Hans Christian Oersted was the first scientist to study electromagnetism. He was a physics professor at the University of Copenhagen. In 1819 he discovered that a magnetic needle is deflected at right angles to a wire carrying an electric current, thus initiating the study of electromagnetism. This discovery, which showed a connection between electricity and magnetism, was followed up by the French scientist André Marie Ampère, who studied the forces between wires carrying electric currents, and by the French physicist Dominique François Jean Arago, who magnetized a piece of iron by placing it near a current-carrying wire. In 1831 the English scientist Michael Faraday discovered that moving a magnet near a wire induces an electric current in that wire, the inverse effect to that found by Oersted: Oersted showed that an electric current creates a magnetic field, while Faraday showed that a magnetic field can be used to create an electric current. The English physicist James Clerk Maxwell, who predicted the existence of electromagnetic waves and identified light as an electromagnetic phenomenon, achieved the full unification of the theories of electricity and magnetism.
             The Briton William Sturgeon invented the first electromagnet in 1823. An electromagnet is a temporary magnet, where the magnetic field only exists when electric current if flowing. An electromagnet is a device consisting of a solenoid (usually a cylindrical coil of insulated wire wound in the form of a helix), in which an iron core is placed. An electric current passed through the coil induces a strong magnetic field along the axis of the helix. When the iron core is placed in this field, microscopic domains that can be considered small permanent magnets in the iron align themselves in the direction of the field, thus increasing greatly the strength of the magnetic field produced by the solenoid. The electric current around the sol
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