Which statement correctly describes the operation of a simple transformer?
A direct current in the primary coil creates a continuously changing magnetic field in the iron core.
The iron core conducts the electrical current directly from the primary coil to the secondary coil.
An alternating current in the primary coil creates a changing magnetic field in the core, which induces an alternating voltage across the secondary coil.
A steady magnetic field in the iron core induces an alternating voltage across the secondary 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.