Two long, straight, parallel wires carry currents that are directed perpendicular to the page as shown in the figure. Wire 1 carries a current I1 into the page (in the negative z direction) and passes through the x axis at x = +a. Wire 2 passes through the x axis at x = -2a and carries an unknown current I2. The total magnetic field at the origin due to the current-carrying wires has the magnitude 2 mu0I1/(2pia). The current I2 can have either of two possible values.
![941_direction.png](https://secure.tutorsglobe.com/CMSImages/941_direction.png)
(a) Find the value of I2 with the smaller magnitude, stating it in terms of I1 and giving its direction.
(b) Find the other possible value of 12.