Q. If the shortest wavelength in the Lyman series is 911.6 $\mathring{\mathrm{A}},\ $the longest wavelength in the same series will be
A) $1600\ \mathring{\mathrm{A}}$
B) $2430\mathring{\mathrm{A}}$
C) $1215\ \mathring{\mathrm{A}}$
D) $\infty$
Explanation
(c) $\frac{\lambda_{l}}{\lambda_{s}} = \frac{R\left( \frac{1}{1^{2}} - \frac{1}{\infty} \right)}{R\left( \frac{1}{1^{2}} - \frac{1}{2^{2}} \right)} = \frac{4}{3}$
$\lambda_{l} = \frac{4}{3}\lambda_{s} = \frac{4}{3} \times 911.6 = 1215.4\ \mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.