Question

A wire is bent to form the double loop shown in figure. There is a uniform magnetic field directed into the plane of the loop. If the magnitude of this field is decreasing, the current will flow from

• A. $a$ to $b$ and $c$ to $d$
• B. $b$ to $a$ and $d$ to $c$
• C. $a$ to $b$ and $d$ to $c$
• D. $b$ to $a$ and $c$ to $d$
• E. answer required

Answer 1

Answer: (C)

$a$ to $b$ and $d$ to $c$

As the field decreases the flux through the loop decreases. By Lenz's Law, to counter this a current in the clockwise direction will flow so that it adds to the decreasing field and hence opposes the decreasing flux. For clockwise direction of current, current will flow from a to b and from d to c.