Question

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

• A. $\frac{GM}{a}$
• B. $\frac{2GM}{a}$
• C. $\frac{3GM}{a}$
• D. $\frac{4GM}{a}$

Answer 1

Answer: (C)

$\frac{3GM}{a}$

Answer 2

gravitational potential at $x$ point
$V _{ x }=\frac{ GM }{ a / 2}+\frac{ GM }{ a }=\frac{3\, GM }{ a }$