Producer gas is produced by .......... of wood.

The daily input of sunlight per square meter per day on the Earth is approximately:

What is the advantage of energy plantations?

Observe the figures $A$ and $B$ given below and answer the following questions.
$(i)$ The power generation by the above two methods is non-polluting. True/False.
$(ii)$ List any two applications of solar energy.
$(iii)$ What is a photovoltaic cell?

For biogas production,besides dung,which one of the following weeds is recommended in our country?

The fuel wood crisis can be overcome by