In terms of geological time scale, the quaternary period consists of two epochs. They are

The planet which is called twin sister of the earth is –

What is the primary source of heat in the Earth’s interior?

Variations in the length of day and night time from season to season are due to –

Which elements are abundant in the formation of interior layer of the earth?

An imaginary line drwan on a globe to divide it into two equal parts is known as the ___________.