Two long parallel wires are at a distance ` 2d` apart. They carry steady equal currents flowing out of the plane of the paper , as shown. The variation of the magnetic field `B` along the line `XX` is given by

Options

A.
B.
C.
D.

Answer

B

Explanation

At the mid-point of the line joining the conductors `vecB=0`. As we come close to the wires, the magnitude of `B` increase. The direction of magnitude fields on opposite sides of a wire will be opposite. Again `vecB=`, as `rto oo`.