Case–I: Point outside sphere.
At point A (r > R), the gravitational field due to the solid sphere is
The gravitational potential at this point is:
Case–II: Point on the surface of sphere
For point B (r = R), just on the surface,
Case–III: Point Inside Sphere
For any point C inside the sphere (r < R)
At the centre of this solid sphere:
I0 = O
The graphical variation of I and V with r is shown in figure below.
For points outside or on surface the sphere behaves as if its entire mass is concentrated at its center
