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4.5.5 The d.c. motor

A simple d.c. motor consists of a coil positioned between magnetic poles. A split-ring commutator connects the d.c. power supply to the coil.

What is the function of the split-ring commutator in this motor?

It reverses the direction of the external magnetic field every half-turn ( $180∘180^\circ$ ) of the coil.

It reverses the direction of the current in the coil every half-turn ( $180∘180^\circ$ ) to ensure continuous rotation in the same direction.

It converts direct current (d.c.) from the supply into high-frequency alternating current (a.c.) to increase the motor's speed.

It disconnects the current permanently once the coil reaches its maximum rotational speed.

4.5.5 The d.c. motor Questions

31 exam-style questions on CIE IGCSE Physics 4.5.5 The d.c. motor. Each one has a worked solution and a mark scheme showing where the marks go.

A simple d.c. motor consists of a coil positioned between magnetic poles. A split-ring commutator connects the d.c. power supply to the coil.

What is the function of the split-ring commutator in this motor?

It reverses the direction of the external magnetic field every half-turn ( $180∘180^\circ$ ) of the coil.

It reverses the direction of the current in the coil every half-turn ( $180∘180^\circ$ ) to ensure continuous rotation in the same direction.

It converts direct current (d.c.) from the supply into high-frequency alternating current (a.c.) to increase the motor's speed.

It disconnects the current permanently once the coil reaches its maximum rotational speed.

31 exam-style questions on CIE IGCSE Physics 4.5.5 The d.c. motor. Each one has a worked solution and a mark scheme showing where the marks go.