Coils P and Q. Current in P induces current in Q. (a) Explain the phenomenon. (b) Two factors affecting current in Q. (c) Direction of current in Q when current is in P and (i) R increases, (ii) R decreases.
(a) Mutual induction: A variation in current within coil P generates a fluctuating magnetic flux, which in turn induces an electromotive force and current in coil Q. (b) 1. The rate at which current changes in P. 2. The quantity of turns present in Q. (c) (i) Identical to the current in P (to counteract a reduction in magnetic flux). (ii) Opposite to the current in P (to counteract an increase in magnetic flux).