Field of a rotating magnet

1. May 8, 2012

StephenD420

Hello everyone,

I have a quick concept question for electrodynamics course. If a cylindrical magnet, axially magnetized, is rotated round its own central axis, axis of symmetry, will this create a rotating magnetic field in the vicinity of the magnet? what if the magnet was rotated around in space instead of around its axis of symmetry, would this create a rotating magnetic field? Or would a diamagnetized magnet work better?

Thanks.
Stephen

2. May 8, 2012

Staff: Mentor

Is there a difference between being rotated around it's axis and being rotated in space?

3. May 8, 2012

StephenD420

Yes say the cylindrical magnet center is positioned at (1,1,1) then when the magnet rotates around its axis it rotates with the center never leaving (1,1,1) but when the magnet rotates in space it would rotate around (0,0,0), so it would go from (1,1,1) to (-1,1,1) to (-1,-1,-1) to (-1,-1,0) and so on... so yes it is different...

thanks.
Stephen

4. May 9, 2012

bump....

5. May 9, 2012

Staff: Mentor

Based on your current knowledge of magnetics, what do you think? Remember that you are in the homework section, so please use the template and show the applicable equations and your own work if possible.

6. May 9, 2012

StephenD420

This is a concept question as I stated in my first post.

For the equations there are the maxwells eqs:
div E = rho/e0
div B= 0
curl E = -dB/dt
curl B = u0*I + u0e0*dE/dt

I created a simulation using Comsol and the flux lines, the vector potental, did rotate, but the vector potentials are just mathematical constructs, not real, so does the real physical magnetic field rotate?

Thanks
Stephen