In a direct current (DC) motor, what is the function of the split-ring commutator?
To reverse the direction of the current in the coil every half rotation, maintaining a constant direction of rotation.
To maintain a constant current direction in the coil throughout the rotation.
To reverse the direction of the external magnetic field every half rotation.
To convert alternating current from the source into direct current for the coil.
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.