In the figure,the inner loop carries a clockwise current I that is increasing.The resistor R is in the outer loop and both loops are in the same plane.The induced current through the resistor R is
A) from a to b.
B) from b to a.
C) There is no induced current through the resistor.

Question

In the figure,the inner loop carries a clockwise current I that is increasing.The resistor R is in the outer loop and both loops are in the same plane.The induced current through the resistor R is 
A) from a to b. 
B) from b to a. 
C) There is no induced current through the resistor.

Quizplus · Accepted Answer

According to Lenz's Law, the induced current in the outer loop will flow in such a direction as to oppose the change in magnetic flux through it. As the current in the inner loop (clockwise) is increasing, it will create a magnetic field which will be directed out of the page. To oppose this change in flux, the induced current in the outer loop (R) should flow from a to b, creating a magnetic field into the page, which will partially cancel out the magnetic field created by the inner loop. Therefore, the correct choice is A.

In the Figure,the Inner Loop Carries a Clockwise Current I