A single circular (radius = R)loop of wire is located in the yz plane with its center at the origin.The loop has a clockwise current as seen from the point (+R,0,0).The direction of the magnetic field at the point
A)(0,0,0)is -i and at the point (+R,0,0)is -i.
B)(0,0,0)is -i and at the point (0,+2R,0)is -i.
C)(0,0,0)is +i and at the point (+R,0,0)is +i.
D)(0,0,0)is +i and at the point (0,+2R,0)is +i.
E)None of the above

Question

Quizplus · Accepted Answer

Using the right-hand rule, we can determine that the magnetic field at the center of a loop of wire is in the direction perpendicular to the plane of the loop. Since the loop is in the yz-plane, the magnetic field direction must be in the x-direction. Additionally, the direction of the magnetic field is determined by the direction of the current flowing through the loop. Since the current is clockwise as seen from the point (+R,0,0), the direction of the magnetic field at the point (0,0,0) is opposite to the direction of the current, which is −i. Therefore, choice A is the correct answer. For choice B, the point given is not on the x-axis, so the magnetic field direction cannot be solely in the x-direction. For choices C and D, the magnetic field direction does not take into account the direction of the current flowing through the loop.

A Single Circular (Radius = R)loop of Wire Is Located