Question

A horizontal loop `abcd` is moved across the pole pieces of a magnet as shown in fig. with a constant speed `v`. When the edge `ab` of the loop enters the pole pieces at time `t=0` sec. which one of the following graphs represents correctly the induced e.m.f. in the coil?

A.
B.
C.
D.

Answer 1

Correct Answer - D
When loop enters in field between the pole pieces, flux linked with the coil first increase (constantly)so a constant emf induces, when coil entered completely within the field, no flux change so `e=0`. When coil exit out, flux linked with the coil decreases, hence again emf induces, but in opposite direction.