NCERT Solutions for Class 10 Science Chapter 14

NCERT Solutions for Class 10 Science Chapter 14 Sources of Energy Page 243 or Page 248 or Page 253 or Page 254 or Exercises in English Medium or पेज 273 के उत्तर or पेज 279 के उत्तर or पेज 285 के उत्तर or पेज 286 के उत्तर or अभ्यास के उत्तर  in Hindi study online or download in PDF format free. Download CBSE Books Solutions Apps based on Updated NCERT Solutions for 2019-20.


Class:10
Subject:Science – विज्ञान
Chapter:Sources of Energy

Table of Contents

NCERT Solutions for Class 10 Science Chapter 14

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English Medium




Hindi Medium

Go back to Class 10 Science Main page

10 Science Chapter 14 Page 243 Answers

Class 10 Science Chapter 14 Sources of Energy page 243 is given below. For other answers, please visit to Page 248 or Page 253 or Page 254 or Exercises or go for हिंदी मीडियम Answers. Visit to Class 10 Science main page or Top of the page.

Class 10 Science Chapter 14 Sources of Energy page 243

10 Science Chapter 14 Page 248 Answers





NCERT Solutions for Class 10 Science Chapter 14 page 248 is given below. For other answers, please visit to Page 243 or Page 253 or Page 254 or Exercises or go for हिंदी मीडियम Answers. Visit to Class 10 Science main page or Top of the page.

NCERT Solutions for Class 10 Science Chapter 14 page 248

10 Science Chapter 14 Page 253 Answers

Class 10 Science Chapter 14 page 253 is given below. For other answers, please visit to Page 243 or Page 248 or Page 254 or Exercises or go for हिंदी मीडियम Answers. Visit to Class 10 Science main page or Top of the page.

NCERT Solutions for Class 10 Science Chapter 14 page 253



10 science chapter 14 ans
10 science ch. 14

10 Science Chapter 14 Page 254 Answers




NCERT Solutions for Class 10 Science Chapter 14 Sources of Energy page 254 is given below. For other answers, please visit to Page 243 or Page 248 or Page 253 or Exercises or go for हिंदी मीडियम Answers. Visit to Class 10 Science main page or Top of the page.

NCERT Solutions for Class 10 Science Chapter 14 Sources of Energy page 254

10 Science Chapter 14 Exercises Answers





NCERT Solutions for Class 10 Science Chapter 14 Exercises solutions is given below. For other answers, please visit to Page 243 or Page 248 or Page 253 or Page 254 or go for हिंदी मीडियम Answers. Visit to Class 10 Science main page or Top of the page.

NCERT Solutions for Class 10 Science Chapter 14 Exercises solutions



10 science ch. 14 exercise answers
class 10 sci. ch. 14 all answers



NCERT Solutions for Class 10 Science Chapter 14 Exercises solutions in pdf form free download

10 विज्ञान अध्याय 14 पेज 273 के प्रश्न उत्तर

10 Science Sources of Energy पेज 273 के उत्तर in Hindi is given below. For other answers, please visit to पेज 279 के उत्तर or पेज 285 के उत्तर or पेज 286 के उत्तर or अभ्यास के उत्तर  or go for English Medium Answers. Visit to Class 10 Science main page or Top of the page.

10 Science Sources of Energy पेज 273 के उत्तर

10 विज्ञान अध्याय 14 पेज 279 के प्रश्न उत्तर





10 Science Chapter 14 पेज 279 के उत्तर in Hindi is given below. For other answers, please visit to पेज 273 के उत्तर or पेज 285 के उत्तर or पेज 286 के उत्तर or अभ्यास के उत्तर  or go for English Medium Answers. Visit to Class 10 Science main page or Top of the page.

10 Science Chapter 14 पेज 279 के उत्तर

10 विज्ञान अध्याय 14 पेज 285 के प्रश्न उत्तर




Class 10 Science Chapter 14 पेज 285 के उत्तर in Hindi is given below. For other answers, please visit to पेज 273 के उत्तर or पेज 279 के उत्तर or पेज 286 के उत्तर or अभ्यास के उत्तर  or go for English Medium Answers. Visit to Class 10 Science main page or Top of the page.

Class 10 Science Chapter 14 पेज 285 के उत्तर
10 sci ch. 14 solutions

10 विज्ञान अध्याय 14 पेज 286 के प्रश्न उत्तर




Solutions for Class 10 Science Chapter 14 पेज 286 के उत्तर in Hindi is given below. For other answers, please visit to पेज 273 के उत्तर or पेज 279 के उत्तर or पेज 285 के उत्तर or अभ्यास के उत्तर  or go for English Medium Answers. Visit to Class 10 Science main page or Top of the page.

