The figure shows four different sets of insulated wires that cross each other at right angles without actually making electrical contact.The magnitude of the current is the same in all the wires,and the directions of current flow are as indicated.For which (if any)configuration will the magnetic field at the center of the square formed by the wires be equal to zero?
A)A
B)B
C)C
D)D
E)The field is not equal to zero in any of these cases.

Question

The figure shows four different sets of insulated wires that cross each other at right angles without actually making electrical contact.The magnitude of the current is the same in all the wires,and the directions of current flow are as indicated.For which (if any)configuration will the magnetic field at the center of the square formed by the wires be equal to zero? 
A)A 
B)B 
C)C 
D)D 
E)The field is not equal to zero in any of these cases.

Quizplus · Accepted Answer

In configuration C, the magnetic fields produced by the wires in the top and bottom rows cancel each other out at the center point, and the magnetic fields produced by the wires in the left and right columns cancel each other out as well. Therefore, the total magnetic field at the center of the square is zero. In all other configurations, there will be a net magnetic field at the center point due to the wires.

The Figure Shows Four Different Sets of Insulated Wires That