electrical

Electrical Instruments MCQ Objective Questions and Answers Page - 5

1.

Which one of the following statements is not correct  ?

Answer/ Hint      

Answer : C

Explanation :

2.

Which one of the following pressure transducers is suitable for measurement of high pressure  ?

Answer/ Hint      

Answer : B

Explanation :

3.

Tachometers are used for only

Answer/ Hint      

Answer : A

Explanation :

4.

The generated emf of a dc tacho-generator is

Answer/ Hint      

Answer : A

Explanation :

5.

AC tachometers are often built with thin metallic drag-cup rotor to

Answer/ Hint      

Answer : C

Explanation :

6.

Transducer for measurement of rotational displacement  is

Answer/ Hint      

Answer : A

Explanation :

7.

An inductive pick-up used to measure the speed of a shaft has 120 tooth wheel. If the number of pules produced in a second is 3000, the rpm of the shaft is

Answer/ Hint      

Answer : B

Explanation :

8.

Doppler shift principle is used in the measurement of

Answer/ Hint      

Answer : C

Explanation :

9.

The accelerometer using  LVDT  has the advantage of

Answer/ Hint      

Answer : D

Explanation :

10.

The accelerometer used for measurement of vibration of large structures is

Answer/ Hint      

Answer : A

Explanation :

11.

The most common transducer for shock and vibration measurement is

Answer/ Hint      

Answer : D

Explanation :

12.

The drawbacks of radiation pyrometers are that

Answer/ Hint      

Answer : D

Explanation :

13.

In optical pyrometers temperature is measured by

Answer/ Hint      

Answer : C

Explanation :

14.

Which of the following is the best method for measurement of temperature of hot bodies radiating energy in visible spectrum  ?

Answer/ Hint      

Answer : C

Explanation :

15.

Which of the following is used to measure temperature inside a boiler furnace  ?

Answer/ Hint      

Answer : B

Explanation :

16.

Which is the most suitable thermocouple transducer for the measurement of temperature in the range of 1,000C  to  1,5000C  ?

Answer/ Hint      

Answer : B

Explanation :

17.

Which of the following thermocouple pairs has maximum sensitivity around 273 K  ?

Answer/ Hint      

Answer : A

Explanation :

18.

Optical pyrometer is generally used to measure

Answer/ Hint      

Answer : C

Explanation :

19.

A Reynold’s number of 1000 indicates

Answer/ Hint      

Answer : B

Explanation :

20.

The flow rate of electrically conducting liquid without any suspended particle cannot be measured by

Answer/ Hint      

Answer : D

Explanation :

21.

A hot-wire anemometer is a device used to measure  :

Answer/ Hint      

Answer : A

Explanation :

22.

The device used for measuring flow of air around an aeroplane is

Answer/ Hint      

Answer : C

Explanation :

23.

Which of the following flow meters is capable of giving the rate of flow as well as the total flow  ?

Answer/ Hint      

Answer : B

Explanation :

24.

The main drawbacks of ultrasonic flow-meter are

Answer/ Hint      

Answer : B

Explanation :

25.

Hydrometer is employed for determination of

Answer/ Hint      

Answer : B

Explanation :

26.

Inductive method can be used for measuring thickness of

Answer/ Hint      

Answer : D

Explanation :

27.

Which of the following transducers is most suitable for monitoring continuous variations in very fine thickness of a material  ?

Answer/ Hint      

Answer : B

Explanation :

28.

The electrical transducers used for continuous recording and control of humidity are

Answer/ Hint      

Answer : D

Explanation :

29.

Measurements of flow, thermal conductivity and liquid level using thermistros make use of

Answer/ Hint      

Answer : A

Explanation :

30.

In viscosity meters the quantity measured is

Answer/ Hint      

Answer : B

Explanation :

31.

The function of the reference electrode in a  pH  meter is to

Answer/ Hint      

Answer : A

Explanation :

32.

The method used for analysis of gases and their mixtures is called as

Answer/ Hint      

Answer : A

Explanation :

33.

The disadvantage(s) of capacitor microphones is/are

Answer/ Hint      

Answer : C

Explanation :

34.

The devices extensively used in sound measurement system are

Answer/ Hint      

Answer : D

Explanation :

35.

A linear displacement digital transducer uses

Answer/ Hint      

Answer : B

Explanation :

36.

Which if the following moving particles cannot be deflected by magnetic fields  ?

Answer/ Hint      

Answer : B

Explanation :

37.

Geiger counter has the advantages of

Answer/ Hint      

Answer : D

Explanation :

38.

