Magnetic Compass

What is a Magnetic Compass?

A compass is an instrument used for navigation and orientation that shows direction relative to the geographic cardinal directions (or points). Usually, a diagram called a compass rose shows the directions north, south, east, and west on the compass face as abbreviated initials. When the compass is used, the rose can be aligned with the corresponding geographic directions; for example, the "N" mark on the rose points northward. Compasses often display markings for angles in degrees in addition to (or sometimes instead of) the rose. North corresponds to 0°, and the angles increase clockwise, so east is 90° degrees, south is 180°, and west is 270°. These numbers allow the compass to show magnetic North azimuths or true North azimuths or bearings, which are commonly stated in this notation. If magnetic declination between the magnetic North and true North at latitude angle and longitude angle is known, then the direction of magnetic North also gives the direction of true North.

Why Magnetic Compass is used?

Magnetic Compass is used to find directions. It is an instrument with a magnetic needle that always points north. The compass is usually a circular instrument with the four cardinal directions of North, South, East & West marked out on its face. The magnetic compass is one of the four great Chinese inventions. An early form of the compass was probably first made in China during the Qin Dynasty   (221-206 BCE).