details about moving coil galvanometer

Hello student,
A moving coil galvanometer is basically an electromechanical instrument which is used for detection of electric currents. It can be used only for figuring out the electric currents and its primary purpose is not measurement of elelctric current but just detection of elelctric currents.
Galvanometer works on the principle of conversion of electrical energy into mechanical energy. When some current flows in some magentioc field, it often faces/experiences some magnetic torque.
τ = nBiA cos θ, where
n is the number of turns of the coil of area A, i is the current passing through it. B is teh strength of magentic field due to magnet NS andθ is the angle which the plane of the coil makes with the magentic field.