Question

The extreme wavelengths of Paschen series are.

• A. $0.365\mu m$and $0.565\mu m$
• B. $0.818\mu m$and $1.89\mu m$
• C. $1.45\mu m$and $4.04\mu m$
• D. $2.27\mu m$and $7.43\mu m$

Answer 1

Answer: (B)

$0.818\mu m$and $1.89\mu m$

Answer 2

In Paschen series

$\frac{1}{\lambda_{\max}\left\lbrack \frac{1}{(3)^{2}} - \frac{1}{(4)^{2}} \right\rbrack}$

⇒ ${\lambda\frac{144}{7R}\frac{144}{7 \times 1.1 \times 10^{7}}^{- 6}}_{\max}$

Similarly ${\lambda\frac{9}{R}\frac{9}{1.1 \times 10^{7}}}_{\min}$