Induction

An emf is induced when the magnetic field in a coil is changed by pushing a bar magnet into or out of the coil. emfs of opposite signs are produced by motion in opposite directions, and the directions of emfs are also reversed by reversing poles. The same results are produced if the coil is moved rather than the magnet—it is the relative motion ...

Electromagnetic induction is produced when an electrically conducting material is exposed to a time-varying magnetic field.

For example, consider a bar magnet placed close to a coil. The galvanometer connected to this coil shows zero current passing through it.

If the bar magnet moves toward the coil, a current flows through the co...