COMEDK2023PhysicsMagnetic Effects of Current
Two very long straight parallel wires carry currents i and 2 i in opposite directions. The distance between the wires is r . 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
Options
- Azero
- B3 ₀ 2 i q v r
- C₀ i q v r
- D₀ 2 i q v r
Correct answer
A. zero
Step-by-step solution
The magnetic field induction at P due to currents through both the wires is B= ₀ 4 2 i (r / 2) + ₀ 4 2(2 i) (r / 2) = ₀ 4 12 i r acting perpendicular to plane of wire inwards. Now, B and v are acting in the same direction, i.e. =0^ Force on charged particle is F=q v B =q v B 0=0 .