A transformer is used to power a low-voltage toy railway system.
Give a reason why the mains plug of the transformer is fitted with a fuse.
Explain how a fuse works to protect the circuit when the current becomes too large.
The mains input (primary) potential difference (p.d.) to the transformer is 240 V a.c. The number of turns on the input (primary) coil is 600 and the number of turns on the output (secondary) coil is 30. Calculate the output (secondary) p.d. from the transformer.
State a suitable material for the core of the transformer.
State a suitable metal for the primary and secondary coils of the transformer.
Explain how the specifications of the coils show that this is a step-down transformer.
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.