem Periodic Table signify an identical outer shell electronic configuration. Similarly in a period, the atomic number increases by one unit as we move from left to right. The position of an element in the table tells us about its chemical reactivity.

Answer. 9.
The ‘p’ in pH stands for potenz in German and it means power. The pH scale was developed to measure the hydrogen ion concentration in a solution. On the pH scale we can measure from 0 (very acidic) to 14 (very alkaline). pH should be thought of simply as a number which indicates the acidic or basic nature of a solution. Higher the hydronium ion concentration, lower the pH value. The pH of a neutral solution like pure water is 7. Values less than 7 on the pH scale represent acidic solutions. When the pH value increases from 7 to 14 it represents an increase in the OH- ion concentration in the solution meaning an increase in the strength of alkali.

Our body works within a pH range of 7.0 to 7.8. Living organisms survive only in a narrow range of pH change. When the pH of rain water is less than 5.4 it is called acid rain. This affects aquatic life. pH is important in our daily lives. It plays a role in our digestive system, self-defense of animals and plants and in tooth decay.

Answer. 10.
While cleaning his garden if the gardener gets rid of all insects including earthworms he is sure to face a number of problems. Initially, the garden may look neat and insect free but soon there will be a loss of fertility in the soil. This is because the tiny organisms like snails, small beetles and earthworms help in decomposing the dead leaves, flowers or fruits that fall down from the plants. Moreover their waste acts as natural manure for the soil. Next the earthworm helps in moving the soil particles up and down in the soil floor. This helps to improve aeration in the soil. In fact, the earthworm is called the farmer’s friend as it improves soil fertility.
OR
In the name of convenience and a modern lifestyle in the last thirty years mankind has adopted several practices whose harmful effects are becoming visible only now. It has led to problems both to the environment and personally to man himself. Today there are mounds of wastes all around us and in particular plastic so that man does not know how to dispose of them. Moreover, the habit of going in for packed food items everywhere has led to several grave health problems staring at mankind. In those days we purchased provisions in the neighbourhood provision store where we could feel the items with our hands and fingers before buying it and then the grocer would pack everything in old paper bits which we would bring home in our own cloth bags. Thus, there was no plastic in use. Moreover the birds, squirrels and some creatures would feed on the grains that would fall outside the shop. With the advent of packed food items available in supermarkets this has stopped and today sparrows have almost become extinct around us. So it is very sensible to go back to the lifestyle of our grandparents.

Answer. 11.
We know that in a flower, the stamens are the male reproductive part and the carpel is the female reproductive part. The stamen consists of the filament and anther. The anther has many yellow coloured pollen-grains which are the male gametes. The carpel consists of stigma, style and ovary. The female gamete or the ovule is found inside the swollen ovary at the bottom of the carpel.

During pollination, the pollen-grains are transferred to the sticky stigma of the flower. After the pollen lands on a suitable stigma, it has to reach the female gametes inside the ovary. For this a tube grows out of the pollen-grain and travels through the style to reach the ovary. After fertilization, the zygote divides several times to form an embryo within the ovule. The ovule developes a tough outer coat and is gradually converted into a seed. The ovary grows rapidly and ripens to form the fruit. Meanwhile, the sepals, petals, style and stigma shrivel and fall off. Sometimes, the sepals alone remain in the fruit. This is seen in brinjal and chillies.

Answer. 12.
(a) Convex mirror.
(b) A convex mirror always produces an erect, virtual and diminished image and gives a wider view as shown in the following figure.

Answer. 13.
A chemical equation can be made more informative by mentioning the physical states of the reactants and products along with their chemical formulae. The gaseous, liquid, aqueous and solid states of the reactants and products are represented by the notations, (g), (I), (aq) and (s) respectively. The word aqueous is written if the reactant or product as a solution in water. When we use the symbol g with H₂O it means in the reaction water is used as steam.
Example : 3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)
In the above example, Fe in the solid state reacts with water in steam form and forms iron oxide in solid form and releases hydrogen gas.
OR
(a) ‘X’ is NaOH.
When NaOH is treated with strong acid like HCl, neutralisation reaction occurs and salt is formed.
NaOH + HCl → NaCl + H₂O
‘X’ strong acid.

(b) No, ‘X’ cannot be stored in aluminium container because aluminium with a coating of oxide reacts with the NaOH to form a salt and water.

Answer. 14.
Many fully differentiated organisms have the ability to give rise to new individual organisms from their body parts. If the individual is somehow cut or broken into many pieces, many of these pieces grow into separate individuals. Simple animals like Planaria and Hydra, when cut up into pieces, each piece can grow into a new and complete organism. This process is called regeneration. Regeneration is carried out by specialised cells. These cells proliferate and give rise to a large number of cells which in turn undergo specialisation to form the complete organism. These changes take place in an organised sequence referred to as development. However regeneration is not the same as reproduction since most organisms would not normally depend on being cut up to be able to reproduce.

Answer. 15.
Natural ecosystems include forests, ponds, lakes etc. Artificial ecosystems include gardens, crop- fields, an aquarium, national parks, national sanctuaries etc.

Natural ecosystem

1. It consists of many species of plants and animals.
2. The genetic diversity is very high.
3. Sunlight is the energy source for the autotrophs.
4. There are long and complex food chains.
5. The natural nutrient cycle is highly eff icient.

Artificial or man-made ecosystem

1. It consists of fewer or selected species of plants and animals.
2. The genetic diversity is low.
3. Sunlight is the ultimate source of energy but artificial supplements are added to promote growth.
4. Food chains are simple and sometimes incomplete.
5. There is incomplete nutrient cycling.

Answer 16.
Electric generator : A labelled diagram of an A.C. electric generator has been drawn in the following figure.

Principle : An electric generator works on the principle of electromagnetic induction phenomenon. According to it, whenever a coil is rotated between the poles of a magnet, an induced current is set up in the coil, whose direction is given by Fleming’s right-hand rule.

Working: Let in the beginning, as shown in figure brushes B₁ and B₂ are kept pressed separately on rings R₁ and R₂ respectively. Let the axle attached to the rings is rotated such that arm AB of the coil moves up and arm CD moves down in the magnetic field. Due to rotation of arms AB and CD induced currents are set up in them. As per Fleming’s right-hand rule induced currents in these arms are along the directions AB and CD respectively. Thus, an induced current flows along ABCD and current in the external circuit flows from B₂ to B₁.

After half a rotation, arm AB starts moving down and the arm CD upward. Therefore, directions of induced currents in these arms change. Thus, net induced current now becomes in the direction DCBA. In the external circuit now current flows from B₁ to B₂. Thus, after every half rotation current changes its direction and an alternating current is obtained from the generator.

Action of brushes : Brushes are kept pressed on the two slip rings separately. Outer ends of the brushes are connected to the galvanometer (or the external load). Thus, brushes help in transferring current from the coil ABCD to the external circuit.

Answer. 17.
Ethanol (C₂H₅OH) is a commercially important hydrocarbon.
Physical properties of ethanol :

1. It is a liquid at room temperature.
2. It is commonly called alcohol and is an active ingredient of all alcoholic drinks.
3. Being a good solvent, it is used in medicines like cough syrup, tonics and tincture iodine.
4. Consumption of even a small amount of pure alcohol called absolute alcohol can be deadly.
5. Consumption of alcoholic drinks is a social problem and it leads to many harmful effects.

Chemical properties of ethanol :
(i) Reaction with sodium: Alcohols react with sodium leading to the evolution of hydrogen. Sodium ethoxide is formed when sodium reacts with ethanol.
2Na + 2C₂H₅OH → 2C₂H₅ONa + H₂
(ii) Reaction on heating: Heating ethanol at 443K with excess concentrated sulphuric acid results in the dehydration of ethanol to produce ethane.

As concentrated sulphuric acid removes water molecule from ethanol it is called a dehydrating agent.
OR

(a) CH₄ + 5O₂ → CO₂ + H₂O + Heat + Light
(b) 2CH₃CH₂ – OH + 2Na → 2C₂H₅ – ONa + H₂
(c) CH₃COOH + NaOH → CH₃COONa + H₂O
(d) CH₃COOH + Na₂CO₃ → 2CH₃COONa + H₂O + CO₂
(e) CH₃COOH + CH₃ – CH₂ – OH → CH₃COOCH₂ – CH₃ + H₂O

Answer. 18.
Double circulation refers to the separate circulation of pure oxygenated blood from the heart to different body parts and the impure deoxygenated blood collected from the different body parts and sent to the heart. This separation allows a highly efficient supply of oxygen to the body. In double circulation blood goes through the heart twice during each cycle. In fact the separation of the right side and the left side of the heart helps to keep the oxygenated and deoxygenated blood from mixing. Animals like birds and mammals which require a lot of energy daily to maintain their body temperature have double circulation. Animals like amphibians and reptiles have a three chambered heart which allows some mixing of blood. They do not require a lot of energy as their body temperature depends on the surrounding temperature. Fishes have only a two-chambered heart. Blood pumped to the gills, is oxygenated there and is sent directly to the rest of the body. Thus blood goes only once through the heart in the fish during one cycle of passage through the body.

Answer. 19.
(a) No, Rohit is incorrect because magnified imag6 of an object cannot be formed by a concave lens ever.
(b) The object should be placed at 2F.


Image obtained is virtual, erect and diminished in case of concave lens.

Answer. 20.
The Modem Periodic Table was able to answer many of the queries posed by Mendeleev’s periodic table. Clear trends could be seen among the groups and periods with regard to some major issues like valency, atomic size and metallic and non-metallic properties.

Atomic size: Atomic size refers to the radius of the atom. It can be visualised as the distance between the centre of the nucleus and the outermost shell of an isolated atom. The atomic radius of hydrogen atom is 37 picometre.

As we move from left to right along a period, the atomic radius decreases. This is due to an increase in nuclear charge which tends to pull the electrons closer to the nucleus and reduces the size of the atom.

