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

a

Explanation

Direction of current in both the wires are same and hence at the centre magnetic field must be zero and direction of magnetic field must be opposite on both sides of the centre. Moreover magnetic field due to straight current wire is inversely proportional to the distance from the wire.