INSTRUMENTATION AND CONTROL SYSTEMS 2 MID ONLINE BITS

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1. "A function of the controlled output, which is compared with the reference input to obtain the

actuating

signal" is called as :->Primary feed back signal

2. "Any finite number of blocks that are series connected my be algebraically combined by

multiplying their

transfer function". This statement is called as :->Blocks in cascades

3. "Applying the force to some elastic member and then measuring the resulting deflection to measure

the

applied force" is used in :->Proving ring

4. "The quality or condition characterizing a process whose value is held constant by controller or is

changed

according to certain law" is called as :->Controlled variable

5. A bellow system is used to measure temperature. The input heat is q. Bellow expansion is x. Then

the transfer

function is :->x / q 6. A control system that has no connection between the output and the input is known as :->Open - loop system

7. A high gauge factor leads to a _ _ _ _ _ _ _ _ _ _ _ _ _ _ :->Large change in resistance for a s mall

change

in strain input

8. A metallic toothed roter having 60 teeth was mounted on a shaft whose speed was to be determined. The

pulses produced in the inductive type magnetic pickup were registered to be 3600 per second.

Estimate the

speed. :->3600 rpm

9. A pendulum scale is a :->Mechanical transducer

10. A Prony brake dynamometer measures :->Engine brake power

11. A signal established as a standard of comparison for a feed back control system by virtue of its

relation to

command is called as :->Set point

12. A signal established as a standard of comparison for a feed back control system by virtue of its

relation to command is called as :->Reference input

13. A strain gauge is used to measure strain of 1 micro-strain. Its initial resistance is 120 ohms and

change in

resistance is 0.00024 Ω. What is the gauge factor :->2

14. A strain gauge with a gauge factor 2 is sued to measure a strain of 1 micro strain. The

corresponding

resistance shown by the strain gauge is 0.00024 ohm. Then the initial resistance is equal to :->120

ohms 15. A strain gauge with initial resistance of 120 Ω and gauge factor of 2 is used to measure strain.

When the

resistance change shown by the instrument is 0.00024 Ω. What is the strain. :->1 micro strain

16. A unity feed back system is :->Closed loop feed back system where the transfer function in

feed back

loop is unity 17. Absolute humidity refers to :->The amount of water vapor actually present in the air

18. Acceleration pickups will be made to have :->High undampe d natural frequency

19. Actuating signal is :->An algebra sum of the reference input and the primary feed back

20. An algebraic sum of the reference input and the primary feed back signal is called as :->Actuating

signal

21. An input that is established or varied by some means external to and independent o f the feed back control

system is called as :->Command

22. An instrument used to measure angular velocity of a shaft either by registering the number of

rotations during

the period of contact or by indicating directly the number of rotations per minute is c alled as :-

>Tachometer

23. Any control system that operates on time basis of :->Open-loop control system

24. Bakelite gauges used for 2000 C will be fixed to components with :->Phenol resin cement

25. Chose the wrong statement :->The Prony brake is much steadier in operation than the rope

brake

dynamo meter 26. Command means :->An input that is established or varied by some means external to and

indepe ndent of

the feed back control system 27. Control systems is :->An assembly of devices and components connected or related, so as to

command,

direct or regulate itself or another system

28. Controlled medium means :->The process material in the controlled system or flowing through

it in

which the variable is to be controlled. 29. Controlled variable means :->The quality or condition characterizing a process whose value is

held

constant by controller or is changed according to certain low. 30. Cradled source or cradled sink are the words associated with :->Torque measure ment

31. Dew point temperature refers to :->Tempe rature whe re the water vapor in the air starts

condensing 32. Digital accelerometer is a :->Deflection type device

33. Direct output one can get from recording psychro meter is :->Dry and wet bulb temperature

34. Direct output one can get from sling psychro meter is :->Dry and wet bulb temperature

35. Dry bulb temperature refers to :->Te mperature of air - wate r vapor mixture as indicated by a

thermometer whose bulb is exposed to the mixture 36. Dual gauge is :->A gauge which is built with two different mate rials and inbuilt te mperature

compensation 37. Dummy strain gauges :->Are bonded to separate unstrained component and suffer resistance

change due

to temperature only

38. Electric cradled dynamo meter is a type of :->Driving dynamo meter 39. For a electrical rheostat y is the input displacement and q0 is the output. The transfer function = :-

