Question

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:

• A. 1 : 4
• B. 4 : 1
• C. 1 : 8
• D. 8 : 7

Answer 1

The correct option is C 1 : 8

We know,

$T\propto r^{3/2}\frac{T_1}{T_2}={\left(\frac{r_1}{r_2}\right)}^{\frac{3}{2}}={\left(\frac{R}{4R}\right)}^{\frac{3}{2}}=\frac{1}{8}$

Hence, option C is correct.