Magnetism

Define a magnet (a magnet is…)

A magnet is an object that produces a magnetic field and attracts magnetic materials

Name the magnetic materials (the magnetic materials are…)

The magnetic materials are iron

Define a magnetic field (a magnetic field is…)

A magnetic field is the region where magnetic materials experience a force

State the rule for magnetic field lines (field lines always…)

Field lines always go from north to south outside the magnet

Explain what field line density shows (density shows…)

Field line density shows the strength of the magnetic field

Define an induced magnet (an induced magnet is…)

An induced magnet is a material that becomes magnetic when placed in a magnetic field

Explain why induced magnets only attract (they only attract because…)

They only attract because their domains align to the external field but do not create repulsion

Describe how to plot a magnetic field (you plot it by…)

You plot it by using iron filings or a plotting compass

Define a solenoid (a solenoid is…)

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

Explain how to increase solenoid strength (you increase it by…)

You increase it by adding an iron core

Define an electromagnet (an electromagnet is…)

An electromagnet is a solenoid with an iron core that can be switched on and off

State one advantage of electromagnets (an advantage is…)

An advantage is that their strength can be controlled

State one use of electromagnets (a use is…)

They are used in electric bells

Explain how an electric bell works (it works because…)

Current magnetises the electromagnet

Define the motor effect (the motor effect is…)

The motor effect is when a current‑carrying wire in a magnetic field experiences a force

State the factors affecting motor effect force (the force increases when…)

The force increases when current

Write the equation for motor effect force (the equation is…)

Force = magnetic flux density × current × length

Define magnetic flux density (flux density is…)

Flux density is a measure of the strength of a magnetic field

State Fleming’s left‑hand rule (it shows…)

It shows the direction of force on a current‑carrying conductor

Explain how an electric motor works (it works because…)

Opposite forces on either side of a coil cause rotation

Define a split‑ring commutator (a commutator is…)

A commutator is a device that reverses current direction to keep a motor spinning

Explain how to increase motor speed (you increase speed by…)

You increase speed by increasing current or magnetic field strength

Explain how to reverse motor direction (you reverse it by…)

You reverse it by reversing current or magnetic field direction

Define a loudspeaker (a loudspeaker is…)

A loudspeaker is a device that converts electrical signals into sound using the motor effect

Explain how a loudspeaker works (it works because…)

Alternating current causes a coil to vibrate

Explain why reversing current reverses cone movement (it reverses because…)

The force direction depends on current direction in the magnetic field

Define a permanent magnet (a permanent magnet is…)

A permanent magnet is a magnet that retains its magnetism without current

Explain why solenoids produce uniform fields (they produce uniform fields because…)

The field inside is strong and parallel due to the coil arrangement

Describe the field around a straight wire (the field is…)

The field is circular around the wire and direction depends on current

State the right‑hand grip rule (it states…)

Thumb shows current direction

Explain how circuit breakers use electromagnets (they use them because…)

High current strengthens the electromagnet

Define attraction between magnets (attraction is…)

Attraction is when opposite poles pull towards each other

Define repulsion between magnets (repulsion is…)

Repulsion is when like poles push away from each other

Explain why repulsion is a test for magnetism (it is a test because…)

Only permanent magnets can repel; induced magnets cannot