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 Faraday's law of electromagnetic induction, an electromotive force (EMF) is induced in a conductor when there is a change in the magnetic field, which is indicated by the increasing magnetic field in this case. The induced EMF creates a current flow in the conductor. According to Lenz's law, the direction of the induced EMF opposes the change in magnetic flux. In this case, the magnetic field is increasing in the upward direction, so the induced EMF will create a current flow in the opposite direction, i.e. clockwise. This means that terminal X will be at a lower potential than terminal Y, making X negative and Y positive. Therefore, the best choice is C.

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