distribution and utilisation and conservation.
Facts that Matter
1. Energy is required for all activities such as cooking, propelling vehicles, driving machinery in industries, etc. Energy can be generated from fuel minerals like coal, petroleum, natural gas, uranium and electricity. Energy resources can be classified as conventional (firewood, cattle dung cake, coal, petroleum, etc.) and non-conventional sources (solar, wind, biogas, etc.).
2. Coal is an important fossil fuel of India. It provides about 80% of the nation’s energy needs.
India is highly dependent on coal for meeting its commercial energy requirements. Coal is found abundantly in the eastern side of the country.
3. In India, coal occurs in rock series of two main geological ages—Gondwana and tertiary.
While Gondwana coal is about 200 million years old, tertiary deposits are approximately 55 million years old. The major resources of Gondwana (metallurgical) coal are located in the Damodar valley (West Bengal, Jharkhand), Jharia, Raniganj and Bokaro. The Godavari, Mahanadi, Sone and Wardha valleys also contain coal deposits. Tertiary coals occur in the north-eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.
4. Natural gas is used as a source of energy as well as an industrial raw material in the petrochemical industry. It is considered an environment friendly fuel because of low carbon dioxide emissions. Natural gas is found in Mumbai High and the Gulf of Cambay. Large reserves of natural gas have been discovered in the Krishna- Godavari basin.
5. Petroleum provides fuel for heat and lighting, lubricants for machinery and raw materials for a number of manufacturing industries. Petroleum refineries act as a “nodal industry” for synthetic textile, fertiliser and numerous chemical industries. About 63 per cent of India’s petroleum production is from Mumbai High, 18 per cent comes from Gujarat and 16 per cent from Assam.
6. Electricity is generated mainly in two ways by hydro turbines to generate hydro electricity and by burning other fuels such as coal, petroleum and natural gas to produce thermal power.
Hydro electricity is a renewable resource.
7. Non-conventional sources of energy such as solar energy, wind, etc. are renewable and therefore there is a pressing need to use these sources.
8. Nuclear or Atomic energy is obtained by altering the structure of atoms. Uranium and thorium, which are available in Jharkhand and the Aravalli ranges of Rajasthan are used for generating atomic or nuclear power. The Monazite sand of Kerala is also rich in thorium.
Power Resources
9. Being a tropical country, India has an abundance of sunlight. Hence, there are huge possibilities of tapping solar energy. Use of solar energy will be able to minimise the dependence of rural households on firewood and dung cakes, which in turn will contribute to environmental conservation and adequate supply of manure in agriculture. Photovoltaic technology converts sunlight directly into electricity. The largest solar plant of India is located at Madhapur, near Bhuj (Gujarat).
10. Wind power is abundant in India. The largest wind farm cluster is located in Tamil Nadu from Nagarcoil to Madurai. Other states with wind farms are Andhra Pradesh, Karnataka, Gujarat, Kerala, etc. Nagarcoil and Jaisalmer make effective use of wind energy.
11. Biogas is produced from shrubs, farm waste, animal and human wastes. It is mostly used for domestic consumption in rural areas. Biogas plants using cattle dung are known as ‘Gobar gas plants’ in rural India.
12. These provide twin benefits to the farmer in the form of energy and improved quality of manure.
Biogas is by far the most efficient use of cattle dung. It prevents the loss of trees and manure due to burning of fuel wood and cow dung cakes.
13. Oceanic tides can be used to generate electricity which is known as tidal energy.
14. Floodgate dams are built across inlets. During high tide water flows in to the inlet and gets trapped when the gate is closed. After the tide falls outside the flood gate, the water retained by the floodgate flows back to the sea via a pipe that carries it through a power-generating turbine. In India, the Gulf of Kuchchh provides ideal conditions for utilising tidal energy.
15. Geothermal energy refers to the heat and electricity produced by using the heat from the interior of the earth. Two experimental projects have been set up in India to harness geothermal energy. One is located in the Parvati valley near Manikarn in Himachal Pradesh and the other is located in the Puga Valley, Ladakh.
16. Energy is a basic requirement for economic development. Every sector of national economy—
agriculture, industry, transport, commercial and domestic—needs inputs of energy. There is an urgent need to develop a sustainable path of energy development. India is presently one of the least energy efficient countries in the world. We have to adopt a cautious approach for judicious use of our limited energy resources.
