250+ Electronic Measurements and Instrumentation MCQ Questions

In this article, we shared the 250 plus electronic measurements and instrumentation MCQ questions and answers to test your knowledge.

Electronic Measurements and Instrumentation MCQ Questions

MCQ on Measurement and Instrumentation

The below list provides all the multiple-choice questions related to the measurement and instrumentation technical subject.

Answers are available at the bottom of the article.

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

A)by using a high series resistance
B)by eliminating the control springs
C)by using a low resistance shunt
D)by making control springs of large moment of inertia

2. The brightest spot, on a cathode ray screen, occurs at

A)brightness is same all over the screen
B)midway between centre and outer periphery of screen
C)the centre
D)the outer periphery

3. Electrodynamic types of instruments are used commonly for the measurement of

D)none of these answers

4. A dynamometer wattmeter can be used for

A)D.C. only
B)A.C. only
C)any of these answers
D)both D.C. and A.C.

5. The total power delivered to a threephase load is equal to

A)algebraic difference of two-watt meters readings
B)vectorial difference of two-watt meters readings
C)algebraic sum of two-wattmeter readings
D)vectorial sum of two-wattmeter readings

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


7. Transmission channels for telemetry are

A)radio links
C)all of these answers
D)ultrasonic and magnetic induction data links
E)optical links

8. ____ is a digital transducer.

D)Piezoelectric transducer

9. A C.R.O. can be used to measure

B)any of these answers
C)d.c. voltages only
D)a.c. voltages only

10. For measuring an unknown electrical quantity, select the meter with

A)highest range and work down
B)any of these answers
C)lowest range and work up
D)with middle range and work up and down on trial and error basis

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

A)Schering bridge
B)Modified De Santy’s bridge
C)Wein bridge
D)None of these answers
E)Any of these answers

12. Which of the following can be measured by a hot wire anemometer ?

A)Very low pressures
B)Liquid discharges
C)Gas velocities
D)Pressure of gases
E)None of these answers

13. In an A.C. co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be

A)out of phase by 90°
B)out of phase by 0°
C)out of phase by 30°
D)out of phase by 60°
E)out of phase by 180°

14. The minimum number of wattmeters required to measure power in an unbalanced three-wire system is


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

A)series with the line
B)parallel with the lint
C)any of these answers
D)across two lines

16. E.m.f. of a weston cell is accurately measured by

A)isothermal voltmeter
B)electrodynamic voltmeter
C)hot wire voltmeter
D)electrostatic voltmeter

17. For measurement of mutual inductance we can use

A)Anderson bridge
B)Maxwell’s bridge
C)Heaviside bridge
D)Any of these answers

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

A)Thermo couple
C)Optical pigometer

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

A)all of these answers
B)commutator motor meters
C)mercury motor meters
D)induction type single phase energy meters

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

A)a few volts only
B)1 kV
C)10 kV
D)5 kV

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

A)creep compensation
B)braking torque
C)none of these answers
D)friction compensation

22. The phenomenon of ‘creeping’ occurs in

D)Watthour meters

23. A wattmeter will be free from the effects of power factor and frequency variations in case

A)damping is not provided
B)voltage coil resistance is zero
C)a capacitance is connected in parallel to pressure coil
D)pressure coil inductance is zero

24. In instruments the term ‘artificial aging’ is associated with

A)permanent magnets
C)controlling torque

25. A moving iron type ammeter has few turns of thick wire so that

A)resistance is less
B)scale is large
C)damping is effective
D)sensitivity is high

26. In measuring instruments a mirror is provided behind the pointer with a purpose that

A)with the help of the mirror it may be seen whether the pointer is bent or not
B)the scale is illuminated through the mirror
C)any of these answers
D)reading errors due to inclined observation are eliminated by removing parallax between the pointer and its image in the mirror

27. Permanent magnets used in instruments are generally made of

B)cast iron
C)stainless steel

28. For thermocouple measuring instruments which of the following statements is incorrect ?

A)If calibrated on D.C. they cannot be used for A.C. signals
B)Their calibration does not change with time or temperature
C)They are incapable of standing any overloads
D)They read r.m.s. values

29. Which of the following is the pH value of pure water ?

D)None of these answers

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


31. Sensitivity of a voltmeter is given by the

A)none of these answers
B)ohms per volt
C)reciprocal of full scale deflection current
D)both ohms per volt and reciprocal of full scale deflection current

