Question

Consider the three long, straight parallel wires shown in figure. There is zero magnetic field at a point the midway between the wires 2 and 3. Find the magnitude and direction of the current in wire 2.

Answer 1

MAGNETIC FIELD AT ANY POINT WILL BE THE VECTORE SUM OF THE FIELD CREATED BY THE INDIVIDUAL WIRE.

B_P=B_P1+B_P2+B_P3

magnetic field due to the wire 1 and 3 are in +z direction the field due to second wire should be in -z direction

there fore the current in the wire2 should be in upward direction

B_P= $\mu$ ₀10/2 $\pi$ 2(K)+ $\mu$ I/2 $\pi$ 1(-K)+ $\mu$ 5/2 $\pi$ 1(K) =0

CALCULATE THE VALUE OF I

I=10 Amp