In the figure,a C-shaped conductor is in a uniform magnetic field B,which is increasing.The polarity of the induced emf in terminals X and Y is
A) X and Y are at the same potential.
B) X is positive and Y is negative.
C) X is negative and Y is positive.

Question

In the figure,a C-shaped conductor is in a uniform magnetic field B,which is increasing.The polarity of the induced emf in terminals X and Y is 
A) X and Y are at the same potential. 
B) X is positive and Y is negative. 
C) X is negative and Y is positive.

Quizplus · Accepted Answer

According to Lenz's law, the direction of the induced current in a conductor opposes the change in magnetic flux that produced it. In this case, the increasing magnetic field will induce a current in the C-shaped conductor that creates a magnetic field that opposes the increasing field. This means that the direction of the induced current will be such that it produces a magnetic field that goes into the page on the left side of the C-shaped conductor and comes out of the page on the right side.
Using the right-hand rule, we can determine that the induced current will flow counterclockwise around the C-shaped conductor, which means that the potential at X will be negative and the potential at Y will be positive. Therefore, the correct choice is C, X is negative and Y is positive.

In the Figure,a C-Shaped Conductor Is in a Uniform Magnetic