Electric potential due to uniformly charged thin spherical shell:

Consider a charged spherical shell of radius R as shown in fig:

1. When the point P lies outside the shell: Electric potential at an outside point is equal to that of point charge located at the centre, which is given by
2. When point P lies on the surface of the shell: the electric potential at the surface of the shell is given by
3. When point p lies inside the shell: The electric field at any point inside the shell is zero. Hence electric potential due to uniformly charged spherical shell is constant everywhere inside the shell and its value is equal to that on the surface, thus