Question

If the ratio of the de-Broglie wavelength associated with the electron moving in $n^{th}$ orbit and $2^{nd}$ orbit is 1.5, the number of waves made by a Bohr electron in one complete revolution in $n^{th}$ orbit of $H-$atom are:

Answer 1

$\lambda =\frac{h}{mv}\propto \frac{nh}{mZ}$
Given: ${\lambda }_n/{\lambda }_2=1.5,n=3$
So, number of waves made by a Bohr electron in one complete revolution is 3.