a soft metal core made into a magnet by the passage of electric current through a coil surrounding it. The strength of an electromagnet can be changed simply by changing the electricity that flows through it. The poles are able to be reversed by reversing the flow of electricity. Electromagnets work because of an electric current creating or producing a magnetic field. William Sturgeon invented an electromagnet using a horseshoe-shaped piece of iron that was wrapped with a loosely wound coil of several turns. Electromagnets are used in every day life, some such as radios, lights and even the microwave.