CAIE IGCSE Physics 4.5.5.2 Operation of an electric motor
Practise explaining how a d.c. motor keeps rotating, using coil force directions, brushes and the split-ring commutator.
- Syllabus
- 2026–2028
- Course
- Physics 0625
Practise explaining how a d.c. motor keeps rotating, using coil force directions, brushes and the split-ring commutator.
Fig. 9.1 shows a simple direct current (d.c.) electric motor. The coil rotates about the axis when there is a current in the coil. The coil is connected to the rest of the circuit by the brushes.

Fig. 9.1
State any difference each of the following changes makes to the rotation of the coil in Fig. 9.1:
changing the polarity of the power supply to that shown in Fig. 9.2

Fig. 9.2
rotates in opposite direction
B1