Electromagnetic Induction

If the wire is then wound into a coil, the magnetic field is greatly                       intensified producing a static magnetic field around itself forming the                shape of a bar magnet giving a distinct North and South pole.
 * Electromagnetic induction is the production of an electromotive force across an electrical conductor in a changing magnetic field

The magnetic flux developed around the coil being proportional to the             amount of current flowing in the coils windings as shown.
 * Electromagnetic Induction by a Moving Magnet

If the magnet is now held stationary and ONLY the coil is moved towards or away from the magnet the needle of the galvanometer will also deflect in either direction. Then the action of moving a coil or loop of wire through a magnetic field induces a voltage in the coil with the magnitude of this induced voltage being proportional to the speed or velocity of the movement.

Then we can see that the faster the movement of the magnetic field the greater will be the induced emf or voltage in the coil, so for Faraday’s law to hold true there must be “relative motion” or movement between the coil and the magnetic field and either the magnetic field, the coil or both can move. Equation for Faraday's law: E: e.m.f induced across the coil Equation for Lenz's law:
 * Faraday's law: Any change in the magnetic environment of a coil of wire will cause a voltage (e.m.f) to be induced in the coil. No matter how the change is produced, the voltage(e.m.f) will be generated. The change could be produced by changing the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out of the magnetic field, rotating the coil relative to the magnet, etc.
 * Lenz's law: When an emf is generated by a change in magnetic flux according to Faraday's Law, the polarity of the induced emf is such that it produces a current whose magnetic field opposes the change which produces it.