What mistakes do students make with Electromagnetism?

Saying the core increases the current in the coil, rather than increasing the magnetic field strength. Choosing steel, nickel, or cobalt for the core. AQA specifically requires iron for electromagnets. Claiming the core stores the magnetism so the electromagnet stays on after the current stops, instead of demagnetising.

What are the exam tips for Electromagnetism in Physics AQA GCSE?

Core questions want the specific material (iron) and the reason; the reason mark usually depends on the material mark. Write both halves of the reason: easily magnetised and easily demagnetised.

AQA · GCSE · Physics

Course version: 8463 · Version from Sept 2016

Adding an iron core increases the strength of the magnetic field of a…

Full specification wording

Electromagnetism: Adding an iron core increases the strength of the magnetic field of a solenoid.

Slide an iron core inside a solenoid and the magnetic field gets much stronger for the same current.

Checked against the AQA 8463 specification (opens in a new tab) on 22 September 2026.

Point 6 of 9

Study notes

From the checked teaching notes for this specification point.

The idea

What earns the marks

Stating that adding an iron core increases the strength of the magnetic field.
Stating that removing the core makes the field weaker at the same current.
Explaining that the core becomes an induced magnet so its field adds to that of the coil.
Justifying iron as the material because it is easily magnetised and demagnetised.

Common mistakes and how to put them right

Saying the core increases the current in the coil, rather than increasing the magnetic field strength.
Choosing steel, nickel, or cobalt for the core.
Put it right: AQA specifically requires iron for electromagnets.
Claiming the core stores the magnetism so the electromagnet stays on after the current stops, instead of demagnetising.
Giving only 'easily magnetised' and leaving out 'and easily demagnetised' when explaining the choice of iron.

Exam tips

Core questions want the specific material (iron) and the reason; the reason mark usually depends on the material mark.
Write both halves of the reason: easily magnetised and easily demagnetised.

Try the lesson

The start of the Electromagnetism: Adding an iron core increases the strength of the magnetic field of a solenoid. lesson, made from checked teaching notes for this specification point.

Have a go first

What happens to the magnetic field of a solenoid when an iron core is placed inside it?

Tip: press 1 to 4 to choose

Listen

Slide an iron core inside a solenoid and the magnetic field gets much stronger for the same current. The core sits in the coil's field and becomes an induced magnet, so its own field adds to the coil's and the total field outside is far greater. Take the core out and the field is weaker again. Iron is the required material because it is magnetically soft: it is easily magnetised and easily demagnetised. This means it strengthens the field while the current flows and loses its magnetism the moment the current stops. Steel is rejected because it is magnetically hard and keeps its magnetism, leaving the electromagnet permanently on. A strong answer earns marks for these points. stating that adding an iron core increases the strength of the magnetic field. stating that removing the core makes the field weaker at the same current. explaining that the core becomes an induced magnet so its field adds to that of the coil. justifying iron as the material because it is easily magnetised and demagnetised. Exam tip: Core questions want the specific material (iron) and the reason; the reason mark usually depends on the material mark.

See it

A top-down flowchart. The top node, 'Iron core inside solenoid', leads to two branches. The first branch goes to 'Core becomes an induced magnet', then to 'Core's field adds to coil's field', then to 'Total field outside far greater'. The second branch goes to 'Iron is magnetically soft', then to 'Easily magnetised and easily demagnetised', which splits into 'Field strengthens while current flows' and 'Loses magnetism when current stops'. Separately, 'Remove the core' leads to 'Field weaker again at same current'. Another separate chain runs from 'Steel is magnetically hard' to 'Keeps its magnetism, leaving electromagnet permanently on'. — Shows how an iron core strengthens a solenoid's field through induced magnetism, why iron is chosen over steel, and what happens when the core is removed.

Label the diagram

Some boxes have lost their names. Pick the right name for each number.

The diagram again, with 3 boxes numbered instead of named. A top-down flowchart. The top node, 'Iron core inside solenoid', leads to two branches. The first branch goes to 'Core becomes an induced magnet', then to 'Core's field adds to coil's field', then to 'Total field outside far greater'. The second branch goes to 'Iron is magnetically soft', then to 'Easily magnetised and easily demagnetised', which splits into 'Field strengthens while current flows' and 'Loses magnetism when current stops'. Separately, 'Remove the core' leads to 'Field weaker again at same current'. Another separate chain runs from 'Steel is magnetically hard' to 'Keeps its magnetism, leaving electromagnet permanently on'.

1Box 1
2Box 2
3Box 3

0 of 3 labelled

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