magnetic needle
It is a very thin magnetised steel needle mounted on a sharp pivot. When suspended freely, its end point in the geographic north-south direction
en-US/mæɡˈnɛdɪk ˈnidəl/
en-GB/mæɡˈnɛtɪk ˈniːdl/
It is a very thin magnetised steel needle mounted on a sharp pivot. When suspended freely, its end point in the geographic north-south direction