A student is experimenting with a low-voltage power supply for an electronic project. The setup uses a step-down transformer connected to the mains AC supply.
The supply voltage is 240 V. The transformer has 800 turns on the primary (input) coil and 50 turns on the secondary (output) coil.
Calculate the output voltage of this transformer.
output voltage = ............................................................ V\text{V}V
Transformers can be step-up or step-down.
Describe the difference in the coil winding arrangement (number of turns on the primary and secondary coils) for these two types of transformers.
Electrical energy is transmitted across the National Grid at very high voltages.
Explain the advantage of transmitting electricity at high voltages, rather than at low voltages.
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.