Final answer:
When the wire between the poles of the horseshoe magnet deflects upward upon closing the switch, it indicates that the left end of the magnet is the North pole.
Step-by-step explanation:
When the switch is closed in the circuit shown in the figure, the wire between the poles of the horseshoe magnet deflects upward. This indicates that the left end of the magnet is a North pole. According to the Right-Hand Rule, the direction of the magnetic field lines around the wire will be clockwise. The magnetic field lines around a north pole of a magnet are directed from the back to the front of the loop, so when the switch is closed and the wire deflects upward, it means that the front (left) end of the magnet is the North pole.