1. Figure 5.5 shows a small magnetised needle P placed at a point O. The arrow shows the direction of its magnetic moment. The other arrows show different positions (and orientations of the magnetic moment) of another identical magnetised needle Q.
a) In which configuration the system is not in equilibrium?
b) In which configuration is the system in (i) stable, and (ii) unstable equilibrium?
c) Which configuration corresponds to the lowest potential energy among all the configurations shown?