Magnetic Fields

Magnetic field

The region around a magnet where a force acts on another magnet or on a magnetic material

Magnetic field line

An imaginary line which indicates the direction of force caused by a magnet

Direction of a magnetic field

From the north (seeking) pole of a magnet to the south (seeking) pole

How magnetic field lines indicate the direction of the field

The field lines have an arrows on them which point from north to south

How magnetic field lines indicate the strength of the field

The closer the lines, the stronger the magnetic field

Where the magnetic field is the strongest

At the poles

Effect of distance on the strength of a magnetic field

The strength of the magnetic field decreases as the distance from the magnet increases

Magnetic field between attracting magnets

The magnetic fields combine to produce a uniform magnetic field

Uniform magnetic field

A magnetic field that has the same strength at every point which is represented by parallel field lines

Magnetic field between repelling magnets

The magnetic fields cancel out

Detecting magnetic fields

A magnetic field is invisible, but it can be detected using a compass

Iron filings

Small pieces of iron used to show the shape of a magnetic field

Plotting compass

Small magnetic compass used to show the shape and direction of a magnetic field

The Earth's magnetic field

A magnetic field produced by the Earth's core, which is made from iron and nickel

How a compass works

The needle of a compass is a small bar magnet that points in the direction of the Earth's magnetic field