Measurement and Instrumentation MCQ Multiple Choice Questions - Page 2 for Practice

Q: 31. For measurements on high voltage capacitors, the suitable bridge is

Correct Answer is: Schering bridge

Q: 33. For measuring current at high frequency we should use

Correct Answer is: thermocouple instrument

Q: 34. If an inductance is connected in one arm of bridge and resistances in the remaining three arms

Correct Answer is: the bridge cannot be balanced

Q: 35. If an instrument has cramped scale for larger values, then it follows

Correct Answer is: logarithmic law

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

Correct Answer is: in series with pressure coil

Q: 41. In a low power factor wattmeter the pressure coil is connected

Correct Answer is: to the load side of the current coil

Q: 44. In a Schering bridge the potential of the detector above earth potential is

Correct Answer is: a few volts only

Q: 45. In a single phase power factor meter the phase difference between the currents in the two pressure coils is

Correct Answer is: exactly 90Â°

Q: 47. In a Weston frequency meter, the magnetic axes of the two fixed coils are

Correct Answer is: perpendicular

Q: 48. In a Weston synchronoscope, the fixed coils are connected across

Correct Answer is: incoming alternator

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

Wein bridge
Modified De Santys bridge
Schering bridge
Any of the above

32. For measuring a very high resistance we should use

Kelvins double bridge
Wheat stone bridge
Meggar
None of the above

33. For measuring current at high frequency we should use

moving iron instrument
electrostatic instrument
thermocouple instrument
none of the above

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

the bridge can always be balanced
the bridge cannot be balanced
the bridge can be balanced if the resistances have some specific values

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

square law
logarithmic law
uniform law
none of the above

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

10Â°
80Â°
120Â°
170Â°

37. 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

unity
0.5
0.3
zero

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

unity
0.8 lagging
0.8 leading
zero

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

0Â°
60Â°
90Â°
120Â°

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

in series with current coil
in parallel with current coil
in series with pressure coil
in parallel with pressure coil

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

to the supply side of the current coil
to the load side of the current coil
in any of the two meters at connection
none of the above

42. In a meggar controlling torque is provided by

spring
gravity
coil
eddy current

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

spring
gravity
eddy currents
all of the above

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

a few volts only
1 kV
5 kV
10 kV

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

exactly 0Â°
approximately 0Â°
exactly 90Â°
approximately 90Â°

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

0.1 Hz
0.25 Hz
0.5 Hz
1.5 Hz

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

parallel
perpendicular
inclined at 60Â°
inclined at 120Â°

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

bus-bars
incoming alternator
a lamp
none of the above

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

out of phase by 90Â°
out of phase by 60Â°
out of phase by 30Â°
out of phase by 0Â°

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

known inductance and resistance
known capacitance and resistance
known resistance
known inductance

51. In an energymeter braking torque is produced to

safe guard it against creep
brake the instrument
bring energy meter to stand still
maintain steady speed and equal to driving torque

52. In majority of instruments damping is provided by

fluid friction
spring
eddy currents
all of the above

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

as long as possible
as short as possible
neither too small not too large
very thick

54. In Weston synchronoscope the moving coil is connected across

bus-bars
incoming alternator
fixed coils
any of the above

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

56. Instrument transformers are

potential transformers
current transformers
both a and b
power transformers

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

Tangent galvanometer
Meggar
Current transformer
None of the above

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

D.C. voltmeter
Ammeter and a known resistance
D.C. potentiometer
None of the above

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

mercury motor meters
commutator motor meters
induction type single phase energy meters
all of the above

60. Most sensitive galvanometer is

elastic galvanometer
vibration galvanometer
Duddlb galvanometer
spot ballistic galvanometer