Quiznetik

Measurement and Instrumentation | Set 1

1. The use of _____ instruments is merely confined within laboratories as stand¬ardizing instruments.

Correct : A. absolute

2. Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?

Correct : B. Indicating instruments

3. _____ instruments are those which measure the total quantity of electricity delivered in a particular time.

Correct : D. Integrating

4. Which of the following are integrating instruments ?

Correct : D. Ampere-hour and watt-hour meters

5. Resistances can be measured with the help of

Correct : D. ohmmeters and resistance bridges

6. According to application, instruments are classified as

Correct : C. both (a) and (b)

7. Which of the following essential features is possessed by an indicating instrument ?

Correct : D. All of the above

8. A _____ device prevents the oscillation of the moving system and enables the latter to reach its final position quickly

Correct : C. damping

9. The spring material used in a spring control device should have the following property.

Correct : D. All of the above

10. Which of the following properties a damping oil must possess ?

Correct : D. All of the above

11. A moving-coil permanent-magnet instrument can be used as _____ by using a low resistance shunt.

Correct : A. ammeter

12. A moving-coil permanent-magnet instrument can be used as flux-meter

Correct : C. by eliminating the control springs

13. Which of the following devices may be used for extending the range of instruments ?

Correct : D. All of the above

14. An induction meter can handle current upto

Correct : D. 100 A

15. For handling greater currents induction wattmeters are used in conjunction with

Correct : B. current transformers

16. Induction type single phase energy meters measure electric energy in

Correct : C. kWh

17. Most common form of A.C. meters met with in every day domestic and industrial installations are

Correct : C. induction type single phase energy meters

18. Which of the following meters are not used on D.C. circuits

Correct : C. Induction meters

19. Which of the following is an essential part of a motor meter ?

Correct : D. All of the above

20. A potentiometer may be used for

Correct : D. all of the above

21. is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another,

Correct : B. Meggar

22. The household energy meter is

Correct : C. an integrating instrument

23. The pointer of an indicating instrument should be

Correct : A. very light

24. The chemical effect of current is used in

Correct : A. D.C. ammeter hour meter

25. In majority of instruments damping is provided by

Correct : C. eddy currents

26. An ammeter is a

Correct : A. secondary instrument

27. In a portable instrument, the controlling torque is provided by

Correct : A. spring

28. The disc of an instrument using eddy current damping should be of

Correct : C. conducting and non-magnetic material

29. The switch board instruments

Correct : A. should be mounted in vertical position

30. The function of shunt in an ammeter is to

Correct : A. by pass the current

31. The multiplier and the meter coil in a voltmeter are in

Correct : A. series

32. A moving iron instrument can be used for

Correct : C. both D.C. and A.C.

33. The scale of a rectifier instrument is

Correct : A. linear

34. For measuring current at high frequency we should use

Correct : C. thermocouple instrument

35. The resistance in the circuit of the moving coil of a dynamometer wattmeter should be

Correct : C. high

36. A dynamometer wattmeter can be used for

Correct : A. both D.C. and A.C.

37. An induction wattmeter can be used for

Correct : B. D.C. only

38. The pressure coil of a wattmeter should be connected on the supply side of the current coil when

Correct : A. load impedance is high

39. In a low power factor wattmeter the pressure coil is connected

Correct : B. to the load side of the current coil

40. In a low power factor wattmeter the compensating coil is connected

Correct : C. in series with pressure coil

41. In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was

Correct : A. unity

42. In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero. The power factor of the load must be

Correct : B. 0.5

43. The adjustment of position of shading bands, in an energy meter is done to provide

Correct : A. friction compensation

44. An ohmmeter is a

Correct : B. moving coil instrument

45. When a capacitor was connected to the terminal of ohmmeter, the pointer indicated a low resistance initially and then slowly came to infinity position. This shows that capacitor is

