For electron moving in nth orbit of H-atom the angular velocity is proportional to

n 1/n n3 1/n3

1/n3

Radius of nth orbital is $ r_n \propto n^2$ Velocity of electron in nth orbital is $ v_n \propto \frac{1}{n}$ $\Rightarrow \text{ Angular Velocity } \propto \frac{v_n}{r_n} = \frac{1}{n^3}$