Two concentric shells of masses `M_(1)` and `M_(2)` are having radii `r_(1)` and `r_(2)`. Which of the following is the correct expression for the gravitational field on a mass `m`?

Options

A. (a) `(G(M_(1)+M_(2)))/(r^(2))," for "rltr_(1)`
B. (b) `(GM_(1)+M_(2))/(r^(2))` for `rltr_(2)`
C. (c) `(GM_(2))/(r^(2))` for `r_(1)ltrltr_(2)`
D. (d) `(GM_(1))/(r^(2))` for `r_(1)ltrltr_(2)`

Answer

D

Explanation

When `rltr_(1)` gravitational intensity is equal to 0
when `rgtr_(1)` gravitational intensity is equal to `(GM_(1))/(r^(2))`
When `rgtr_(2)` gravitational intensity is equal to
`(G(M_(1)+M_(2)))/(r^(2))`