Physics 5054 · O Level · Forces on a current-carrying conductor

Forces on a current-carrying conductor — practice question

Fig. 6.1 illustrates the arrangement of a basic electric motor. As current passes through the coil, the coil begins to rotate. A student sees that the coil moves in the direction indicated by the curved arrow in Fig. 6.1.
(a(i))[1]

State what happens to the motor if a stronger magnet is used.

(a(ii))[1]

On Fig. 6.1 mark and label: • the current direction in the coil • the direction of the magnetic field.

(a(iii))[2]

Explain why the coil rotates.

(b(i))[3]

On Fig. 6.3 sketch the shape of the magnetic field produced. Show the direction of the magnetic field on the pattern you draw.

(b(ii))[2]

The currents in the two wires make the wires push apart. Explain how the current in one wire produces a force on the other wire.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Spins faster / stronger force / more powerful motor / larger turning effect

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