Two long, straight, parallel wires of length 4.0 m carry parallel currents of 3.5 A and 1.2 A.
(a) If the wires are separated by a distance of 3.5 cm, what is the magnitude of the force between the two wires?
(b) Is this force attractive or repulsive?
(c) If the currents are in opposite directions (antiparallel), how do the answers to parts (a) and (b) change?