A long, straight wire going through the origin is carrying a current of 3.00 A in the positive z-direction (Fig, P19.44). At a point a distance r = 1.20 m from the origin on the positive x-axis, find the a. magnitude and b. direction of the magnetic field. At a point the same distance from the origin on the negative y-axis, find the c. magnitude and d. direction of the magnetic field. Figure P19.44 Details An illustration shows a wire along z axis carrying current I upward. Vector B in xy plane is a circle of radius r.