Also aptly named, electromagnet is a type of magnet which the magnetic field is obtained from the electric. The magnetic field is generated when the electrical current is turned on and disappears when the current ceases, that is, electromagnet needs a continuous supply of electrical current to maintain the magnetic field which unlike the permanent magnets. Danish scientist Hans Christian Ørsted first discovered that electric current can generate magnetic field in 1820. British scientist William Sturgeon invented electromagnet by wound electrified wire around the insulating bar in 1824, then United States scientist Joseph Henry further systematically improved and popularized it. A conventional electro-magnets is manufactured by wrapping the conductive wire in tight coils around the ferrous core. Electromagnet has the capacity to attract or hold ferromagnetic materials with varying degrees of force and to release the objects as required. It is widely served as a core component in motors, generators, loudspeakers, and magnetic separation applications.
