DVD drive motor. Coloured scanning electron micrograph (SEM) of the electric motor from a computer DVD disk drive. The turntable has been removed to show the interior. The central hole contains the spindle on which the turntable turns. Around the hole are 6 small electromagnets, composed of copper wire (yellow) wound around metal bars. These electromagnets are fed with current, which generates a magnetic field. This interacts with permanent magnets on the turntable (not seen), causing it to spin at a constant speed. Magnification: x10 when printed 10 centimetres wide.