(a)[4]
A solenoid is joined in series with a resistor, as shown in Fig. 7.1. While the magnet is moved into the solenoid, thermal energy is transferred to the resistor. Use laws of electromagnetic induction to explain where this thermal energy comes from.
(b)[4]
Explain why, in a transformer, the alternating current in the primary coil is not in phase with the alternating e.m.f. induced in the secondary coil.