Wavelength of a particle moving with relativistic speed

Question

Obtain expression for the wavelength of a particle moving with relativistic speed.

Solution

The relativistic momentum of a particle is given by

When did Bohr hydrogen atom approaches classical condition

Here our problem is to prove that the Bohr hydrogen atom approaches classical conditions when n becomes very large and small quantum jumps are involved.

To prove this let us compute the frequency of a photon that is emitted in the transition between the adjacent state