Page 113 - ICSE Science 3 : E-book

the hotter it is. The sun is also spring
responsible for the changes in

seasons. The earth moves around
winter
the sun. Due to this, the amount of

sunlight received by each part of
summer
the earth changes everyday. This
change causes seasons. Summer,

monsoon and winter are the three
main seasons. Spring and autumn
autumn
come in between these seasons. monsoon
We wear clothes and eat food
according to the season. Eff ect of sun on seasons

Sources of Energy

The resources from which we get energy are called sources of energy. They can be

broadly classifi ed into renewable and non-renewable sources of energy.
Renewable sources of energy are the energy sources that can be used again and

again. These are present in abundance in nature. Solar energy is also a renewable

source of energy. Other examples include wind energy and hydroelectric energy.

solar energy wind energy hydroelectric energy
Renewable sources of energy

• Wind energy is the energy obtained from the moving air. It is used in the large

farm fi elds to run windmills.
• Hydroelectric energy is the energy obtained from the running water of streams

and rivers. Dams are built on rivers to trap energy from the running water.

All these energy sources are used to produce electricity.

Non-renewable sources of energy are the energy sources that are found in limited
quantity. Coal, petroleum and natural gas are some non-renewable energy sources.

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