CBSE Class 10 Science Sources of Energy Assignment Set A

Read and download free pdf of CBSE Class 10 Science Sources of Energy Assignment Set A. Get printable school Assignments for Class 10 Science. Standard 10 students should practise questions and answers given here for Chapter 14 Sources Of Energy Science in Grade 10 which will help them to strengthen their understanding of all important topics. Students should also download free pdf of Printable Worksheets for Class 10 Science prepared as per the latest books and syllabus issued by NCERT, CBSE, KVS and do problems daily to score better marks in tests and examinations

Assignment for Class 10 Science Chapter 14 Sources Of Energy

Class 10 Science students should refer to the following printable assignment in Pdf for Chapter 14 Sources Of Energy in standard 10. This test paper with questions and answers for Grade 10 Science will be very useful for exams and help you to score good marks

Chapter 14 Sources Of Energy Class 10 Science Assignment

Question : Which of the following is not a bio mass energy source? 
a. Nuclear energy
b. Wood
c. Gobar gas
d. Coal
Answer : A 
Explanation: Nuclear energy is not a biomass energy source because it is not produced by any type of biological activity but produced from Uranium and Thorium.
Question : Which of the following nuclei are isotopes? 
Answer : A 
Explanation: Isotopes are the elements with same atomic number but different mass numbers. In the above given elements A and C are having same atomic number 88 but different mass number 226 and 228 respectively. 
Question : The conditions for producing biogas is? 
a. water but not air
b. Air but not water
c. Neither air nor water
d. Air and water
Answer : A
Explanation: Biogas means a gas produced by the anaerobic digestion or fermentation of organic matter. The organic matter can be manure, sewage sludge, municipal solid waste, biodegradable waste or any other biodegradable feedstock. Biogas is mainly methane and carbon dioxide.
Question : Match the following with correct response. 
a. 1-D, 2-A, 3-C, 4-B
b. 1-B, 2-D, 3-A, 4-C
c. 1-A, 2-C, 3-B, 4-D
d. 1-C, 2-B, 3-D, 4-A
Answer : B 
i. Fuel burns without smoke is Coke---Coke is a fuel with few impurities and a high carbon content, usually made from coal. It is the solid carbonaceous material derived from destructive distillation of low-ash, lowsulphur bituminous coal. Cokes made from coal are grey, hard, and porous.
... Coke is also used to manufacture water gas ii. Material suitable for producing biogas is Paper scrap---Biogas means a gas produced by the anaerobic digestion or fermentation of organic matter. The organic matter can be manure, sewage sludge, municipal solid waste, biodegradable waste or any other biodegradable feedstock. Biogas is mainly methane and carbon dioxide iii. Production of biogas by biomass is by Anaerobic fermentation--
Biogas is a biofuel produced from the anaerobic fermentation of carbohydrates in plant material or waste (eg food peelings or manure) by bacteria. It is mainly composed of methane, with some carbon dioxide and other trace gases.
iv. Manure is Spent slurry---Bio-Gas produced is also used for Power Generation with the help of genset. The Biogas plant Spent Slurry (rich in nutrients than fresh cow dung) is used as Manure for plantation in gaushala and all around it and this slurry is also vermin-composted and marketed
Question : Match the following with correct response. 
a. 1-A, 2-C, 3-B, 4-D
b. 1-D, 2-A, 3-C, 4-B
c. 1-C, 2-B, 3-D, 4-A
d. 1-B, 2-D, 3-A, 4-C
Answer : C 
1. A semiconductor is used to develop electric power is Solar cell--- Construction and working of Solar Cell. It essentially consists of a silicon PN junction diode(semiconductor) with a glass window on top surface layer of P material is made extremely thin so, that incident light photon's may easily reach the PN junction. When these photons collide with valence electrons
2. Indirect harnessing of solar energy is from Hydel power plant----
Hydroelectric energy can be defined as a form of hydropower where the motion of running water (kinetic energy) is converted into electricity. The water cycle is driven directly by solar energy. When the sun heats the water in the ocean, some of the water on the surface is vaporized
3. Can be harnessed 24 hours through out the year is Geothermal energy--Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma
4. The temperature in the region of focus is very high in Solar concentrations--Concentrated solar power (also called concentrating solar power, concentrated solar thermal, and CSP) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight, or solar thermal energy, onto a small area.

