A square loop of side `5` cm enters a magnetic field with `1cms^(-1)`. The front edge enters the magnetic emf?

Options

A.
B.
C.
D.

Answer

C

Explanation

when loop is entering in the field, magnetic flux linked with the loop increase so induced emf in it `e=Bvl=0.6xx10^(-2)xx5xx10^(-2)=3xx10^(-4)V` (negative).
when loop completely entered in the field (after `5` sec) flux linked with the loop remains constant so `e=0`.
After `15` sec, loop begins to exit out, linked magnetic flux decrease so induced emf `e=3xx10^(-4)V`(positive).