Question

The first member of the Paschen series in hydrogen spectrum is of wavelength 18,800 Å. The short wavelength limit of Paschen series is

• A. 1215 Å
• B. 6560 Å
• C. 8225 Å
• D. 12850 Å

Answer 1

Answer: (C)

8225 Å

Answer 2

First member of Paschen series mean it's ${\lambda\frac{144}{7R}}_{\max}$

Short wavelength of Paschen series means ${\lambda\frac{9}{R}}_{\min}$

Hence $\frac{\lambda_{\max}}{\lambda_{\min} = \frac{16}{7}}$ ⇒

${\lambda{\frac{7}{16}\frac{7}{16}}_{\max}}_{\min}$