Page 44 - Science Class 6 Times Publication

Sources of heat

There are various sources of heat. Some of the sources of heat are as
follows:

a) The sun b) Fuels c) Electricity
d) Friction e) Combustion of food in the body

The sun

The sun is the main source of heat. All
animals and plants get heat from the sun.
The heat of the sun is called solar heat.
We use solar heat for drying clothes,
drying crops and food grains. Plants use
solar energy for the preparation of food by
photosynthesis process. Animals get their
foods from plants. Thus, all animals and
plants use solar heat.

Activity 4.1

Take a hand lens and focus sunlight on a piece of paper by moving
the lens closer or farther. Keep the lens in the same condition for a
while. What happens to the paper?

Observation: The paper burns due to the solar heat focused on the
paper.

Conclusion: If the heat of the sun is focused at a point, it can burn
the things.

Fuels

Fuels like petrol, coal, diesel, kerosene, rewood, cake of cattle dung,
gobar gas, etc are also the sources of heat. Heat can be produced by
burning these fuels. Heat of the fuels is used to cook food, to run
vehicles, machines, etc.

Times' Crucial Science and Environment 40 Book 6