12.3 What is the shortest wavelength present in the Paschen series of spectral lines?

Hint: Use the Rydberg's formula.

Step 1: Write an expression for the Rydberg's formula.
Rydberg's formula is given as,
$\frac{hc}{\lambda }=21.78×{10}^{-19}\left[\frac{1}{{n}_{1}^{2}}-\frac{1}{{n}_{2}^{2}}\right]$
where,
h=Planck's constant $=6.62×{\mathit{10}}^{\mathit{-}\mathit{34}}\mathit{}\mathit{}\mathit{J-sec}$ and c =  speed of light =$3×{10}^{8}m/s$

Step 2: Find the value of n1 and n2 for shortest wavelength in Paschen series.
The shortest wavelength present in the Paschen series of the
spectral lines is given for values,

Step 3: Find the shortest wavelength in Paschen series.