Solutions for Class 10 Science Chapter 14 पेज 286 के उत्तर

10 विज्ञान अध्याय 14 अभ्यास के प्रश्न उत्तर





NCERT Solutions for Class 10 Science Chapter 14 Sources of Energy अभ्यास के उत्तर in Hindi is given below. For other answers, please visit to पेज 273 के उत्तर or पेज 279 के उत्तर or पेज 285 के उत्तर or पेज 286 के उत्तर or go for English Medium Answers. Visit to Class 10 Science main page or Top of the page.

NCERT Solutions for Class 10 Science Chapter 14 Sources of Energy अभ्यास के उत्तर




10 sci chap 14
10 science chapter 14 in pdf

Visit to Class 10 Science main page or Top of the page



Class X Science – Sources of Energy
Important Questions with Answers for CBSE Exams: 2019-20

Question 1:
What is meant by a source of energy? OR What are the factors that should be taken into consideration for selecting a source of energy? List any three.
Answer 1:
We need energy to perform various functions of life. The materials that provide the requisite amount of energy is the source of energy. For example,
(i) We need heat energy to cook food. The various sources are: Fuels, wood, coal, kerosene, cooking gas etc.
(ii) We need energy for our transport. The various sources are: petrol, diesel.
(iii) We need energy to light bulbs, tubes, to run radio, television and other power appliances. The source is electricity.
(iv) Production in factories and agriculture also need energy. The source is diesel and electricity.

Question 2:
What is geothermal energy?
Answer 2:
The interior or deeper regions of earth’s crust are very hot. The temperature is so high that even rocks melts. If this heat is utilized as a source of energy, it is called geothermal energy.



Question 3:
Differentiate between renewable and non-renewable source of energy with one example for each.
Answer 3:
(i) Non-renewable sources: Fossil fuels like coal, petroleum and natural gas are non-renewable energy sources. These are produced over millions of years due to slow changes and under special circumstances. These are not continuous processes and further it is not becoming possible to discover their new deposits. With the present rate of their consumption, it is estimated that known deposits of petroleum in our country will be exhausted in another 200 years and that of coal may last for another 250 years.
(ii) Renewable sources: The energy derived from flowing water, wind, tides, ocean waves and bio-gas are the renewable sources. These sources can be harnessed into energy so long as the earth derives its heat and light from the sun or so long as the present solar system exists. Nuclear energy and geothermal energy is also likely to be available for a much longer time. Wood is another renewable source of energy. Though it takes almost 15 years for a tree to mature, this and nuclear energy are also classified as renewable sources.

Question 4:
What are the two disadvantages of burning fossil fuels? OR State with reason three disadvantages of using fossil fuels.
Answer 4:
(i) Burning of coal and petroleum lead to air pollution.
(ii) They cause acid-rain by forming oxides of carbon, nitrogen and sulphur. This affects our water and soil sources.
(iii) Burning of fossil fuels cause smog which causes breathing problems and other hazards.


More Questions for Exams

Question 1:
Why is bio-gas considered an ideal fuel for domestic use? OR Bio-gas is an excellent fuel. List three reasons to justify this statement.
Answer 1:
Bio-gas is considered a good domestic fuel because of the following reasons:
(i) Bio-gas burns without any smoke and so does not cause air pollution.
(ii) Bio-gas produces a large amount of heat per unit mass and thus has high calorific value.
(iii) Bio-gas does not leave any residue on burning and is thus a clean fuel.
(iv) Bio-gas does not cause any storage problem. It can be continuously supplied by the pipes directly from the gas plant.
(v) The production of bio-gas does not involve any running cost and is cheaper than most common fuels.

Question 2:
What are fossil fuels?
Answer 2:
Coal, petroleum and natural gas are examples of fossil fuels. These are found in nature due to the decomposition of animals and plants which have remained embedded inside earth’s crust due to geological changes over millions of years.

Question 3:
What are wind energy farms?
Answer 3:
The rotatory motion of the windmill can be utilized to rotate the armature of an electric generator in order to produce electricity. However, the electricity produced by a single windmill is quite small and thus cannot be used for commercial purpose. Therefore, a number of windmills are erected over a large area. The energy output of each windmill is coupled. This is called wind energy farms. The most essential condition for creating wind energy farms is to locate an area where wind blows for greater part of the year at a speed of about 15 km/h.

Question 4:
Out of two solar cooker, one was covered by a plane glass slab and the other was left open. Which of the two solar cookers will be more effective and why?
Answer 4:
The solar cooker covered with glass slab will be more efficient because the heat rays trapped in its will not be able to escape easily. Thus, the heating in this case will be better.

Download Solutions Apps for offline use.

What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?

Solar cooker uses Sun’s energy to cook food stuff. It is inexhaustible, clean and renewable source of energy. It is free for all and available in unlimited amount. Hence, operating a solar cooker is not expensive.
Disadvantage of a solar cooker is that it (solar cooker) is very expensive. It works only in sunlight. Hence, on cloudy day, it becomes useless.
The places where the days are too short or places with cloud covers round the year, have limited utility for solar cooker.

