JEE Mains · Physics · STD 12 - 12. atoms
A hydrogen atom changes its state from \(n=3\) to \(\mathrm{n}=2\). Due to recoil, the percentage change in the wave length of emitted light is approximately \(1 \times 10^{-\mathrm{n}}\). The value of \(\mathrm{n}\) is _______. [Given \(\mathrm{Rhc}=13.6 \mathrm{eV}, \mathrm{hc}=1242 \mathrm{eV} \mathrm{nm}\), \(\mathrm{h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}\), mass of the hydrogen atom \(\left.=1.6 \times 10^{-27} \mathrm{~kg}\right]\)
- A \(5\)
- B \(7\)
- C \(9\)
- D \(11\)
Answer & Solution
Correct Answer
(C) \(9\)
Step-by-step Solution
Detailed explanation
\(\Delta \mathrm{E}=13.6\left(\frac{1}{2^2}-\frac{1}{3^2}\right)=1.9 \mathrm{eV}\) \(\Delta \mathrm{E}=\frac{\mathrm{hc}}{\lambda}\) \(\lambda=\frac{\mathrm{hc}}{\Delta \mathrm{E}}\) \(\mathrm{P}_{\mathrm{i}}=\mathrm{P}_{\mathrm{f}}\)…
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