Galvanometer

Q. Electric field inside an uniformly charges non conducting sphere

Q.

What is the difference between galvanometer and ballistic galvanometer?

Q.

Which of the following statements is false ?

1. Wheatstone bridge is the most sensitive when all the four resistances are of the same order of magnitude.

2. In a balanced Wheatstone bridge if the cell and the galvanometer are exchanged, the null point is disturbed.

3. A rheostat can be used as a potential divider.

4. Kirchhoff’s second law represents energy conservation.

Q. To increase galvanometer range and convert it to an ammeter we should decrease its overall resistance.

1. False
2. True

Q. The deflection in a moving cell galvanometer falls from 50 to 10 divisions when a shunt of 12 ohm is connected across it. The resistance of the galvanometer coil is

1. 24 ohm
2. 36 ohm
3. 48 ohm
4. 60 ohm

Q. A galvanometer having a resistance of $8\Omega$ is shunted by a wire of resistance $2\Omega$. If the total current is 1 ampere, the part of it passing through the shunt will be

1. 0.25 amp
2. 0.8 amp
3. 0.2 amp
4. 0.5 amp

Q. A moving coil galvanometer is converted into an ammeter reading upto 0.03 A by connecting a shunt of resistance 4r across it and into an ammeter reading upto 0.06 A when a shunt of resistance r connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used.

1. 0.01 A
2. 0.02 A
3. 0.03 A
4. 0.04 A

Q. A galvanometer gives full scale deflection of $1\text{volt}$ when acting like a voltmeter when connected in series with $2\text{k}$$\Omega$ resistance. The same galvanometer gives $500\text{mA}$ full scale deflection when acting like a ammeter when connected with shunt resistance of value $0.2\Omega$ in parallel. Find out the resistance of galvanometer (in $\Omega$).

1. $108$
2. $222$
3. $250$
4. $1.5$

Q. When a $12\Omega$ resistor is connected with a moving coil galvanometer, then its deflection reduces from 50 divisions to 10 divisions. The resistance of the galvanometer is

1. $24\Omega$
2. $36\Omega$
3. $48\Omega$
4. $60\Omega$

Q. What should you do to a galvanometer to increase its range and convert it to an ammeter?

1. Change the dial markings on the galvanometer
2. Decrease its overall resistance
3. Increase its overall resistance
4. Use better batteries on it

Q. What should you do to a galvanometer to increase its range and convert it to an ammeter?

1. Change the dial markings on the galvanometer
2. Decrease its overall resistance
3. Increase its overall resistance
4. Use better batteries on it

Q. A galvanometer shows a reading of $0.65\text{mA}$. When a galvanometer is shunted with a $4\Omega$ resistance, the deflection is reduced to $0.13\text{mA}$. If the galvanometer is further shunted with a $2\Omega$ wire, the new reading will be (the main current remains the same)

1. $0.60\text{mA}$
2. $0.08\text{mA}$
3. $0.12\text{mA}$
4. $0.05\text{mA}$

Q. A galvanometer has coil resistance of $99\Omega$ with full scale deflection current of 0.01A.

1. With shunt of $11\Omega$ it is converted to ammeter of range 0.1 A.
2. With shunt of $1\Omega$ it is converted to ammeter of range 1A.
3. With resistance of $9901\Omega$ in series it becomes voltmeter of range 100 V.
4. With resistance of $101\Omega$ in series it becomes voltmeter of range 20V.

Q. A moving coil galvanometer of resistance $100\Omega$ is used as an ammeter using a resistance $0.1\Omega$. The maximum deflection current in the galvanometer is $100\mu \text{A}$. Find the minimum current in the circuit, so that the ammeter shows maximum deflection

1. $100.1\text{mA}$
2. $1000.1\text{mA}$
3. $10.01\text{mA}$
4. $1.01\text{mA}$

Q. A moving coil galvanometer of resistance $20\Omega$ gives a full scale deflection when a current of $1\text{mA}$ is passed through it. It is to be converted into an ammeter reading $20\text{A}$ on full scale. But the shunt of $0.005\Omega$ only is available. What resistance should be connnected in series with the galvanometer coil?

1. $39.995\Omega$
2. $60.995\Omega$
3. $79.995\Omega$
4. $80.995\Omega$

Q. A galvanometer having a resistance of $8\Omega$ is shunted by a wire of resistance $2\Omega$. If the total current is 1 ampere, the part of it passing through the shunt will be

1. 0.25 amp
2. 0.8 amp
3. 0.2 amp
4. 0.5 amp

Q. A galvanometer, having a resistance of $50\Omega$ gives a full scale deflection for a current of 0.05 A. the length in meter of a resistance wire of area of cross-section $2.97\times {10}^{-2}c{m}^2$ that can be used to convert the galvanometer into an ammeter which can read a maximum of 5A current is : ( Specific resistance of the wire $=5\times {10}^{-7}\Omega m$)

1. 9
2. 6
3. 3
4. 1.5