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
An electron in a circular orbit of radius $0.05 \mathrm{~nm}$ performs $10^{16}$ revolution/second. What is the magnetic moment due to the rotation of electron? $\left(\mathrm{e}=1.6 \times 10^{-19} \mathrm{C}\right)$
PhysicsMagnetic Effects of CurrentMHT CETMHT CET 2021 (24 Sep Shift 1)
Options:
  • A $3.21 \times 10^{-23}$
  • B $2.16 \times 10^{-23}$
  • C $3.21 \times 10^{-22}$
  • D $1.26 \times 10^{-23}$
Solution:
1246 Upvotes Verified Answer
The correct answer is: $1.26 \times 10^{-23}$
$\begin{aligned} & \mathrm{r}=0.05 \mathrm{~nm}=0.05 \times 10^{-9} \mathrm{~m}=5 \times 10^{-11} \mathrm{~m} \\ & \mathrm{f}=10^{16} \mathrm{r} \cdot \mathrm{p} . \mathrm{s} \\ & \mathrm{M}=\mathrm{IA}=\mathrm{ef} \pi \mathrm{r}^2 \\ & =1.6 \times 10^{-19} \times 10^{16} \times 3.14 \times\left(5 \times 10^{-11}\right)^2 \\ & =1.26 \times 10^{-23} \mathrm{~A}-\mathrm{m}^2\end{aligned}$

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.