Very Short Answers

Question :  How is the slurry left in a bio-gas plant, in the end, used? 
Answer : The slurry left behind is removed periodically and is used as excellent source of manure, rich in nitrogen and phosphorous.
Question : Name the fuel that provides most of the energy needs of the world. 
Answer : Petroleum and coal (fossil fuel) provides most of the energy needs of the world.
Question : Give one disadvantage of nuclear power. 
Answer :  Nuclear fuels are non-renewable sources of energy and large amount of radioactive materials, which are toxic in nature, are released in the environment which are extremely hazardous to the health of living being for thousands of years. The major disadvantage of nuclear power is Emission and poor management of radioactive waste. 
Question : What is a chain reaction? 
Answer : • A chemical reaction or other process in which the products themselves promote or spread the reaction.
• The self-sustaining fission reaction spread by neutrons which occurs in nuclear reactors and bombs.

Short Answers

Question :  Why a heap of coal or wood does not catch fire at room temperature though sufficient quantity of oxygen is present in air ? 
Answer :  One of the conditions of combustion to take place is that the fuel temperature should be more than ignition temperature.
Question : Why are many thermal power plants set up near coal or oil fields? 
Answer : Thermal Power plant is a power plant where steam is ued to drive a steam turbine and the heat required for the process is obtained from coal and oil .The thermal power plants are usually set up near coal or oil fields so that the fuel can be easily obtained and the problem of air pollution while transporting the fuel may be minimized.
Question :  Reena's father works with a company that builds dams. Once he took her to the site, where a dam was being build. Reena saw a group of people sitting there and shouting slogans against the building of dam. She talked to the group of people and asked them about their problems and then discussed it with her father. She then tried to convince people to talk with the authorities and come to an amicable solution. The discussion was successful. Reena's father was very proud of his daughter. Now, answer the following questions: 
i. Why was Reena's father proud of his daughter?
ii. Why was the group of people protesting against the building of the dam?
iii. Reena's contribution to the peaceful resolution of the conflict proved a boon for many citizens of the country. How?
Answer : i.Reena's father was very proud of his daughter because she resolved the conflict peacefully and smartly.
ii.One of the major disadvantages of the construction of dams is the dislocation of local people. That's why the local people were protesting against it.
iii.Reena acted as a bridge between the local people and the authorities. She helped authorities by convincing people for discussions with them. She also played a major role in the construction of dam which then helped in controlling flood in river and also in irrigation.
Question : Name two energy sources that you would consider to be renewable. Give its reason. 
Answer :  Solar energy, wave energy, tidal energy, wind energy all are renewable sources of energy.
The solar energy is free and can be used anywhere with ease. Solar energy can be used to produce electric energy in solar cells. It can be used for solar water heaters and in solar cookers.
Wind is also available source of energy almost everywhere and can be used to run wind farms to produce electricity, to draw water from the wells and grind the grains.

