Q 12-12-122JEE MainJEE Main 2017 (2 Apr)Easy
Some energy levels of a molecule are shown in the figure. The ratio of the wavelengths $r = \dfrac{\lambda_1}{\lambda_2}$ is given by:
Answer: (A) $r = \dfrac13$
$\lambda = \dfrac{hc}{\Delta E}$.
- $\lambda_2$: from $-E$ to $-\frac43E$, $\Delta E_2 = \dfrac E3$
- $\lambda_1$: from $-E$ to $-2E$, $\Delta E_1 = E$
$$r = \frac{\lambda_1}{\lambda_2} = \frac{\Delta E_2}{\Delta E_1} = \frac{E/3}{E} = \frac13$$
Solution by Sreeraj P, M.Sc Physics