32. Moving iron meters are extensively used for the measurement of A.C. voltage and current because

A)it is very accurate
B)no current flows through the moving element and is robust
C)its torque weight ratio is more
D)none of these answers

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

A)potential transformers
B)none of these answers
C)current transformers
D)power transformers

34. Ring specimens can be tested for its magnetic properties by

A)Any of these answers
B)Maxwell’s bridge
C)A.C. potentiometer
D)Oscillographic method
E)Campbell’s bridge

35. The ratio error of a current transformer is due to

A)exciting current
B)lagging power factor
C)corona effects
D)stray magnetism

36. In an oscilloscope a moving wave form can be made stationary by adjusting which of the following ?

A)horizontal position control
B)sync-amplitude control
C)coarse frequency control
D)vertical positioning control

37. The electrical power to a meggar is provided by

B)permanent magnet D.C. generator
C)any of these answers
D)A.C. generator

38. ___ cannot be used to measure pressure.

B)Strain gauge
C)Pirani gauge

39. In the measurement of power by two wattmeter method, when the readings of the two wattmeters are equal and opposite, it can be concluded that power factor is


40. In Weston synchronoscope the moving coil is connected across

B)any of these answers
C)fixed coils
D)incoming alternator

41. ____ method is suitable for the measurement of a resistance of expected value less than one ohm.

A)Loss of charge
C)Wheatstone bridge
D)Kelvin’s double bridge

42. The operating voltage of a meggar is about

A)100 V
B)12 V
C)40 V
D)6 V

43. An ammeter is a

A)secondary instrument
B)recording instrument
C)integrating instrument
D)absolute instrument

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

A)Permanent magnet moving coil type ammeter
B)Dynamometer type instrument
C)Induction type instrument
D)Thermocouple type instrument

45. The Lissajous pattern of eight, on an oscilloscope, keeps on changing the shape when the ratio of frequencies is

A)not exactly 1 : 1
B)not exactly 2 : 1
C)exactly 3 : 1
D)exactly 4 : 1

46. The function of shunt in an ammeter is to

A)increase the resistance of ammeter
B)increase the sensitivity of the ammeter
C)none of these answers
D)by pass the current

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

A)the same dimension but different number of turns
B)the same dimensions and the same number of turns
C)the same number of turns but different dimensions
D)none of these answers

48. Rosette gauges are used to

A)measure variable strain
B)compensate for temperature variations
C)measure strain in more than one direction
D)amplify strain values

49. A phase shifting transformer is used in conjunction with

A)D.C. potentiometer
B)Drysdale potentiometer
C)A.C. co-ordinate potentiometer
D)Crompton potentiometer

50. High voltage tests are

A)sustained low frequency tests
B)high frequency tests
C)all of these answers
D)constant direct current tests
E)surge tests

51. Alternating current is measured by

A)electrostatic ammeter
B)induction ammeter
C)moving iron repulsion -type voltmeter
D)permanent magnet type ammeter

52. ___ can measure only pressure.

A)Bubble gauge method
B)Belt type meter
C)Radioactive method

53. The chemical effect of current is used in

A)D.C. ammeter hour meter
B)none of these answers
C)D.C. energy meter
D)D.C. ammeter

54. Which of the following is an analogue transducer ?

B)Strain gauge
D)All of these answers

55. An electrodynamic meter can be used to measure

A)none of these answers
B)both A.C. voltages and D.C. voltages
C)A.C. voltages
D)D.C. voltages

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

A)one voltmeter and one ammeter
B)any of these answers
C)one voltmeter, one ammeter and one energy meter
D)one voltmeter, one ammeter and one wattmeter

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

B)almost zero
C)none of these answers

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

A)Should have low specific resistance
B)Should be non-magnetic
C)All of these answers
D)Should not be subjected to fatigue
E)Must be of low temperature co-efficient

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

A)None of these answers
B)Small range thermocouple voltmeter
C)D.C. potentiometer
D)Small range moving coil voltmeter

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

A)necessary to use a volt ratio box in conjunction with the potentiometer
B)not necessary to standardise the potentiometer
C)necessary to standardise the potentiometer
D)none of these answers

61. Torque weight ratio will be least in ____ instruments.

A)all of these answers
C)moving iron
D)moving coil

62. An induction meter can handle current upto

A)30 A
B)100 A
C)10 A
D)60 A

63. ____ can measure pressure directly ?

