Question

Two long, straight wires carry equal currents in opposite directions as shown in figure. The separation between the wires is 5.0 cm. The magnitude of the magnetic field at a point P midway between the wires is ____ μT
(Given: $\mu_0 = 4\pi \times 10^{-7} \, \text{TmA}^{-1}$)

Answer 1

The magnetic field $B$ at a point midway between two parallel currents in opposite directions is:

$B = \frac{\mu_0 I}{2 \pi a} \times 2 = \frac{4 \pi \times 10^{-7} \times 10}{\pi \times (2.5 \times 10^{-2})}$ $= 16 \times 10^{-5} = 160 \, \mu T$