Physics - Modern Physics Question with Solution | TestHub

If$\mathrm{n}$, is the value of excited state, then

number of spectral lines$=\frac{\text{n}\left(\text{n}-1\right)}{2}$

Energy of electron in ground state= – (ionisation energy)$=-\text{13.6} \mathrm{eV}$

Final energy$\text{-13.6+13.056=-0.544 eV}$

If$\mathrm{n}$be the value of excited state, then

$\text{-}\frac{\text{13.6}}{{\mathrm{n}}^2}=-\text{0.544}$

$\Rightarrow {\text{n}}^2=25$

$\Rightarrow \text{n}=5$

Now, the number of spectral lines are

$=\frac{\text{n}\left(\text{n}-1\right)}{2}=\frac{5\times 4}{2}=10\text{ lines}$