>

40. For a power limit of 25,000 HP which dynamometer you will suggest :->Water vertex

dynamometer 41. For a speed limit of 10,000 rpm which dynamometer you will suggest :->Wate r vertex

dynamometer

42. For a spring mass dash pot system, input is x(t1 ), output is f(t), k is spring stiffness, c is dash point coefficient

'm' is the mass the transfer function is :->

43. For a strain gauge the gauge factor is 2 and the resistance is 120 ohms. If the strain sensed is 2

micro strains.

The change is resistance = :->ohms

44. For a temperature control system 'q' in is heat input, θ is temperature to be to maintained in the

system is the

ambient temperature, q is the leakage to the surroundings, R is the resistance and C is the

capacitance, then the input and output relations are written up :->

45. For a temperature range of 80 - 930 C, on can use a :->Duco gauges

46. For a water turbine input is the flow of water (q) flowing through the turbine. The output of the

turbine speed

is w. The transfer function is :->w / q

47. For many metals the resistivity :->Will not change with strain

48. For most metallic strain gauges, most of the resistance change comes from :->Change in length

and area 49. For semiconductor gauges the change in resistance is due to :->Change in resistivity 50. Froudes absorption dynamometer is a :->Vortex type hydraulic dynamometers

51. Gauge using carrier material made with paper, impregnated with nitro cellulos e cement and

bonded with

cellulose constituents are called as :->Duco gauges

52. Gravimetric hygro meter is used to :->To calibrate other humidity measuring devices

53. Greater lineaxity and lack of hysteresis is possible with :->Servo accelerometer

54. Hydraulic dynamometer :->Use fluid friction for dissipating the energy

55. Hygrometer is :->Instrument used to measure relative humidity

56. In a differential angular potential mater one arm is set at reference inclination θ1. The other arm

inclination is

θ0 . If 'e' is the output voltage then the transfer function is :-> 57. In n type semi - conductor gauges resistance decrease with :->Tensile Strain

58. In P type semi - conductor gauges resistance increases with :->Tensile Strain

59. In Poisson's arrangement (one gauge perpendicular to other) the bridge output when compared t o

quarter

bridge output is :->(1 + µ ) times 60. In the seismic mass type vibrometer the desirable damping ratio is approximately :->65 %

61. In the seismic mass type vibrometer the influence of damping ratio on seismic mass output for

high values of

w/wn :->Negligible

62. In the sesimic mass type vibrometer, when the frequency ratio is considerably greater than one, the

complitude ratio nears to _ _ _ _ _ _ _ _ _ _ _ _ _ _ :->Near to unity

63. Instrument used to help is measuring humidity is :->Psychoro meter

64.is the change in output voltage of (Vs is excitation voltage, F is gauge factor, E is strain) :->Quarter

bridge 65.is the change in output voltage of (Vs is excitation voltage, F is gauge factor, E is strain) :->Half

bridge

66. Load limiting torque is :->Max possible torque which a dynamometer can exert 67. Manipulated variable means :->The quality on condition that is varied as a function of the

actuating

signal so as to change the value of controlled variable.