What are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?

Industrialization increases the demand for energy. Fossil fuels are easily accessible sources of energy that fulfil this demand. The increased use of fossil fuels has a harsh effect on the environment. Too much exploitation of fossil fuels increases the level of greenhouse gas content in the atmosphere, resulting in global warming and a rise in the sea level.
It is not possible to completely reduce the consumption of fossil fuels. However, some measures can be taken such as using electrical appliances wisely and not wasting electricity. Unnecessary usage of water should be avoided. Public transport system with mass transit must be adopted on a large scale. These small steps may help in reducing the consumption of natural resources and conserving them.

What is a good source of energy?

A good source of energy should have the following qualities:
It should be easily available.
It should do a large amount of work (or produce large amount of heat) per unit volume/mass.
It should be easy to store and transport.
It should be economical.
It should cause less environmental pollution.

What is a good fuel?

A good fuel produces a large amount of heat on burning, does not produce a lot of smoke and is easily available.

If you could use any source of energy for heating your food, which one would you use and why?

We shall use LPG/CNG gas or electricity for heating our food because these are efficient ways of supplying energy. Thermal efficiency of the energy source is large, there is less pollution and the source can be used easily.

What are the disadvantages of fossil fuels?

There are following disadvantages of fossil fuels like coal and petroleum:
Burning of coal or petroleum causes air pollution.
Acidic oxides like oxides of carbon, nitrogen and sulphur are released on burning fossil fuels. These oxides lead to acid rains, which affect our water and soil resources.
Carbon dioxide gas also causes greenhouse effect in atmosphere.
Fossil fuels are non-renewable sources of energy.

Why are we looking at alternate sources of energy?

Fossil fuels, which have been traditionally used by human beings as an energy sources, are non-renewable sources of energy. These sources of energy are limited and cannot replenish on their own. They are being consumed at a large rate. If this rate of consumption continues, then the fossil fuels would be exhausted from the Earth. Therefore, we should look for alternate sources of energy.

How has the traditional use of wind and water energy been modified for our convenience?

To use energy of flowing water large dams are built in hilly regions to store huge amount of water at a height. The stored water from high level in dam is carried through pipes to the turbine at the bottom of the dam and runs hydropower plant.
Similarly, the wind energy is used to generate electricity. For the same purpose, the rotatory motion of windmill is used to tum the turbine of the electric generator.

What kind of mirror – concave, convex or plain – would be best suited for use in a solar cooker? Why?

A solar cooker uses heat of the sunlight to cook the food. A concave mirror is used in order to reflect and focus sunlight at a particular area. The mirror focuses all the incident sunlight at a point. The temperature at that point increases, thereby cooking and heating the food placed at that particular area.

What are the limitations of the energy that can be obtained from the oceans?

Energy from the oceans can be obtained in the form of tidal energy, wave energy and ocean thermal energy. But these energy sources suffer from the following limitations:
There are very few locations where dams to utilise tidal energy can be built.
Cost of installation of power houses is extremely high and efficiency of plants is comparatively small.
Power plants built in oceans or at sea-shores will need high continuous maintenance as chances of corrosion are extremely high.

What is geothermal energy?

Geothermal energy is the heat energy present inside earth in certain regions called hot spots. Due to geological changes, molten rocks formed in the deeper hot regions of earth’s crust are pushed upwards and are trapped in hot spots. When underground water comes in contact with the hot spot, steam is generated. This steam is routed through a pipe to a turbine and used to generate electricity.

What are the advantages of nuclear energy?

The advantages of nuclear energy are as follows:
Large amount of energy is produced per unit mass.
It does not produce smoke. It is a clean energy.
Fission of one atom of uranium produces 10 million times the energy released by burning of one atom of carbon.
Fusion of four hydrogen atoms produces huge amount of energy.

Can any source of energy be pollution-free? Why or why not?

No source of energy can be pollution-free. It is considered that solar cells are pollution-free. However, even their making causes environmental damage indirectly. Also, in the case of nuclear energy, there is no waste produced after the fusion reactions. However, it is not totally pollution-free. To start the fusion reactions, approximately 10,000,000 K temperature is required, which is provided by fission reactions. The wastes released from fission reactions are very hazardous. Hence, no source of energy is pollution-free.

Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?

Hydrogen can be considered a cleaner fuel because its burning produces water vapour which is non-polluting. However, due to explosive nature of hydrogen, its storage and transportation is difficult.

Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.

Coal and petroleum are two exhaustible sources of energy. These fuels were formed over millions of years ago and there are only limited reserves. If we continue to use them as at present, these reserves will be exhausted very soon.

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