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Important Questions

Sources of Energy • Class 10 Science

❓ Important Questions

These questions cover major concepts, comparisons, reasoning, applications and exam-oriented preparation.

Section A – Very Short Answer
Q1

What is meant by a good source of energy?

A good source of energy should provide useful energy efficiently and should be convenient, economical and relatively safe to use.
Q2

What is a renewable source of energy?

A renewable source is one that is naturally replenished on a timescale suitable for human use.
Q3

Give two examples of non-renewable sources.

Coal and petroleum.
Q4

What is a solar cell?

A solar cell converts solar radiation directly into electrical energy.
Q5

What is biogas?

Biogas is a combustible gas mixture produced by anaerobic decomposition of organic matter.
Q6

What is nuclear fission?

Nuclear fission is the splitting of a heavy atomic nucleus into smaller nuclei with release of energy.
Section B – Short Answer Questions
Q7

Why are fossil fuels called non-renewable sources?

They form over geological timescales and are consumed much faster than they can naturally form.
Q8

Why is solar energy considered renewable?

Solar radiation is continuously supplied by the Sun on a human timescale.
Q9

Why are wind turbines constructed at windy locations?

Higher and more consistent wind speeds can provide greater and more reliable energy production.
Q10

Why is biogas considered a useful fuel?

It can be produced from organic waste, provides a combustible fuel and can leave behind useful digested material.
Q11

Why does a hydroelectric power station need water stored at height?

Stored water possesses gravitational potential energy that can be converted into kinetic and then electrical energy.
Q12

Why are fossil fuels associated with air pollution?

Their combustion releases carbon dioxide and, depending on fuel and combustion conditions, pollutants such as particulate matter, sulphur compounds and nitrogen oxides.
Section C – Reasoning Questions
Q13

Why can't solar energy be relied upon equally at all times?

Solar output varies with time of day, season, weather and location, so generation is not constant.
Q14

Why can wind energy not be used equally everywhere?

Useful wind generation requires suitable wind speed and consistent wind conditions, which vary with location.
Q15

Why are large dams sometimes opposed despite producing clean electricity during operation?

Large reservoirs can submerge land, alter ecosystems, affect river flow and may require displacement of communities.
Q16

Why is nuclear energy described as a high-energy-density source?

Nuclear reactions can release very large amounts of energy from relatively small quantities of nuclear fuel.
Section D – Comparison Questions
Q17

Compare renewable and non-renewable sources of energy.

Renewable sources are naturally replenished, while non-renewable sources have finite reserves and are depleted with use. Examples include solar/wind versus coal/petroleum.
Q18

Compare solar energy and fossil fuels.

Solar energy is renewable and does not require fuel combustion during operation, whereas fossil fuels are finite and their combustion releases pollutants and greenhouse gases.
Q19

Differentiate between solar cell and solar cooker.

A solar cell converts sunlight into electrical energy, whereas a solar cooker uses solar radiation mainly for heating and cooking.
Q20

Differentiate between thermal power and hydroelectric power.

Thermal power commonly uses heat from fuel combustion to drive a turbine, while hydroelectric power uses the energy of water.
Section E – Long Answer Questions
Q21

What characteristics should an ideal source of energy possess?

Discuss high energy output, convenient storage and transport, easy use, economic viability, availability and relatively low environmental impact.
Q22

Explain the working of a hydroelectric power plant.

Explain storage of water at height, flow through turbines, mechanical rotation and generation of electricity.
Q23

Explain the advantages and limitations of solar energy.

Discuss renewable supply, absence of fuel combustion during operation and suitability for remote use, along with intermittency, area requirements and initial cost.
Q24

Explain the environmental effects of using fossil fuels.

Discuss air pollution, greenhouse-gas emissions, mining, land degradation and other ecological impacts.
Section F – Application / Competency
Q25

A village has abundant sunlight but no reliable grid electricity. Which energy technology could be useful?

Solar photovoltaic systems can be useful because solar radiation can be directly converted into electricity.
Q26

A farming community produces large quantities of cattle dung. Which useful energy source can be generated from it?

Biogas can be produced through anaerobic digestion.
Q27

A region has strong and steady winds for most of the year. Which renewable energy source is especially suitable?

Wind energy is suitable because turbines can convert the kinetic energy of moving air into electrical energy.
Q28

Why might a coastal area be considered for tidal or wave-energy projects?

The periodic movement of seawater can provide mechanical energy that may be converted into useful electrical energy.
Section G – Diagram-Based Questions
Q29

Draw and label a solar cell system used to generate electricity.

Show solar panel, sunlight, connecting circuit and electrical load.
Q30

Draw a hydroelectric power plant.

Show reservoir, dam, water flow, turbine and generator.
Q31

Draw a wind turbine and show the conversion of energy.

Show moving air, turbine blades, shaft and generator.
Q32

Draw a biogas plant and label its major parts.

Show inlet, digester, gas holder/outlet and slurry outlet.

⚡ Final Exam Focus

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