Bohr's model of hydrogen atom
In order to explain the stability of atom and its line spectra, Bohr gave a set of postulates:
An electron in an atom revolves in certain circular orbit around the nucleus. These are the orbits for which `mvr=(nh)/(2pi)`
In these allowed orbits, the electron does not radiate energy.
When an electron jumps from higher energy level `E_(n_2)` to lower energy orbit `E_(n_1)`, radiation is emittd and frequency of emitted electron is given by `v=(E_(n_2)-E_(n_1))/h`. Further the radius of the `n^(th)` orbit of hydrogen atom is `r=(n^2h^24piepsilon_0)/(4pi^2me^2)` and energy of the `n^(th)` orbit is given by `E_n=-13.6/n^2 eV`.
The angular momentum of the orbital electron is integarl multiple of

Options

A. h
B. `2pih`
C. `h/2pi`
D. none of these.