O a a 12 7x Two long wires are parallel to the zaxis and are located at x = 0, y = ta. Take a = 14 cm. a) Find B at point P with b = 6 cm, given that the wires carry equal currents in opposite direction I1 = 12 = 5 A. B = 1.21 . 10 5 it Oj)T b) At what point is B equal to 20 % of the magnitude of the magnetic field at origin (0, 0, 0)? (Hint, find the magentic field at origin first.) b cm