For example, elements of period II, Li(152), Be(lll), B(88), C(77), N(74), 0(66) we can see how the atomic radius gradually decreases in size.

As we move down the group, the atomic size increases. This is because new shells are being added as we go down the group. This increases the distance between the outermost electrons and the nucleus so that the atomic size increases in spite of the increase in nuclear charge.

For example, Group I elements are Na (86), Li(152), K(231), Rb (244), Cs(262).

Such trends can be observed in all the groups and periods of the Modem Periodic Table.

Answer. 21.
Importance of wildlife are :

1. They maintain an ecological balance of nature.
2. It provides a great biological diversity.
3. Many valuable products like musk, ivory, leather etc. are obtained from them.

Some measures to conserve wild life are :

1. Implementation of Laws to give severe punishment to those people who kill wild animals.
2. Protection of their natural habitats.
3. Maintenance of wildlife in protected areas like sanctuaries, national parks, biosphere reserves etc.
4. Educating people about the importance of wildlife.

Examples of endangered plant species are Pitcher plant, Snow Orchid and examples of endangered animal species are Indian salamander, Indian wolf, One-homed rhinocerous etc.
OR
Grass → Insects → Frog → Snake → Peacock

The above sequence represents a food chain operating in an ecosystem. The series of organisms which eat and are eaten by others is called a food chain. Each level of the food chain is called a trophic level. Generally the autotrophs or producers are the first trophic level. They trap the solar energy and make it available for the heterotrophs or consumers. The herbivores or the primary consumers come at the second level, small carnivores or secondary consumers come at the third level and larger carnivores or tertiary consumers come at the fourth trophic level. Food forms the source of energy for each level of organism and helps it to perform the various functions of life. There is a flow of energy from one trophic level to another. Solar energy is trapped by the autotrophs during photosynthesis. This energy flows from one trophic level to the next. It has been found that only 1/1 Oth of the energy is capable of moving to the next level. That is why as we move up the food chain we find fewer and fewer organisms. Also every food chain does not have more than three to four levels. The length and complexity of the food chains vary greatly. Each organism is generally eaten by two or more organisms which in turn are eaten by several others. So in any ecosystem, instead of a single straight food chain we can see many branching chains forming a food web.

SECTION-B

Answer. 22.
When an iron rod is dipped into a solution of copper sulphate, copper is displaced because iron is more reactive than copper. So, it displaces copper and forms iron sulphate.

Answer. 23.
The solution of the colour is green and that of the coating is reddish-brown. This is because iron being more reactive than Cu displaces Cu from CuSO₄ and forms green coloured solution of FeSO₄ and a reddish-brown layer of Cu get deposited.

Answer. 24.
While preparing a temporary stained mount of a leaf epidermal peel, extra stain is removed with the help of the filter paper. The filter paper absorbs the extra starch.

Answer. 25.
I is correct because in binary fission of Amoeba, nucleus divides first, then the cytoplasm and daughter cells are formed.

Answer. 26.
In series, the equivalent resistance
R_s = R₁ + R₂
In parallel, the equivalent resistance

OR
R₁, R₂ and V are connected in parallel. This is because these circuit components have two common points.

Answer. 27.

We hope the CBSE Sample Papers for Class 10 Science paper 9 help you. If you have any query regarding CBSE Sample Papers for Class 10 Science paper 9, drop a comment below and we will get back to you at the earliest.

CBSE Sample Papers for Class 10 Science Paper 6

These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 6.

Time allowed: 3 hours
Maximum marks : 80

General Instructions

• The question paper comprises two sections, A and B. You are to attempt both the sections.
• All questions are compulsory.
• All questions of Section-A and B are to be attempted separately.
• There is an internal choice in two questions of three marks each and one question of five marks.
• Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
• Question numbers 3 to 5 in Section-A are two marks questions. These are to be answered in 30 words each.
• Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
• Question numbers 16 to 21 in Section-A are 5 mark questions. These are to be answered in 70 words each.
• Question numbers 22 to 27 in Section-B are based on practical skills. Each question is a two marks question. These are to be answered in brief.

SECTION – A

Question. 1.
What are biodegradable substances ? Give two examples.

Question. 2.
What does the peripheral nervous system consist of ?

Question. 3.
What are isotopes ?

Question. 4.
What is Snell’s law of refraction ?

Question. 5.
Compare natural and artificial ecosystems ?

Question. 6.
What is the principle on which an electric motor works ? What are the special features of commercial electric motors ?
OR
A wire of length L and resistance R is stretched so that its length is doubled and the area of cross-section is halved. How will its :
(a) resistance change ?
(b) resistivity change ?
Justify your answer in each case.

Question. 7.
List the properties of magnetic lines of force.

Question. 8.
What is amalgam ? What are the benefits of alloying ?

Question. 9.
Is it necessary to mention the physical states of the reactants and products in a chemical equation. Explain with an example.

Question. 10.
Describe the ovary of the flower with a labelled diagram.
OR
What is the role of seminal vesicles and prostrate gland ?

Question. 11.
How does phototropism occur in plants ?

Question. 12.
If the image formed by a lens for all positions of an object placed in front of it is always erect and diminished what kind of lens is it? Justify with a ray diagram. If the power of the lens is -10 D, what is its focal length?

Question. 13.
Show the formation of chlorine molecule using electron dot structure.
OR
What is the role of metal of reagents written on arrows in the given chemical reactions ?

Question. 14.
Why should we use our resources judiciously ?

Question. 15.
Why are platelets needed by our body ?

Question. 16.
Name the type of mirror used in the following situations :
(a) Headlights of a car.
(b) Side/rear-view mirror of a vehicle.
(c) Solar furnace.
Support your answer with reason.

Question. 17.
How could the Modem Periodic Table remove various anomalies of Mendeleev’s Periodic Table ?
OR
What were the limitations of Mendeleev’s periodic table ?

Question. 18.
What is the response of plants to stimuli known as ? Describe the different types of these movements.

Question. 19.
What is Ohm’s law ? Draw the circuit for verifying Ohm’s law. If you draw a graph between the potential difference and the current flowing through a metallic conductor, what kind of curve will you get ? Explain how would you use this graph to determine the resistance of the conductor ?

Question. 20.
Discuss the properties of ionic compounds with regard to their melting and boiling point and conduction of electricity.

Question. 21.
What is hydroelectricity or hydel electricity ? What should one has to keep in mind while constructing a dam ?
OR
What is the importance of forest as a resource ? What are the causes of deforestation ?

SECTION – B

Question. 22.
Why does silver turn black when exposed to air ?

Question. 23.
What happens when dry slaked lime [Ca (OH)₂] reacts with chlorine ? What is the product used for ?

Question. 24.
Draw a labelled diagram of the human brain. What is the function of the medulla ?

Question. 25.
Which of the following actions we should adopt and why ?

(a) Taking a bus or using your personal vehicle.
(b) Using ordinary bulbs or LED bulbs in your homes.
(c) Taking the stairs or using the lift.
(d) Wearing extra woollen clothes or using the heater.

Question. 26.
Find the least count of a milliammeter in which there are 20 divisions between 400 mA and 500 mA marks.
OR
While experimentally verifying Ohm’s law, a student observed that the pointer of the voltmeter coincides with 15th division when the voltmeter has a least count of 0.05 V. Find the observed reading of voltmeter.

Question. 27.
Raju places a candle flame at a distance of about 60 cm from a convex lens of focal length 10 cm and focuses the image of the flame on a screen. Then he slowly moves the flame towards the lens and each time gets the image on the screen.

(a) In which direction from the lens, does he move the screen to focus the image ?
(b) What is the change in the size of the image ?
(c) How does the intensity of the flame change as the flame moves towards the lens ?
(d) At what point approximately between the flame and the lens will the image be inverted and of the same size ?

ANSWERS

SECTION – A

Answer. 1.
Biodegradable substances are those substances that can be broken down by biological processes. Some examples are remains of plants and animals and vegetable wastes that our houses produce daily.

Answer. 2.
The peripheral nervous system consists of the cranial nerves and the spinal nerves. While cranial nerves arise from the brain, the spinal nerves arise from the spinal cord.

Answer. 3.
Isotopes are atoms of elements having different mass numbers or atomic mass but the same atomic numbers.

Answer. 4.
According to Snell’s law of refraction, the ratio of sine of angle of incidence to the sine of angle of refraction is constant for a given pair of media.
sine of angle of incidence / sine of angle of refraction = constant
OR
\(\frac { sin\quad i }{ sin\quad r } \) = constant = n
This constant is called refractive index.

Answer. 5.
Natural ecosystems are the ones found in nature such as forests, ponds and lakes. Artificial ecosystems are man-made such as gardens and crop-fields.

Answer. 6.
A motor works on the principle that when a rectangular coil is placed in a magnetic field and current is passed through it, a force acts on the coil which rotates it continuously. When the coil rotates, the shaft attached to it also rotates. In this way the electrical energy supplied to the motor is converted into the mechanical energy of rotation. Electric motor is an important component in electric fans, refrigerators, mixers, washing machines, computers and mp3 players.
The commercial motors use :
(a) An electromagnet in place of the permanent magnet.
(b) Large number of turns of the conducting wire in the current-carrying coil.
(c) A soft iron core on which the coil is wound and the coils is called an armature. The soft iron core becomes magnetised and increases the strength of magnetic field. This makes the motor more powerful.
OR
(a) Here, length is doubled and area of cross-section is halved. Thus, a wire of length l and area of cross-section A becomes a wire of length 2l and area of cross-section \(\frac { A }{ 2 }\)

i.e., resistance becomes four times.
Resistivity of a substance does not depend on its length or area of cross-section. It depends on the nature of the material and temperature. Hence, there is no change.

