Final answer:
Unlike magnetic poles attract each other because the magnetic field lines between them become denser, indicating a force of attraction.
Step-by-step explanation:
When placed near each other, unlike magnetic poles attract each other. This is because magnetic poles come in pairs: north and south. For instance, a north pole of one magnet will be attracted to the south pole of another magnet. If you put two like poles together, such as two north poles or two south poles, they will repel each other, causing the magnetic field lines to diverge. Conversely, unlike poles being brought together will lead to an attraction, with the magnetic field lines becoming denser between them.