Question

Two parallel straight wires 10.0 cm apart carry currents in opposite directions (Fig. 20–24). Current I_1=5.0 A is out of the page, and I_2=7.0 A is into the page. Determine the magnitude and direction of the magnetic field halfway between the two wires.

Answer 1

Net magnetic field

$B=B_1+B_2$

$B=\frac{\mu _0}{2\pi}(\frac{i_1}{r_1}+\frac{i_2}{r_2})$

$B=\frac{4\pi}{2\pi}(\frac{5}{0.05}+\frac{7}{0.05})$

$B=2\times(100+140)=480T$

Direction into the page