Which one of the following modifications may increase the senstivity of moving coil galvanometer?
`1^(st)` Way : By using spring of smaller torsion constant.
`2^(nd)` Way : By using a smaller coil
`3^(rd)` Way : By using a stronger magnet
`4^(th)` Way: By using a coil having fewer number of turns.

Which of the following material is used in making the core of a moving coil galvanometer?

Which of the following material is used in making the core of a moving coil galvanometer?

The sensitivity of a moving coil galvanometer can be increased by (1) decreasing the couple per unit twist of the suspension (2) increasing the number of turns in the coil (3) decreasing the area of the coil (4) decreasing the magnetic field

Assertion : The sensitivity of a moving coil galvanometer is increased by using a soft iron cylinder as a core inside the coil. Reason : Soft iron has a high magnetic permeability and cannot be easily magnetised or demagnetised.

Answer the following: (a) With the help of a diagram , explain the principle and working of a moving coil galvanometer . (b) What is the importance of a radial magnetic field and how is it produced ? (c) Why is it while using a moving coil galvometer as a voltmeter a high resistance in series is required whereas in an ammeter a shunt is used ?

In a moving coil galvanometer, there is a coil of copper having number of insulated turns N, each of area A. The coil is suspended in a radial magnetic field B. The moment of inertia of the coil about its rotational axis is I. The scale divisions in the galvanometer are n and resistance of the coil is R. If a current i_0 in the coil produces a deflection of pi//3 radian to the pointer of galvanometer, the value of torsional constant of the spring is