Q. In an atom, the two electrons move round the nucleus in circular orbits of radii $R$ and $4R$. The ratio of the times taken by them to complete one revolution is
A) 1/4
B) 4/1
C) 8/1
D) 1/8
Explanation
(d) $\frac{R_{1}}{R_{2}} = \frac{n_{1}^{2}}{n_{2}^{2}} = \frac{1}{4}\therefore\frac{n_{1}}{n_{2}} = \frac{1}{2}$
$\frac{T_{1}}{T_{2}} = \left( \frac{n_{1}}{n_{2}} \right)^{3} = \left( \frac{1}{2} \right)^{3} = \frac{1}{8}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.