$A$ bioenergy source obtained by fermentation to supplement fossil fuel petrol is:

The sap of which plant is considered a good substitute for diesel oil?

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?

Which of the following is a non-renewable source of energy?

Which of the following is a non-conventional energy source?

Biogas is a mixture of