Important Questions for Class 10 Science Chapter 14 – Sources of Energy
Home/CBSE/Important Questions for Class 10 Science Chapter 14 – Sources of Energy

Important Questions for Class 10 Science Chapter 14 – Sources of Energy

Important Questions for Class 10 Science Chapter 14 – Sources of Energy is important for students to prepare well for their board examination. The chapter covers how our energy requirements increase as our means of living increase. In order to meet our energy needs, we are exploring new energy sources and improving energy efficiency. Furthermore, we will examine the technology available to use that source and how its impacts the environment will be impacted by the use of that source.

While solving important questions for class 10 Science chapter 14 – Sources of Energy, students are required to pay attention dealing with the following topics:

  • How can you find a reliable source of energy?
  • How do you define good fuel?
  • Sources of conventional energy
  • Technology improvements in the use of conventional energy sources
  • Sources of energy that are not conventional or alternative

Below are some of the important questions for class 10 science chapter 14 – Sources of Energy from an examination point of view.

Class 10 Science Important Questions Chapter 14 – Sources of Energy

Q1. (a) Name the device used to convert

(i) Solar energy into heat and

(ii) solar energy into electricity.

(b) Explain the working of the windmill


(a) (i) A solar cooker converts solar energy into heat.

(ii) A solar cell converts solar energy into electricity.

(b) The kinetic energy of the wind is used to rotate the blades of the windmill when the wind blows at a minimum speed of 15 km/hr. The blades’ rotational energy is used to rotate the generator’s armature, which then produces electricity.

Q2. Name three forms in which energy from the ocean is made available for use. What are OTEC power plants? How do they operate?


  • Muscular energy is obtained from the food we consume to execute various actions such as taking a bath or climbing stairs.
  • Fossil fuel energy is utilized to get to school by bus or car, which comes from fossil fuels such as gasoline, diesel, and compressed natural gas (CNG).
  • Chemical energy is obtained from breakfast and the food we eat.

Q3. List three forms of energy we use when we wake up from morning till we reach school. Also from where do, we get these different forms of energy?


  • Tidal energy
  • Ocean waves energy
  • Ocean thermal energy

Ocean thermal energy conversion plants, or OTECs, are power facilities that convert ocean thermal energy into electricity. Boiling liquids like chlorofluorocarbons or ammonia or are necessary to operate OTEC at a temperature difference of 20℃ or more between the surface water of the ocean and the inner water of the ocean. 

The high-pressure vapors of the liquid rotated the turbine of the generator, which produced energy.

Q4. Why are we looking at alternate sources of energy?


Fossil fuels are non-renewable energy sources that have finite reserves. As a result, we must protect them. We may soon run out of energy if we continue to consume these resources at the current rate. To avoid a situation like this, we’re exploring other energy sources.

Q5. The biggest source of energy on Earth’s surface is

(a) Biomass

(b) Solar radiations

(c) Tides

(d) Winds


(b) The biggest source of energy on Earth’s surface is solar radiation.

Q6. What is meant by the term ‘Biomass’?


Biomass : Cow-dung, various plant materials like the residue after harvesting the crops, vegetable wastes and sewage which can be decomposed in the absence of oxygen is called biomass.

Q7. List any four disadvantages of using fossil fuels for the production of energy.


Disadvantages of using fossil fuels for the production of energy are :

  • Fossil fuels are non-renewable source of energy.
  • It causes air pollution to the environment.
  • It takes millions of years for its formation.
  • It causes acid rain.

Q8. Which one of the following statement is not true about nuclear energy generation in a nuclear reactor?

(a) Energy is obtained by a process called nuclear fission.

(b) The nucleus of Uranium is bombarded with high energy neutrons.

(c) A chain reaction is set in the process.

(d) In this process a tremendous amount of energy is released at a controlled rate.


(b) In a nuclear reactor, to produce nuclear energy, uranium is bombarded with low energy neutrons.

Q9. Assertion (A) : In the process of nuclear fission, the amount of nuclear energy generated by the fission of an atom of uranium is so tremendous that it produces 10 million times the energy produced by the combustion of an atom of carbon from coal. Reason (R) : The nucleus of a heavy atom such as uranium, when bombarded with low energy neutrons, splits apart into lighter nuclei. The mass difference between the original nucleus and the product nuclei gets converted to tremendous energy.

(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion (A).

(b) Both (A) and (R) are true, but (R) is not the correct explanation of the assertion (A).

(c) (A) is true, but (R) is false.

(d) (A) is false, but (R) is true.


(a) Both (A) and (R) are true and (R) is the correct explanation of the assertion (A).

Q10. Explain the principle and process of converting ocean thermal energy into electricity. 


Principle : There is a temperature difference between the water at the surface of the sea and deep below the sea. The difference in temperature at many places is of the order of 20°C. This difference in temperature can be exploited to produce electric energy in ocean thermal energy conversion plant (OTEC).

Working : In one of the methods, a low melting point liquid or fluid such as ammonia (volatile liquid) or chlorofluorocarbon (CFC) is used to run the turbine of a generator. The warm surface water is used to boil the liquid like ammonia or CFC in a heat exchanger and vapours thus formed are used to drive the turbine of the generator. In another exchanger cold water from the depth of the ocean is pumped up to condense the vapours of the ammonia again to liquid. This ammonia is reused and the cycle repeats.