The south pole is the one that is opposite the north pole. Like magnetic poles repel one another. Unlike genetic poles attract one another. An electromagnet is made up of coils of wire, and must have an external source of current to maintain a magnetic field. A permanent magnet retains its magnetic field indefinitely.
All magnets have an invisible force field , or lines of force, outside themselves.
These lines of force are directed from the north to the south pole of the magnet. A bar magnet has opposite poles at opposite ends. A curved, or horseshoe magnet, has opposite poles on each side of the air gap. A ring magnet has no poles. Magnetic Permeability Magnetic permeability is the ability to concentrate lines of genetic force.