Two identical long conducting wires AOB and COD are placed at right angle to each other, with one above other such that 0 is their common point for the two. The wires carry currents, respectively. Point P is lying at distance d from 0 along a direction perpendicular to the plane containing the wires. The magnetic field at the point P will be
The magnetic field at the point P, at a perpendicular distance d from 0 in a direction perpendicular to the plane ABCD due to currents through AOB and COD are perpendicular to each other. Hence,