Problem 3.269

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 \(\mathbf{p}_ {m}\). Find the magnitude and direction of the force vector applied to the loop if the vector \(\mathbf{p}_ {m}\) (a) is parallel to the straight conductor; (b) is oriented along the radius vector \(\mathbf{r}\) (c) coincides in direction with the magnetic field produced by the current \(I\) at the point where the loop is located.