Q106 / 120 · VITEEE 2012 · Physics
If hydrogen atom is its ground state absorbs, $10.2 \mathrm{eV}$ of energy. The orbital angularmomentum is increase by
- Correct answerA$1.05 \times 10^{-34} \mathrm{~J} / \mathrm{s}$
- B$3.16 \times 10^{-34} \mathrm{~J} / \mathrm{s}$
- C$2.11 \times 10^{-34} \mathrm{~J} / \mathrm{s}$
- D$4.22 \times 10^{-34} \mathrm{~J} / \mathrm{s}$
Solution
Electron goes to its first excited state $(\mathrm{n}=2)$ from ground state $(\mathrm{n}=1)$ after absorbing $10.2 \mathrm{eV}$ energy
$$
\begin{array}{l}
\therefore \text { Increase in momentum }=\frac{\mathrm{h}}{2 \pi} \\
=\frac{6.6 \times 10^{-34}}{6.28} \\
=1.05 \times 10^{-34} \mathrm{~J}-\mathrm{S}
\end{array}
$$
Hence, the correct answer is option: 'A'.