Lenz's law: 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

Lenz's law: 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 emf in a conductor is such that it opposes the change that caused it. In this case, the magnetic field is increasing, so the induced emf will produce a magnetic field opposing the increase. This can only happen if a current flows in the conductor in such a way that it creates a magnetic field opposite to the external one. By applying the right-hand rule, it can be seen that a current will circulate clockwise in the conductor, looking from the left side. This means that terminal X will be negative (current flows out of it) and terminal Y will be positive (current flows into it). Therefore, the correct answer is C.

Lenz's Law: in the Figure, a C-Shaped Conductor Is in a Uniform