Question

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

• A. $-\frac{3 G M}{a}$
• B. $-\frac{2 G M}{a}$
• C. $-\frac{G M}{a}$
• D. $-\frac{4 G M}{a}$

Answer 1

Answer: (A)

Potential at the given point $=$ Potential at the point due to the shell $+$ Potential due to the particle
$=-\frac{G M}{a}-\frac{2 G M}{a}=-\frac{3 G M}{a}$