We know that (a) like electrical charges repel each other and (b) substances which allow charges to move through them are called conductors. In the light of these facts, find where the charge placed on a conductor resides.

Explanation

Let us consider a spherical conductor, and negative charge is placed at the centre. Different negatively charged particles repel each other. Because the body is a conductor, the charges can move freely through the body. They are repelled to the boundaries. As such charge placed on a conductor, always resides on outer surface of it.