Chapter 21.2, Problem 2cTH

Suppose that a third wire (carrying the same current $i_o$ out of the page) is placed such that the magnetic field at point P has zero magnitude. Determine the location of the third wire. (Hint: You will need to know how the magnetic field depends on the distance from the wire. This relationship can be found in your text.)

Clearly indicate on the diagram at right the correct location of the new wire. Explain how you determined your answer.