Home - Education Resources - Science of NDT - Magnetism


After reading this section you will be able to do the following:

  • Define a magnetic field and explain how it is created.



  1. In the previous experiment you saw how the electron spins and travels around the nucleus of an atom. What does that cause to happen?

What is a magnetic field and how is it created?

A magnetic field describes a volume of space where there is a change in energy. Later, you will see a simple way to detect a magnetic field with a compass. As Ampere suggested, a magnetic field is produced whenever an electrical charge is in motion. The spinning and orbiting of the nucleus of an atom produces a magnetic field as does electrical current flowing through a wire. The direction of the spin and orbit determine the direction of the magnetic field. The strength of this field is called the magnetic moment.

The motion of an electric charge producing a magnetic field is an essential concept in understanding magnetism. The magnetic moment of an atom can be the result of the electron's spin, which is the electron orbital motion and a change in the orbital motion of the electrons caused by an applied magnetic field.