As shown in the figure, a C-shaped conductor is in a uniform magnetic field B out of the page, and this field is increasing. What is the polarity of the induced emf in terminals X and Y?
A) X and Y are at the same potential.
B) X is positive and Y is negative.
C) Y is positive and X is negative.

Question

As shown in the figure, a C-shaped conductor is in a uniform magnetic field B out of the page, and this field is increasing. What is the polarity of the induced emf in terminals X and Y? 
A) X and Y are at the same potential. 
B) X is positive and Y is negative. 
C) Y is positive and X is negative.

Quizplus · Accepted Answer

According to Faraday's law of electromagnetic induction, the induced emf is proportional to the rate of change of magnetic flux through the loop. In this case, the magnetic field is increasing out of the page, which means the magnetic flux through the loop is also increasing. The direction of the induced current in the loop is such that it opposes the change in magnetic flux that produces it. Using the right-hand rule, we can determine that the induced current will flow clockwise around the loop, so the potential difference across the terminals X and Y will be such that Y is positive and X is negative. Therefore, the correct answer is C.

As Shown in the Figure, a C-Shaped Conductor Is in a Uniform