question_answer

Assuming the earth to be a sphere of uniform density, the acceleration due to gravity inside the earth at a distance of r from the centre is proportional to                                                               [JEE ONLINE 12-05-2012]

A)  r                     

B)       \[{{r}^{-1}}\]

C) \[{{r}^{2}}\]               

D)      \[{{r}^{-2}}\]

Correct Answer: A

Solution :

[a] Acceleration due to gravity at depth d from the surface of the earth or at a distance r from the centre 'CV of the earth

Hence