A student is investigating a simple AC generator and wishes to decrease the maximum electromotive force (e.m.f.) induced in the coil.
Which modification to the generator would result in a decrease in the maximum induced e.m.f.?
Increase the rotational frequency of the coil.
Increase the cross-sectional area of the coil.
Replace the soft iron core inside the coil with a non-magnetic plastic core.
Increase the number of turns of wire in the coil.
275 exam-style questions on CIE IGCSE Physics 4.5 Electromagnetic effects, covering 4.5.1a Electromagnetic induction, 4.5.1b Direction of an induced e.m.f., 4.5.2 The a.c. generator, 4.5.3a Magnetic effect of a current and its applications, 4.5.3b Strength and direction of the field around wires and solenoids, 4.5.4a Force on a current-carrying conductor, 4.5.4b Force on beams of charged particles, 4.5.5 The d.c. motor, 4.5.6a Construction and operation of a transformer, 4.5.6b Turns ratio and current in a transformer, and 4.5.6c High-voltage transmission of electricity. Each one has a worked solution and a mark scheme showing where the marks go.