Two circular loops of current parallel to the z = 0 plane are arranged to form a Helmholtz coil. The center of one loop is at (0,0,0) m, and the center of the other loop is at (0,0,4) m. The radius of each loop is 2 m, and each loop carries a current of 5 A in the abφ direction. Find the magnetic field at (a) (0,0,0) and