How Do Electric-magnets Work?

This is a little complex explanation but I guess it's a complex subject:

Inductance
 
From Wikipedia, the free encyclopedia
   

 

Inductance is that property in an electrical circuit where a change in the current flowing through that circuit induces an electromotive force (EMF) that opposes the change in current (See Induced EMF).
In electrical circuits, any electric current I produces a magnetic field and hence generates a total magnetic flux Φ acting on the circuit. This magnetic flux, due to Lenz's law tends to act to oppose changes in the flux by generating a voltage (a back EMF) that counters or tends to reduce the rate of change in the current. The ratio of the magnetic flux to the current is called the self-inductance which is usually simply referred to as the inductance of the circuit. The term 'inductance' was coined by Oliver Heaviside in February 1886.^[1] It is customary to use the symbol L for inductance, possibly in honour of the physicist Heinrich Lenz.^{[2] [3]}
In honour of Joseph Henry, the unit of inductance has been given the name henry (H): 1H = 1Wb/

     
//

Electric-magnets or electromagnets as they are otherwise called- function on a very basic principle- that is by running some electric current through a piece of wire so that you create a magnetic field. Based on this simple idea all kinds of things like solenoids, motors, heads for tape drives and hard disks and many other things can be created.

An electric-magnet basically starts with some source of power or a battery and a wire. TH e battery basically produces electrons. There are two ends in the battery- one will be marked plus and the other end is marked minus. The electrons will collect at the negative end and they can be permitted to flow to the positive end. You can do this with the help of a wire. The electrons will flow as soon as possible. Normally the battery will drain pretty fast. Usually a load is connected to the middle to help the electrons do some work. TH load can be a radio, light bulb or whatever. Ultimately a magnetic field is created in the wire. This field is the basis of an electric-magnet.