Question

Consider the situation shown in figure. The wire AB is slid on the fixed rails with a constant velocity. If the wire AB is replaced by a semicircular wire, the magnitude of the induced current will
(a) increase
(b) remain the same
(c) decrease
(d) increase or decrease depending on whether the semi-circle bulges towards the resistance or away from it.
Figure

Answer 1

The correct option (b) Remain same   Explanation: Rate of change of area with remain same even if wire is replaced by semicircular wire,  ∴ induced current will be same as earlier one as I = (e/R) & e i.e. induced emf is function of area because e = – N (dɸ/dt) = – N (d/dt) (ABcoswt).