Words that Matter
1. Lignite: It is a low grade brown coal, which is soft with high moisture content.
2. Bituminous: Coal that has been buried deep and subjected to increased temperatures is bituminous coal.
3. Anthracite: It is the highest quality of hard coal.
4. Hydro-electricity: It is generated by fast flowing water.
5. Thermal electricity: It is generated by using coal, petroleum and natural gas.
6. Tidal energy: It refers to the electricity which is generated by oceanic tides.
7. Geo-thermal energy: It refers to the heat and electricity produced by using the heat from the interior of the Earth.
8. Biogas: It is produced by using shrubs, farm waste, animal and human waste.
NCERT TEXTBOOK QUESTIONS SOLVED
Q1. Answer the following questions in about 30 words:
Distinguish between conventional and non-conventional sources of energy.
[CBSE 2005(C), 2009(F), 2013]
Ans. Conventional and non-conventional sources of energy
Conventional sources Non-conventional sources 1. Conventional sources of energy are 1. The non-conventional sources are
in use from the past. in use from recent times.
2. They spread pollution. 2. These are eco-friendly.
3. Conventional sources of energy are 3. Non-conventional sources of energy generally exhaustible. are usually inexhaustible.
4. These include firewood, cattle dung 4. These include solar, wind, tidal, cake, coal, petroleum, natural gas geo-thermal, biogas and atomic and electricity (both hydel and energy.
thermal).
Q2. Answer the following questions in about 120 words.
(i) Describe the distribution of coal in India.
(ii) Why do you think that solar energy has a bright future in India?
Ans. (i) Coal is an important fossil fuel of India. It is the most abundantly available fossil fuel. It provides about 80% of the nation’s energy needs. India is highly dependent on coal for meeting its commercial energy requirements. In India, coal occurs in rock series of two main geological ages—Gondwana and tertiary. While Gondwana coal is about 200 million years old, tertiary deposits are approximately 55 million years old. The major resources of Gondwana coal which are metallurgical coal, are located in the Damodar valley (West Bengal, Jharkhand). Jharia, Raniganj and Bokaro are important coalfields.
The Godavari, Mahandi, Sone and Wardha valleys also contain coal deposits.
Tertiary coals occur in the north-eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.
(ii) (a) Being a tropical country, India has an abundance of sunlight. Hence, there are huge possibilities of tapping solar energy.
(b) Photovoltaic technology converts sunlight directly into electricity. Solar energy is becoming popular in rural and remote areas.
(c) Use of solar energy will be able to minimise the dependence of rural households on firewood and dung cakes, which in turn will contribute to environmental conservation and adequate supply of manure in agriculture.
(d) Solar energy is a non-conventional source of energy and also eco-friendly. The largest solar plant of India is located at Madhapur, near Bhuj (Gujarat) where solar energy is used to sterlise milk cans.
MORE QUESTIONS SOLVED
I. MULTIPLE CHOICE QUESTIONS Choose the correct answer:
1. Which one is not a conventional source of energy?
(a) Coal (b) Biogas
(c) Firewood (d) Petroleum
2. Decaying plants in swamps produce what ... .
(a) Peat (b) Lignite
(c) Bituminous (d) Coal
3. The principal lignite reserves are used for ... .
(a) Generation of wind power (b) Generation of electricity (c) Generation of thermal power (d) None of the above
4. The major resources of Gondwana coal are located in ... . (a) Wardha valley (b) Godavari valley
(c) Sone valley (d) Damodar valley
5. Heavy industries and thermal power stations are located on or near the coalfields because ... .
(a) coal is a bulky material (b) coal loses weight on use
(c) coal transportation is very costly (d) all of the above
6. The oldest oil-producing state in India is ... .
(a) Assam (b) Gujarat
(c) Maharashtra (d) Tamil Nadu
7. The full form of CNG is ... .
(a) Compound Natural Gas (b) Complex Natural Gas (c) Compound New Gas (d) Compressed Natural Gas 8. There are over ... thermal power plants in India.
(a) 210 (b) 310
(c) 410 (d) 510
9. The largest solar plant of India is located at ... .
(a) Madhapur (b) Nagarcoil
(c) Jaisalmer (d) Madurai
10. Nagarcoil and Jaisalmer are well known for effective use of ... in the country.
(a) solar energy (b) wind energy
(c) tidal energy (d) atomic energy
11. The most important oil field in Gujarat is ... .
(a) Ankaleshwar (b) Vadodara
(c) Kalol (d) Hajira
12. Neyveli has reserves of ... .
(a) Anthracite (b) Poat
(c) Lignite (d) Bituminous
13. Which one of the following non-conventional sources of energy is harnessed in the Parvati Valley near Manikaran in Himachal Pradesh?
