Figure ??a?? shows in cross section, two long, parallel wires carrying current and separated by distance L. The ratio i1/i2 of their currents is 4.00; the directions of the currents are not indicated. Figure ??b?? shows the y component B, of their net magnetic field along the x axis to the right of wire 2. The vertical scale is set by Bys, = 4.0nT, and the horizontal scale is set by x3 = 20.0 cm. (a) At what value of x > 0 is By maximum?

(b) If i2 = 3 mA, what is the value of that maximum? What is the direction (into or out of the page) of?

(c) i1 and

(d) i2?

x (cm) (b) (a)