If an electron is doing n revolutions per second then we can say the current is,
i=Tq=Tewe know thatT=n1.
⇒i=Te=ne
Now, magnetic field at the center of a circular loop is
B=2rμ0i=2rμ0ne
An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field produced at the center has magnitude:
Held on 30 Apr 2015 · Verified 9 Jul 2026.
2πrμ0ne
Zero
rμ0n2e
2rμ0ne
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