what is the principle of moving coil galvanometer?
The Princciple of MCG is that a current carrying coil, when placed in an extrernal magnetic field, experiences a torque.
Torque = mxB = NIABsinθ
Here, sinθ=1 a the galvanometer uses a cylindrcals soft iron core which makes the magntic field radial
Hence, torque = NIAB.