What is a dip needle and how is it similar to a compass?

A dip needle is just like a conventional compass, but instead of holding it horizontally, it is held vertically. It is a magnetic needle used for navigational purposes just like a compass, but is used predominantly when traveling around the north and south poles. Instead of measuring horizontal magnetic deflection, the dip needle measures vertical magnetic inclination. When over the equator, the magnetic field of Earth is parallel to the surface of the Earth. The closer one gets to the magnetic poles, however, the less pilots rely on compasses, and the more they rely on dip needles to tell them how close they are to the poles. The closer one gets to a pole, the more vertical the magnetic field becomes, because it’s turning into the surface of Earth. Therefore, when directly over the magnetic poles, the dip needle points directly downward.


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