Magnetic Fields

Magnetic Field

The region around a magnetic where a force acts on a magnetic material is called the magnetic field.

Magnetic materials are either:

  1. Iron
  2. Steel
  3. Nickel
  4. Cobalt

The force between a magnet and a magnetic material is always an attractive force.

The magnetic field looks like this:

Magnetic Fields, figure 1

Yes, you might be asked to draw it - don’t forget to put in the arrows! Notice how the field comes out of the north and into the south.

Strength of the Magnetic Field

The strength of the field is strongest at the poles of the magnet. The further away from the poles, the weaker the field and the weaker the force.

Compasses

A compass contains a small bar magnet. The Earth has a magnetic field around it.

The needle of a compass points in the direction of Earth’s magnetic field. This provides evidence that the Earth’s core is made up of a magnetic material.

We can use this knowledge to be able to use a compass to plot the magnetic field around a magnet:

Magnetic Fields, figure 1

One can the plot the points of the compass to draw out the magnetic field.

The closer to the pole of a magnet the stronger/weaker the field.
Stronger