68. Mark the Transmission dynamometer :->Flash light torsion dynamometer 69. Mechanical strain gauges can measure :->Static and quasi static strains

70. Mechanical strain gauges cannot be employed for :->Dynamic strains

71. Mechanical torsion meter measures :->Twist on the shaft

72. Negative feed back will _ _ _ _ _ _ _ _ _ _ _ the error :->Reduce

73. Null - balance accelerometer have :->Feed back signal

74. On a strain gauge torsional meter :->Four gauges, two gauges in torsion, two gauges in

compressor 75. Out of the following gauges which one is having large mass :->Unbonded

76. Out of the following instrument which can be used as both vibrometer and accelerometer after

doing some

modifications. :->Sesimic mass type

77. Out of the following instruments which can be used as both vibrometer and accelerometer after doing some

modifications. :->Seismic mass type

78. Out of the following instruments which employs the concept of resonance as the means of speed

measurement

:->Vibrating Reed Tachometer

79. Out of the following instruments which instrument has highest speed range :->Slipping clutch

tachometer 80. Out of the following instruments which instrument has highest speed range :->Centrifugal force

Tachometer 81. Out of the following instruments which occupies less space for the same power :->Hydraulic

dynamo meter 82. Out of the following instruments which one is practically more valuable for general monitoring

than for test

work. :->Vibrating Reed Tachometer

83. Out of the following instruments, which instrument will yield information about only amplitude of

vibration :-

>Wedge vibrometer 84. Out of the following speed measuring instruments which one put less load on the machine whose

speed is

being measured :->Revolution counter

85. Out of the following vibrating measuring instrument which one will use 'resonance' as a means of

measurement. :->Reed vibrometer

86. Out of the following which instrument you will recommend for high frequency response in

acceleration

measurement :->Pie zo - electric

87. Out of the following which is contact less electrical tachometer :->Photo electric Tacho meter

88. Out of the following which is contact less non electrical Tacho meter :->Vibrating reed Tacho

meter 89. Out of the following which is not of the seismic mass type transducer :->Reed vibrometer

90. Out of the following which is not the part of a seismic transducers :->Reed

91. Out of the following, which one will not increase the sensitivity of wheat stone bridge in strain

measurement.

:->Small excitation voltage

92. Paper impregnated with phenolic resin used as a backup material for gages to be used at :->2000 C

93. Positive feed back will _ _ _ _ _ _ _ _ _ the error :->Increase

94. Power assisted steering in automobile is an example of :->Servo mechanis m

95. Primary feed back signal means :->A function of the controlled output, which is compared

with the

reference input to obtain the actuating signal 96. Prony brake dynamometer :->Will absorb the powe r i.e. being measured

97. Proving ring is a :->Mechanical transducer

98. Psychro meter is :->Instrume nt used to measure wet bulb and dry bulb temperature

99. Ratio between humidity of air to the humidity of saturated air is called as :->Relative humidity

100.Ratio of mass of water vapor to the mass of dry air in a given volume of air-water vapor mixture

is

called as :->Specific humidity

101.Reed vibrator will yield information about :->Frequency only

102.Reference input means :->A signal established as a standard of comparison for a feed back

control system by virtue of its relation to command 103.Relative humidity refers to :->Ratio of humidity of air with the humidity of saturated air 104.Relative output displacement of a sesimic mass instrument is a not function of :->Mass

105.Set point means :->A signal established as a standard of comparison for a feed back control

system by virtue of its relation to command 106.Simply turning the accelerometer upside down is :->Constant acceleration method of

calibration

107.Strain gauge accelerometer is a type of :->Seismic mass type accelerometer

108.Stroboscope is used in :->Torsion measure ment

109.Stroboscopic method of vibration measurement will yield the information about :->Frequency

only 110.Tachometer are used to measure :->Angular velocity

111.Temperature at which the water vapor in the air starts condensing is called as :->Dew point

temperature 112.Temperature of air - water vapor mixture as indicated by a thermometer w hose bulb is e xposed to

the

mixture :->Dry bulb temperature

113.Temperature of air - water vapor mixture as registered by a thermometer w hose bulb is covered

by a

wick maintained continuously wet is called as :->Wet bulb tempe rature

114.The advantage of capacitive and inductance transducers have :->Retaining calibration

115.The amount of water vapor actually present in the air is called as :->Absolute humidity

