Question

State the underlying principles of working of a moveing coil galvanometer. Write the two reasons why a galvonmeter cannot be used as such to measure current in a given circuit.Name any two factors on which that current sensitivity of a galvanometer depends.

Answer 1

Principle of working of a moveing coil galnometer : The working is bassed on the fact that current carrying coil suspended in a magnetic field experience a torque.
(ii) The galvonmeterf cannot be used to measure the value of the current in a given circuit due to following two reasons:
(a) Galvanometer is a very device, its gives a full scale deflection for a current of the order of `muA`.
(b). Fing currents, the galvanometer has to be connected in series, and as it has a large resistance, this will change the value of the current in the circuit.
(iii) The current sensitivity of the galvanometer depends upon the number of truns N and cross section area of the coil A.