A hollow metal sphere of radius 10 cm is charged such that the potential on its surface is 80 V. The potential at the centre of the sphere is ?

A hollow metal sphere of radius 10 cm is charged such that the potential on its surface is 80 V. The potential at the centre of the sphere is ?

(a) 0 V

(b) 80 V

(c) 800 V

(d) 8 V

Answer :  (b) 80 V