Explain the origin of the spectral lines of hydrogen atom using Bohr's theory. Draw the energy level diagram of hydrogen atom showing its various spectral series.

Explanation of origin of spectral lines of hydrogen atom $\displaystyle 1$ Energy level diagram showing various spectral series of hydrogen atom $\displaystyle 2$ When an electron makes a transition from higher energy level to a lower energy orbit, a photon is emitted having energy equal to energy difference between these two orbits. [Do not deduct marks for not showing transition in diagram]