Q. The acceleration due to gravity is $g$ at a point distant $r$ from the centre of earth of radius $R$. If $r < R$, then
A) $g \propto r$
B) $g \propto r^{2}$
C) $g \propto r^{- 1}$
D) $g \propto r^{- 2}$
Explanation
(a) Inside the earth $g^{'} = \frac{4}{3}\pi\rho Gr\ \therefore g' \propto r$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.