The masses of two planets are in the ratio `1 : 2`. Their radii are in the ratio `1 : 2`. The acceleration due to gravity on the planets are in the ratio

Options

A. `3 : 5`
B. `1 : 2`
C. `5 : 3`
D. `2 : 1`

Answer

D

Explanation

`g=(GM)/(R^(2)),(g_(1))/(g_(2))=(M_(1))/(R_(1)^(2))xx(R_(2)^(2))/(M_(2))=(1)/(2)xx(4)/(1)=(2)/(1)`
`therefore g_(1) : g_(2) = 2 : 1`