A)Bourden tube
C)Strain gauge

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

A)to the load side of the current coil
B)in any of the two meters at connection
C)none of these answers
D)to the supply side of the current coil

65. A potentiometer works on

A)none of these answers
B)magnetic effect
C)electro-magnetic induction
D)heating effect

66. The temperature of a furnace can be measured by

A)bimetallic thermometer
B)clinical thermometer
C)optical pyrometer
D)mercury thermometer

67. Instrument transformers are

A)both current transformers and potential transformers
B)power transformers
C)potential transformers
D)current transformers

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

A)none of these answers
B)sine of deflection angle
C)balancing weight
D)deflection angle

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

A)approximately 0°
B)exactly 0°
C)exactly 90°
D)approximately 90°

70. A double beam oscilloscope has

A)two electron guns
B)two different phosphor coatings
C)two screens
D)one wave form divided into two parts

71. Various adjustments in an energy meter include

A)temperature compensation
B)light load or friction
C)all of these answers
D)lag and creep
E)overload and voltage compensation

72. ___ type instrument can have full scale deflection of 300 degrees.

B)Hot wire
D)None of these answers

73. Standard resistor is made from


74. Phosphor coating for cathode ray tubes is provided on

A)inside surfaces only
B)both the inside surfaces & outside surfaces
C)within the glass
D)outside surfaces only

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

A)D.C. potentiometer
B)Ammeter and a known resistance
C)D.C. voltmeter
D)None of these answers

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

A)none of these answers
B)high reluctance of magnetic path
C)high resistance of the coil
D)low reluctance of magnetic path

77. The output of LVDT is in the form of

B)linear displacement of core
C)rotary movement of core
D)high frequency signals

78. In an instrument hysteresis means

A)the change in same reading when input is first increased and then decreased
B)the reliability of the instrument
C)the inaccuracy due to chance in temperature
D)the repeatability of the instrument

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

A)inclined at 60°
B)inclined at 120°

80. In an energy meter braking torque is produced to

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

81. ___ frequency meter can be used for the measurement of radio frequency.

B)Electrical resonance
C)Any of these answers

82. For measuring a very high resistance we should use

A)None of these answers
C)Wheat stone bridge
D)Kelvin’s double bridge

83. Dead time of the instrument is

A)the largest change of input quantity for which t,here is no output of the instrument
B)none of these answers
C)the time required by an instrument to begin to respond to a change in the measure and
D)the time required by an instrument for initial warming up

84. A multimeter can be used for measuring

A)D.C. quantities only
B)A.C. quantities only
C)D.C. as well as A.C. quantities
D)any of these answers

85. Which of the following is the merit of a moving iron instrument ?

A)It can be used at high frequencies
B)It has linear scale
C)It can be used under severe overload conditions
D)Its current sensitivity is high

86. Volt box is a component to

A)compare voltage in a box
B)measure voltage
C)extend voltage range
D)none of these answers

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


88. The e.m.f. of a Weston standard cell can be measured by

A)hot wire voltmeter
B)electrodynamometer type volt-meter

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

A)Damping device
B)Controlling device
C)All of these answers
D)Deflecting device

90. Which of the following properties are measured by a Q-meter ?

A)Electrical properties of capacitors only
B)Electrical properties of both the coils and capacitors
C)Electrical properties of the coils only
D)Mechanical properties of the coils only

91. Which of the following methods is used to shield a dynamometer type wattmeter against stray fields ?

A)Meter is earthed
B)Meter components are made of nonmagnetic materials
C)Neutral wire connection is provided
D)Meter is housed in a soft iron case

92. Which of the following instruments cannot be used for the measurement of A.C. as well as D.C. quantities ?

A)Induction type instruments
B)Electrostatic instruments
C)Hot wire instruments
D)Moving iron instruments

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

A)it is light
B)it is good conductor
C)all of these answers
D)it is indigenously available

94. Harmonic distortion is due to which of the following ?

A)None of these answers
B)Linear behaviour of circuit elements
C)Change in behaviour of circuit elements due to change in temperature
D)Non-linear behaviour of circuit elements

95. A multirange instrument has

A)variable turns of coil
B)any of these answers
C)multicoil arrangement
D)multiple shunt or series resistances inside the meter
E)multi range meters inside the measurement system

