Name one source of energy which is not derived from solar energy directly or indirectly.

What difference would you expect in the charging of car battries

(i) in bright sunlight

(ii) on a cloudy day

(iii) at night?

What substance is obtained as a residue when wood is burned in a limited supply of air?

What name is given to the heat energy obtained from hot rocks inside the earth?

Name the agent which decomposes animal dung into biogas.