Answer and Explanation:
A horseshoe-shaped magnet, that is, a "U" shape, has stronger attraction and repulsion capacities than that presented by a bar-shaped magnet. This is because the lines of the magnetic field on the "U" magnet are more dense and therefore promote a stronger magnetic field. This strong magnetic field exists because in a "U" shaped magnet, the magnetic poles are on the same plane, allowing a better fluctuation of the lines of the magnetic field.