Question

57 Magnetic fields produced by parallel currents Infinitely long straight parallel wires carry the illustrated currents with identical currents. Consider the magnetic field at the points A, B (nidway between the wires) and C. In each case rank the magnetic fields at the indicate locations in order of increasing magnitude. Indicate equality whenever it occurs. Case a) Case b) d l IA

Answer 1

Magnetic field due to current carrying wire is

$\vec B = \dfrac { \mu_0 I\vec dl \times \vec r}{2\pi r^2}$

Here r is distance of the point where magnetic field is calculated from current carrying wire.

$B = \dfrac { \mu_0 I }{2\pi r}$

When both wire have current in same direction

Order of magnetic field at A ,B and C is A=C >B

When wires have current flowing in opposite direction

Order is B>(A=C)

Please rate it up thanks :)