A small current-carrying loop is located at a distance r from a long straight conductor with current I. The magnetic moment of the loop is equal to Pm,. Find the magnitude and direction of the force vector applied to the loop if the vector Pm,
(a) Is parallel to the straight conductor;
(b) Is oriented along the radius vector r;
(c) Coincides in direction with the magnetic field produced by the current I at the point where the loop is located.