A sphere has a radius of 90 cm and it can be charged to a potential of 1000 volt. Find the capacity of the sphere and (b) the charge on it.

A solid sphere and a hallow sphere of equal radius are raised to same potential. Then

The potential at the centre of a hollow charged sphere is 900 volts. Find the charge on the sphere in micro-coulomb if the sphere is of radius 10 cm.