Q. The energies of three conservative energy levels $L_3,L_2 and L_1$ of hydrogen atom are $E_0, \frac{4E_0}{9} and \frac{E_0}{4}$
respectively. A photon of wavelength $\lambda$ is emitted for a transition $L_3 to L_1$. What will be the wavelength of emission for transition $L_2 to L_1$?
$$\begin{gathered} 1. \frac{16\lambda }{31} \\ 2. \frac{27\lambda }{7} \\ 3. \frac{19}{20}\lambda \\ 4. \lambda \end{gathered}$$