two parallel long, straight wires are 0.0040 m apart and carry currents of 5.0 a and 10 a, respectively. determine the net magnetic field midway between the wires. take b as positive if it is going into the page. group of answer choices 5.0 x 10-4 t -1.0 x 10-3 t 1.0 x 10-3 t -5.0 x 10-4 t