Two coaxial, coplanar circular loops and have radii and , respectively. The larger…
PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
Two coaxial, coplanar circular loops P and Q have radii 20cm and 5cm, respectively. The larger loop P carries a steady current of 5A in the clockwise direction as seen by an observer looking along the common axis toward the loops.
(i) If the current in P is switched off to zero in 0.10s, determine the direction of the induced current in Q. Support your answer with reasoning based on changing magnetic flux.
(ii) While the current is falling, what is the nature (attractive or repulsive) of the net force experienced by Q? Explain.
(iii) Suppose instead that the current in P is increased uniformly from 5A to 10A in 0.10s. Repeat parts (i) and (ii) for this case.