Answer. 7.
Properties of magnetic field lines :

1. Magnetic field lines follow the direction from the North Pole to the South Pole.
2. Magnetic field lines always form closed circular loops.
3. Magnetic field lines do not cross one another.
4. Closer the field lines; stronger is the magnetic field and vice-versa.
5. Magnetic field lines are closer near the poles; which shows greater strength of magnetic field near the poles.

Answer. 8.
Amalgam is an alloy in which one of the constituent metal is mercury. Alloying is a good method of improving the properties of a metal. An alloy can have the properties of its constituents. An alloy is a homogeneous mixture of two or more metals or a metal and a non-metal. The electrical conductivity and melting point of an alloy is less than that of pure metals. Iron is a widely used metal. Usually iron in its pure state is very soft and easily stretched. When mixed with a little carbon it becomes hard and strong. Similarly when iron is mixed with nickel and chromium it produces stainless steel which is hard and resistant to rust. Solder, an alloy of lead and tin has a low melting point and is used for welding electrical wires together. Brass, an alloy of copper and zinc and bronze, an alloy of copper and tin are not good conductors of electricity though copper is used for making electrical circuits.

Answer. 9.
A chemical equation can be made more informative by mentioning the physical states of the reactants and products along with their chemical formulae. The gaseous, liquid, queous, and solid states of the reactants and products are represented by the notations, (g), (1), (aq) and (s) respectively. The word aqueous is written if the reactant or product s present as a solution in water. When we use the symbol (g) with H₂O it means in the reaction water is used as steam.
Example : 3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)
In the above example, Fe in the solid state reacts with water in steam form and forms iron oxide in solid form and releases hydrogen gas.

Answer. 10.
The carpel is the female reproductive part of the flower which is present in the centre of the flower. It ^ consists of three parts. The upper part which is sticky and is called the stigma, the middle elongated part is called the style and the swollen bottom part is called ovary. The ovary contains the ovules and each ovule has an egg inside. The male germ-cell produced by the pollen grain fuses with the female germ cell in the ovule. This is called fertilisation and it results in the formation of the zygote. This zygote grows into a new plant.

The sperms are formed in the testes which are located outside the abdominal cavity. The sperms formed are delivered through the vas deferens which unites with a tube coming from the urinary bladder. The urethra is thus a common passage for both the sperms and urine. Seminal vesicles and prostate gland are two glands associated with the male reproductive system. These glands produce secretions that are added to the sperm during its movement through the vas deferens. The secretions provide a fluid medium to facilitate easy movement of the sperms and they also nourish the moving sperms. It is primarily the tail of the sperm which helps it in swimming in this fluid medium.

Answer. 11.
Phototropism means the response of plant parts towards sunlight. Here sunlight is the stimulus, while the shoot system responds positively to sunlight the root system responds negatively to sunlight. Different plant hormones help to coordinate growth, development and responses to the environment. They are synthesised at places away from where they act and simply diffuse to the area of action. When growing plants detect light, a hormone called auxin which is synthesised at root tips helps the cells to grow longer. When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot. This concentration of the auxin stimulates the cells to grow longer on the side of the shoot which is away from light. Thus, the plant appears to bend towards light.

Answer. 12.
If the image formed by a lens for all positions of an object placed in front of it is always erect and diminished, it is a concave lens.

As f has negative value so, it is a concave lens.

Answer. 13.
Chlorine atom has the atomic number 17. This means it has 17 electrons too. Its electronic configuration is 2,8 and 7. So it has a valency of 7. Now 2 chlorine atoms combine to form a chlorine molecule. Each atom is 1 short of the stable configuration. This is set right by sharing 1 electron each between the 2 atoms. Thus a single covalent bond is formed between the 2 chlorine atoms.

OR
(a) Ni acts as a catalyst.
(b) Concentrated H₂SO₄ acts as a catalyst.
(c) Alkaline KMnO₄ acts as an oxidising agent.

Answer. 14.
All the things we use or consume like food, clothes, our shelter, books, toys, furniture, tools and vehicles are obtained from resources on this earth. The only thing we get from outside is the energy from the sun. This too is processed by the living organisms and various physical and chemical processes on the earth before we can use it. We should use resources judiciously because they are limited. We have an ever-increasing human population due to improved health care and this has brought about an increased demand for all the resources. The management of natural resources requires a long-time perspective so that they will last for the future generations and will not be exploited over a short period of time. Resource management must be focussed on an equitable distribution of resources so that it is not just a handful of rich and powerful people who benefit from this. In addition, when we extract these resources we must ensure a safe disposal of the wastes too. This is called sustainable natural resource management.

Answer. 15.
Platelets or thrombocytes are one of the constituents of blood the other two being the red blood corpuscles or erythrocytes and white blood corpuscles or leucocytes. Whenever there is an injury in the body bleeding starts. The body cannot afford to lose blood. In addition, leakage of blood leads to a drop in pressure which affects the pumping of the heart. To avoid this the body immediately informs the platelets to reach the site of injury. The platelets that keep circulating in the body quickly reach the site of bleeding and form a barrier or plug which stops the bleeding. That is why platelets are needed by our body.

Answer. 16.
(a) Concave mirror (b) Convex mirror (c) Concave mirror.
Explanation:

(a) Concave mirror is used in the headlights of a car. This is because concave mirrors can produce powerful parallel beam of light when the light source is placed at their principal focus. This powerful beam of light helps us to see things upto a considerable distance in the darkness of night.
(b) Convex mirror is used in side/rear view mirror of a vehicle. Convex mirrors give a virtual, erect, and diminished image of the objects placed in front of it. Because of this, they have a wide field of view. It enables the driver to see most of the traffic behind him/her.
(c) Concave mirrors are convergent mirrors. That is why they are used to construct solar furnaces. When solar furnace is placed at focus of concave mirror, sun rays after reflection from its surface gets converged at focus with much intense heat and solar furnace gets very hot.

Answer. 17.
Modem Periodic Table removes various anomalies of Mendeleev’s Periodic Table on the following points :

1. Position of isotopes : As Modem Periodic Table is based on atomic number, isotopes can be placed at one place in same group in Modem Periodic Table.
2. Anomalous Position of some pair of elements: In Mendeleev periodic table, some of the elements having higher atomic mass are placed before the elements having lower atomic mass. This defect of Mendeleev periodic table was overcome in Modem periodic table since it is based on atomic numbers.
3. Prediction of new elements: In long form of periodic table, the position and properties of new elements can be predicted easily on the basis of their atomic numbers or electronic configuration.

OR
The limitations of Mendeleev’s periodic table are as follows :

1. Hydrogen could not be given a fixed position. Electronic configuration of hydrogen is similar to alkali metals. It was able to combine with halogens, oxygen and sulphur to form compounds having similar formulae. Hydrogen could also exist as diatomic molecules just like halogens and could combine with metals and non-metals to form covalent compounds.
2. There was confusion regarding isotopes. Isotopes were discovered long after Mendeleev had done his periodic classification. Isotopes of an element have similar chemical properties but different atomic masses.
3. Atomic masses do not increase in a regular manner in going from one element to the next. Hence it was not possible to predict how many elements could be discovered between two elements.

Answer. 18.
Plants show two different kinds of movements one dependent on growth and the other independent of growth. The response of plants to stimuli is called trophic movements. The word tropism means response to stimuli. Though plants do not have an elaborate nervous system they do respond to a variety of stimuli. Response of plants to the stimulus of light is known as phototropism. The stem and its parts are phototrophic. The response of plants to water is known as hydrotropism. Roots respond to the presence of water by growing towards it. Response to gravitational pull is called geotropism. Roots are geotropic. Response of plants or their parts to the stimulus of touch is called thigmotropism. Some plants like the pea plant are very tender and climb up on supports for their growth. When their tendrils come in contact with any support, the tendrils immediately curl round the support and get a good grip.

Answer. 19.
Ohm’s law states that the electric current flowing through a metallic wire is directly proportional to the potential difference V across its ends provided its temperature remains the same.
In other words V α I
or
V/I = constant = R
or
V = I × R
Where R is a constant for a given metallic wire and is called its resistance.

If a graph is drawn between the potential difference (V) and current (I) the graph is found to be a straight line passing through the origin. This clearly shows that current is directly proportional to the potential difference. So the ratio V/I is a constant. This is the resistance of the conductor. The gradient of the straight line graph represents the resistance of the conductor.

Answer. 20.
Ionic compounds are formed by the transfer of electrons from one atom to another in an effort to get the stable electronic configuration in their outermost shell. The bond formed is called electrovalent bond and the atoms in that are either positive or negative ions. These ions are held together by strong forces of attraction. Hence ionic compounds are usually solids.

1. Ionic compounds have high melting and boiling points this means a lot of energy is required to break the strong inter-ionic attraction.
2. A solution of ionic compounds contains ions which move to the oppositely charged electrodes when current passes through the solution. Ionic compounds do not conduct electricity in the solid state as ions cannot move about. Ionic compounds conduct electricity in the molten state as the electrostatic forces between the ions is overcome by the heat.

Answer. 21.
Hydroelectricity or hydel electricity is the generation of electricity using the power of water. It is a means to generate electricity either from the kinetic energy of flowing water or the potential energy of falling water. In our country we primarily focus on storing huge quantities of water by building dams across rivers. The water from the high levels in the dam is carried through pipes to a turbine at the bottom of the dam. As rains regularly fill up the dams one need not worry about the generation of electricity. However while constructing dams one has to keep in mind a few things.

1. Not to affect large areas of agricultural land.
2. To safeguard the human habitation around the dam.
3. To ensure that vegetation is not submerged under water in the dams giving rise to air pollution on rotting.