116.The average speed measurements are given by :->Drag cup tachometer

117.The bridge constant (sensitivity) of full bridge arrangement when two strain gauges of adjacent

limbs

suffer positive strain and the two remaining gauges suffer negative sign (when compared to quarter

bridge) :-

>Quadruple

118.The bridge constant (sensitivity) of half bridge arrangement where two strain gauge s suffer equal

and

opposite strains is (when compared with quarter bridge) :->Doubled

119.The calibration standard for hygrometer is :->Gravimetric hygrometer

120.The capacitive and inductive transducers cannot be used in some applications due to :->Large

mass and size

121.The change in output voltage dvo for half bridge is _ _ _ _ _ _ _ _ Where Vs is the excitation voltage

F is the gauge factor

E is the strain :->VsF E / 2

122.The change in output voltage for full bridge is _ _ _ _ _ _ _ _ _

Where Vs is the excitation voltage

F is the gauge factor

E is the strain :->VsF E

123.The change in output voltage for quarter bridge is _ _ _ _ _ _ _ _ _ _

Where Vs is the excitation voltage

F is the gauge factor

E is the strain :->VsF E / 4

124.The desired condition of the controlled variable is :->Reference

125.The direct output from dynamometer is :->Torque

126.The drag cup Tacho meter principle is based on :->Torque generated by eddy current

127.The electric switch is an example of :->Open-loop control system

128.The name of the element, which determines the difference between the reference point and

measured

variable is. :->Controlled

129.The out put of the ballast circuit when compared with quarter bridge configuration of wheat stone

bridge :->Equal

130.The output of a standard strain gauge load cell is :->

131.The output of Dunmore type absorption hygro meter is :->Relative humidity

132.The particular variable to be regulated is known as :->Controlled

133.The phase angle Ø of sesimic mass instrument output is a not function of :->Mass

134.The phase shift in vibrometer seismic mass type is :->Linear shift with frequency

135.The prime objective of any control system is to maintain the _ _ _ _ _ _ _ _ _ _ _ variable at the

reference set point :->Controlled

136.The principle behind multi- level platform scale in force measurement is :->Balance the force

against

a known gravitational force on a standard mass 137.The principle behind the hydraulic load cell in force measurement is :->Translating the force to a

fluid pressure and the measuring the resulting pressure

138.The principle behind the proving ring is :->Applying the force to some elastic me mber and

then

measuring the resulting deflection. 139.The process material in the controlled system or flowing through it in which the variable is to be

controlled is called as :->Controlled medium

140.The quality or condition that is varied as a function of the actuating signal so as to change the

value of

controlled variable. :->Manipulated variable

141.The resistance change in a metallic strain gauge is a factor of :->Change in area and length

142.The seismic mass instrument measures :->The relative displacement between mass housing

143.The seismic mass transducer for the measurement of acceleration and vibra tion is a :->Second

order

instrument 144.The sensitivity of wire - wounded strain gauge will increase with increase in :->Gauge factor 145.The speed of a sealed compressor units can be measured by :->Vibrating reed Tachometer

146.The stroboscopic method of speed measurement has the advantage that :->There is no need of any

physical contact between the instrument and the rotating shaft 147.The Tacho generator principle is based on :->Tacho generator 148.The Tacho meter principle is based on :->Faraday's law

149.The Tacho meter which operates based on torque generated from eddy currents is :->Drag cup

type 150.The width of the wedge at the point where the image over lap while using the vibrating edge for

vibration measurement is :->Double the amplitude of motion

152.'Time between the pulses' will be used to measure torque in the following way of torque

measurement.

