plz answer

Asked by tangocharliee | 15th Nov, 2009, 03:10: PM

Expert Answer:

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.


Answered by  | 17th Dec, 2009, 11:48: AM

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