OR
Forests are an important natural resource due to following reasons :

1. Forests provide us wood, dry fruits, spices, gums, resins, dyes, tannins and various products like honey, camphour, rubber etc.
2. The roots of trees hold the soil firmly preventing soil erosion.
3. It absorbs carbon dioxide from atmosphere and release oxygen which is life supporter.
4. It absorbs carbon dioxide which is a greenhouse gas thus plays an important role in reducing global warming.
5. It increases frequency of rainfall and regulates water cycle.
6. It serves as a shelter for wild life.

Causes of deforestation are :

1. Large scale deforestation for demand of wood, timber as raw materials for industries, domestic purposes etc.
2. Construction of dams, reservoirs, roads, railways.
3. Setting up of factories and industries.
4. Construction of big apartments to provide space to the growing population.
5. Shifting cultivation for agriculture.
6. Over-grazing by livestock.

SECTION – B

Answer. 22.
Silver turns black when exposed to air because it undergoes oxidation and forms silver oxide.
2Ag(s) + O₂ (g) → 2AgO(s)

Answer. 23.
When dry slaked lime Ca(OH)2 reacts with chlorine it forms bleaching powder.
Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂ O
Bleaching powder is used as a bleaching agent in textile industry and laundry units as a disinfectant, as an oxidising agent in chemical industries and in bleaching wood pulp in paper factories.

Answer. 24.
The medulla controls several involuntary actions like salivation, vomiting, blinking of the eye and blood pressure.

Answer. 25.

(a) We should take the public transport because it would save fuel.
(b) We should use LED bulbs in my house because it will help conserve electricity and bring down the electric bills.
(c) We should take the stairs because it would be good physical exercise for us and we can save on electricity.
(d) We should prefer wearing extra woollen clothes to using the heater because this saves electricity.

Answer. 26.

Answer. 27.

(a) further away from the lens to focus the image on the screen.
(b) The image increases in size.
(c) As the flame moves towards the lens, the intensity of the image decreases.
(d) When the flame is placed 20 cm from the lens on its left side we get an inverted and same size image.

We hope the CBSE Sample Papers for Class 10 Science paper 6 help you. If you have any query regarding CBSE Sample Papers for Class 10 Science paper 6, drop a comment below and we will get back to you at the earliest.

CBSE Sample Papers for Class 10 English Communicative Set 4

These Sample papers are part of CBSE Sample Papers for Class 10 English Communicative. Here we have given CBSE Sample Papers for Class 10 English Communicative Set 4

Time allowed: 3 hours
Maximum marks: 80

General Instructions

❖ The question papers divided into three sections :
Section A : Reading 20 marks
Section B : Writing and Grammar 30 marks
Section C : Literature 30 marks
❖ All questions are compulsory.
❖ You may attempt any section at a time.
❖ All questions of that particular section must be attempted in the correct order.

SECTION-A : READING
(Attempt all question from this section)

Question 1.
Read the passage given below and answer the questions that follow:
1. Over the centuries, people have created many rituals to accompany the consumption of their favourite drinks—tea and coffee. Just think of the Japanese tea ceremony, British afternoon tea or the morning coffee ritual in countless societies. Why are these drinks so popular ? The answer is their secret ingredient- caffeine. In the modem world, the new caffeine ‘delivery systems’ are canned ‘energy’ drinks. The more modem our world gets, the more we seem to need caffeine. People have known for years that caffeinated drinks make you less tired and more alert. This dual power of caffeine to counteract physical fatigue and increase alertness is a part of the reason why it is the world’s most popular mood-altering drug.
2. Most people don’t think twice about their caffeine intake. However, it raises blood pressure and thus increases the risk of heart diseases. So, the widespread use of caffeine is now a cause for concern among scientists and public health authorities. On the other hand, much of the research suggests that caffeine may have benefits for human health. Studies have shown it helps to relieve pain, reduces asthma symptoms and increases reaction speed. Despite this, a study in Ireland recommended that children and pregnant women, among other groups, shouldn’t drink energy drinks.
3. ‘For most of human existence, the pattern of sleeping and waking has followed sunrise and sunset,’ explains Charles Czeisler, a neuroscientist at Harvard Medical School. ‘Electric lights’ and caffeinated food and drinks allowed people to follow a work schedule set by the clock, not by daylight or the natural sleep cycle’.
4. ‘Caffeine helps people to override the human rhythm that is in all of us,’ says Czeisler. ‘Nevertheless/ he says solemnly, ‘there is a heavy, heavy price to pay for all this extra wakefulness.’ Without adequate sleep – the conventional eight hours out of each 24 is about right- the human body will not function at its best, physically, mentally or emotionally, the doctor says.
5. According to Czeisler, the modem craving for caffeine is a ‘Catch 22 situation’. ‘The main reason that people want caffeine is to stay awake/ he says. ‘But the main reason that people can’t stay awake is they don’t get enough regular sleep because they use caffeine.’

1.1. Attempt any eight of the following questions on the basis of the passage you have read: [1 x 8 = 8]
(i) What rituals did people create to drink tea or coffee and also give example ?
(ii) Why are these drinks popular in many societies ?
(iii) How is caffeine delivered in the modern times ?
(iv) Why is caffeine the most mood altering drug ?
(v) What are the contradicting effect of caffeine on health ?
(vi) Who shouldn’t consume caffeine ?
(vii) How has caffeine and electric light altered the life pattern ?
(viii) What is the heavy price we might pay with caffeine dominating our lifestyles and inadequate sleep ?
(ix) Why is the ‘Catch 22’ situation mentioned in the passage ?

Question 2.
Read the passage given below and answer the questions that follow : [12]
1. Peru’s Inca Indians first grew potatoes in the Andes Mountains in about 200 BC. Spanish conquistadors brought potatoes to Europe and colonists brought them to America. Potatoes are fourth on the list of the world’s food staples-after wheat, com and rice.
2. Today, Americans consume about 140 pounds of potatoes per person every year, while Europeans eat twice as many. One of our favourite ways to eat potatoes is in the form of potato chips. While Benjamin Franklin was the American ambassador to France, he went to a banquet where potatoes were prepared in 20 different ways. Thomas Jefferson, who succeeded Franklin as our French ambassador, brought the recipe for thick-cut, French fried potatoes to America. He served French fries to guests at the White House in 1802 and at his home, Monticello.
3. A Native American chef named George Crum created the first potato chips on August 24,1853, at Moon Lake Lodge in Saratoga, New York. He became angry when a diner complained that his French fries were too thick, so he sliced the potatoes as thin as possible, making them too thin and crisp to eat with a fork. The diner loved them and potato chips were bom. In 1860, Chef Crum opened his own restaurant and offered a basket of potato chips on every table.
4. Joe “Spud” Murphy and Seamus Burke produced the world’s first seasoned crisps, cheese and onion and salt and vinegar chips, in the 1950s in Ireland. In the United Kingdom and Ireland, crisps are what we, in the United States, call potato chips, while their chips refer to our French fries. Ketchup-flavoured chips are popular in the Middle East and Canada. Seaweed-flavoured chips are popular in Asia, and chicken-flavoured chips are popular in Mexico.
5. Other flavours from around the world include : paprika, pickled onion, bearnaise, meat pie, chili crab, salmon teriyaki, borscht, Caesar salad, roasted sausage, firecracker lobster, roast ox, haggis and black pepper, olive and spaghetti. About 27 pounds of potato chips are produced from 100 pounds of potatoes. Americans consume 2-4 billion pounds of potato chips every year and spend more than $ 7 billion a year on them.

2.1 On the basis of your reading of the passage, answer any four of the following questions in about 30-40 words each: [2 x 4 = 8]
(i) How did potatoes reach Europe and who were the first to grow potatoes ?
(ii) How did potatoes French fries became so popular in America and when ?
(iii) How can you say that potatoes are favourite in America and Europe ?
(iv) How were potato chips born ?
(v) In what manner has potato chips or fries become so important ?

2.2 On the basis of your reading of the passage, fill any two of the following blanks with
appropriate words / phrases. [1 x 2 = 2]
(i) Potatoes are fourth on the list of the world’s food staples
(ii) One of our favourite ways to eat potatoes is in the form of
(iii) Americans consume 2-4 billion pounds of potato chips every year and spend more than

2.3 Attempt any two of the following. Find out the words that mean the same as below:
[1 x 2 = 2]
(i) primary (paragraph 1)
(ii) eat (paragraph 2)
(iii) marinated (paragraph 5)

SECTION-B : WRITING AND GRAMMAR
(Attempt all question from this section)

Question 3.
(a) You ordered some books and stationery items from M/s. Oxford University Press, Darya Ganj, Delhi. When you checked the parcel, it contained damaged/defective items. Write a letter to the concerned firm to replace the things at their cost. Sign yourself as Sanjay/Sonia of M-3, Ashok Vihar, Bengaluru. [8]

OR

(b) You are the sales manager of Helpline communications making an inquiry on I phones X advertised in The Herald. You need 25,000 pieces for the office you have opened.