(a) Solar energy (b) Tidal energy
(c) Geothermal energy (d) Wind energy
14. Which one of the following fuels is considered environment-friendly?
(a) Coal (b) Petroleum
(c) Natural gas (d) Firewood
15. About sixty per cent of India’s petroleum production comes from the region of ...
(a) Gujarat (b) Rajasthan
(c) Assam (d) Mumbai High
16. Tertiary coal occur in the region of ... .
(a) Damodar valley (b) Wardha valley (c) Godavari valley (d) North-eastern states
Ans. 1—(b) 2—(b) 3—(a) 4—(b) 5—(d) 6—(a)
7—(d) 8—(b) 9—(a) 10—(b) 11—(a) 12—(c)
13—(c) 14—(c) 15—(d) 16—(d)
II. VERY SHORT ANSWER TYPE QUESTIONS
Q1. Mention any four activities which require energy.
Ans. Energy is needed to
(i) Cook food (ii) Provide light and heat
(iii) Propel vehicles (iv) Drive machinery in industries Q2. Mention any four conventional sources of energy.
Ans. Firewood, cattle dung cake, coal and natural gas are conventional sources of energy.
Q3. Mention any four unconventional sources of energy.
Ans. Solar, wind, tidal and bio-gas are the unconventional sources of energy.
Q4. Which are the two most common sources of energy in rural India?
Ans. Firewood and cattle dung cake are the two most common sources of energy in rural India.
Q5. Why is using dung cake being discouraged?
Ans. Using dung cake is being discouraged because it consumes most valuable manure which could be used in agriculture.
Q6. Which is the most abundantly available fossil fuel?
Ans. Coal is the most abundantly available fossil fuel.
Q7. How is coal formed?
Ans. Coal is formed due to the compression of plant material over millions of years.
Q8. How is peat produced? Mention one feature of it.
Ans. Peat is produced by decaying of plants in swamps.
Features: It has a low carbon high moisture contents and low heating capacity.
Q9. Which is a low grade brown coal? Mention one feature of it?
Ans. Lignite is a low grade brown coal.
Feature: It is soft with high moisture content.
Q10. Where are the principal lignite reserves found?
Ans. The principal lignite reserves are found in Neyveli in Tamil Nadu.
Q11. Which is the most popular coal?
Ans. Biluminous coal is the most popular coal.
Q12. Which is the highest quality hard coal?
Ans. Anthracite is the highest quality hard coal.
Q13. Name two important coalfields of India.
Ans. Jharia and Bokaro.
Q14. How is natural gas used?
Ans. Natural gas is used as a source of energy as well as an industrial raw material in the petrochemical industry.
Q15. Why is natural gas considered an environment-friendly fuel?
Ans. Natural gas is considered an environment-friendly fuel because of low carbon dioxide emissions.
Q16. Name the key users of natural gas.
Ans. The power and fertiliser industries are the key users of natural gas.
Q17. How is hydro-electricity generated?
Ans. Hydro-electricity is generated by fast flowing water.
Q18. Name a few multi-purpose projects of India.
Ans. (i) Bhakra Nangal
(ii) Damodar Valley Corporation (iii) Kopili Tydel Project
Q19. How is thermal electricity generated?
Ans. Thermal electricity is generated by using coal, petroleum and natural gas.
Q20. How many thermal power plants are there in India?
Ans. There are over 310 thermal power plants in India.
Q21. Where are uranium and thorium available in India? What are they used for?
Ans. Uranium and thorium are available in Jharkhand and the Aravali ranges of Rajasthan. They are used for generating atomic or nuclear power.
Q22. Where is the largest wind farm cluster located in India?
Ans. The largest wind farm cluster is located in Tamil Nadu from Nagarcoil to Madurai.
Q23. Which energy can be produced from ocean water?
Ans. Tidal energy can be produced from ocean water.
Q24. Which region of India provides ideal conditions for utilising tidal energy?
Ans. In India, the Gulf of Kuchchh provides ideal conditions for utilising tidal energy.
Q25. What is meant by geo-thermal energy?
Ans. Geothermal energy refers to the heat and electricity produced by using the heat from the interior of the earth.
II. SHORT ANSWER TYPE QUESTIONS
Q1. In the present day energy crisis what steps will you like to take for saving
energy? (CBSE 2015)
Ans. (i) Energy is a basic requirement for economic development. Hence, there is an urgent need to develop a sustainable path of energy development. Promotion of energy conservation and increased use of renewable energy sources are the twin planks of sustainable energy.
(ii) We have to adopt a cautious approach for the judicious use of our limited energy resources. As concerned citizens we can do our bit by using public transport systems instead of individual vehicles.
(iii) Switching off electricity when not in use, using power-saving devices and using non-conventional sources of energy are other important steps for saving energy.
Q2. Why is the use of non-conventional sources of energy becoming essential these
days? [V. Imp.]
Ans. The use of non-conventional sources of energy is becoming necessary because of the following reasons:
(i) The growing consumption of energy in the country has made us dependent on fossil fuels such as coal, oil and gas and it may lead to shortages in the supply of oil, gas and coal in future.
(ii) Rising prices of oil and gas has adversely affected the foreign exchange.
