Fig. 8.1 shows a flat coil positioned horizontally inside a magnetic field. The diagram marks N, S, coil, axis, and points A and B. The coil is linked to a cell, and the coil rotates.
(a)[1]
Determine which way side AB moves relative to the plane of the coil.
(b)[2]
Explain how you worked out the direction in (a).
(c)[2]
State and explain what occurs when the coil reaches the vertical position.
(d)[3]
Explain the roles of the split-ring commutator and the brushes in the motor’s operation.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “A downward movement / into the page / anticlockwise rotation” …