96. A Hall’s effect pick up can be used for the measurement of

A)temperature change
B)magnetic flux
C)relative humidity
D)none of these answers

97. The switch board instruments

A)should be mounted in vertical position
B)either should be mounted in vertical position or should be mounted in horizontal position
C)neither should be mounted in vertical position nor should be mounted in horizontal position
D)should be mounted in horizontal position

98. Radio frequency can be measured by which of the following frequency meters ?

A)Weston frequency meter
B)Electrical resonant frequency meter
C)None of these answers
D)Hetrodyne frequency meter

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

A)to increase the range
B)to render the measurement accurate
C)for safety reasons
D)none of these answers

100. The sensitivity inaccuracy of an instrument does not depend on

B)frequency response
C)all of these answers
D)amplitude distortion

101. ___ voltmeter has the least power consumption.

A)Hot wire type
B)Electrostatic type
C)Moving iron attraction type
D)Induction type

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

A)load impedance is low
B)load impedance is high
C)supply voltage is low
D)none of these answers

103. The scale of a rectifier instrument is

A)neither linear nor non-linear
D)either linear or non-linear

104. Which of the following can be measured by Solometers ?

A)Electrical signals
B)Temperature inputs
C)Thermal radiations
D)Optical inputs

105. A voltage of about 200 V can be measured

A)none of these answers
B)a D.C. potentiometer in conjunction with a known resistance
C)a D.C. potentiometer in conjunction with a volt ratio box
D)directly by a D.C. potentiometer

106. Most sensitive galvanometer is

A)elastic galvanometer
B)Duddle galvanometer
C)spot ballistic galvanometer
D)vibration galvanometer

107. A portable instrument is likely to have ____ clamping.

C)eddy current
D)fluid friction

108. ____ will always indicate true r.m.s. value in respective of the wave form ?

A)Moving iron meter
B)None of these answers
C)Digital voltmeter
D)Thermocouple meter

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

A)none of these answers
C)incoming alternator
D)a lamp

110. Moving coil and moving iron type instruments can be distinguished by looking at

A)size of terminals
B)their range

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

A)any of these answers
B)bottom of the scale
C)top of the scale
D)middle of the scale

112. In hot wire instruments the sensing wire is made of


113. The meter constant of single phase energy meter is expressed in terms of


114. The internal resistance of a voltmeter must be very high so that

A)range is high
B)minimum current passes through the meter
C)loading effect is maximum
D)accuracy is high

115. The readings of a dynamometer type wattmeter can be highly erratic at

A)high voltages
B)fluctuating loads
C)low power factors
D)low frequencies

116. An ohmmeter is a

A)moving coil instrument
B)moving iron instrument
C)dynamometer instrument
D)none of these answers

117. Murray loop test can be used for location of

A)none of these answers
B)both the ground fault and the shortcircuit fault
C)short circuit fault on a cable
D)groundlault on a cable

118. Damping of the Ballistic galvanometer is made small to

A)make the system oscillatory
B)make the system critically damped
C)get first deflection large
D)get minimum overshoot

119. Basically a potentiometer is a device for

A)measuring a current
B)none of these answers
C)comparing two voltages
D)comparing two currents
E)measuring a voltage

120. Potentiometer is a

A)comparison instrument
B)integrating instrument
C)calibrating instrument
D)indicating instrument

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

A)less than full-scale error
B)greater than full-scale error
C)equal to half of full-scale error
D)equal to full-scale error

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

A)None of these answers
B)Commutator motor meters
C)Mercury motor meters
D)Induction meters

123. Changes in atmospheric temperature, humidity etc. cause ____ errors.


124. Wattmeter cannot be designed on the principle of

A)electrostatic instrument
B)electrodynamic instrument
C)moving iron instrument
D)thermocouple instrument

125. Load cell is essentially a ____

A)none of these answers
B)strain gauge
D)photovoltaic cell

126. Which of the following instruments can be made using magnetic effect ?

A)All of these answers
C)Energy meters

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

A)magnetic screening
B)Wagner earthing device
C)wave filters
D)any of these answers

128. Null type recorders are

A)bridge recorders
B)LVDT recorders
C)any of these answers
D)potentiometric recorder

129. In optical pyrometer temperature is measured by

A)thermocouple effect
B)comparing the brightness of the source with the brightness of a standard source
C)none of these answers
D)photocell principle

130. The advantage of digital tape recording is that

A)it gives highly accurate results
B)it is insensitive to tape speed
C)all of these answers
D)information can be directly fed to digital computers for processing and control
E)it needs simple data conditioner

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

A)Any of these answers
B)Hay’s bridge
C)Maxwell Wein bridge
D)Maxwell’s bridge

132. A very accurate voltmeter, when used to measure voltage across a low resistance, gives inaccurate reading because

A)any of these answers
B)none of these answers
C)the sensitivity of the meter is too low
D)the current drawn by the meter is too low
E)the higher scale has been selected

133. ____ is not an element of electropneumatic pressure transmitter.

