Question

A hollow spherical conductor of radius 2 cm is charged with 62.8 statC. Determine the surface density of charge on the Inner and outer surfaces of the conductor. If the sphere be a solid one what will be the values of the above quantities?

Answer 1

No charge resides on the inner surface of a hollow conductor. So surface density of charge on the internal surface of the hollow sphere is zero. Surface density of charge on the external surface of the sphere,
`sigma=Q/(4 pi r^2) , ` Q=62.3 statC , r= 2cm
`=62.8/(4pi(2)^2) = 62.8/(16pi)` = 1.249 statC . `cm^(-2)`
If the sphere be a solid one, it has no internal surface. The surface area of a hollow sphere and that of a solid sphere of the same radius are equal. So the surface density of charge on the external surface of the solid sphere will be the same as that of the hollow sphere.