A long straight wire is in the plane of a rectangular conducting loop.The straight wire carries a constant current i, as shown.While the wire is being moved toward the loop, the current in the loop is:
A)zero
B)clockwise
C)counterclockwise
D)clockwise in the left side and counterclockwise in the right side
E)counterclockwise in the left side and clockwise in the right side

Question

A long straight wire is in the plane of a rectangular conducting loop.The straight wire carries a constant current i, as shown.While the wire is being moved toward the loop, the current in the loop is: 
A)zero 
B)clockwise 
C)counterclockwise 
D)clockwise in the left side and counterclockwise in the right side 
E)counterclockwise in the left side and clockwise in the right side

Quizplus · Accepted Answer

When the straight wire is moved towards the rectangular loop, the magnetic field produced by the wire changes with time. According to Faraday's law of electromagnetic induction, this change in magnetic field induces an electromotive force in the loop, which in turn causes a current to flow in the loop.

The direction of the induced current is such that it opposes the change in magnetic field that produced it. In this case, as the wire is being moved towards the loop, the induced current will produce a magnetic field that opposes the magnetic field of the wire.

Using the right-hand rule for magnetic fields, we can see that the induced current will produce a magnetic field that points into the plane of the loop on the left side and out of the plane of the loop on the right side. This means that the induced current will flow counterclockwise in the left side of the loop and clockwise in the right side of the loop. Therefore, the answer is C) counterclockwise.

A Long Straight Wire Is in the Plane of a Rectangular