The minimum speed of wind necessary for the satisfactory working of a wind generator to produce electricity is about :

The product of petroleum used to drive heavy vehicles like trucks is :

The efficiency of the solar cooker can be increased by using  ___with it.

____are devices which work on wind.

The energy produced inside the Sun is due to

The constituents contained in petroleum are separated by subjecting to a process called

Coal is a _________ source of energy.

The main constituent present in LPG(cooking gas) is

Find the odd one which doesn't come into the group