Question

Two very long, straight and parallel wires carry steady currents I and 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. The magnitude of the force due to the 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. $0$

Answer 1

The correct option is D $0$

According to gives information following figure can be drawn, which shows that direction of magnetic field is along the direction of motion of charge so net force on it is zero.

if the currents are parallel then the net magnetic field at midpoint will be zero, Hence, no magnetic force acts on it.