C)Flapper nozzle mechanism
D)Operational amplifier

134. ___ type instrument has identical calibration for A.C. as well as D.C. values ?

B)Moving iron
C)Moving coil
D)Hot wire

135. The household energy meter is

A)an indicating instrument
B)none of these answers
C)a recording instrument
D)an integrating instrument

136. In order to get best results, indicating instruments are

C)critically damped
D)damped slightly less than the critical value

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

A)any of these answers
B)the bridge cannot be balanced
C)the bridge can be balanced if the resistances have some specific values
D)the bridge can always be balanced

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

C)ballistic galvanometer

139. A digital voltmeter claims Which of the following advantage ?

A)No observational error and faster reading speed
B)It is versatile and accurate
C)All of these answers
D)Its output can be fed to memory devices and stored
E)Low power requirements and less cost

140. ___ give the value of the quantity to be measured in terms of the constants of the instruments and their direction only.

A)Recording instruments
B)Integrating instruments
C)Secondary instruments
D)Absolute instruments

141. A potentiometer may be used for

A)calibration of voltmeter
B)measurement of current
C)measurement of resistance
D)all of these answers
E)calibration of ammeter

142. By which of the following methods an ammeter can be converted to a voltmeter ?

A)By installing the instrument in parallel with the circuit
B)By putting a large resistance in parallel with the actual measuring part of the instrument
C)By putting a large resistance is series with the actual measuring part of the instrument
D)By changing the scale

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

A)load impedance is high
B)none of these answers
C)supply voltage is low
D)load impedance is low

144. Swamping resistance is used to

A)compensate the error due to strong magnetic field
B)both compensate the error due to temperature variations and compensate the error due to strong magnetic field
C)none of these answers
D)compensate the error due to temperature variations

145. Which of the following instruments may be used to measure D.C. voltage accurately ?

A)Moving iron type instrument
B)None of these answers
C)Moving coil type instrument
D)Electrodynamic type instrument

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

A)electromagnetic coupling
B)both electrostatic coupling and electromagnetic coupling
C)electrostatic coupling
D)none of these answers

147. A milli-ammeter can be used as

A)both voltmeter and ammeter
B)none of these answers
C)a voltmeter
D)an ammeter only

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

A)In the first third of the scale
B)In about the middle of the scale
C)In the last third of the scale
D)In the first half of the scale

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

A)All of these answers
B)Potential transformers
D)Current transformers

150. A ____ device prevents the oscillation of the moving system and enables the lat: ter to reach its final position quickly

A)any of these answers

151. Deflection of a hot wire instrument is proportional to

A)r.m.s, value of alternating current
B)maximum value of alternating current
C)instantaneous value of alternating current
D)average value of alternating current

152. For measuring the resistance of the elements of an attenuator which of the following is the best choice ?

B)Maxwell’s bridge
D)Wheatstone bridge

153. ___ type instrument has identical calibration for A.C. as well as D.C. values ?

A)Hot wire
B)Moving iron
D)Moving coil

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

A)single-phase winding
B)two-phase winding
C)any of these answers
D)three-phase winding

155. Commonly used standard capacitor is

A)electrostatic type
B)multilayer parallel plate type
C)spherical type
D)concentric cylindrical type

156. Which of the following cannot be measured by Ring-balance meter ?

A)Differential pressure
D)Mass flow rate

157. Moving parts of instruments are supported in ____ bearings.


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

A)from a source which is not the same as the unknown voltage
B)from a battery
C)any of these answers
D)from the same source as the unknown voltage

159. An induction wattmeter measures

A)only the true power
B)the apparent power
C)the true power and the reactive power
D)the reactive power

160. ___ instrument is free from hysteresis and eddy current errors.

