Two very long, straight, parallel wires carry steady currents I & −I respectively. The distance between the wires is d. At a certain instant of time, a point charge q is at a point equidistant from the two wires, in the plane of the wires. Its instantaneous velocity v is perpendicular to this plane. Find the magnitude of the force due to the magnetic field acting on the charge at this instant.
a. 2πdμ0Iqv
b. πdμ0Iqv
c. πd2μ0Iqv
d. 0