JEE Main Solved Paper 2017 Question 17

Question: Some energy levels of a molecule are shown in the figure. The ratio of the wavelengths $ r={\lambda_1}/{\lambda_2}, $ is given by: JEE Main Solved Paper-2017

Options:

A) $ r=\frac{3}{4} $

B) $ r=\frac{1}{3} $

C) $ r=\frac{4}{3} $

D) $ r=\frac{2}{3} $

Show Answer

Answer:

Correct Answer: B

Solution:

  • $ \Delta E=\frac{hC}{\lambda } $ For $ {\lambda_1} $ $ -E-(-2E)=\frac{hC}{{\lambda_1}} $ $ {\lambda_1}=\frac{hC}{E} $ For $ {\lambda_2} $ $ -E-( -\frac{4E}{3} )=\frac{hC}{{\lambda_2}} $ $ {\lambda_2}=\frac{3hC}{E} $ $ \frac{{\lambda_1}}{{\lambda_2}}=r=\frac{1}{3} $