Chapter 7 — Energy — How Things Work

Chapter 7 of the Class 5 The World Around Us NCERT textbook (Our Wondrous World), "Energy — How Things Work", explains what energy is and how it drives everything from movement and sound to heat and light — download the PDF and read a summary of how food, fuel, electricity, and clean sources like the Sun, wind, and water all power the world around us.

• What Energy Is — Energy is what makes things move, light up, produce sound, do work, and change temperature. The chapter connects this idea to everyday observations — cooking in a kitchen, a flying snake gliding, vehicles on the road — showing that energy is always at work around us.
• Sources of Energy — Food, Fuel, and Electricity — Food gives energy to all living things, including humans and animals. Vehicles run on fuels like petrol and diesel, while electricity powers fans, lights, and machines in homes, schools, and industries. Burning fuels like wood or coal produces smoke and pollution, so they must be used carefully.
• Clean Energy from Sun, Wind, and Water — Solar panels capture sunlight and turn it into electricity; windmills use wind movement; fast-moving rivers and falling water also generate electricity. Energy made from these natural sources does not pollute the planet and is called clean energy.
• Energy Efficiency and Safe Use — Energy efficiency means using less energy to do the same work — for example, LED bulbs give the same light as older bulbs but use less electricity. Electricity is useful but dangerous if misused, so the chapter lists clear safety rules such as not touching plugged-in wires or inserting objects into sockets.
• Stored Energy — The body stores energy for future use, which is why we can still run even if we skip a meal. Batteries in torches and toys are another example of stored energy that can be used when needed.

1. 01Energy is what makes things move, produce sound, light up, or change temperature — it is behind every activity we see in nature and at home.
2. 02Food is the source of energy for all living things, including humans and animals; petrol and diesel fuel vehicles.
3. 03Burning coal is the main way most electricity is produced today, but it releases smoke and harmful gases that pollute the air.
4. 04Solar panels, windmills, and flowing water can generate electricity without causing pollution — this is called clean energy.
5. 05The Bhadla Solar Park in Rajasthan is one of the largest solar power plants in the world; Cochin International Airport in Kerala runs entirely on solar energy.
6. 06The Sun gives Earth more energy in one hour than all humans on Earth use in a whole year.
7. 07Energy efficiency — such as using LED bulbs instead of older bulbs — helps save resources and reduce waste.