Quick check · one tap
What is the main difference between an alternator and a dynamo?
Alternator uses slip rings (AC) Alternator is for cars only
Magnetism & Electromagnetism is a core part of GCSE Physics. Revise the key concepts and common mistakes below, then lock them in with the free games.
Key concepts Generator effect Moving a wire in a field induces a voltage
Right-hand rule Used for generators — same fingers, opposite hand
Alternator AC generator — uses slip rings
Dynamo DC generator — uses a split-ring commutator
Transformer Two coils on an iron core that change voltage
Vp/Vs = Np/Ns Voltage ratio equals turns ratio in a transformer
Solenoid Coil of wire — makes a uniform field like a bar magnet
Electromagnet Solenoid with an iron core — magnetism you can switch
Motor effect A current in a magnetic field feels a force
F = B × I × L Force (N) = field (T) × current (A) × length (m)
Left-hand rule Thumb force, first finger field, second finger current
Tesla Unit of magnetic flux density, symbol T
Magnetic pole End of a magnet — north or south
Pole rule Like poles repel, unlike poles attract
Show all 14 key concepts What your exam board covers Where Magnetism & Electromagnetism sits in each exam board's specification. Tap a board to see what it lists.
AQA Magnetism and electromagnetism Spec 8463 Permanent and induced magnetism, magnetic forces and fields The motor effect Induced potential, transformers and the National Grid (physics only) Source: AQA GCSE Physics (8463) specification — Subject content , accessed 23 June 2026.
CCEA 2.4 Magnetism and electromagnetism Spec 1210 Part of: Unit 2 — Waves, light, electricity, magnetism, electromagnetism and space physics
Source: CCEA GCSE Physics (2017) specification , accessed 9 July 2026.
Edexcel Topic 12 — Magnetism and the motor effect Spec 1PH0 Part of: Paper 2 topics
Source: Pearson Edexcel GCSE (9–1) Physics (1PH0) specification , accessed 23 June 2026.
Eduqas/WJEC Magnetism and electromagnetism Spec C420P (QAN 601/8624/0) Permanent and induced magnetism, magnetic forces and fields Magnetic effects of currents and the motor effect Induced potential and transformers Microphones, speakers and oscillating currents Source: Eduqas/WJEC GCSE Physics specification (from 2016) , accessed 24 June 2026.
Edexcel IGCSE Magnetism and electromagnetism Spec 4PH1 (a) Units (b) Magnetism (c) Electromagnetism (d) Electromagnetic induction Source: Pearson Edexcel International GCSE Physics (4PH1) specification , accessed 23 June 2026.
L Learn Magnetism & Electromagnetism step by step
Free interactive mini-lessons: short screens, worked examples and quick checks. Pick your exam board:
Common mistakes to avoid Questions where students often pick the tempting wrong answer — make sure you know the right one:
What is the main difference between an alternator and a dynamo? ✗ Alternator is for cars only ✓ Alternator uses slip rings (AC); dynamo uses a split-ring commutator (DC)
Which change does NOT increase the induced voltage in a coil? ✗ Spinning the coil faster ✓ Using fewer turns of wire
What produces a magnetic field around a wire? ✗ The metal in the wire is naturally magnetic. ✓ A moving electric charge — i.e. an electric current.
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