Magnets

[David HK]

Whilst thinking about magnets and polarisation (North and South poles etc) it occured to me that I can easily understand a rectangular magnet having a N & S pole.

However, how does one sort out the polarisation of a round magnet? Is it on the ring edge, or, each face? Or somewhere else?

Dave

[maker of toys]

Artificial magnets can have any polarization you are willing to pay for.  The ceramic rings that make up the rotors for brushless fans often have 4 or 8 poles, polarized radially.  Speaker magnets (IIRC) are often polarized axially (through the faces)

I recently saw an advertisement for surplus 6" x 1/2" x 1/8" N45 mags.  they were polarized through the 6"x 1/8" faces. . .why, I couldn't tell you. . .

-Dan

[jmk]

 You could buy some of the fluid that they sell at Forcefield, and drop it in it. The fluid will show you.

[Gordy]

Or a cheap compas (for finding your way out of the woods) passed near the magnet will show you where the poles are.

The fluid mentioned will too. But one the cheap wrap the magnet in a layer of celefane ( plastic wrap, for easy cleanup of mag when done) and springkle some iron filings/grindings over and around the magnet.

Gordy

[nothing to lose]

Rubber type fridge magnets are strange, alot of opposite poles all on the same face. Sort of like pin heads poked in to fill the surface and any head could be either S or N poles. The poles are smaller than pin heads of course, probably a magnetic dust randomly molded into a rubber mat or something.

As said, basically you can get anything the way you want to pay for. Spheres, little round magnet balls??? Still wondering what I could use those for.