Question 4.
Write a short story, in about 200-250 words, with any one set of the cues given below. Give a suitable title to the story.
Medina woke up to loud noises downstairs and she jumped out of bed and she ran down to see what it was… [10]

OR

Jess, John and Kumar were excited to go the summer camp in Goa and they were eager with spirits high as they got piled into a bus which took them to the camp center…

Question 5.
Fill in any four of the following blanks choosing the most appropriate option from the ones given below. Write the answers in your answer -sheet against the correct blank numbers.
[1 x 4 = 4]
(a) Harish Mathur………..happy to get a new telescope as one of his birthday gifts.
(i) is
(ii) was
(iii) were
(iv) wear

(b) Harish………… gazing at the stars with his grandfather
(i) enjoying
(ii) enjoyed
(iii) enjoy
(iv) enjoys

(c) Mr.Mathur knows………… about the plantes and spaces.
(i) a lot
(ii) a lots
(iii) lots of
(iv) lot of

(d) He was a teacher for ………….. years in local schools.
(i) many
(ii) more
(iii) much
(iv) few

(e) Harish has………. serious thoughts about becoming an astronaut.
(i) has
(ii) had
(iii) have
(iv) having

Question 6.
In the following passage one word has been omitted in each line. Write the missing word, in any four sentences of the given paragraph, along with the word that comes before and the word that comes after it in the space provided. [1 x 4 = 4]

Question 7.
Rearrange any four of the following word clusters to make meaningful sentences. [1 x 4 = 4]
(a) class/ in/ our / writer/ Jasmine/ the/is/ most/ talented
(b) published/ she/ to/ be/ hopes/ a/ writer/ although
(c) Like/to/as/well/study/Jasmine/communications/would
(d) used/because/ grandmother/her/tell/to/tales/folk
(e) would/ on/ sit/ she/ grandmother’s/listen/lap/ and/ her/to/stories/great

SECTION-C : LITERATURE
(Attempt all question from this section)

Question 8.
Read the extract given below and answer the questions that follow. Write the answers in your answer sheets in one or two lines only.  [1 x 4 = 4]
(a) “Not too bad – but far too long.
The technique was fine of course
But it lacked a certain force.”
(i) Why is the frog making the above comments ?
(ii) What defects does he point out in the nightingale’s songs ?
(iii) What was the reaction of the nightingale to the above comments ?
(iv) ‘It lacked a certain force’- Why is this ironic ?

OR

(b) I’ll tell you what I’ve got to do. On Monday next I’ve got to do three things.
(i) To whom are these words spoken and by whom ?
(ii) What is the reaction of the listener to the speaker’s declaration ?
(iii) What made Abel decide on three things ?
(iv) In what manner was Abel’s decision a shock to his children ?

Question 9.
Answer any four of the following questions in 30-40 words each: [2 x 4 = 8]
(i) How did the poet come to know about the broken statue of Ozymandias ?
(ii) Why did the two boys survive only on one black bread and figs, despite making a decent earning ?
(iii) Why is Mrs. Packletide compared to ‘Nimrod’ ?
(iv) What surprising revelation is made by the ghost ? Why did the writer not believe her ?
(v) How does the poet compare ‘gilded monuments’ with ‘powerful rhyme’ ?

Question 10.
Attempt any one out of the two following long answer type questions in 100-120 words. [8]
(a) Discuss the character sketch of Mrs. Jordan and Mrs. Slater as opposed to the characters of their husbands.

OR

(b) John’s apprehensions about his wife’s reaction to her encounter with the ghost are unfounded. Justify.

Question 11.
(a) Answer the following question based on prescribed novel text for extended reading in about 200-250 words. [10]

The Diary of a Young Girl

(i) How does Anne feel about the laws that restrict the Jews’ freedom ?

OR

(ii) What role does the diary play in Anne’s life ?

(b) Answer the following question based on the prescribed novel text for extended reading in about 200-250 words.

The Story of My Life

(i) Describe Helen Keller’s stay at the Perkins Institute for the Blind in Boston.

OR

(ii) Draw a character sketch of Anne Mansfield Sullivan highlighting her monumental efforts and patience to teach a deaf and dumb girl to speak and write.

ANSWERS
SECTION-A

Answer 1.
1.1

1.  Over the centuries, people have created many rituals to accompany the consumption of their favourite drinks i.e., tea and coffee. Ex-Japanese tea ceremony, British afternoon tea etc.
2.  These drinks are popular because of their secret ingredient-caffeine.
3.  In the modem times, caffeine is delivered in the form of canned energy drinks.
4.  The dual power of caffeine to counteract physical fatigue and increase alertness is the reason why it is the world’s most popular mood-altering drug.
5.  Caffeine raises blood pressure and thus increases the risk of heart diseases. On the other hand, it helps to relieve pain, reduces asthma symptoms and increases reaction speed.
6.  A study in Ireland recommended that children and pregnant women shouldn’t consumer energy drinks.
7.  Electric lights and caffeinated food and drinks allowed people to follow a work schedule set by the clock, not by daylight or the natural sleep cycle.
8.  Without adequate sleep, the conventional eight hours out of each 24 is about right, the human body will not function at its best, physically, mentally or emotionally.
9.  The ‘Catch-22’ situation is an ironical situation as the main reason that people want caffeine is to stay awake but they can’t stay awake because they take caffaiene which doesn’t let them sleep for suggested hours.

Answer 2.
2.1 (i) Peru Inca Indian were the first to grow potatoes in 200 BC in Andes Mountains and Spanish conquistadors brought potatoes to Europe.
(ii) When Benjamin Franklin was the American ambassador to France he found potatoes made in 20 different ways and when Thomas Jefferson succeeded him he found the French fries and brought it to America.
(iii) We can say that potatoes are the favourite for Americans as they consume about 140 pounds of potatoes every year and the Europeans eat double that amount.
(iv) When a diner complained that potato chips were too thick, the attending Native American chef named George Crum cut the potatoes so thin and fried them and that’s how potato chips were born.
(v) Potato chips have become so popular that there are so many flavours across the world and 2-4 billion pounds of potato chips are consumed every year which shows that potato chips are important.

2.2. (i) Potatoes are fourth on the list of the world’s food staples-after wheat, com, and rice.
(ii) One of our favourite ways to eat potatoes is in the form of potato chips.
(iii) Americans consume 2-4 billion pounds of potato chips every year and spend more than $7 billion a year on them.

2.3. (i) first
(ii) consumer
(iii) pickled

SECTION-B

(a)
M-3, Ashok Vihar,
Bengaluru
Karnataka
10th May, 20xx
M/s. Oxford University Press,
Darya Ganj,
Delhi.

Sub.: Our Order No. 1105, dated 31st March, 2018

Dear Sir,

I had purchased some books and stationary item from you but the books sent by you are badly damaged. I think your assistant had not packed them with proper care. Some books are of old editions. They are tom and the pages are all scattered or missing.
It has become quite necessary for me to return the books. You are, therefore, requested to replace them and send the new books with great care. In the transaction, no fault lies on us. So, you are requested to bear the cost yourself.

I hope you will be careful in future and send the books at the earliest.

Yours Faithfully,
Sanjay

OR

(b)
Helpline Communication,
2nd line road, Military Line,
Tirunelveli- 5
1st August, 20 xx Sales Manager,
Tele-Communication Ltd.
25, Gurgaon- 6

Sub.: An inquiry for price of Mobile sets

Dear Sir,

Would you kindly give us a detailed information about the I phone X mobile sets recently advertised by you in “The Herald”. We are impressed by the description of the respective mobile set as advertised by you and would like to purchase if terms and conditions are found to be suitable. Our annual requirement of such set is around twenty-five thousand (25,000) pieces.
As we handle a lot of mobile sets each year, we hope and trust you will quote the most favourable prices and terms.

Yours faithfully,
M. A. Kishore Purchase Manager

Answer 4.

Fuss over nothing

Medina woke up to loud noises downstairs and she jumped out of bed and she ran down to see what it was. It was early in the morning and she came running to find out what was the commotion all about. She saw all the girls in the hostel talking aloud each discussing what made that noise. Someone said it was a box rolled over, some said it could be somebody who stalked and that got the girls spooked.
It was so typical of a girls hostel and I asked if anyone got around to check where the noise came from or if they were with the warden. But the reply was negative as they all had huddled together talking nonstop.
I took the courage to go check out though I was scared to the bones. I walked stealthily with a friend at my hand and soon found that the main door to the hostel has been left open scaring us more than ever before.
We rushed out to see who could have let the door open and we heard another scream, this time from my friend. When I turned to see what had happened, I saw an old branch from the tree fell near my friend and soon found that there was just another bigger branch that had fallen down. Now that we knew the reason for all the commotion, we all headed back to our rooms. I was unhappy that nothing more exciting happened.

OR

Fire and bear

Jess, John and Kumar were enthusiastic to go to the summer camp in Goa and they were eager and had their spirits high as got piled into a bus which took them to the camp center along with the kids from other schools. They were excited to make new friends and the bus soon started rolling. The bus was noisy with all of the children talking and laughing loud. The camp director Mr. Kishore asked us to settle down and slowly the noise died and he introduced us to the rules and safety precautions we needed to follow through the trip until we got back.
The children were paired with other members and Jess, John and Kumar looked at one another with doubtful expressions and disappointment as they thought they would be together. But anyway, they were paired with Sheila, Sheena and Rohan. They had to do a few chores together like cleaning the camp site, fetching water from the nearby river, keeping watch at night and helping in the kitchen. The kids enjoyed chores though a little grumpily as they were not used to work much at home but they were picking up.
They went trekking, long walks, taking log of the flora and fauna for their report and nights were fun as the groups got together to report their findings and experiences around the camp fire. At night John and Rohan had to keep a watch and not let the fire die. They talked for sometime and dozed a little when Rohan alerted John that there was a bear nearby. They soon got alert and saw the bear approaching them. They immediately got alert and showed their torch lights steadily at the bear’s eyes for minutes which seemed like eternity for the two and waited in patience until the bear left them, as bears do not like bright light shining at them and soon it was dawn they were ready to tell their thrilling night watch experience.

Answer 5.
(a) was
(b) enjoy
(c) a lot
(d) many
(e) had

Answer 6.

Answer 7.
(a) Jasmine is the most talented writer in our class.
(b) Although she hopes to be a published writer.
(c) Jasmine would like to study communications as well.
(d) Because her grandmother used to tell her folk tales.
(e) She would sit on her grandmother’s lap and listen to her great stories

SECTION-C

Answer 8.
(a) (i) The frog is making the above comments because he wishes to impress the nightingale as if he is an expert and let him train her.
(ii) The frog states that her songs lacked energy and were too long.
(iii) The nightingale was impressed with the comments of the frog as she was very vulnerable and innocent.
(iv) The above given line spoken by the frog is ironic because the frog has force for sure, but no finess in his voice.

