A magnetised needle in a uniform magnetic field experiences a torque but no net force. An iron nail near a bar magnet, however, experiences a force of attraction in addition to a torque. Why?

Explanation

The needle experiences a torque but no net force if the needle is placed at an angle from the direction of a uniform magnetic field.
An iron nail, being of bigger size, experiences a non-uniform magnetic field due to the bar magnet. The induced magnetic moment in the nail, thus, experiences both force as well as torque. The net force is attractive in nature because nearer end of nail bahaves as opposite pole and experiences attractive force which is greater than the repulsive force experienced by farther end of nail which develops the same polarity as the nearer end of bar magnet.