Three long straight parallel wires are placed in a line, with 40 cm between neighboring wires, as shown in the figure. Wires 1 and 2 carry currents directed into the page, while wire 3 carries a current directed out of the page. Wire 1 experiences no net force due to the other two wires.
(a) What is the ratio of the magnitude of the current in wire 3 to that in wire 2?
(b) What is the ratio of the net force per unit length experienced by wire 3 to that of wire 2? For wire 3, account for the net effect of wires 1 and 2 on wire 3; for wire 2, account for the net effect of wires 1 and 3 on wire 2. Use a positive sign if these two vectors are In the same direction, and a negative sign if they are In opposite directions.