Two long, parallel copper wires of diameters 2.3 mm carry currents of 7.0 A in opposite directions. (a) Assuming that their central axes are separated by width W = 20 mm, calculate the magnetic flux per meter of wire that exists in the space between those axes. (b) What percentage of this flux lies inside the wires? (c) Repeat part (a) for parallel currents. Units (a) 1.3e-5 T-m