Electric motor. Internal components of an electric motor from an electric drill, including the coils of wire (centre left), and the rotating shaft (lower right). The external casing is at left. The drill bit fits into the rotating shaft, which is rotated by the electric motor. An electric motor converts electrical energy into mechanical motion, here rotary motion. This motor works on the principles of electromagnetism. The electric current running through the coils forms a magnetic field that rotates a magnet.