Atoms And Nuclei Question 97
Question: The ratio of the longest to shortest wavelengths in Brackett series of hydrogen spectra is [EAMCET (Engg.) 2000]
Options:
A) $ \frac{25}{9} $
B) $ \frac{17}{6} $
C) $ \frac{9}{5} $
D) $ \frac{4}{3} $
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Answer:
Correct Answer: A
Solution:
For Bracket series $ \frac{1}{{\lambda_{\max }}}=R[ \frac{1}{4^{2}}-\frac{1}{5^{2}} ]=\frac{9}{25\times 16}R $ and $ \frac{1}{{\lambda_{\min }}}=R[ \frac{1}{4^{2}}-\frac{1}{{{\infty }^{2}}} ]=\frac{R}{16}\Rightarrow \frac{{\lambda_{\max }}}{{\lambda_{\min }}}=\frac{25}{9} $