Magnetism (Revision)

Ferromagnatic Material

A magnet can attract certain type of metal.

The metals that can be attracted by a magnet are called the “magnetic materials” of “ferromagnetic materials”. Examples of magnetic materials are iron, steel, nickel and cobalt

Magnetic Field

A magnetic field is a region in the surrounding of a magnet which a magnetic material experiences a detectable force.

Magnetic Field Line

The magnetic filed of a magnet is represented by the magnetic field line.

The closer the field line, the stronger the field. Magnetic field A is stronger than magnetic field B because the line in magnetic field A is closer.

The magnetic field line flowing out from the North pole and flowing into the South pole.

Compass in a magnetic Field

The pointer of the compass is always in the direction of the magnetic field.

If a compass is placed near to a current carrying wire, the pointer of the compass will point along the direction of the magnetic field generated by the current.