A current of 4.0 A is maintained in a single circular loop having a circumference of 80 cm. An external magnetic field of 2.0 T is directed so that the angle between the field and the normal of the plane of the loop is originally 20. a) Determine the magnitude of the torque exerted on the loop by the magnetic forces acting upon it. b) As the loop rotates, when is the torque on it maximized, and what is the magnitude of the maximum torque it will experience?