Q9: Two long, straight, parallel wires carry currents that are directed perpendicular to the page as shown in Figure P30.9. Wire 1 carries a current I1 into the page (in the negative z direction) and passes through the x axis at x = 1a. Wire 2 passes through the x axis at x = 22a and carries an unknown current I 2. The total magnetic field at the origin due to the current-carrying wires has the magnitude 2m0I 1/(2pa). The current I 2 can have either of two pos- sible values.
(a) Find the value of I 2 with the smaller magnitude, stating it in terms of I 1 and giving its direc- tion.
(b) Find the other possible value of I 2.