A)Moving coil permanent magnet type
C)Moving coil dynamometer type
D)Moving iron

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

A)Wien’s bridge
B)Schering bridge
C)Maxwell bridge
D)Kelvin bridge

162. For protecting a galvanometer during transport

A)the terminals are kept open circuited
B)a capacitor is connected across the terminals
C)critical damping resistance is connected across the terminals
D)the terminals are kept shorted

163. Which of the following is measured by using a vector voltmeter ?

A)All of these answers
B)Complex insertion loss
C)Amplifier gain and phase shift
D)Filler transfer functions

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

A)precision or accuracy
C)dynamic deviation
D)static sensitivity

165. Which of the following gets varied by the focus adjustment of an oscillograph ?

A)Filament voltage
B)Second anode voltage
C)Grid voltage of cathode ray tube
D)Accelerating voltage

166. The dissipation factor of a capacitor can be measured with

A)Campbell bridge
B)Schering bridge

167. High voltage tests are

A)surge tests
B)constant direct current tests
C)high frequency tests
D)sustained low frequency tests
E)all of these answers

168. In a meggar controlling torque is provided by

D)eddy current

169. Relative permitlivity can be measured by ____ bridge

B)De santy

170. Which of the following will happen if a voltmeter is connected like an ammeter in series to the load?

A)A very high current will flow
B)The meter will burn out
C)The measurement will be too high
D)There will be almost no current in the circuit

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

A)as short as possible
B)neither too small not too large
C)as long as possible
D)very thick

172. In electrical measuring instruments, electrical energy is converted to

A)heat energy
B)mechanical energy
C)chemical energy
D)light energy

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

A)All of these answers
B)An operating torque system
C)A braking device
D)Revolution registering device

174. Which of the following cannot be measured by multimeters ?


175. Control springs are made up of

D)phosphor bronze

176. Operating torques in analogue instruments are

A)vibration and balancing
B)deflecting, control and damping
C)deflecting and control
D)deflecting and damping

177. When the damping of an instrument is adjusted to enable the pointer to rise quickly to its deflected position without overshooting, in that case the instrument is said to be

A)dead beat
C)off beat

178. LVDT possesses the following advantage

A)Excellent repeatability
B)Infinite resolution
C)All of these answers
D)High linearity of output

179. The input impedance of a C.R.O. is

B)around 1000 ohms
C)around 100 ohms
D)around one mega-ohm

180. ___ is the commonly used material for thermocouples.

C)Any of these answers

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

A)none of these answers
B)either of fast or slow

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

C)None of these answers

183. In majority of instruments damping is provided by

A)fluid friction
B)eddy currents
D)all of these answers

184. The accuracy of a meter is determined by ____ deflection.

B)one-tenth of full scale
C)one-fourth of full scale

185. Which of the following is determined by a hydrometer ?

A)Specific gravity of liquids
B)Specific gravity of gases
C)Relative humidity
D)Specific gravity of solids

186. Air friction clamping is achieved by the movement of aluminium piston in a cylinder when

A)piston will have close fitting in the cylinder so,that no air can pass from the circular contact between the two
B)none of these answers
C)piston will have small circular clearance so that air can pass with hinderance
D)piston will have circular clearance so that air can pass freely

187. Meggar will give resistance values which

A)remain constant irrespective of the speed
B)decrease with the speed of the hand driven dynamo
C)any of these answers
D)increase with the speed of the hand driven dynamo

188. 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


189. Which of the following are integrating instruments ?

B)Ampere-hour and watt-hour meters

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

A)none of these answers
B)square law
C)uniform law
D)logarithmic law

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

A)Should be non-evaporating
B)The viscosity of the oil should not change with the temperature
C)All of these answers
D)Must be a good insulator
E)Should not have corrosive action upon the metal of the vane

192. A dummy strain gauge is used to

A)none of these answers
B)compensate for temperature variations
C)improve the stability of the system
D)increase the sensitivity of measuring system

193. ____ is used to measure flow of air around an aeroplane.


