CBSE Class 12-science Answered
Hi dear,
A non conducting magnet indicates the magnet is not an electro-magnet. For example, ceramic is a non conducting magent. An electro-magent is one which becomes a magnet when current flows through it.
A charged disc rotating at constnt angular velocity is equivalent to a steady current in circular wire. We need to calculate this current to find the magnetic field. Let us consider any one cross-section of the wire and all charges must pass through this crosssection in one time period of revolution.
Hence current is:
I = q/T = q (ω / 2π)
Magnetic field due to steady current in a circular wire is:
B = µoI / 2R
Substituting for current , we have,
B = µoqω / 4πR
Hope this helped.
Regards
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