Two electrons X and Y revolve in n= 2 and n = 3, respectively. What will be the ratio of their velocities ?

4 : 9 2 : 3 3 : 2 9 : 4

3 : 2

Use : mvr = \(\frac{nh}{2 \pi}\) r ∝ n2 $\Rightarrow v \propto \frac{1}{n}$