A circular loop of wire having a radius of 8.0 cm carries a current of 0.20 A. A vector of unit length and parallel to the dipole moment i, of the loop is given by 0.60i - 0.80j If the loop is located in a uniform magnetic field given by B = (0.25 T) i + (0.30T) k, find

(a) The torque on the loop (in unit vector notation) and

(b) The magnetic potential energy of the loop.