Correct : B. all right

46. For measuring a very high resistance we should use

Correct : C. Meggar

47. The electrical power to a meggar is provided by

Correct : B. permanent magnet D.C. generator

48. In a meggar controlling torque is provided by

Correct : C. coil

49. The operating voltage of a meggar is about

Correct : D. 100 V

50. Murray loop test can be used for location of

Correct : C. both the ground fault and the short-circuit fault

51. Which of the following devices should be used for accurate measurement of low D.C. voltage ?

Correct : B. D.C. potentiometer

52. It is required to measure the true open circuit e.m.f. of a battery. The best device is

Correct : C. D.C. potentiometer

53. A voltage of about 200 V can be measured

Correct : B. a D.C. potentiometer in conjunction with a volt ratio box

54. A direct current can be measured by

Correct : B. a D.C. potentiometer in conjunction with a standard resistance

55. To measure a resistance with the help of a potentiometer it is

Correct : B. not necessary to standardise the potentiometer

56. A phase shifting transformer is used in conjunction with

Correct : B. Drysdale potentiometer

57. Basically a potentiometer is a device for

Correct : A. comparing two voltages

58. In order to achieve high accuracy, the slide wire of a potentiometer should be

Correct : A. as long as possible

59. To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken

Correct : C. from the same source as the unknown voltage

60. The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a

Correct : B. two-phase winding

61. In an AC. co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be

Correct : A. out of phase by 90°

62. A universal RLC bridge uses

Correct : B. Maxwell Wein bridge for measurement of inductance and modified De Santy's bridge for measurement of capacitance

63. For measurements on high voltage capacitors, the suitable bridge is

Correct : C. Schering bridge

64. In an Anderson bridge, the unknown inductance is measured in terms of

Correct : B. known capacitance and resistance

65. Wagner earthing device is used to eliminate errors due to

Correct : A. electrostatic coupling

66. For measurement of mutual inductance we can use

Correct : C. Heaviside bridge

67. For measurement of inductance having high value, we should use

Correct : C. Hay's bridge

68. If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is

Correct : A. 10°

69. In a Schering bridge the potential of the detector above earth potential is

Correct : A. a few volts only

70. To avoid the effect of stray magnetic field in A.C. bridges we can use

Correct : A. magnetic screening

71. If an inductance is connected in one arm of bridge and resistances in the remaining three arms

Correct : B. the bridge cannot be balanced

72. A power factor meter has

Correct : A. one current circuit and two pres¬sure circuits

73. The two pressure coils of a single phase power factor meter have

Correct : A. the same dimensions and the same number of turns

74. In a single phase power factor meter the phase difference between the currents in the two pressure coils is

Correct : C. exactly 90°

75. In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at

Correct : D. 120°

76. In a vibrating reed frequency meter the natural frequencies of two adjacent reeds have a difference of

Correct : C. 0.5 Hz

77. In a Weston frequency meter, the magnetic axes of the two fixed coils are

Correct : B. perpendicular

78. A Weston frequency meter is

Correct : B. moving iron instrument

79. A Weston synchronoscope is a

Correct : C. dynamometer instrument

80. In a Weston synchronoscope, the fixed coils are connected across

Correct : B. incoming alternator

81. In Weston synchronoscope the moving coil is connected across

Correct : A. bus-bars

82. The power factor of a single phase load can be calculated if the instruments available are

Correct : B. one voltmeter, one ammetqr and one wattmeter

83. The desirable static characteristics of a measuring system are

Correct : B. accuracy, sensitivity and reproducibility

84. The ratio of maximum displacement deviation to full scale deviation of the instrument is called

Correct : C. linearity

85. Systematic errors are

Correct : D. all of the above

86. Standard resistor is made from

Correct : B. maganin

87. Commonly used standard capacitor is

Correct : B. concentric cylindrical type

88. Operating torques in analogue instruments are

Correct : C. deflecting, control and damping

89. Commonly used instruments in power system measurement are

Correct : A. induction

90. Damping of the Ballistic galvanometer is made small to

Correct : A. get first deflection large

91. If an instrument has cramped scale for larger values, then it follows

Correct : B. logarithmic law

92. Volt box is a component to

Correct : A. extend voltage range

93. E.m.f. of a Weston cell is accurately measured by

Correct : A. electrostatic voltmeter

94. The gravity controlled instrument has crowded scale because current is proportional to

Correct : C. sine of deflection angle

95. A sensitive galvanometer produces large deflection for a

Correct : A. small value of current

96. A multirangq instrument has

Correct : A. multiple shunt or series resistances inside the meter

97. The rectifier instrument is not free from

Correct : C. frequency error

98. Alternating current is measured by

Correct : A. induction ammeter

99. Most sensitive galvanometer is

Correct : D. spot ballistic galvanometer

100. Instrument transformers are

Correct : C. both (a) and (b)