The non-renewable sources of energy are :

1. Coal
2. Petroleum
3. Natural gas
4. All of the above

In a hydroelectric plant :

1. Water is converted to steam to turn turbines and produce electrical energy.
2. Potential energy of stored water is converted into electrical energy.
3. Kinetic energy of stored water is converted into electrical energy.
4. All of the above.

Select the renewable and non-renewable sources of energy from the following —

(a) Coal
(b) Wood
(c) Water
(d) Diesel
(e) Wind
(f) Oil

What is the main source of energy for the earth?