(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Disk of radius S has uniform charge Q on surface. Roates with angular velocity w = w z(^) about symmerty axis Z. I am asked to find magnetic field (I believe I have that answer though it's messy and maybe wrong) vector potential (of which I have no idea) and the torque on a magnet with magnetic dipole m = m s(^) place in the equitorial plane at a distance s from the center of the disk.

2. Relevant equations

???

3. The attempt at a solution

The first part I have NO idea on.

For the second part, torque = mXB

m = Iarea = I*pi*S^2

But where does the distance s go? Thank you!

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# Homework Help: Magnetic torque/vector potential

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