Question

a) Why are solar heating devices painted black?

b) Name two such devices and state two limitations of these.

Answer 1

a)

1. Black color is a very good absorber of heat but a very poor reflector.
2. So, it is used to absorb the maximum amount of heat from the sunlight.
3. It is used in solar heating devices to maximize the absorption of heat.

b)

Two devices are:-

1. Solar cooker
2. Solar water heater

Limitations:-

1. It cannot be used at night.
2. The heating process of solar devices is very slow.
3. It is weather dependent.