Long Answers

Question :  What are environmental consequences of the increasing demand for energy ? What steps would you suggest to reduce energy consumption ? 
Answer : The demand of energy is increasing day by day. Exploiting any source of energy may disturb the environment in one way or other. For example getting energy from fossil fuel may cause lot of pollution in air. Getting energy by nuclear fission may create problem of disposal of nuclear waste. Steps for reducing energy consumption should be such that we get maximum energy from least fuel. For this:
i. Under the given situation technology utilized should be the best possible. For example using smokeless chulhas should be preferred to traditional chulhas.
ii. Energy should be extracted by most economic method under the given situation.
Whereas energy extraction by solar cell may be useless in big towns due to cost factor, it may be indispensable for artificial satellites.
iii. Wastage of energy should be strictly avoided. Energy saves is equal to energy produced.
iv. Sources of energy should be such that it causes the lease damage to environment.
Question :  What is combustion ? What are the essential conditions for combustion to take place? 
Answer :  A very large number of substances burn in oxygen (presence in air) with the release of large amount of heat and light. Substance which burns in the presence of air is called combustible material. Oxygen present in air helps in burning of the substance and is called supporter of combustion. Chemical reaction responsible for release of energy is called combustion. The substance which burns on heating in oxygen or air is called combustible substance. Wood, coal, paper, coke, hydrogen, CNG (compressed natural gas), LPG (liquefied petroleum gas) kerosene, diesel, alcohol, ether, petrol etc.
Are all examples of combustible substances. Air contains about 21% of oxygen by volume and 78% nitrogen. Whereas nitrogen is neither combustible nor supports combustion. However oxygen is a strong supporter of combustion. If we allow a substance to burn in pure oxygen (as in welding arc), we observe very fast burning.
Kindling or Ignition Temperature : The minimum temperature to which a substance must be heated before it catches fire is called kindling or ignition temperature. If the temperature of the substance is less than kindling or ignition temperature, it will not catch fire even if it is placed in pure oxygen. Ignition temperature of phosphorus is 35oC. Phosphorus will not catch fire if its temperature is less than 35oC. It will catch fire when its temperature is above 35oC. Inflammable substances are those which can easily catch fire. There ignition temperature is very low. It is usually less than 100oC. A minor spark is sufficient to cause serious accident.
Alcohol, carbon disulphide, ether, benzene, petrol, LPG, nylon fibres are inflammable substances. You must have observed that you ignite LPG burner (used by your mother in kitchen) with a gas lighter which gives a very small (point) spark.
Conditions Necessary for Partial/Complete Combustion
i. There must be a combustible substance.
ii. There must be a supporter of combustion.
iii. Temperature of combustible substance is to be more than ignition temperature for the substance.
If any of the three conditions is not obeyed, the combustion will not take place.



Question : Name the component of sunlight, exposure to which may cause skin cancer.

Question : Flowing water possess which type of energy.

Question : Name one place in India where wind energy power station is installed.

Question : What is a solar panel?

Question : What type of energy transformation takes place during winding of spring of a clock?

Question : Write two differences between renewable and non – renewable sources of energy.

Question : What is the principle of solar cooker? Name two types of solar cooker.

Question : Name any two types of harmful nuclear radiations emitted during nuclear fission.

Question : What is thermal power plant? Where it is preferably situated?

Question : What is the principle of solar cooker? Give two limitations and two advantages of solar cooker.

Question : Name the fuel for hydro power plant. Mention two advantages and disadvantages of producing electricity at the hydro power plant.

Question : Explain why:

a) It is difficult to burn a piece of wood fresh from a tree.

b) Pouring dry sand over the fire extinguishes it.

c) It is difficult to use hydrogen as source of energy.

Question : What are the different types of energies obtained from sea? Explain.

Question : a) What is a principle of Biogas?

b) Explain it working in brief.

c) Draw a labelled diagram of biogas.


1. Name the materials used for making solar cells.

A. Silicon, Germanium and Selenium

2. What fraction of solar energy reaches the earth‘s surface?

A. 47%

3. Name the process that produces a large amount of energy in the sun.

A. Nuclear fusion

4. Why is biogas called a clean fuel?

A. Because it- (i) leaves no ash (ii) does not cause pollution (iii) does not produce any poisonous gas.


1. What is the use of black painted surface in solar heating devises.

2. Why are bio gas plants considered to be boon to the farmers? Give reason.

3. Hydroelectricity generated at a dam may be considered another form of solar energy. Why?

4. How is the slurry left over after the generation of biogas in biogas plant used?

5. Why is charcoal considered to be a better fuel than wood?

6. Why a solar cooker cannot be used for frying or making chapattis?

7. In parabolic reflector type coolers, even temperature up to 1800C- 2000C can be attained. How?

8. Modern chulahs are more efficient than traditional chulahs. Why?

9. How is hydro energy converted into electrical energy?

10. Explain, why only a part of the solar energy that strikes the upper regions of atmosphere reaches the surface of the earth?


