Physics 9702 · AS & A Level · Electromagnetic induction

Electromagnetic induction — practice question

(a)[2]

Define the term magnetic flux.

(b)

A square wire coil with side length $12\,\text{cm}$ has $8$ insulated turns. It is held stationary in a uniform magnetic field. The coil’s plane is perpendicular to the field, as shown in Fig. 6.1. The flux density $B$ of the field changes with time $t$ as shown in Fig. 6.2.

(b(i))[3]

Determine the magnetic flux linkage in the coil at time $t = 0.60\,\text{s}$. Include a unit in your answer.

(b(ii))[1]

State how Fig. 6.2 shows that the electromotive force (e.m.f.) $E$ induced across the terminals between $t = 0$ and $t = 0.60\,\text{s}$ is constant.

(b(iii))[2]

Calculate the magnitude of $E$.

(c)[3]

The method in (b) is carried out again, but this time the coil terminals are connected together. State and explain what happens to the coil when the terminals are joined during the change in magnetic flux density shown in Fig. 6.2.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: Magnetic flux is the product of flux density and area

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