Physics 9702 · AS & A Level · Electromagnetic induction

Electromagnetic induction — practice question

(a)[2]

State the principle known as Lenz’s law.

(b(i)1)[1]

Fig. 7.1 shows a simple transformer with a soft-iron core. Explain why iron is used for the core.

(b(i)2)[2]

Fig. 7.1 shows a simple transformer with a soft-iron core. Explain why the core is laminated.

(b(ii))[4]

An e.m.f. is induced in the secondary coil of the transformer. Explain how the current in the primary coil leads to this induced e.m.f.

(b)

Fig. 7.1 shows a simple transformer with a soft-iron core.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: The induced e.m.f./current acts so as to oppose the change that produces it

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