Ammeter MCQ | Electricalvoice

Ammeter MCQ

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
Answer. d

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
Answer. c

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

Reason (R): shunt may be connected in series or in 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
Answer. c

4. Sensitive low voltage electronic components are protected from

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

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
Answer. a

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

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

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
Answer. c

8. Internal resistance of an ideal ammeter is

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

9. Which instrument has the lowest resistance?

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

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
Answer. c

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
Answer. d

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
Answer. a

13. The measurement range of an ammeter can be increased by using a

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

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)
Answer. c

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
Answer. a

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
Answer. a

17. An instrument which detects electric current is known as

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

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
Answer. a

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
Answer. d

20. Ammeters are always connected in

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