If the earth suddenly shrinks (without changing mass) to half of its present radius, the acceleration due to gravity will be

Options

A. 4 g
B. 2 g
C. g/2
D. g/4

Answer

A

Explanation

Since, `g=(GM)/(R^(2))" "…(i)`
`g'=(GM)/((R//2)^(2))" "…(ii)`
or `" "g'=4(GM)/(R^(2))`
or `" "g'=4g" "["From Eq. (i)"]`