NCERT Solutions for Class 5 EVS Chapter 7: Energy — How Things Work – Free PDF Download

Chapter 7 of Class 5 EVS, Our Wondrous World, Energy — How Things Work, explains what energy is and the different forms it takes in everyday life.

Last Updated: August 27, 2026

NCERT Solutions for Class 5 EVS Chapter 7: Energy — How Things Work

What this chapter teaches.
What energy is — whatever makes things move, shine, make sound, or become hot or cold; different forms of energy — heat, light, sound, and electrical energy; natural energy sources — the Sun (solar energy), wind, and flowing water; fuels like wood, coal, and petrol; and how energy is used and conserved in everyday life.

Discuss (Textbook Questions)

What makes these things move, shine, make a sound or get warm and cold?
Energy — in different forms such as electrical, heat, light, or sound energy — is what makes things move, shine, produce sound, or change temperature.

What kind of fuel do you use at home for cooking?
(Open-ended, household-specific.) Common answers include LPG (cooking gas), electricity (induction), or, in some rural homes, wood/biomass or kerosene.

What are the problems of using too much wood or coal?
Burning wood or coal releases smoke and harmful gases that pollute the air and contribute to health problems and climate change; cutting wood for fuel also leads to deforestation, which harms wildlife and the environment.

Activities

Activity 1 — Balloon air rocket.
To make the balloon-powered toy move faster, use a bigger balloon or blow more air into it (more stored energy); to slow it down, use less air or add more friction/weight.

Activity 2 — Rubber-band guitar.
Thinner, tighter rubber bands vibrate faster and produce a higher-pitched sound, while thicker or looser bands vibrate more slowly and produce a lower, deeper sound.

Activity 4 — Diya (oil lamp) as fuel.
(a) A diya with more oil/wick burns longer, because it has more fuel to sustain the flame. (b) The oil (or wax, in a candle) acts as the fuel here — it is drawn up the wick and burns to produce heat and light.

Activity 5 — Electrical devices at home.
Examples of things that run on electricity: fan, bulb/tube light, refrigerator, television, mixer-grinder, and mobile charger — each converts electrical energy into motion, light, cooling, sound, or heat.

Activity 6 — Pinwheel.
When wind blows on the pinwheel (or you blow on it), it spins — showing that moving air (wind) carries energy that can be converted into motion.

Activity 7 — Sunlight in focus (magnifying glass).
When sunlight is focused through a magnifying glass onto paper, the concentrated light energy converts to heat energy at that point, and the paper can scorch or catch fire — showing how much energy sunlight carries.

Activity 8 — Water wheel.
Yes, flowing water pushes against the wheel’s blades and makes it turn, showing that moving water carries energy that can be converted into motion — the same principle used in hydroelectric power plants.

Let Us Reflect (End-of-Chapter Questions)

1. What will happen if there is no electricity in your house for a day? Fans, lights, refrigerators, and most appliances would stop working; food might spoil without refrigeration; and daily tasks like studying at night, charging devices, or cooking (if using an electric stove) would become difficult.
2. Why is it better to use solar or wind energy instead of coal? Solar and wind energy are renewable (they do not run out) and do not produce smoke or pollution when generating electricity, while burning coal is a non-renewable resource that pollutes the air and contributes to climate change.
3. Give two examples where you have seen energy being stored. A charged mobile phone battery stores electrical energy for later use; a wound-up toy or clock spring stores mechanical energy that is released as it unwinds.
4. What is the one thing you can do at home to save energy? (Open-ended.) Sample answer: switching off lights, fans, and other appliances when not in use.
5. Find out how many kilometres a vehicle travels per litre of petrol or diesel (its mileage), and discuss why saving fuel matters. (Open-ended, family-research task.) Mileage varies by vehicle, typically 15-25 km/litre for cars and higher for two-wheelers; saving fuel matters because petrol and diesel are limited (non-renewable) resources and burning them causes air pollution.
6. Look around your home or classroom. List three objects that use energy and mention their source of energy. Sample answer: a table fan (electrical energy), a torch (chemical energy from batteries), and a solar-powered calculator or lamp (solar energy from sunlight).
7. Create and Share: (a) Draw or make a simple plan of a ‘clean energy home.’ (b) Make ‘my energy diary’ for one day, recording how many times you used electricity or fuel. (Open-ended creative/project task.) (a) A clean-energy home plan might include solar panels on the roof, a rainwater-fed water heater, energy-efficient LED bulbs, and good natural ventilation/lighting to reduce electricity use. (b) The energy diary should list each use of a fan, light, appliance, or vehicle through one full day, helping the student notice patterns of energy use.

Why This Chapter Matters

Understanding where energy comes from and how it’s used builds awareness of conservation and the value of natural energy sources.

How to Use These Solutions

Walk around your home together and identify every device that uses energy, discussing what form of energy each one relies on. Download the full chapter from our Class 5 EVS NCERT book page, or browse the Class 5 hub.

More on This Chapter

See also the Extra Questions and Revision Notes for this chapter.

Frequently Asked Questions

What is energy?
Whatever makes things move, shine, make sound, or become hot or cold.

Name a natural source of energy.
The Sun (or wind, flowing water).

What does the “Let Us Reflect” section of this chapter ask students to do?
It is the textbook’s own set of seven end-of-chapter reflection tasks — on a day without electricity, storing energy, saving fuel, and designing a clean-energy home — answered in full above.

Written by Satish

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