Q 11-07-159JEE MainJEE Main 2021 (27 Aug, Shift 2)Easy
A mass of $50$ kg is placed at the center of a uniform spherical shell of mass $100$ kg and radius $50$ m. If the gravitational potential at a point, $25$ m from the center is $V$ kg m$^{-1}$. The value of $V$ is:
Answer: (C) $-4G$
Inside the shell its potential is constant: $-\dfrac{G\times100}{50} = -2G$.
Point mass at $25$ m: $-\dfrac{G\times50}{25} = -2G$.
$V = -2G - 2G = -4G$.
Solution by Sreeraj P, M.Sc Physics