An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole in the center of the coil. The magnetic field disappears when the current is turned off. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet.
Closeup of a large Henry electromagnet
Industrial electromagnet lifting scrap iron, 1914
Laboratory electromagnet. Produces 2 T field with 20 A current.
Magnet in a mass spectrometer
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.
A magnetite rock is being pulled by a neodymium magnet on top.
Hard disk drives record data on a thin magnetic coating
Magnetic hand separator for heavy minerals
Magnets have many uses in toys. M-tic uses magnetic rods connected to metal spheres for construction.