I start the introduction with a question: Will increasing current in an electromagnet increase the power of the electromagnet?.
The electromagnet we will be making is a very primitive one compared to that of the complexity of modern electromagnets found in machinery, but the way it works is almost identical. Electromagnetic technology is extremely complex and because it is an electromagnet, the higher the current, the stronger it becomes, and with this an electromagnet can become incomprehensively strong. Such an example is that used in theme park rides to stop moving parts etc. these electromagnets are in fact so strong that when uncovered, if you were to stand with a spanner in your hand 10 metres away, it would pull the spanner out of your hand along with the rest of your arm! To understand fully how an electromagnet works read on .
When an insulated wire is wrapped around some form of iron, nickel or cobalt core, whether it be a nail or a u-shaped core, and then attached to a power supply it creates an electromagnet capable of picking anything from the size of a paperclip right up to anything as big as a car and bigger! Obviously such a primitive electromagnet would not be able to lift a car but a more advanced one would have no problem lifting a car. When the power supply is cut off the items picked up will fall off. This is because the current creates a magnetic field and this magnetic field is lost when it is turned off.
When a current channels through an electromagnet a magnetic field is produced. This field is built up in a series of concentric rings. The diagram below shows a cross-section of a wire's magnetic field. As you come further away from the wire the field weakens and spreads further apart from each ring.
There are four main factors that affect the strength and size of this field:.
Number of coils.
Size and shape of core.
Material of core (iron being the strongest).