Given the value of Rydberg constant is 10⁷ m^-1, the wave number of the last line of the Balmer series in hydrogen spectrum will be [NEET 2016]

Given, Rydberg constant,   $R={10}^7{ \mathrm{m}}^{-1}$

For last line in Balmer series,  $n_2=\infty ,n_1=2$

As we know that,

$\frac{1}{\lambda }=R\left(\frac{1}{n_1^2}-\frac{1}{n_2^2}\right)$

$\Rightarrow \frac{1}{\lambda }={10}^7\left(\frac{1}{2^2}-\frac{1}{\infty }\right)$

$v=\frac{1}{\lambda }=\frac{{10}^7}{4}=0.25\times {10}^7{ \mathrm{m}}^{-1}$