question_answer

Three coplanar, parallel, long straight wires are equally spaced, that is, the distance between each pair of successive wires is the same. The first and the third wire carry currents of 1 A each, in the same direction. What must be the current in the second wire (wire in the middle), so that the other two wires do not feel any net force?

A)  \[0.25\text{ }A\]in opposite direction to those in the first and the third

B)  \[0.5\text{ }A\]in the same direction as those in the first and the third

C)  \[0.5\text{ }A\]in the opposite direction to those in the first and the third

D)  \[0.25\text{ }A\]in the same direction as those in the first and the third