OR

(b) (i) These words are spoken by Abel to his family.
(ii) The family is taken a back when they hear Abel stating that he is going to do something about the present predicament.
(iii) Abel decided on those three things due to the family’s negligence towards him.
(iv) Abel’s decision was shocking for his children because they thought in spite of being so complacent and negligent they can come back and take their father’s property.

Answer 9.
(i) The story of Ozymandias was told to the poet by a speaker who had met the traveller from an ancient land. The story of Ozymandias’ statue have been passed through generations by the word of mouth. This escalates a hint of obscurity and mystery to the statue.
(ii) Nicola and Jacopo were desperate to make as much money as possible in order to provide for the medical care of their sister Lucia, who was undergoing a treatment for T.B. They worked late at night and often waited for the last bus to sell the unsold papers because every bit mattered and that’s why they survived only on one bread and figs.
(iii) Nimrod is considered a biblical legendary hunter known for his prowess and it is clear that Mrs. Packletide is such a person who is having true penchant for the sport. The author uses the comparison to convey out her vanity and make a mockery of her.
(iv) The writer is pleasantly, surprised that all the good plots for his ghost stories have been inspired and fueled by the ghost Helen. The writer finds it very difficult to believe in the ghost as he had never seen her before. But the ghost states that she had sat on his shoulders prompting the plots for his stories.
(v) Both ‘gilded monuments’ and ‘powerful rhyme’ are used in memory of someone. The poet, however feels that his love for his friend will stand the test of time when monuments might be destroyed.

Answer 10.
(a) Both Mrs. Slater and Mrs. Jordan are clever, mean and manipulative without a tinge of empathy towards their father. They are ready to reap the benefits without doing anything for it. We see Amelia take away her father’s slippers, bureau and clock; while Elizabeth takes away her father’s watch. The ladies are not concerned about their deeds but rather have more pleasure in being presentable and showy for their father’s funeral. They are carried away by appearances and look at their father’s death as a part of drama where they need to be right in their costumes.

OR

(b) John believed that his wife was a sensitive little woman who was too scared of even a mouse. A real heart attack would happen to her if she saw a ghost in her living room. But his doubts were unfounded. Lavinia did not tremble for a moment and patiently observed and listened to Helen, the ghost. She never swooned and there was a satisfied smile on her face instead. She seemed more confident than John expects and is glad that Helen is actually helping John. John’s apprehensions about his wife’s reaction seems baseless instead he finds that there is a satisfied smile on her face.

Answer 11.
(a) (i) The Franks left Germany to live in Holland because they felt they could escape persecution. After the Germans invaded Holland in 1940, however, the same laws imposed in Germany were extended to the Netherlands. Anne thinks that the laws are unjust but she does not completely understand why the Jewish people have been singled out for this discrimination. She wishes that next time the Jews will be chosen for something good rather than something ‘ bad. Anne feels that it is unfair that the Jews cannot use streetcars, they must wear yellow stars, and must attend a particular Jewish school. Nonetheless, she is still optimistic about her family’s safety and feels relatively secure about her future. Anne accepts the restrictions as a fact of life in Amsterdam and she is thankful to the Dutch people for their sympathy, especially the ferryman, who let the Jews ride the ferry because they are not allowed to ride streetcars.

Once the SS call up for Margot, Anne realises that she is not safe from the Nazis. Her entire life and worldview is quickly transformed as she is forced into hiding. As Anne hears about more of her friends being taken to concentration camps, her fears grow and she questions why the Jews are being restricted. She also questions why she remains relatively safe while her friends outside have to suffer so much. Anne says that she does not blame the Dutch people for her family’s misfortune and her sense of perspective allows her to realise that the non-Jewish Dutch also suffer greatly during the war. When she hears that the Dutch are becoming more anti-Semitic, she is disheartened but remains optimistic about humanity.

OR

(ii) When Anne first begins writing in her diary as a thirteen-year-old girl, she feels that her friends and family all misunderstand her. Thus, she first turns to the diary as a new friend and confidant, counting on the diary to be the sympathetic, non judgmental friend she has been unable to find elsewhere. Once she goes into hiding in the Annexe, Anne feels even more misunderstood. She thinks her mother is cold and callous and feels that the other adults consider her a nuisance. The diary offers Anne much solace in the Annexe because she is in the need of companionship. Until she befriends Peter, she has no one other than her diary with whom she can openly share her fear, anger, sadness and hope. Anne calls the diary “Kitty,” indicating that she considers it a close friend. She writes to Kitty as if it was a person.

Writing conscientiously in the diary helps Anne redirect her resilient feelings instead of expressing them outrightly and causing damage to the fragile relationships within the Annexe. When everyone around her is feeling anxious and tense, Anne turns to her diary for comfort because she does not want to burden the already strained adults with her own concerns. In this way, Anne becomes very independent at a young age.

Moreover, Anne’s constant diary-writing enables her to discover her inner voice and her ability as a writer. The diary gives her the private place to explore her increasingly profound thoughts and ideas. Looking back after two years in the Annexe, Anne is able to look at the invaluable record of her experiences and analyse how she has grown and changed. In this sense, the diary becomes a substantial and a significant tool for Anne’s maturity.

(b) (i) It was Alexander Graham Bell who advised Helen’s parents to contact the Perkins Institute for Blind for her education. This was the same institute where Laura Bridgman, a deaf and a blind child had been educated and it was located in South Boston. Michael Anagnos, the director, asked the former student Anne Sullivan to become Keller’s instructor. Miss Sullivan herself was visually impaired.

Helen made friends with the little blind children. It was a unique pleasure to talk with other blind children in her own language. Until then, she had been speaking through an interpreter like a foreigner. All the eager and loving children gathered a round her and joined heartily in her frolics. They would enjoy reading the books with their fingers. They were so happy and contented that she lost all sense of pain in the pleasure of their companionship. With the blind children she felt thoroughly at home in her new environment.

Helen learnt to speak in the spring of 1890. The impulse to utter audible sounds had always been strong within her. Mrs. Lamson, who had been one of Laura Bridgeman’s teachers came to see Helen. She had taught a deaf and blind child to speak in Norway. Helen resolved that she would learn to speak. Miss Fuller offered to teach her and gave eleven lessons in all. Her first connected sentence was, “it is warm.” This was the beginning of a new journey that would take Helen places and become a source of encouragement to many across the globe.

OR

Miss Anne Mansfield Sullivan had been the singular and paramount influence on the life, character and achievements of Helen Keller. She gave a new direction, meaning and purpose to Helen’s dark life. Miss Sullivan inherited all those traits and characteristics that go into the making of a perfect teacher. She was a picture of tireless patience and unending devotion. It was her constant encouragement, help and guidance that made Helen Keller, the first deaf and blind in the world to earn a bachelor’s degree.

It was Graham Bell who advised the parents of Helen Keller to contact the Perkins Institute for the Blind. The director, Mr. Anagnos asked a former student Miss Anne Sullivan to become Keller’s instructor. Miss Sullivan was herself a visually impaired 20 years old lady. It was the beginning of a 49-year-long relationship. The relationship evolved into Miss Sullivan becoming Helen’s governess and then eventual companion. Anne Sullivan arrived at Keller’s house in March 1887. She immediately began to teach Helen to communicate by spelling words into her hand, beginning with “d-o-1-1” for the doll. It was Miss Sullivan who unfolded and developed Helen’s skills and possibilities. It was Sullivan’s genius as a teacher, her sympathy and her loving tact Which made learning so beautiful and interesting for Keller. She felt that she was inseparable from her student. All that was best in Helen Keller had been awakened by the loving touch of Miss Sullivan. Anne Sullivan stayed as a companion to Helen Keller long after she taught her. Anne Sullivan married John Macy in 1905. She remained a constant companion to Keller until she died in 1936.

We hope the CBSE Sample Papers for Class 10 English Communicative Set 4 help you. If you have any query regarding CBSE Sample Papers for Class 10 English Communicative Set 4, drop a comment below and we will get back to you at the earliest.

CBSE Sample Papers for Class 10 Science Paper 4

These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 4

Time allowed: 3 hours
Maximum marks : 80

General Instructions

• The question paper comprises two sections, A and B. You are to attempt both the sections.
• All questions are compulsory.
• All questions of Section-A and B are to be attempted separately.
• There is an internal choice in two questions of three marks each and one question of five marks.
• Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
• Question numbers 3 to 5 in Section-A are two marks questions. These are to be answered in 30 words each.
• Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
• Question numbers 16 to 21 in Section-A are 5 mark questions. These are to be answered in 70 words each.
• Question numbers 22 to 27 in Section-B are based on practical skills. Each question is a two marks question. These are to be answered in brief.

SECTION-A

Question 1.
What is the difference in the function of trypsin and pepsin ?  [1]

Question 2.
What is regeneration and where do you see it ?  [1]

Question 3.
What is galvanisation ?  [2]

Question 4.
An object is placed at a distance of 15 cm from a convex lens of focal length 20 cm. List out the characteristics of the image formed.  [2]

Question 5.
Compare the chromosome arrangement of men and women.  [2]

Question 6.
V = \(\frac { W }{ Q } \) What does this equation tell us ? The unit of V is named after which famous
scientist ? How is potential difference measured ?  [3]

OR

The current through a 16 V tungsten filament lamp connected to a 16 V accumulator of negligible resistance is 4.0 A. Calculate:

1. The resistance of the filament,
2. The power of the lamp, and
3. The electrical energy in kWh consumed in 6 hours.

Question 7.
There are three resistors of r ohm each and a battery of E volts. How should these resistors be connected to get maximum current ? Show with a circuit diagram and find out the current drawn from the battery.  [3]

Question 8.
How does carbon manage to exist in different forms ? What are the different forms ?  [3]

Question 9.
What is water of crystallisation ? Name some elements that have these crystallisation molecules and some crystalline solids that do not contain water of crystallisation.  [3]

Question 10.
Why were objections raised to the building of dams in our country ? Which movement was Medha Patkar associated with ?  [3]

OR

What we as an individual can do to reduce our consumption of the various natural resources ?

