Page 234 - Primary Five Science

Importance of convection

 To move out smoke from chimneys of the kitchen

 Convection currents help to drive out bad smell through

vent pipe of a VIP latrine.

 A lit cigarette is kept burning by convection current

 Boiling water

 Convection currents help us to get fresh air in our houses.

 A Charcoal stove, flat iron and a lantern lamp continue burn-

ing by convection currents

3. Radiation
This is the process by which heat travels through vacuum

When heat travels by radiation, it doesn’t need any medium of
transmission.

Examples of radiation in nature

1. Heat from the sun reaches us by radiation.

2. Heat from a fire

3. When you sit near a fire place, charcoal stove, cooker, etc,

you receive heat by radiation.

4. Heat from a light bulb

5. Heat from anything else which is warmer than its surround-

ings.

Importance of radiation

1. Radiant heat from the sun helps to dry our clothes and har-

vested crops
2. Heat from the fire reaches our bodies by radiation

3. Radiant heat from the sun helps in rain formation.