Physics - Modern Physics Question with Solution | TestHub

For Balmer series,$n_f=2$and$n_i=3,4,5....$

Frequency, of 1st spectral line of Balmer series

$f$$=$$R{Z}^2 c\left(\frac{1}{2^2}-\frac{1}{3^2}\right)$

or$f=R{Z}^2 c\times \frac{5}{36}$...(i)

Frequency, of 2nd spectral line of Balmer series

$f’ =$$R{Z}^2 c\left(\frac{1}{2^2}-\frac{1}{4^2}\right)$

or$f\prime =R{Z}^2 c\times \frac{3}{16}$....(ii)

From equation. (i) and (ii), we have

$\frac{f}{f\prime }$$=\frac{20}{27}$

$\therefore f^{\prime }=\frac{27}{20} f=1.35 f$