In an atom two electrons move around the nucleus in circular orbits of radii R and 4R. The ratio of the time taken by them to complete one revolution is 

Options

A. `1:4`
B. `2:1`
C. `1:4`
D. `1:8`

Answer

C

Explanation

`(r_1)/(r_2) =(n_1^2)/(n_2^2) implies R/(4R) implies (n_1)/(n_2) =1/2 therefore (T_1)/(T_2) = (n_1^3)/(n_2^3) = 1/8`