(iii) The growth of the national economy is getting slowed down.
(iv) Ever-increasing use of fossil fuels is causing serious environmental problems.
(v) Non-conventional sources of energy are renewable and also eco-friendly.
Q3. What efforts can be made to conserve energy resources in India?
Ans. Following efforts can be made to conserve energy resources in India:
(i) Using public transport instead of individual vehicle.
(ii) Switching off electricity when not in use.
(iii) Using power-saving devices.
(iv) Non-conventional resources should be used more and more because they are renewable and eco-friendly.
(v) Use of automobiles, engines should be decreased and electric motors should be introduced.
(vi) Judicious use of our limited energy resources.
Q4. Which is the most abundantly available fossil fuel in India? What are the four major forms of it? Write main features of each form. (CBSE 2008) Ans. Coal is an important and abundantly available fossil fuel in India. It is formed due to the compression of plant material over millions of years. It is a bulky material and loses weight on use as it is reduced to ash.
The four major forms of coal are:
(i) Peat: Decaying plants in swamps produce peat. It has a low carbon and high moisture contents and low heating capacity.
(ii) Lignite is a low grade brown coal, which is soft with high moisture content.
The principal lignite reserves are in Neyveli in Tamil Nadu and are used for generation of electricity.
(iii) Bituminous coal is buried deep and subjected to increased temperatures. It is the most popular coal in commercial use. Metallurgical coal is high grade bituminous coal which has a special value for smelting iron in blast furnaces.
(iv) Anthracite is the highest quality hard coal.
Q5. “India is highly dependent on coal for meeting its commercial energy requirement.” Support the statement with three arguments. (CBSE 2011) Ans. (i) In India, coal is the most abundantly available fossil fuel. It provides a
substantial part of the nation’s energy needs.
(ii) It is used for power generation, to supply energy to industry as well as for domestic needs.
(iii) It is used as a raw material in the making of coal tar and coal gas.
Q6. How is biogas produced? Why it is called ‘Gobar gas plant’ in rural area?
Ans. (i) Biogas is produced from shrubs, farm waste, animal and human wastes.
It is mostly used for domestic consumption in rural areas.
(ii) Decomposition of organic matter yields gas, which has higher thermal efficiency in comparison to kerosene, dung cake and charcoal.
(iii) Biogas plants are set up at municipal, cooperative and individual levels.
Biogas plants using cattle dung are known as Gobar gas plants in rural India.
(iv) These provide twin benefits to the farmer in the form of energy and improved quality of manure.
(v) Biogas makes the most efficient use of cattle dung.
(vi) It prevents the loss of trees and manure due to burning of fuel wood and cow dung cakes.
Q7. Which is the next major source of energy after coal, in India? Describe any
two advantages of it. (CBSE 2008)
Ans. Petroleum is a major energy source in India after coal. The two advantages of petroleum are:
(i) It provides fuel for heat and lighting, lubricants for machinery and raw materials for a number of manufacturing industries.
(ii) Petroleum refineries act as a “nodal industry” for synthetic textile, fertiliser and numerous chemical industries.
(iii) About 63 per cent of India’s petroleum production is from Mumbai High, 18 per cent comes from Gujarat and 16 per cent from Assam.
Q8. How is Nuclear energy obtained?
Ans. Nuclear energy is obtained by altering the structure of atoms. When such an alteration is made, much energy is released in the form of heat and this is used to generate electric power. Uranium and Thorium, which are available in Jharkhand and the Aravalli ranges of Rajasthan are used for generating atomic or nuclear power. The monazite sands of Kerala is also rich in Thorium.
Q9. What are the various uses of coal?
Ans. Coal provides a substantial part of the nation’s energy needs. It is used:
(i) for power generation
(ii) to supply energy to industry as well as for domestic needs. India is highly dependent on coal for meeting its commercial energy requirements.
Q10. Why is solar energy more developed in western Rajasthan? Give three points to support your answer.
Ans. (i) Western Rajasthan is blessed with an abundance of sunlight.
(ii) It has less tree cover.
(iii) It has very less rainfall as it is located on the leeward side of the western ghats.
Q11. Give a brief description of the petroleum occurrences in India. (HOTS) Ans. The petroleum occurrences in India are usually associated with anticlines and fault trap in rock formations of the tertiary age. In regions of folding, anticlines or domes, it occurs where oil is trapped in the crest of the up fold. The oil bearing
layer is a porous limestone or sandstone through which oil may flow. The oil is prevented from rising or sinking by interviewing non-porous layers.
Petroleum is also found in fault traps between porous and non-porous rocks. Gas, being lighter, usually occurs above the oil.
Petroleum is also found in fault traps between porous and non-porous rocks. Gas, being lighter, usually occurs above the oil.