일반물리학 2 — Magnetic Fields Due to Currents: Problem 12

12 Figure 29-30a shows, in cross section, two long, parallel wires carrying current and separated by distance L. The ratio $i_1/i_2$ of their currents is 4.00; the directions of the currents are not indicated. Figure 29-30b shows the y component $B_y$ of their net magnetic field along the x axis to the right of wire 2. The vertical scale is set by $B_{ys} = 4.0 \text{ nT}$, and the horizontal scale is set by $x_s = 40.0 \text{ cm}$. (a) At what value of $x > 0$ is $B_y$ maximum? (b) If $i_2 = 3 \text{ mA}$, what is the value of that maximum? What is the direction (into or out of the page) of (c) $i_1$ and (d) $i_2$?