A particle of mass M is suited at the centre of a spherical shell of same mass and radius a. The gravitational potential at a point situated at a/2 distance from the centre, will be:

Options

(a) – 3GM / a
(b) – 2GM / a
(c) – GM / a
(d) – 4GM / a

Correct Answer:

– 3GM / a

Explanation:

Potential at the given point = Potential at the point due to the shell + Potential due to the particle
= – GM / a – 2GM / a = – 3GM / a