The expected answers were:
- (i) Lenz’s law states that the direction of an induced e.m.f. is always such that it tends to set up a current opposing the motion or the change of flux responsible for inducing that e.m.f.
OR
Lenz’s law states that the direction of an induced e.m.f. tends to oppose the cause.
(ii) Any three of the following applications were acceptable:
Electric bells Circuit breaker
Electric fan Ignition assembly
Transformer Miniature Circuit Breaker
Contactor Solenoid
Electric motor Buzzers
Telephones Radio receivers
Loudspeakers Relays
- l = 0.4 m, v = 3 m/s , B = 1.5 T
e = Blv sin
= 1.5 x 0.4 x 3 sin 900
= 1.8 V.
The question was on Electromagnetic Field. The question was popular with the candidates. The performance was reported to be above average