Strong Rare-Earth Ring Magnets in Assorted Sizes and Shapes

Electromagnets are used when very strong magnets are required. Electromagnets are produced by placing a metal core (usually an iron alloy) inside a coil of wire that carries an electric current. The electricity in the coil produces a magnetic field. The strength of the electromagnet depends on the strength of the electric current and the number of coils of wire. Its polarity depends on the direction of the current flow. While the current flows, the core behaves like a magnet, but as soon as the current stops, the magnetic properties are lost. Electric motors, televisions, maglev trains, telephones, computers, and many other modern devices use electromagnets.