194. The pointer of an indicating instrument should be

A)either very light or very heavy
B)neither very light nor very heavy
C)very heavy
D)very light

195. Scale of an instrument will be uniform if

A)deflecting torque varies directly as the deflection angle and control torque varies directly as the deflection angle
B)damping torque varies directly as the deflection angle
C)deflecting torque varies directly as the deflection angle
D)control torque varies directly as the deflection angle

196. The advantage of moving coil permanent magnet type instrument is

A)low power consumption
B)all of these answers
C)efficient eddy current damping
D)no hysteresis loss

197. For measuring current at high frequency we should use

A)none of these answers
B)moving iron instrument
C)thermocouple instrument
D)electrostatic instrument

198. Which of the following resistances is shown by a needle in a meggar not in operation ?

A)none of these answers
C)1000 ohms
D)500 ohms
E)zero ohm

199. The use of ____ instruments is merely confined within laboratories as standardizing instruments.

E)none of these answers

200. A wave guide acts as ____ a pass filter

C)none of these answers

201. A Weston synchronoscope is a

A)dynamometer instrument
B)moving iron instrument
C)moving coil instrument
D)none of these answers

202. Which of the following can be measured with the help of piezo-electric crystal ?

C)None of these answers

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

A)0.25 Hz
B)0.5 Hz
C)1.5 Hz
D)0.1 Hz

204. ___ can measure only level.

A)Strain gauge
B)Radioactive method

205. The power of a n-phase circuit can be measured by using a minimum of

A)2n wattmeter elements
B)(n + 1) wattmeter elements
C)n wattmeter elements
D)(n – 1) wattmeter elements

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

A)none of these answers

207. ___ is a low cost thermocouple


208. An induction wattmeter can be used for

A)A.C. only
B)D.C. only
C)any of these answers
D)both D.C. and A.C.

209. The reed frequency is essentially

A)a deflection measuring system
B)an oscillatory measuring system
C)a vibrational measuring system
D)a recording measuring system

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

A)to pass electric current to moving system
B)to apply controlling torque
C)to apply controlling torque and to pass electric current to moving system
D)none of these answers

211. Which of the following is the most suitable transducer for monitoring continuously variations in very fine thickness (say of paper in a paper industry) ?

C)Strain gauge
D)Any of these answers
E)Capacitance transducer

212. A dummy bridge employing strain gauge provides ____

C)temperature compensation
D)none of these answers

213. In the measurement of power by two wattmeter method, when the readings of the two wattmeters are equal and opposite, it can be concluded that power factor is


214. ___ bridge is preferred for the measurement of inductance having high Q-factor.


215. Which of the following can be measured by the use of a Schering bridge ?

A)All of these answers
B)Dielectric loss and power factor
C)Frequency and capacitance
D)Variable resistances

216. Hot wire instruments read

A)r.m.s. value
B)average value
C)peak value
D)none of these answers

217. A Weston frequency meter is

A)dynamometer instrument
B)moving iron instrument
C)moving coil instrument
D)none of these answers

218. Weston cell is a

A)good standard of voltage
B)none of the above
C)good source of current
D)good source of power

219. In a 3-phase power measurement by two wattmeter method, both the wattmeters had identical readings.

The power factor of the load was

B)0.8 lagging
D)0.8 leading

220. Which of the following instruments can be used for measuring 132 kV A.C. voltage ?

A)Moving coil voltmeter
B)Moving iron voltmeter
C)Electrostatic voltmeter
D)Hot wire voltmeter

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


222. A moving iron instrument can be used for

A)D.C. only
B)both D.C. and A.C.
C)none of these answers
D)A.C. only

223. The rectifier instrument is not free from

A)wave shape error
B)frequency error
C)temperature error
D)all of these answers

224. To measure radio frequency, the suitable frequency meter is

A)Weston frequency meter
B)electrical resonance frequency meter
C)hetrodyne frequency meter
D)reed vibrator frequency meter

225. The electrical power to a meggar is provided by

A)any of these answers
B)permanent magnet D.C. generator
D)A.C. generator

226. Thermistors have ____ temperature coefficient.

A)low and negative
B)high and positive
C)low and positive
D)high and negative

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

C)eddy currents
D)all of these answers

228. By a ‘Rotameter’ we can measure

B)specific gravity

229. Systematic errors are

A)environmental errors
B)instrumental errors
C)all of these answers
D)observational errors

230. ___ meter has the best accuracy

A)Rectifier type

231. A dynamometer type wattmeter has

A)logarithmic scale
B)uniform scale
C)non-linear scale
D)square law scale

232. Unit of deflection sensitivity of CRO is

A)none of these answers
B)meter per volt
D)mm per mV

233. Meggar is operated by

A)an external voltage source
B)internal battery
C)none of these answers
D)an internal hand driven generator

234. An instrument’s reliability means

A)the degree to which the repeatability continues to remain within specific limits
B)the extent to which the characteristics remain linear
C)the life of the instrument
D)all of these answers

