A circular loop of wire having a radius of 8.0 cm carries a current of .20A. A vector of unit length and parallel to the dipole moment M of the loop is given by 0.60i-.80j. If the loop is located in a uniform magnetic field given by B=(0.25T)i+(.30T)k, find a)the torque on the loop(in unit vector notation) and b) the magnetic potential energy of the loop.