NEET Solved Paper 2017 Question 14

Question: The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is

Options:

A) 0.5

B) 2

C) 1

D) 4

Show Answer

Answer:

Correct Answer: D

Solution:

For last Balmer series For last Lyman series $ \frac{1}{{\lambda_b}}=R[ \frac{1}{2^{2}}-\frac{1}{{{\infty }^{2}}} ] $ $ {\lambda_b}=\frac{4}{R} $

For last Lyman series $ \frac{1}{{\lambda_l}}=R[ \frac{1}{1^{2}}-\frac{1}{{{\infty }^{2}}} ] $ $ {\lambda_1}=\frac{1}{R} $ $ \frac{{\lambda_b}}{{\lambda_l}}=\frac{\frac{4}{R}}{\frac{1}{R}} $ $ \frac{{\lambda_b}}{{\lambda_l}}=4 $