A small bar magnet hangs horizontally from a thread in the gap of a horseshoe magnet. The small magnet has a north pole labelled P and a south pole labelled Q. It is initially held at right angles to the line joining the north and south poles of the horseshoe magnet. The small magnet is released. Ignore the Earth's magnetic field. Which change occurs?
It turns until P points towards the south pole of the horseshoe magnet.
It remains at right angles to the line joining the poles.
It continues turning without settling between the poles.
It turns until P points towards the north pole of the horseshoe magnet.