A hollow metal sphere of radius 10cm is charged such that the potential in its surface is 5volt . What is the potential at the centre of the sphere?

Answer 1

When a conductor is at equilibrium, the electric field inside it is constrained to be zero. Since the electric field is equal to the rate of change of potential, this implies that the voltage inside a conductor at equilibrium is constrained to be constant at the value it reaches at the surface of the conductor.