A closed, circular loop has a counter-clockwise current flowing through it as viewed by a person on the right, as shown in the figure. If a second closed circular loop with the same radius approaches this loop with constant velocity along a common axis as shown, in what direction will a current flow in the approaching loop as viewed by the person on the right?
A) clockwise
B) counter-clockwise
C) No current will be induced because the velocity of approach is constant.

Question

A closed, circular loop has a counter-clockwise current flowing through it as viewed by a person on the right, as shown in the figure. If a second closed circular loop with the same radius approaches this loop with constant velocity along a common axis as shown, in what direction will a current flow in the approaching loop as viewed by the person on the right? 
A) clockwise 
B) counter-clockwise 
C) No current will be induced because the velocity of approach is constant.

Quizplus · Accepted Answer

According to Lenz's law, the direction of the induced current in the second loop will be such that it opposes the change in magnetic flux through it. As the approaching loop moves towards the first loop, the magnetic flux through the second loop increases, so the induced current in the second loop must be in the opposite direction to the current in the first loop, which is counter-clockwise. Therefore, the induced current in the second loop will be clockwise, as viewed by the person on the right.

A Closed, Circular Loop Has a Counter-Clockwise Current Flowing Through