Question 11.
What would be the consequence of a decrease in haemoglobin in our body ?  [3]

Question 12.
What is the power of accommodation of the human eye ? Why does the image distance not change even though the object distance keeps changing ?  [3]

Question 13.
pH is of great importance in our daily lives. Give three examples to prove this.  [3]

OR

A compound prepared from gypsum has the property of hardening when mixed with the right amount of water. Identify the compound and write its chemical formula. Write the chemical equation of its preparation. Mention any two uses of this compound.

Question 14.
How do Mendel’s experiments show that traits maybe dominant or recessive ?  [3]

Question 15.
What are the differences between arteries and veins ?  [3]

Question 16.
What is the role of an electric fuse in a domestic circuit ? What kind of material is used in making the fuse wire and why ?  [5]

Question 17.
Carbon compounds are poor conductors of electricity. Explain with reference to their bonding.  [5]

OR

Soaps and detergents are both types of salts. State the difference between the two. Write the mechanism of the cleansing action of soaps. Why do soaps not form lather (foam) with hard water? Mention any two problems that arise due to the use of detergents instead of soaps.

Question 18.
How we should lead our life in the present day to be more environment friendly ?  [5]

Question 19.
(a) Define optical centre of a spherical lens.  [5]
(b) A divergent lens has a focal length of 20 cm. At what distance should an object of height 4 cm from the optical centre of the lens be placed so that its image is formed 10 cm away from the lens ?
(c) Show the ray diagram for the above.

Question 20.
How did the Modem Periodic Table remove the anomalies of Mendeleev’s Periodic Table ?  [5]

Question 21.
The touch-me-not plant folds its leaves in response to touch. How does this reaction happen in the plant ?  [5]

OR

What are reflex actions ? Give examples ? Explain reflex arc by an example with labelled diagram.

SECTION-B

Question 22.
(a) An atom has an electronic configuration of 2,8,7. What is the atomic number of this element ?  [2]
(b) Can you find out the element with atomic number 17 ? What kind of bond will it form on combination with other atoms ?

Question 23.
What is a thermite reaction and where is it used ?  [2]

Question 24.
Why and how is the brain protected ?  [2]

Question 25.
When you cut open a hibiscus flower what are the major parts you see ? Draw and label them.  [2]

Question 26.
In an experiment to study the dependence of potential difference (V) on the electric current (I) across a conductor (resistor), if the circuit is on for a long time, then select two correct options from the ones given below:  [2]

1. Zero error of the ammeter will be changed.
2. Zero error of the voltmeter will be changed.
3. Value of resistance will be changed.
4. Resistor will be heated.

OR

Draw a circuit to study the dependence of current on the potential difference across a resistor.

Question 27.
An object of height 2.5 cm is placed at a distance of 15 cm from the optical centre ‘O’ of a convex lens of focal length 10 cm. Draw a ray diagram to find the position of the image formed. Mark the optical centre, ‘O’, principal focus ‘F’ and height of the image on the diagram.  [2]

ANSWERS
SECTION-A

Answer 1.
Trypsin is an enzyme found in the pancreatic juice which helps to digest proteins whereas Pepsin is an enzyme found in the stomach and it helps to digest proteins too.

Ansswer 2.
Regeneration is the ability of organisms to give rise to new individual organisms from their body parts. If an individual is cut or broken up into many pieces, these pieces can grow into separate individuals. This is seen in simple animals like Hydra and Planaria.

Ansswer 3.
Galvanisation is the process of applying a protective zinc coating to iron or steel, to prevent rusting.

Ansswer 4.
Given: u = -15 cm, ƒ= 20 cm

According to formula,

\(\frac { 1 }{ f } =\frac { 1 }{ \upsilon } -\frac { 1 }{ u } \)
\(\frac { 1 }{ 20 } =\frac { 1 }{ \upsilon } +\frac { 1 }{ 15 } \)
\(\frac { 1 }{ 20 } -\frac { 1 }{ 15 } =\frac { 1 }{ \upsilon } \)
\(-\frac { 1 }{ 60 } =\frac { 1 }{ \upsilon } \)
\(\upsilon =-60cm\)

The four characteristics of the image formed by the lens are:

• It is a virtual image.
• It is an erect image.
• It is an enlarged image.
• It is at a distance of 60 cm on the same side of the lens as the object.

Ansswer 5.
Human beings have 23 pairs of chromosomes. One chromosome of each pair is maternal and one is paternal. Of the 23 pairs, 22 pairs are called perfect pairs. One pair called the sex chromosomes are different. In women there are two X chromosomes while in men there is one X and one Y chromosome. So women are XX and men are XY.

Ansswer 6.
The given equation tells us the relationship between potential difference, charge, and work done to move the charge. The equation shows that the electric potential difference between two points in , an electric circuit carrying some current is the work done to move a unit charge from one point to another. The unit of V is named after Alessandro Volta, an Italian physicist. The S.I. unit of potential difference is volt.

OR

Given: V = 16 volt, I = 4.0 ampere, t = 6 hours

• Resistance, R = V/I = \(\frac { 16 }{ 4 } \) = 4Ω
• Power,P = V x I = 16 x 4 = 64W
• Electrical energy, W = VIt = 16 x 4 x 6 = 384 Wh = 0.384 kWh

Ansswer 7.
These resistors should be connected in parallel with the battery to get maximum current.

Let the equivalent resistance be R Ω.

\(\frac { 1 }{ R } =\frac { 1 }{ r } +\frac { 1 }{ r } +\frac { 1 }{ r } \)
\(\frac { 1 }{ R } =\frac { 1+1+1 }{ r } =\frac { 3 }{ r }\)
\(R=\frac { r }{ 3 } \)
V=I × R

According to ohm’s law,

Current(I) = E × \(\frac { 3 }{ r } =\frac { 3E }{ r } \)

Answer 8.
The process by which carbon exists in different forms is called allotropy. The different compounds have the same chemical properties but very different physical properties. Diamond and graphite are the two allotropic forms of carbon. There is a difference in the properties because of a difference in which the carbon atoms are bonded to one another. In diamond, each carbon atom is bonded to four other carbon atoms forming a rigid three-dimensional structure. In graphite, each carbon atom is bonded to three other carbon atoms in the same plane giving a hexagonal array. One of these is a double bond and thus the valency of carbon is satisfied.

Answer 9.
Water of crystallisation is the fixed number of water molecules present in one formula unit of a salt. When we heat the crystals, this water is removed and the salt turns white. 1 formula unit of CuSO₄ has 5 water molecules so it is written as CuSO₄.5H₂O. Gypsum is another salt which has water of crystallisation. It has 2 water molecules. It has the formula CaSO₄.2H₂O. The crystalline solids which do not contain water of crystallisation are NaCl, KNO₃, C₁₂H₂₂O₁₁ and KMnO₄.

Answer 10.
Dams are built to generate hydroelectric power. Water is stored in huge dams built at great heights. Since the water in the reservoir would be refilled every time it rains hydroelectric power is a renew-able source of energy. However, there are some problems associated with the construction of dams. Large areas of agricultural land and human habitation has to be sacrificed. Large ecosystems could be destroyed while submerged and rotting vegetation could give rise to greenhouse gases. Suitable and satisfactory rehabilitation of the displaced people has to be ensured. Medha Phatkar is a famous social activist and she was associated with the “Narmada Bachao Andolan” against the construction of the Sardar Sarovar project on river Narmada.

OR

As an individual we can follow the principle of reduce, recycle and reuse (3Rs strategy) to reduce our consumption of the various natural resources.

1. Reduce: We can reduce our consumption of various resources like electricity consumption by switching off unnecessary lights and fans.We can save water by immediately repairing faulty taps and should ensure there is no unnecessary wastage of water. We should not waste food and can prepare only as much as required.
2. Recycle : We must clearly segregate recyclable wastes like plastic, paper, metal and glass and use them to make something fresh instead of preparing something new.
3. Reuse: In this process, we need to find alternative uses for the things that we once considered waste. Used bottles or containers can be used to store various things at home. One side papers can be used for writing on the other side as a scribbling pad. Recycling of used things greatly reduces waste generation.
   Finally we must manage our natural resources in such a way that they shall last for the future generations and are not exploited for short time gains.

Answer 11.
A decrease in the amount of haemoglobin in our body means anaemia and a general weakness of the body. Haemoglobin is the oxygen carrying pigment of the blood. In its absence very little oxygen would be transported which means all the cells will not receive their supply of oxygen. In the absence of oxygen, food will not be oxidised and there will be no release of energy. This in turn affects the body’s ability to do work.

Answer 12.
The ability of the eye lens to adjust its focal length is called power of accommodation of the human eye.
The focal length of the human eye lens can change i.e., increase or decrease depending on the distance of the object from the eye and because of this the image distance does not change. As the distance of the object from the eye varies, the ciliary muscles modify the curvature of the lens to change its focal length.

Answer 13.
pH is important in our daily lives. It plays a role in our digestive system, self-defence of animals and
plants and in tooth decay.

1. Digestive system: Our stomach produces hydrochloric acid to help in digestion of food. Some¬times during indigestion or when a person is hungry for long too much of acid is produced and this causes pain and irritation. To neutralise this, the patient is given antacids which contains a mild base.
2. Self-defence of animals and plants : Sometimes when we are stung by a honey-bee or ants it causes pain, swelling and irritation. This is due to an acid produced at the site of the sting. For relief, baking soda is used as it contains a mild base.
3. Tooth decay: Tooth decay is caused by bacteria which produce acids using the left-over food in our mouth. This can be avoided by cleaning the mouth regularly after eating. Toothpastes are slightly basic and they neutralise the excess acid in the mouth and prevent tooth decay.

