Why does a coil spin when current runs through it in a magnetic field?

[KingNothing]

Hey all, we are doing a unit in magnetism right now in school...some of it really baffles me. like why a metal coil when induced with a current and placed over a magnet will spin.

And another thing I don't get is: If you take a magents with a N and S end, and cut it in half, you get two magnets with N and S ends. What's up with that?

 

[Jdo300]

Ok I can answer the part about cutting the magnet in half for you. If you look at a magnet down at the microscopic level, it is made up of lots of little parts called magnetic domains. The orientations of these domains are what determine the direction of the poles of the magnet. For instance, in a normal hunk of metal, all the domains in it are randomly oriented so the metal doesn't have a north or south pole. But in magnetized permanent magnets, all the magnetic domains are pointing in one direction. So if you take the magnet and cut it in half, you've essentially just made two separate magnets with their own north and South Pole. It's the little domains that determine the polarity, not the magnet as a whole. So, if you're wondering why there is not such a thing as a one polled magnet, the reason why is because of the domains that make up the magnet, they are each tiny magnets with north and south poles themselves. Now as far as the electromagnet coil you were talking about, could you elaborate on what you were doing with it?