Q84 / 120 · VITEEE 2015 · Physics

The angular momentum of an electron in Bohr's hydrogen atom whose energy is $-3.4 \mathrm{eV}$, is

  • A
    $\frac{5 h}{2 \pi}$
  • B
    $\frac{h}{2 \pi}$
  • Correct answer
    C
    $\frac{h}{\pi}$
  • D
    $\frac{2 h}{3 \pi}$

Solution

Energy of electron in nth orbit of hydrogen atom $\begin{aligned} & E_{n}=-\frac{13.6}{n^{2}} \mathrm{eV} \\ \Rightarrow & 3.4=-\frac{13.6}{n^{2}} \Rightarrow n^{2}=4 \end{aligned}$ or, $\mathrm{n}=2$ Angular momentum of electron $\mathrm{L}=\frac{\mathrm{nh}}{2 \pi}=\frac{2 \mathrm{~h}}{2 \pi}=\frac{\mathrm{h}}{\pi}$

Hence, the correct answer is option: 'C'.

Relevant Questions