Two very long straight parallel wire carry steay currents i. and 2i in opposite directions . The disatance between the waire is d . At a certain instant of time a point charge q is at a point equadistant from the two wires in the plane of the wires . Its instantaneous velocity v is perpendicular to this plane . The magnetude of the magnetic field acting on the charge at this isntant is

Options

A. `(mu_(0)Iqv)/(2pid)`
B. `(mu_(0)Iqv)/(pid)`
C. `(2mu_(0)Iqv)/(pid)`
D. Zero

Answer

D

Explanation

Net magnetic field due to both the wires will be downward as shown in the figure.

Since, anglebetwene v and b is `180^(@)` , therefore magnetic force `F_(m)=q(vxxb)=0`