The unit of reduction factor of the tangent galvanometer is 

1. Ampere

2. Gauss

3. Radian

4. None of these

A voltmeter of resistance 1000 Ω gives full-scale deflection when a current of 100 mA flow through it. The shunt resistance required across it to enable it to be used as an ammeter reading 1 A at full-scale deflection is :

1. 10000 Ω

2. 9000 Ω

3. 222 Ω

4. 111 Ω

A galvanometer of \(50~\Omega \) resistance has 25 divisions. A current of 4 × 10^–4 A gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 V, it should be connected with a resistance of:

1. 2500 Ω as a shunt

2. 2450 Ω as a shunt

3. 2550 Ω in series

4. 2450 Ω in series

A moving coil galvanometer of resistance 100Ω is used as an ammeter using a resistance 0.1Ω. The maximum deflection current in the galvanometer is 100 mA. Find the minimum current in the circuit so that the ammeter shows maximum deflection :

1. 100.1 A

2. 1000.1 mA

3. 10.01 mA

4. 1.01 mA

A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 volt, the resistance in ohms needed to be connected in series with the coil will be 

(1) 99995

(2) 9995

(3) 10³

(4) 10⁵

To make the field radial in a moving coil galvanometer :

1. The number of turns in the coil is increased

2. Magnet is taken in the form of horse-shoe

3. Poles are cylindrically cut

4. The coil is wounded on the aluminum frame

In a moving coil galvanometer, the deflection of the coil $\theta$ is related to the electrical current i by the relation

1. $i\propto \tan \theta$                 

2. $i\propto \theta$ 

3. $i\propto {\theta }^2$                    

4. $i\propto \sqrt{\theta }$ 

A moving coil galvanometer has N number of turns in a coil of effective area A, it carries a current I. The magnetic field B is radial. The torque acting on the coil is 
 

1. $N{A}^2{B}^{2}I$                          

2. $NAB{I}^2$

3. $N^{2}ABI$                            

4. $NABI$

Which among the following options needs to be decreased to increase the sensitivity of a moving coil galvanometer?

A ring of radius R, made of an insulating material carries a charge Q uniformly distributed on it. If the ring rotates about the axis passing through its center and normal to the plane of the ring with constant angular speed $\omega$, then the magnitude of the magnetic moment of the ring is:

1. $Q\omega R^2$                       2. $\frac{1}{2}Q\omega R^2$

3. $Q{\omega }^{2}R$                       4. $\frac{1}{2}Q{\omega }^{2}R$