An input voltage of 15 V is supplied to the primary coil of an ideal transformer. An output voltage of 75 V is produced across the secondary coil.
The 15 V supply at the primary coil is now replaced with a 30 V supply.
What is the new output voltage across the secondary coil?
15 V15\text{ V}15 V
30 V30\text{ V}30 V
90 V90\text{ V}90 V
150 V150\text{ V}150 V
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.