Video narration
What happens when a magnet and a wire move relative to each other? A bicycle dynamo gives a clue: as the wheel turns, a lamp glows. But there's no battery. Michael Faraday found that a changing magnetic field through a conductor produces an induced current. A galvanometer detects this current by the movement of its pointer. Move the magnet one way, and the pointer deflects. Reverse the motion, and the current reverses, so the pointer swings the other way. Now hold everything still. The pointer returns toward zero, because the magnetic field is no longer changing. You can also create a change by switching current on or off in a nearby coil. So a magnet does not make electricity just by being nearby. The key is change. Yes-when the magnetic field through a conductor changes, it induces a current. That is electromagnetic induction.