Magnet

Magnet

An object that produces a magnetic field and can attract magnetic materials such as iron

Magnetic material

A material that is attracted to a magnet (e.g. iron, nickel, cobalt)

Magnetic force

A non-contact force that acts between magnets or magnetic materials

Non-contact force

A force that acts at a distance without physical contact

North pole

The north-seeking end of a magnet

South pole

The south-seeking end of a magnet

Like poles

Poles that are the same (N-N or S-S) and repel each other

Unlike poles

Poles that are different (N-S) and attract each other

Repulsion

A force that pushes two magnets apart

Attraction

A force that pulls two magnets together

Testing for a magnet

Repulsion with a known magnet proves an object is a magnet (iron only attracts)

Magnetic field

The region around a magnet where magnetic forces act

Field lines

Lines used to represent a magnetic field

Direction of field lines

From the north pole to the south pole outside the magnet

Spacing of field lines

Shows field strength (closer lines = stronger field)

Uniform magnetic field

A field where lines are parallel and evenly spaced

Plotting compass

A small compass used to show the direction of magnetic field lines

Iron filings

Small pieces of iron used to visualise magnetic field patterns

Earth’s magnetic field

The magnetic field surrounding Earth

Compass

A device with a magnetised needle that shows direction

How a compass works

The needle aligns with Earth’s magnetic field, pointing North-South

Freely suspended magnet

A magnet that can rotate and aligns with Earth’s magnetic field

Magnetic field around a wire

A circular field produced when current flows in a wire

Right-hand grip rule

A method to determine the direction of the magnetic field around a wire

Solenoid

A coil of wire that produces a magnetic field when current flows

Magnetic field of a solenoid

Similar to the field of a bar magnet

Electromagnet

A magnet made by passing current through a coil wrapped around an iron core

Iron core

A material used to increase the strength of an electromagnet

Increasing electromagnet strength

Increase current, increase number of turns, use a better core (e.g. iron)

Switching electromagnets

Can be turned on and off by controlling the current

Advantages of electromagnets

Can be switched on/off and strength can be changed

Disadvantages of electromagnets

Require electrical energy to work

Uses of electromagnets

Scrap yard cranes, maglev trains, electric bells, door locks

Maglev train

A train that uses magnetic repulsion to levitate above the track

Magnetic field pattern of a bar magnet

Field lines curve from north to south

Magnetic field strength

Strongest at the poles of a magnet

Magnetic shielding

Using materials like iron to block magnetic fields

Permanent magnet

A magnet that produces its own magnetic field without electricity

Induced magnetism

When a material becomes temporarily magnetised in a magnetic field