Electromagnetism describes the relationship between electricity and magnetism. Nearly everyone, at some time or another, has had the opportunity to play with magnets. Most of us are acquainted with bar magnets or those thin magnets that usually end up on refrigerators. These magnets are known as permanent magnets. Although permanent magnets receive a lot of exposure, we use and depend on electromagnets much more in our everyday lives. Electromagnetism is essentially the foundation for all of electrical engineering. We use electromagnets to generate electricity, store memory on our computers, generate pictures on a television screen, diagnose illnesses, and in just about every other aspect of our lives that depends on electricity.
Electromagnetism works on the principle that an electric current through a wire generates a magnetic field. This magnetic field is the same force that makes metal objects stick to permanent magnets. In a bar magnet, the magnetic field runs from the north to the south pole. In a wire, the magnetic field forms around the wire. If we wrap that wire around a metal object, we can often magnetize that object. In this way, we can create an electromagnet.
Experiments Involving Electromagnetism
In order to find out more about electromagnetism, and do an experiment of your own, click on one of the pictures below. Try making your own:
Using Electromagnetism in Medicine
Find out how doctors use electromagnets in Magnetic Resonance Imaging (MRI) to help diagnose illnesses.