Two concentric shells of masses `M_(1)` and `M_(2)` are concentric as shown. Calculate the gravitational force on m due to `M_(1)` and `M_(2)` at points P,Q and `R`.

Options

A. `F_(P) =0`
B. `F_(Q)=(GM_(1)m)/(b^(2))`
C. `F_(R)=(G(M_(1)+M_(2)))/(c^(2))`
D. All are correct

Answer

D

Explanation

At P, F = 0
At Q, `F=(GM_(1)m)/(b^(2))`
At R, `F=(G(M_(1)+M_(2))m)/(c^(2))`.