Magnetic Effects Of Current Question 424
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) Zero
B) $ \frac{{\mu_{0}}n^{2}e}{r} $
C) $ \frac{{\mu_{0}}ne}{2r} $
D) $ \frac{{\mu_{0}}ne}{2\pi r} $
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Answer:
Correct Answer: C
Solution:
[c] Radius of circular orbit = r No. of rotations per second = n i.e., $ T=\frac{1}{n} $ Magnetic field at its centre, $ B_{c}=? $ As we know, current $ i=\frac{e}{T}=\frac{e}{(1/n)}=en= $ equivalent current Magnetic field at the centre of circular orbit, $ B_{c}=\frac{{\mu_{0}}i}{2r}=\frac{{\mu_{0}}ne}{2r}. $
BETA