Scintillation counters have the advantage(s) of

Answer/ Hint      

Answer : D

Explanation :

39.

Analog data acquisition system are used when

Answer/ Hint      

Answer : A

Explanation :

40.

In AC bridge if the supply frequency is 1000 Hz, the detector will be

Answer/ Hint      

Answer : D

Explanation :

41.

_____________  bridge is used for the precise measurement of inductances over a wide range.

Answer/ Hint      

Answer : C

Explanation :

42.

Which of the following bridges is used to measure power factor?

Answer/ Hint      

Answer : C

Explanation :

43.

Moving parts of instruments are supported in  ___________  bearings.

Answer/ Hint      

Answer : A

Explanation :

44.

A power factor meter has  ____________  control springs.

Answer/ Hint      

Answer : D

Explanation :

45.

Dead time of the instrument is

Answer/ Hint      

Answer : B

Explanation :

46.

In resistance thermometers platinum is used because of

Answer/ Hint      

Answer : C

Explanation :

47.

Changes in atmospheric temperature, humidity etc. cause  __________ errors.

Answer/ Hint      

Answer : C

Explanation :

48.

In electrical measuring instruments, electrical energy is converted to

Answer/ Hint      

Answer : A

Explanation :

49.

Megger is used to measure

Answer/ Hint      

Answer : C

Explanation :

50.

Sensitivity of a voltmeter is given by the

Answer/ Hint      

Answer : C

Explanation :

51.

Control springs are made up of

Answer/ Hint      

Answer : A

Explanation :

52.

In the case of indicating instruments the function of the control spring is

Answer/ Hint      

Answer : C

Explanation :

53.

Torque weight ratio will be least in ___________  instruments.

Answer/ Hint      

Answer : A

Explanation :

54.

Megger is operated by

Answer/ Hint      

Answer : C

Explanation :

55.

Megger will give resistance values which

Answer/ Hint      

Answer : C

Explanation :

56.

Primary of an instrument transformer (C.T.) is connected in

Answer/ Hint      

Answer : A

Explanation :

57.

Vibrating reeds are used in which of the following instruments?

Answer/ Hint      

Answer : B

Explanation :

58.

If voltage supply to the energy meter is more than the rated value, energy meter will run

Answer/ Hint      

Answer : A

Explanation :

59.

Aluminium is selected as the material for rotating disc of energy meter because

Answer/ Hint      

Answer : D

Explanation :

60.

For making shunts the material suitable is that which has

Answer/ Hint      

Answer : D

Explanation :

61.

Meter ranges are so selected that the indications are obtained near the

Answer/ Hint      

Answer : C

Explanation :

62.

For measuring an unknown electrical quantity, select the meter with

Answer/ Hint      

Answer : A

Explanation :

63.

Moving iron meters are extensively used for the measurement of AC voltage and current because

Answer/ Hint      

Answer : A

Explanation :

64.

Moving iron instruments are rarely used in low power high resistance circuits because of

Answer/ Hint      

Answer : C

Explanation :

65.

Scale of an instrument will ne uniform if

Answer/ Hint      

Answer : C

Explanation :

66.

Swamping resistance is used to

Answer/ Hint      

Answer : A

Explanation :

67.

Which of the following instruments may be used to measure DC voltage accurately?

Answer/ Hint      

Answer : B

Explanation :

68.

A high resistance is usually connected in series with an electrostatic voltmeter

Answer/ Hint      

Answer : C

Explanation :

69.

A milli-ammeter can be used as

Answer/ Hint      

Answer : C

Explanation :

70.

Weston cell is a

Answer/ Hint      

Answer : C

Explanation :

71.

Deflection of a hot wire instrument is proportional to

Answer/ Hint      

Answer : C

Explanation :

72.

Following type of instrument is used to measure very small currents of high frequency

Answer/ Hint      

Answer : D

Explanation :

73.

In which part of the scale does the pointer indicate most accurately?

Answer/ Hint      

Answer : D

Explanation :

74.

The accuracy of a meter is determined by  ____________  deflection.

Answer/ Hint      

Answer : D

Explanation :

75.

The sensitivity inaccuracy of an instrument does not depend on

Answer/ Hint      

Answer : D

Explanation :

76.

The error, when reading at half-scale in an instrument, is

Answer/ Hint      

Answer : D

Explanation :

77.

An instrument’s reliability means

Answer/ Hint      

Answer : C

Explanation :

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Electrical Instruments MCQ Objective Questions and Answers Page - 5