An ideal transformer has N1 N_1\,N1 turns on its primary coil and N2 N_2\,N2 turns on its secondary coil. The input voltage across the primary coil is V1 V_1\,V1 and the output voltage across the secondary coil is V2V_2V2.
Which equation correctly expresses V2 V_2\,V2 in terms of the other quantities?
V2=V1×N1N2V_2 = V_1 \times \frac{N_1}{N_2}V2=V1×N2N1
V2=V1×N2N1V_2 = V_1 \times \frac{N_2}{N_1}V2=V1×N1N2
V2=V1N1×N2V_2 = \frac{V_1}{N_1 \times N_2}V2=N1×N2V1
V2=V1×N1×N2V_2 = V_1 \times N_1 \times N_2V2=V1×N1×N2
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.