Topic 6 – Magnetism

Magnetic Poles

All magnets have a north pole and a south pole

Magnetic Attraction

Opposite magnetic poles attract and like poles repel

Magnetic Field Lines

Magnetic field lines show the direction and strength of a magnetic field

Permanent Magnet

A permanent magnet remains magnetised without an external field

Induced Magnet

An induced magnet loses magnetism when removed from a magnetic field

Electromagnet

An electromagnet is produced when current flows through a coil of wire

Electromagnet Strength

The strength of an electromagnet increases with current turns and an iron core

Motor Effect

A force acts on a current carrying conductor in a magnetic field

Fleming Left Hand Rule

Fleming’s left hand rule predicts the direction of force motion and current

DC Motor Purpose

A DC motor converts electrical energy into kinetic energy

Split Ring Commutator

The split ring commutator allows continuous rotation in a motor

Uses of Electromagnets

Electromagnets are used in cranes relays and electric bells

Force on Wire Factors

The force depends on current magnetic field strength and direction

Magnetic Flux Density

Stronger magnetic fields produce greater forces

Motor Applications

Electric motors are used in fans drills and electric vehicles