In moving iron instruments, eddy current damping cannot be used as 

(a) They have a strong operating magnetic, field (b) They are not normally used in vertical position (c) They need a large damping force, which can only be provided by air friction (d) The introduction of a permanent magnet required for eddy current damping would distort the existing weak operating magnetic field
A

1 Answer

Answer :

In moving iron instruments, eddy current damping cannot be used as The introduction of a permanent magnet required for eddy current damping would distort the existing weak operating magnetic field

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