235. For malting shunts the material suitable is that which has

A)same resistance temperature co-efficient as the coil of the instrument
B)negligible thermoelectric e.m.f. with copper
C)been annealed properly so that its resistance does not change with time
D)all of these answers

236. Damping in an instrument provides

A)good accuracy
B)braking action on a meter pointer
C)starting torque on the meter pointer
D)counter torque to deflection torque

237. A Q-meter measures

A)accurate values of electrical quantities
B)properties of the coils
C)losses in a capacitor

238. The instrument used for the measurement of power at 500 MHz is

B)compensated wattmeter
C)none of these answers
D)electrodynamometer wattmeter

239. A phase shifting transformer is used in conjunction with

A)Drysdale potentiometer
B)D.C. potentiometer
C)A.C. co-ordinate potentiometer
D)Crompton potentiometer

240. A power factor meter has _____ control springs.


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

A)in series with pressure coil
B)in parallel with current coil
C)in parallel with pressure coil
D)in series with current coil

242. The principle of Pirani gauge is based on ____ of the medium.

A)none of these answers
D)thermal conductivity

243. In resistance thermometers platinum is used because of

A)none of these answers
B)low cost, high stability and wide operating range
C)low cost and high stability
D)low cost

244. ___ instrument will draw least current from the circuit in which it is incorporated.

B)Hot wire

245. The principle on which vector voltmeter is based is

A)that it measures the amplitude of a single at two points and at the same time measures their phase difference
B)that it works on the principle of complex variation
C)same as digital meter
D)that it measures the response of linear ramp voltage

246. ___ damping method is common in moving coil instruments.

B)Eddy current

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

A)known capacitance and resistance
B)known resistance
C)known inductance and resistance
D)known inductance

248. Synchro is a

A)an angular position transducer
B)parabolic transducer
C)a variable transducer
D)a synchronizing transducer

249. Two holes in the disc of energymeter are drilled at the opposite sides of the spindle to

A)increase its braking torque
B)eliminate creeping at no load
C)improve its ventilation
D)increase its deflecting torque

250. The cathode of a C.R.O. is usually coated with

A)tungsten or thorium oxide
B)alkali metals
C)barium or strontium oxide
D)copper oxide

251. ____ is not a signal conditioner

B)Equalising network
C)Damping network
D)Signal converter

252. The Q-meter Works on the principle of

A)mutual inductance
B)parallel resonant circuit
C)series resonant circuit

253. The static error band of an instrument implies

A)the error produced when the pen is stopped at some deflection
B)the error introduced in low varying inputs
C)the accuracy of the instrument
D)the irrepeatibility of the instrument

254. The desirable static characteristics of a measuring system are

A)accuracy and reproducibility
B)accuracy, sensitivity and reproducibility
C)drift and dead zone
D)static error

255. Which of the following devices may be used to measure accurately the interelectrode capacitances ?

A)Schering’s bridge
B)Wien’s bridge
D)De Santy’s bridge

256. Commonly used instruments in power system measurement are

C)moving coil or iron

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

A)none of these answers
B)conducting and non-magnetic material
C)conducting and magnetic material
D)non-conducting and magnetic material

258. A universal RLC bridge uses

A)Maxwell Wein bridge for measurement of inductance and Wein bridge for measurement of capacitance
B)Any of these answers
C)Maxwell bridge configuration for measurement of inductance and De Santy’s bridge for measurement of capacitance
D)Maxwell Wein bridge for measurement of inductance and modified De Santy’s bridge for measurement of capacitance

259. In brewing process the degree of fermentation is measured by

A)combustibility meter
B)conductivity meter
C)any of these answers
D)pH meter

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

B)Current transformer
C)None of these answers
D)Tangent galvanometer

261. A ____ is used to measure frequency in wave guides.

C)cavity resonator

262. 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

A)none of these answers
B)all right

263. Resistances can be measured with the help of

B)ohmmeters and resistance bridges
C)all of these answers

264. An instrument transformer is used to extend the range of

A)electrostatic instrument
B)any of these answers
C)moving coil instrument
D)induction instrument

265. In an ammeter, the shunt resistance is usually ____ meter resistance.

A)of any value
B)equal to
C)greater than
D)less than

266. A sensitive galvanometer produces large deflection for a

A)large value of current
B)small value of current
C)none of these answers
D)large value of voltage
E)large value of power

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