Which component of a compass is primarily used to determine the direction?

The needle of a compass is the component that is primarily used to determine direction. It is magnetized and aligns itself with the Earth's magnetic field, typically pointing toward the magnetic north pole. When using a compass, the user must read the position of the needle in relation to the compass housing and the directional arrow to ascertain their heading. The needle is crucial because its movement allows the user to identify where north is located, thus allowing for navigation and orientation.

Other components, such as the base plate, compass housing, or directional arrow, provide structure and reference points but do not determine direction on their own. The base plate helps with ease of carrying and combining the compass with maps, while the compass housing encases the needle and often has degree markings. The directional arrow, often found within the housing, serves as a guide for indicating the intended direction of travel relative to the north indicated by the needle. Each of these components plays a supportive role, but the needle is essential for actually establishing direction.