Why is the coil of moving coil galvanometer wound over a metallic frame??
Answers
Explanation:
The coil of a galvanometer is wound on a metal frame so that it provide electromagnetic damping due to production of eddy currents in the frame which oppose the motion of the coil.
We know that metal is good conductor of electricity. While metal comes in conduct of the electricity then it creates electromagnetic field and it own-self forms a temporary magnet until it gets the supply of electricity. And as soon as the electric supply gets off then the metal losts its magnetic property. And it is the reason of using metallic wound to controlling the movement of the coil of the galvanometer. Because,as soon as the metallic wound acquires the magnetic property then it starts moving and while it losts its magnetic property then too the coil stops moving.