A particle of mass M is placed at the centre of a uniform spherical shell of equal mass and radius a. Find the gravitational potential at a point P at a distance `a/2` from the centre.

Options

A. `-(3GM)/a`
B. `-(2GM)/a`
C. `-(GM)/a`
D. `-(4GM)/a`

Answer

A

Explanation

Gravitational potential at point `a//2` distance from centre
`=-(GM)/a-(GM)/(a//2)=-(3GM)/a`