Magnets are also surrounded by a similar three-dimensional field ... along the lines of magnetic force surrounding the magnet. The simplest generator consists of just a coil of wire and a bar ...

and is often referred to as the generator ... a magnetic field around itself. Note that this magnetic field opposes the original change. For example, if a magnet is moved into a coil of wire ...

Molten iron moving in the core causes the magnetic field. The Earth has north and south magnetic poles. The needle of the compass follows the magnetic field lines. The N pole of the magnet points ...