Neet Solved Paper 2013 Question 34
Question: Ratio of longest wavelengths corresponding to Lyman and Bulmer series in hydrogen spectrum is
Options:
A) $ \frac{5}{27} $
B) $ \frac{3}{23} $
C) $ \frac{7}{29} $
D) $ \frac{9}{31} $
Show Answer
Answer:
Correct Answer: A
Solution:
- wavelength for Lyman series $ {\lambda_L}=\frac{1}{R( 1-\frac{1}{4} )}=\frac{4}{3R} $ And wavelength for Balmer series $ {\lambda_L}=\frac{1}{R( \frac{1}{4}-\frac{1}{9} )}=\frac{1}{R( \frac{5}{36} )}=\frac{36}{5R} $
$ \therefore $ $ \frac{{\lambda_L}}{{\lambda_B}}=\frac{4}{3R}\times \frac{5R}{36}=\frac{5}{27} $
$ \Rightarrow $ $ {\lambda_L}:{\lambda_B}=5:27 $
