Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Using Bohr's model, the orbital period of electron in hydrogen atom in $\mathrm{n}^{\text {th }}$ orbit is $\left(\epsilon_{0}=\right.$ permittivity of free space, $\mathrm{h}=$ Planck's constant, $\mathrm{m}=$ mass of electron,
$\mathrm{e}=$ electronic charge $)$
PhysicsAtomic PhysicsMHT CETMHT CET 2020 (19 Oct Shift 2)
Options:
  • A $\frac{8 \epsilon_{0}^{2} \mathrm{n}^{3} \mathrm{~h}^{3}}{\mathrm{me}^{4}}$
  • B $\frac{2 \epsilon_{0}^{2} \mathrm{n}^{3} \mathrm{~h}^{3}}{\mathrm{~m} \mathrm{e}^{4}}$
  • C $\frac{2 \varepsilon_{0} \mathrm{n}^{2} \mathrm{~h}^{2}}{\mathrm{me}^{4}}$
  • D $\frac{4 \epsilon_{0}^{2} \mathrm{n}^{3} \mathrm{~h}^{3}}{\mathrm{me}^{4}}$
Solution:
1191 Upvotes Verified Answer
The correct answer is: $\frac{4 \epsilon_{0}^{2} \mathrm{n}^{3} \mathrm{~h}^{3}}{\mathrm{me}^{4}}$
(B)
$\begin{array}{l}
\mathrm{T}=\frac{2 \pi \mathrm{r}}{\mathrm{V}} ; \quad \mathrm{r}=\frac{\mathrm{n}^{2} \mathrm{~h}^{2} \epsilon_{0}}{\pi \mathrm{h} \mathrm{e}^{2}} \\
\mathrm{~V}=\frac{\mathrm{e}^{2}}{2 \pi \epsilon_{\mathrm{o}} \mathrm{n}}
\end{array}$
putting the values of $\mathrm{V}$ and $\mathrm{r}$,
$T=\frac{4 \epsilon_{0}{ }^{2} \mathrm{n}^{3} \mathrm{~h}^{3}}{\mathrm{me}^{4}}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.