(3) An electromagnet is a coil of wire wound around an iron core. Electromagnets are used in electric bells. When the current flows through the circuit, the electromagnet makes a magnetic field. The electromagnet attracts the springy metal arm. The arm hits the gong, which makes a sound. The circuit is broken now and the arm is out of position. The electromagnet is turned off and the springy metal arm moves back. The circuit is complete again.