In the sketch to the right, a long straight wire is in the plane of a rectangula
ID: 1545985 • Letter: I
Question
In the sketch to the right, a long straight wire is in the plane of a rectangular conducting wire loop. The current in the straight wire is up. At some point the current in the straight wire starts to decrease in magnitude. This decreased current leads to an induced current in the wire loop. In which direction will the induced current in the wire loop be? Explain how you reached this conclusion. How would your answer be different if the wire loop was on the left side of the wire instead of the right side?Explanation / Answer
due to current in the wire in up direction , using right hand curl rule , magnetic flux linked with the loop is inward. as the current in the wire starts to decrease, the magnetic flux linked with loop in inward direction starts to decrease too. To resist this change in magnetic flux, the loop induces current to produce its own magnetic field to counter the change. the loop has to increase the magnetic field in inward direction to compensate for the decrease in magnetic flux due to decrease in current in wire. so using right hand rule , the direction of induced current comes out to be clockwise.
when the loop is on left side , the direction of magnetic flux linked with it using right hand rule is outward. when current in wire decrease , magnetic flus linked with loop in outward direction decrease. to compensate for the change , loop produce its own magnetic field in outward direction by inducing current in it in outward direction. using right hand rule , the direction of induced current in the loop has to be counterclockwise for the magnetic field to be outward.
hence direction of induced current is counter-clockwise.