Question

Two different loops are concentric and lie in the same plane. The current in the outer loop is clockwise and increasing with time. The induced current in the inner loop then is

• A. clockwise
• B. zero
• C. counter clock wise
• D. in a direction that depends on the ration of the loop radii

Answer 1

Answer: (C)

counter clock wise

Current will induced in inner loop in counter clockwise direction. According to Lenz law induced emf always gives rise to a current whose magnetic field opposes the change in magnetic flux.

Emf is given by

$e=\frac{-d\varphi }{dt}$

$IR=\frac{-d\varphi }{dt}$

$I=\frac{1}{R}\frac{-d\varphi }{dt}$