Question

State the property of black surface which is used in the working of solar heaters

Answer 1

Black attract heat towards it. It is a good conductor of heat,it absorbs light. That is why the surface the of a solar cooker is painted with black.
Hope it helps!

Answer 2

It absorbs maximum amount of heat energy (from the sun) and hence, the water contained in the solar heater also becomes hot (due to flow of heat from hot body to cold body)