Q. 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 a/2 distance from the centre, will be
A) −4GM/a
B) −3GM/a
C) −2GM/a
D) −GM/a
Explanation
[Solution from source] Inside the shell its potential is constant at −GM/a. The point mass at the centre contributes −GM/(a/2) = −2GM/a. Total V = −2GM/a − GM/a = −3GM/a. Forgetting the shell gives −2GM/a. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.