Question

Identify the correlation between the first two words and suggest the suitable words in the fourth place:
Coal: thermal :: water storage:

Answer 1

Coal is used as a fuel which generates heat and increases the temperature, also called as thermal power while water is stored and is used to produce energy in the form of hydroelectric power. Hydroelectricity is produced through the storage of water in the dams etc and later is used to generate electricity.

So, the answer is 'Coal: thermal:: water storage: hydroelectric power'