Re: Magnetism: compare magnetic fields

sci wrote:
> Looking for a direct mathmatical comparison between the magnetic field
> produced by an electronic current (i) and that of a fixed magnet of a
> given strength.

See Biot-Savart Law. Also look up solenoids. A tightly wound solenoid 
has a magnetic field that is exactly like that of a natural bar magnet.

The workings of a magnetic are due to the spin of electrons in the atoms 
of the magnet and the fact that the spins are aligned over large regions 
of the magnet. All magnetism, as far as anybody knows, is do to electric 
charges in motion. No one has ever seen a magnetic monopole.

Bob Kolker