A magnetic pole on a magnet is the area where the magnetic field lines originate.
A magnetic field line (or line of magnetic flux) is the name for a line of magnetic force that a magnet emanates.
There are two types of magnetic poles: the north pole and the south pole. These magnetic poles are attracted to the magnetic north and south poles of the earth, hence why they can be used as a compass.
The point on a magnet where the north pole meets the south pole is known as the magnet’s magnetic axis.
Magnetic field of a magnet
A magnetic field fills the space around a magnet in an invisible dome of magnetic field lines, inside and outside of the magnet, travelling from the north pole to the south pole.
The magnetic field is the part of a magnet which allows the attraction and repulsion of ferromagnetic materials.
By attaching a ferromagnetic material to a magnet, a closed circuit is formed by the magnetic field travelling from the north pole, through the ferromagnetic material, and then to the south pole, holding them together.
The shape and size of a magnetic field changes with every magnet, as each type is unique. The shape of the magnetic field is determined by the route the magnetic field lines take from the north to the south pole, whereas the size is determined by the overall strength of the magnet.
The shape of a magnetic field determines the area around the magnet that can attract ferromagnetic materials. For example, a pot magnet can only pick up ferromagnetic material from its base as this is the only area where the magnetic field protrudes out of the casing.
Whereas a bar magnet, on the other hand, which has a magnetic field all around it, can attract ferromagnetic materials from any direction.
A magnetic field cannot be blocked in any way as it is a continuous circuit. However, magnetic fields can be redirected with the use of ferromagnetic materials. This method is referred to as ‘using a keeper’.
For more information on a magnetic keeper, see the Magnets glossary