We showed that if we moved the magnet up and down inside the coil, we got a reading on the voltmeter. In this case, south pole into the hole went positive and south pole out went negative. In other words, changing direction of movement makes the voltage flip from positive to negative so we have made AC electricity. It also works if you hold the magnet still but move the coil up and down.
You get the same thing if you move a copper wire up and down between the poles of a powerful horseshoe magnet. We say that there are invisible flux lines going from the north pole to the south pole which make up the magnetic field (it is possible to use iron filings to show them). The copper wire was chosen because it is not a magnetic metal. It cuts down through the flux lines like a cheese wire through cheese. As long as it is MOVING you get a voltage induced. Downwards made a negative voltage and upwards made a positive voltage.
Finally I waved the powerful magnet near the coil. It didn't even have to go into the coil to get an induced voltage. As it moved, the flux lines coming out from it cut through the coil. All of the methods shown are called ELECTROMAGNETIC INDUCTION. They are used in generators and make AC electricity.
The non-essential part is to say that they work by getting the magnetic field to drag electrons along inside the wire. Moving electrons = electric current.
