question_answer

A conducting square loop of side L and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A magnetic induction B constant in time and space, pointing perpendicular and into the plane at the loop exist everywhere with half the loop outside the field, as shown in figure. The induced emf is                     [AIEEE 2002]

A) zero

B) RvB

C) \[\frac{vBL}{R}\]

D) vBL

Correct Answer: D

Solution :

[d] As the side BC is outside the field no emf is induced across BC. Since, AB and CD are not cutting any flux, the emf induced across these two sides will also be zero.

The side AD is cutting the flux and emf induced across this side is BvL with corner A at higher potential.