H2 Physics 9478 · Topic 16
Electromagnetic induction: flux, laws and transformers
Define the linked quantity before taking its rate of change, use Lenz's law as an energy-consistent direction rule, and keep simple applications and ideal-transformer ratios within their stated assumptions.
Before you begin
Study each reviewed objective cluster, then use the recorded diagnostic and repair plan. H2 practice evidence remains separate from H1 and H3.
Be comfortable with: Electromagnetic Forces objective chainCurrent Electricity objective chain
How the ideas connect
- Magnetic flux and flux linkage
- Induction experiments, Faraday's law and Lenz's law
- Simple applications of electromagnetic induction
- Simple iron-core ideal transformers
Learn in order
Lesson route
Objective clusters
- 01Magnetic flux and flux linkage 18(a)–(c)Learn and apply 3 reviewed syllabus outcomes in one coherent cluster.
- 02Induction experiments, Faraday's law and Lenz's law 18(d)–(e)Learn and apply 2 reviewed syllabus outcomes in one coherent cluster.
- 03Simple applications of electromagnetic induction 18(f)Learn and apply 1 reviewed syllabus outcomes in one coherent cluster.
- 04Simple iron-core ideal transformers 18(g)Learn and apply 1 reviewed syllabus outcomes in one coherent cluster.
Prove your understanding
Practice and repair
Key ideas and reference
Use this concise Electromagnetic induction: flux, laws and transformers checklist to locate the right objective cluster. Full definitions, derivations and worked examples stay in the linked lessons.
- Define the linked quantity before taking its rate of change, use Lenz's law as an energy-consistent direction rule, and keep simple applications and ideal-transformer ratios within their stated assumptions.
- Magnetic flux and flux linkage 18(a)–(c)
- Induction experiments, Faraday's law and Lenz's law 18(d)–(e)
- Simple applications of electromagnetic induction 18(f)
- Simple iron-core ideal transformers 18(g)
Course coverage and review details
Topic 18 states no explicit exclusions. Flux uses area perpendicular to B; flux linkage is NΦ for N linked turns. Faraday's law uses the rate of change of linkage and Lenz's law fixes polarity relative to an explicit sign convention. The simple Blv motional-e.m.f. form requires mutually perpendicular conductor length, velocity and uniform field. Ideal transformer ratios assume common linked flux, alternating operation and no winding or core losses. AL-EMI-05 enrichment applications remain outside this official chain.
Coverage is reviewed against 9478 topic 18(a)–(g), PDF page 27. Selected-response progress does not by itself prove constructed, diagrammatic or practical performance.
Reviewed 2026-08-01