Question

Two very long straight parallel wires carry currents of same magnitude and in the same direction. 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 $\overrightarrow{v}$ is perpendicular to this plane. The magnitude of the force due to magnetic field acting on the charge at this instant is

• A. $\frac{{\mu }_{0}Iqv}{2\pi d}$
• B. $\frac{{\mu }_{0}Iqv}{\pi d}$
• C. $\frac{2{\mu }_{0}Iqv}{\pi d}$
• D. $Zero$

Answer 1

The correct option is D

$Zero$

Since both wires carry currents in same direction, B at midpoint of the two wires is zero and hence no net magnetic force is exerted on the charge q.