Question

Two long, straight wires, each carrying a current of 5 A, are placed along the x- and y-axes respectively. The currents point along the positive directions of the axes. Find the magnetic fields at the points (a) (1 m,1 m), (b) (-1 m, 1 m), (c) (-1 m,-1 m) and (d) (1 m,-1 m).

Answer 1

(a) At point (1m, 1m).

Magnetic fields due to each wire are same in magnitude but opposite in direction.

Hence net magnetic field =0

(b) At point (-1 m,1 m) magnetic field due to these two wires

$=(\frac{2\times {10}^{-7}\times 5}{1}+\frac{2\times {10}^{-7}\times 5}{1})$

along z-axis

$=2\times {10}^{-6}T$ along z-axis

$=2\pi T$ along z-axis.

(c) Similar as (a), net magnetic field B=o

(d) Similar as (b), here net magnetic field are in opposite z-direction and its magnitude

$B=2\mu T$