What Do Magnets Do?
- They attract certain materials eg
iron
steel
nickel
cobalt
- Magnetic materials are attracted to the poles of the magnet.
On a bar magnet the poles are at either end of the magnet. Poles occur
in pairs of equal strength.
- One pole - North seeking pole - N pole- pointing roughly to the Earth's
North pole.
Other pole - South - S pole
Unlike poles attract
- Force between magnetic poles decreases as their separation increases.
Test for a Magnet
A permanent magnet causes repulsion with one pole when the poles are brought
in turn near a suspended magnet.
An unmagnetised magnet material would be attracted to both poles.
Repulsion is the only sure test for a magnet
- Magnetism can work over a distance and magnets can exert a force (push or
pull) on objects without making contact with them.
Just think about the effect of the Earth's magnetic field on a compass
needle.
Contents
History of magnetism, What is a magnet
Magnetic fields
The Earth's magnetic field
Theory of magnetism
Induced magnetism
Magnetic properties of iron and steel
Storing magnets
Making a magnet
Electro-magnets
Primary science applications
Fleming's Left Hand Rule
Self assessment
Comments, reflections and study action plan