OR

Gypsum is a salt which has water of crystallisation. It has 2 water molecules as water of crystallisation. When it is heated it loses the water molecules and becomes calcium sulphate hemihydrate (CaSO₄.1/2H₂O) this is called Plaster of Paris. It is a white powder and when mixed with water it changes again to gypsum which is a hard solid mass.

Uses of Plaster of Paris:

• It is used as plaster for supporting fractured bones in the right position.
• It is used for making toys, materials for decoration and for making smooth surfaces.

Answer 14.
Mendel performed his experiments using contrasting characters of pea plants. He crossed a tall plant (TT) and a dwarf plant (tt). In the F₁ generation he found all plants to be tall. Now Mendel wanted to see if all the tall plants of F1 generation were like the tall parents. So he self-pollinated the F1 tall plants. In F2, he found 3/4^th plants were tall and rest l/4^th were dwarf. This clearly shows that though both the tall and dwarf characters were inherited in F1, only tallness trait expressed itself. This means both TT and Tt are tall plants while tt is a dwarf plant. Hence, a single copy of T is enough to express tallness while 2 copies of t are required to express dwarfness. Moreover Tt did not express any in between character. Thus Mendel’s experiments clearly show that traits could either be dominant or recessive.

Answer 15.

Answer 16.
The electric fuse plays an important role in the domestic circuit. It is a safety device which is used to limit the current in an electric circuit. The use of a fuse safeguards the circuit and the appliances connected in that circuit from being damaged. The fuse is always connected in series with the device. A fuse is a short piece of wire of uniform area of cross-section and high resistance, made up of a material of low melting point, so that it may easily melt due to overheating when current in excess to the prescribed limit passes through it. Generally an alloy of lead and tin is used as the material of the fuse wire because its melting point is low and resistivity is more than that of copper, aluminium, etc.

The main fuse in domestic wiring is encased in a cartridge of porcelain of similar material with metal ends. The fuses for domestic purposes are rated as 1 A, 2 A, 3 A, 5 A, 10 A etc.

Answer 17.
Carbon compounds are poor conductors of electricity. Carbon has a valency of 4. To attain the stable configuration of noble gases, carbon atom needs to either gain or lose 4 electrons.

1. If it were to gain 4 electrons it would become C^4- anion, but this makes it difficult to hold onto the 10 electrons.
2. If it were to lose 4 electrons it would become C⁴⁺ cation, but this means a lot of energy would be required to pull out the 4 electrons and leave the carbon atom with 6 protons and 2 electrons. The easy way out is to share the 4 electrons with atoms of either carbon or other elements. The shared pair is then common to both the atoms. This bond formed by a sharing of electrons is called as covalent bond and such compounds are known as covalent compounds. As there are no charged particles available covalent compounds are poor conductors of electricity. They have low melting and boiling points too.

OR

Mechanism of the cleansing action of soaps : The dirt present on clothes is organic matter and insoluble in water. Therefore, it cannot be removed by only washing with water. When soap is dissolved in water, its hydrophobic ends attach themselves to the dirt and removes it from the cloth. Then, the molecules of soap arranges themselves in micelles form and traps the dirt at the centre of the cluster. These micelles remain suspended in the water. Hence, the dust particles are easily rinsed away by water.

Soaps do not form lather with hard water : Soap is a sodium or potassium salt of long chain fatty acids. Hard water contains salts of calcium and magnesium. When soap is added to hard water, calcium and magnesium ions present in water displaces sodium or potassium ion present in soap forming insoluble substance called scum. A lot of soap is wasted in this process.
Problems that arise due to the use of detergents instead of soap:

• Detergents being non-biodegradable, they accumulate in the environment causing pollution. In soil, the presence of detergents leads to pH changes making soil infertile.
• The entry of detergents into food chain leads to bioaccumulation in living beings and tends towards serious health issues.

Answer 18.
To be more environment-friendly in the present day we should make the following changes in our life-style.

1. We should use the public transport system instead of personal vehicle for commuting.
2. We should look to use non-conventional sources of energy wherever feasible.
3. We should strictly follow the policy of Reduce, Reuse and Recyle.
4. We should avoid wastage of resources in our day to day lives such as water, electricity and cooking gas.
5. While adopting a modem life style we must look at sustainable development and reduced generation of waste.
6. Let us adopt back to nature techniques wherever possible. Let us use well ventilated rooms instead of air-conditioners. Let us have a roof garden to keep our homes cool naturally.

Answer 19.
(a) Optical centre is a point on the principal axis of the lens such that a ray of light passing through it emerges parallel to its direction of incidence.
(b) Given :ƒ= – 20 cm, h_o = 4 cm and υ = -10 cm

\(\frac { 1 }{ f } =\frac { 1 }{ \upsilon } -\frac { 1 }{ u } \)
\(\frac { -1 }{ 20 } =-\frac { 1 }{ 10 } -\frac { 1 }{ u } \)
\(\frac { 1 }{ u } =-\frac { 1 }{ 10 } +\frac { 1 }{ 20 } \)
\(\frac { 1 }{ u } =\frac { -2+1 }{ 20 } =\frac { -1 }{ 20 } \)
u = 20 cm
\(m=\frac { { h }_{ i } }{ { h }_{ 0 } } =\frac { \upsilon }{ u } \)
\(\frac { { h }_{ i } }{ 4 } =\frac { -10 }{ -20 } \)
2h_i = 4
h_i = 2 cm

(c)

Answer 20.
In 1913, Henry Moseley showed that the atomic number of an element is a more fundamental property than its atomic mass. So Mendeleev’s Periodic law was modified and the atomic number was adopted as the basis of the Modern Periodic Table. Prediction of properties of elements could be made more accurately when elements are arranged on the basis of increasing atomic number. The Modem Periodic Law states that, ” properties of elements are a periodic function of their atomic numbers”.

The Modem Periodic table has 18 vertical columns called groups and 7 horizontal rows called periods. The position of an element in the Periodic Table tells us about its chemical reactivity. The valence electrons determine the kind and number of bonds formed by an element. The metallic character decreases across a period while it increases down a group. While metals occur on the left of the periodic table non-metals occur on the right side of the periodic table. In the centre there is space for the metalloids.

Answer 21.
The touch-me-not plant folds its leaves as soon as it is touched. The plant moves its leaves in response to touch. If we think about where exactly the plant is touched, and what part of the plant actually moves it is obvious that the movement happens at a point different from the point of touch. Here movement has happened at points far away from the point where it was touched. Thus information about the touch has been communicated. The plant uses electrical-chemical means to convey information from cell to cell but unlike animals there is no specialised tissue in plants for the conduction of information. Plant cells change shape by changing the amount of water in them resulting in swelling and shrinking of the leaves.

OR

Reflex action is a quick, automatic, involuntary, unconscious response in the body brought about by a stimulus. Examples of reflex action:

• Withdrawal of hand suddenly on touching a hot plate.
• Withdrawal of finger suddenly when pricked by a thorn.
• Shivering of our body on feeling cold.
• Sudden closure of our eyelids when bright light falls on our eye.

Reflex arc: It is the shortest route taken by impulse from receptor to effector.
Example: When we touch a hot plate by our finger, we instantly withdraw our hand. Here stimulus is touching a hot plate, receptors are our fingers. The specialized epithelial cells of our fingers respond to stimulus and convert into impulse. This impulse is carried by sensory neuron to spinal cord which generates a motor impulse. This impulse is carried by motor neuron to effector organ i.e., muscles of hand. Response is withdrawal of our hand.

SECTION-B

Answer 22.
(a) The electronic configuration is 2,8,7 means the atomic number is 2+ 8+ 7,
which is equal to 17.
(b) The element with atomic number 17 is chlorine (Cl). With a valency of 7 it tends to gain an electron from another combining atom so that it can get the stable octet configuration. On gaining an electron it becomes electronegative ion or anion. So it forms electrovalent or ionic bonds with other atoms.

Answer 23.
Thermite reaction is a reaction between a metal and a non-metal. During this reaction a large amount of heat is produced which changes the metal into a molten state. The reaction of aluminium with ferric oxide is a thermite reaction. It is used for welding or joining railway tracks or cracked machine parts.

Fe₂0₃ + 2Al → 2Fe + Al₂0₃ + Heat

Answer 24.
The brain is the main coordinating centre of the body. The brain and the spinal cord make up the central nervous system. The brain is a delicate organ and needs to be carefully protected. It lies inside a bony box called cranium. Further inside the cranium and around the brain there are 3 layers filled with the cerebro-spinal fluid which act as shock absorbers.

Answer 25.
On opening a section of the hibiscus flower we can see the green sepal first, then the colourful petals and next the slender stamens. The stamen or the male reproductive part consists of the anther and filament. In the centre we can see the female reproductive part called carpel. It consists of 3 parts, stigma, style and the ovary at the bottom.

Answer 26.
(c) Value of resistance will be changed.
(d) Resistor will be heated.

Answer 27.
The required ray diagram, is drawn as follows:

Given: u = -15 cm, h₀ = 2.5 cm, ƒ = 10 cm
We Know that

\(\frac { 1 }{ f } =\frac { 1 }{ \upsilon } -\frac { 1 }{ u } \)
\(\frac { 1 }{ 10 } =\frac { 1 }{ \upsilon } -\frac { 1 }{ (-15) } \)
\(\frac { 1 }{ \upsilon } =\frac { 1 }{ 10 } -\frac { 1 }{ 15 } =\frac { 1 }{ 30 }\)
Image distance, υ = 30 cm
\(\frac { { h }_{ i } }{ { h }_{ 0 } } =\frac { \upsilon }{ u } \)
\(\frac { { h }_{ i } }{ 2.5 } =\frac { 30 }{ -15 } \)
h_i = -5 cm

Therefore, a real, inverted and magnified image of size 5 cm is formed at a distance of 30 cm from the lens.

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