1. a) What is a good source of energy?

b) Name one good source of energy.

c) It is a renewable source of energy?

d) Is it conventional or non – conventional source of energy?

e) What other name is give to it?

f) What is a fossil fuel?

g) Name any other two fossil fuels.

2. a) Which is the ultimate source of all forms of energy?

b) Can you explain?

c) Name some renewable source of energy arising due to sun.

d) Name some non – renewable source of energy arising due to sun.

e) Why is the energy contained in fossil fuels considered due to sun‘s energy?

f) Name any source of energy not influenced by sun‘s energy.

3. a) What is the principle of nuclear energy?

b) What are the kinds of nuclear reaction?

c) Which of these can be used for destructive purposes?

d) Which of these can be used to produce energy for common use?

e) What is nuclear fission?

f) Name two substances which are easily fissionable.

g) What are these substances called?

h) What is this phenomenon of breaking up of radioactive isotopes called?

i) Name the rays emitted.


1. Which component of solar radiations produces heat?

2. Name a form of energy that can be harnessed from the oceans.

3. Name the main component of biogas.

4. Name a fuel which is considered cleaner that CNG.

5. What is common between an atom bomb and a nuclear reactor?

6. What is the main transformation of energy during working of a windmill?

7. What are the conditions to achieve nuclear fusion?


1. I am a force that cannot be created but my form may be changed.

2. I am an important part of the system that transforms that transforms K.E. / P.E. into electrical energy.

3. I have been used to produce energy for a long time and my origin is in the remains of plants and animals.

4. I used to thrown as a waste material for centuries. But I am given an honourable name and a useful work to perform.

5. I have a huge body capable of eating water from any source with a decorative head called Hydroelectric power station.

6. I resemble a fossil fuel but find use as self sustained source of energy especially in rural areas.

7. I produce a chain of reactions each step capable of producing tremendous amount of energy.

8. I am associated with nuclear reactions but deliver heat in critical conditions.

9. I am the lightest fuel with a large potential as a source of energy.

10. I deliver hot springs with taking any energy from man – made sources or sun.



1. A type of metal that allows only partial current to pass (13)

3. A device to harness kinetic energy of wind (8)


2. Vegetable and animal waste (7)

4. Process to increase percentage of fissionable material (10)

Sources of energy questions


Chapter 01 Chemical Reactions and Equations
CBSE Class 10 Science Chemical Reactions and Equations Assignment

More Study Material

Where can I download in PDF assignments for CBSE Class 10 Science Chapter 14 Sources Of Energy

You can download free Pdf assignments for CBSE Class 10 Science Chapter 14 Sources Of Energy from

The assignments for Chapter 14 Sources Of Energy Class 10 Science for have been made based on which syllabus

The Chapter 14 Sources Of Energy Class 10 Science Assignments have been designed based on latest CBSE syllabus for Class 10 Science issued for the current academic year

Can I download and print these printable assignments for Science Chapter 14 Sources Of Energy Class 10

Yes, These printable assignments for Chapter 14 Sources Of Energy Class 10 Science are free to download and print

How many topics are covered in Chapter 14 Sources Of Energy Science assignments for Class 10

All topics given in Chapter 14 Sources Of Energy Science Class 10 Book for the current academic year have been covered in the given assignment

Is there any charge for this assignment for Chapter 14 Sources Of Energy Science Class 10

No, all Printable Assignments for Chapter 14 Sources Of Energy Class 10 Science have been given for free and can be downloaded in Pdf format

How can I download the printable test assignments for Chapter 14 Sources Of Energy Science Class 10

Just click on the View or Download button below, then another window with the Pdf will be visible, just click on the Pdf icon to download the free assignments for Chapter 14 Sources Of Energy Class 10 Science

Are these assignments available for all chapters in Class 10 Science

Yes, apart from Science you can download free assignments for all subjects in Class 10

Can I download solved assignments for Chapter 14 Sources Of Energy CBSE Class 10 Science

Our team of expert teachers at have provided all answers for the practice questions which have been given in Class 10 Science Chapter 14 Sources Of Energy assignments