Question

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
A.
B.
C.
D.

Answer 1

Correct Answer - B
(b) The wires are at A and B perpendicular to the plane of paper
current is toward the reader. Let us consider certain
points.
pointC: The magnetic field at C due to `A(vecB_(CA))` is in upward
direction but magnetic field at C due to B is in downward
direction. Net field is zero.
Point E: Magnetic field due to A is upward and magnetic
field due to B is downward but `|vecB_(EA)|lt|vecB_(EB)| implies` Net field upward.
Similarly, other points can be considered.