1. Electromagnetism

2. Imagine a world without Talking on a telephone Watching TV Listening to a radio or CD Not being able to use anything that plugs into a socket

3. Hans Christian Oersted In 1820 he was doing a demonstration using electric current. As he passed current through a wire, a compass needle deflected. He discovered that magnetism is related to electricity.

4. Generators and Motors Phone has both generator and motor Mouthpiece has generator to convert motion of voice into electrical impulse Earpiece has motor to convert electrical energy into mechanical motion of the speaker. Both contain magnets and electromagnetic devices.