A transformer has NpN_{\text{p}}Np turns in the primary coil and NsN_{\text{s}}Ns turns in the secondary coil.
Which row gives the values of NpN_{\text{p}}Np and NsN_{\text{s}}Ns for a transformer that steps up a voltage of 240 V to 9600 V?
Np=300N_{\text{p}} = 300Np=300, Ns=12 000N_{\text{s}} = 12\,000Ns=12000
Np=300N_{\text{p}} = 300Np=300, Ns=120 000N_{\text{s}} = 120\,000Ns=120000
Np=12 000N_{\text{p}} = 12\,000Np=12000, Ns=300N_{\text{s}} = 300Ns=300
Np=120 000N_{\text{p}} = 120\,000Np=120000, Ns=300N_{\text{s}} = 300Ns=300
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.