FIGURE 28-2
-Fig. 28-2 shows four different sets of wires that cross each other without actually touching. The magnitude of the current is the same in all four cases, and the directions of current flow are as indicated. For which 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 equal to zero in all four cases.

Question

FIGURE 28-2 
-Fig. 28-2 shows four different sets of wires that cross each other without actually touching. The magnitude of the current is the same in all four cases, and the directions of current flow are as indicated. For which 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 equal to zero in all four cases.

Quizplus · Accepted Answer

In configuration C, the currents in opposite wires flow in opposite directions, creating magnetic fields that cancel each other out at the center of the square.

FIGURE 28-2 -Fig. 28-2 Shows Four Different Sets of Wires That Cross