Question

A body of mass $m$ is placed at the centre of a spherical shell of radius $R$ and mass $M.$ the gravitational potential on the surface of the shell is

• A. $-\frac{G}{R}(M+m)$
• B. $-\frac{G}{R}(M-m)$
• C. $-\frac{G}{R}\left(\frac{mM}{M+m}\right)$
• D. $-\frac{G}{R}\left(\frac{mM}{M-m}\right)$

Answer 1

The correct option is A $-\frac{G}{R}(M+m)$

Assuming both body to be a point at centre . Potential at a distance $R$ will give the required ans

$V=\frac{-GM}{R}-\frac{Gm}{R}=-\frac{G(M+m)}{R}$.