State Bohr's postulate to define stable orbits in hydrogen atom . How does de Broglie's hypothesis explain the stability of these orbits ?

(i) State Bohr's quantization condition for defining stationary orbits . How does de- Broglie hypothesis explain the stationary orbits ? (ii) find the relation beween the three wavelengths lambda_(1), lambda _(2) " and " lambda_(3) from the energy level diagram shown :

(i) State Bohr's quantization condition for defining stationary orbits . How does de- Broglie hypothesis explain the stationary orbits ? (ii) find the relation beween the three wavelengths lambda_(1), lambda _(2) " and " lambda_(3) from the energy level diagram shown :

If the radius of third Bohr orbit in hydrogen atom is r, then de-Broglie wavelength of electron in this orbit is