Two transformers, X X\,X and YYY, each have 1500 turns on their primary coils and 500 turns on their secondary coils. Both transformers are 100% efficient.
The secondary of transformer X X\,X is connected to the primary of transformer YYY.
Transformer Y Y\,Y provides a heater with a current of 1.8 A.
What is the current being supplied to the primary of transformer XXX?
5.4 A5.4\text{ A}5.4 A
1.8 A1.8\text{ A}1.8 A
0.6 A0.6\text{ A}0.6 A
0.2 A0.2\text{ A}0.2 A
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.