A bar magnet is oriented above a copper ring, as shown in the figure. If the magnet is kept fixed while the ring is dropped, what is the direction of the current induced in the ring, as viewed from below the ring?
A) There is no current in the ring.
B) counterclockwise
C) clockwise

Question

A bar magnet is oriented above a copper ring, as shown in the figure. If the magnet is kept fixed while the ring is dropped, what is the direction of the current induced in the ring, as viewed from below the ring? 
A) There is no current in the ring. 
B) counterclockwise 
C) clockwise

Quizplus · Accepted Answer

As the ring falls towards the magnet, the magnetic field passing through the ring increases. According to Faraday's law of electromagnetic induction, this changing magnetic field induces an electric current in the ring. By Lenz's law, the direction of the induced current is such that it opposes the change causing it. In this case, the induced current would create a magnetic field that opposes the motion of the magnet. From the position below the ring, the motion of the magnet would be clockwise. Therefore, the induced current in the ring would be counterclockwise, which is option C.

A Bar Magnet Is Oriented Above a Copper Ring, as Shown