Neet Solved Paper 2015 Question 32
Question: An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field produced at the centre has magnitude
Options:
A) $ \frac{{\mu _0}ne}{2\pi r} $
B) zero
C) $ \frac{{\mu _0}n^{2}e}{r} $
D) $ \frac{{\mu _0}ne}{2r} $
Show Answer
Answer:
Correct Answer: D
Solution:
As $ I=\frac{q}{t} $ So, for an electron revolving in a circular orbit of radius r q = e and t = T
$ \Rightarrow \ I=\frac{e}{T}=\frac{e}{2\pi /\omega }=\frac{\omega e}{2\pi }=\frac{2\pi ne}{2\pi }=ne $
The magnetic field produced at the centre is $ B=\frac{{\mu _0}I}{2R}=\frac{{\mu _0}ne}{2r} $
