Question

The ratio of the largest to shortest wavelength in Lyman series of hydrogen spectra is

• A. $\frac{25}{9}$
• B. $\frac{17}{6}$
• C. $\frac{9}{5}$
• D. $\frac{4}{3}$

Answer 1

Answer: (D)

$\frac{4}{3}$

For Lyman series $\frac{1}{{\lambda }_{max}}=R[\frac{1}{1^2}-\frac{1}{2^2}]=\frac{3}{4}R$ and
$\frac{1}{{\lambda }_{min}}=R[\frac{1}{1^2}-\frac{1}{{\infty }^2}]=\frac{R}{1}$

$\Rightarrow \frac{{\lambda }_{max}}{{\lambda }_{min}}=\frac{4}{3}$