1. The hot wire ammeter

1. Is used only for dc circuits
2. High precision instrument
3. Used only for ac circuit
4. Reads equally well on dc and ac circuit

2. The internal resistance of the milliammeter must be very low for

1. High accuracy
2. High sensitivity
3. Minimum effect on the current in the circuit
4. Maximum voltage drop across the meter

3. Assertion (A): shunt of an ammeter has low resistance.

原因(R):并联连接在系列或parallel with an ammeter.

1. Both A and R are true and R is correct explanation of A
2. Both A and R are true, but R is not correct explanation of A
3. A is true, R is false
4. A is false, R is true

4. Sensitive low voltage electronic components are protected from

1. Static charge
2. Induction circuit
3. Lightening
4. All of these

5. In order to convert to galvanometer into an ammeter

1. A small resistance is connected in parallel to the coil of galvanometer
2. A large resistance is connected in parallel to the coil of galvanometer
3. A small resistance is connected in series to the coil of galvanometer
4. A large resistance is connected in series to the coil of galvanometer

6. Which one of the following is used to measure direct current?

1. Voltmeter
2. Ammeter
3. Pyrometer
4. Coupler

7. A 10 mA ammeter has a resistance of 50 ohms. It is to be converted to a 1 A ammeter. The value of shunt resistance should be

1. 5 ohms
2. 0.1 ohms
3. 0.505 ohms
4. 0.05 ohms

8. Internal resistance of an ideal ammeter is

1. Zero
2. Infinite
3. Small
4. Big

9. Which instrument has the lowest resistance?

1. Ammeter
2. Voltmeter
3. Megger
4. Frequency meter

10. A DC ammeter has a resistance of 0.1 ohm and the current range is 0-100 A. If the range is to be extended to 0-500A, then meter requires shunt resistance of

1. 0.010 ohm
2. 0.011 ohm
3. 0.025 ohm
4. 1.0 ohm

11. In electrodynamometer ammeter, the deflection of the pointer is proportional to

1. Mean of current in fixed coil and moving coil
2. Square of the current in moving coil
3. RMS value of current in fixed coil
4. Mean-square of currents in fixed coil and moving coil

12. The multiplying power of the shunt of a milliammeter is 8. If the circuit current is 200 mA. Then current through the meter is

1. 25 mA
2. 200 mA
3. 1600 mA
4. 3200 mA

13.一个安培计可以公司的测量范围reased by using a

1. High resistance in shunt
2. Low resistance in shunt
3. High resistance in series
4. Low resistance in series

14. An ammeter has a current range of 0-5 A, and its internal resistance is 0.2 ohm. In order to change the range to 0-25 A, what should be the value of resistance added and how it would connect with meter (i.e. series/parallel)?

1. (0.05 ohm/series)
2. (0.05 ohm/Parallel)
3. (0.20 ohm/parallel)
4. (0.20 ohm/series)

15. Clamp on ammeter is used for measurement of

1. Large alternating currents
2. Small direct currents
3. Small alternating currents
4. Large direct currents

16. Range of ammeter can extend by connecting

1. A shunt parallel to ammeter
2. A shunt in series to ammeter
3. A multiplier parallel to ammeter
4. A multiplier in series to ammeter

17. An instrument which detects electric current is known as

1. Voltmeter
2. Rheostat
3. Wattmeter
4. Galvanometer

18. A dc circuit can be represented by an internal voltage source of 50 V with an output resistance of 100 kΩ. In order to achieve 99 % accuracy for voltage measurement across its terminals, the voltage measuring device should have

1. A resistance of atleast 10MΩ
2. A resistance of 100 kΩ
3. A resistance of atleast 10 Ω
4. None of these

19. A voltage using a 20 microammeter movement has a sensitivity of

1. 20 micro-ohm/volt
2. 1000 ohm/volt
3. 20,000 ohm/volt
4. 50,000 ohm/volt

20. Ammeters are always connected in

1. Series
2. Parallel
3. Either
4. None