:->Electrical

153.To avoid moisture absorption the following type of cement will be selected :->non - hygroscopic

154.To have a large change in resistance for a small changing in strains, one has to use :->A strain

gauge

with a large gauge factor

155.To increase the range of use, input frequencies of a sesimic mass type vibrometer should be :- >Above

the instrume nt undamped natural frequency 156.Traffic light at a junction is an example of :->Open - loop control system

157.Transfer function is :->Output / input

158.Translating the force to a fluid pressure and then measuring the resulting pressure to me asure the

applied force is used in :->Hydraulic load cell

159.Transmission dynamometers :->Will measure powe r whe n it is being transferred from one

place

to other place 160.Unlimited values of static accelerations can be fed to accelerometers during calibration by :-

>Centrifuge method

161.Vibrating wedge is used to measure :->Amplitude of vibration

162.Vibration pickups will be made to have :->Low undampe d natural frequency

163.Vibrometer out put is proportional to :->Displace ment

164.VsF E is the change in output voltage of (Vs is excitation voltage, F is gauge factor, E is strain) :-

>Full bridge

165.When a disk is rotating at 900 rpm, the frequency of light where image of a single mark on the

disk appears as double and stationery is :->1800 rpm

166.When a disk is rotating at 900 rpm. The frequency of light where image of a s ingle mark on the

disk

appears single stationery mark is :->450 rpm

167.When one strain gauge is used the bridge output is k. When 'n' no of strain gauges is used then the

output voltage is :->n k

168.When the shafts are inaccessible, then what type of Tachometer will be used to measure speeds. :-

>Vibrating reed Tachometer

169.When the wet bulb and dry bulb temperature are known from the psychometric charts we ca n find

out

:->Specific humidity

170.When using a wheat stone bridge circuit for measuring strain, the accurate technique is initial

resistance is equal to :->Balanced condition (Null) 171.Which bonding material will be used to bond strain gauges at 200 0 C :->The rmoset

172.Which bonding material will be used to bond strain gauges at 800 C :->The rmo plastic

173.Which bonding material will be used to bond strain gauges at greater than 200 0 C :->Special

ceramic

174.Which instrument uses the principle of "change of electrical resistance with change in humidity"

as the

humidity measuring technique. :->Dunmore hygro meter

175.Which of the following cannot be the controlled variable of a servomechanism :->Torque

176.Which of the following cannot be used for dynamic straining :->Balanced condition (Null)

177.Which of the following gauge will exhibit freedom form faulty insulation :->Unbonded type

178.Which of the following gauges are less suit to measure bending strains :->Unbonded type

179.Which of the following gauges have high gauge factor :->Semi - conductor gauges

180.Which of the following gauges have poor heat dissipation :->Unbonded type

181.Which of the following gauges have very little or no transverse sensitively :->Unbonded type

182.Which of the following gauges will exhibit less creep hystersis :->Unbonded type

184.Which of the following is a characteristic of closed- loop system :->The error signal activates

the control element to minimize the error and bring the system output to the desired value

185.Which of the following is a desired characteristic for strain gauge bonding materials. :->High

dielectric strength 186.Which of the following is a desired characteristic for strain gauge bonding materials. :->Non -

hygroscopic 187.Which of the following is a multi lever balancing type force measuring instrument :->Pendulum

scale

188.Which of the following is a null type instrument :->Servo accelerometer 189.Which of the following is disadvantage with ballast circuit :->Providing temperature

compensation

is difficult 190.Which of the following is not a method of temperature compensation in strain gauge :->Duco

gauge 191.Which of the following is the characteristic of open - loop system :->For the given set-input, the

re

may be big vibration of the controlled variable 192.Which of the following material has a negative gauge factor, when used as strain gauge :->Nickel

193.Which of the following materials will be used for strain gauges tha t can be used for static strain

measurement :->Advance

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194.Which of the following materials will be used for that can be used for high temperature

applications :-

>Iridium platinum

195.Which of the following materials will be used for that can be used for dynamic strain

measurements :-

>Nichrome

196.Which of the following strain gauge are brittle and not suitable for measurement of large strains :-

>Semi - conductor gauges

197.Which of the gauge has inherent temperature compensatio n :->Dual gauge

198.Which type of gauge you will recommend, for curved bonded surface :->Foil gauges

199.Which type of the following gauge the gauge factor is not constant but varies with strain and

temperature :->Se mi - conductor gauges

200.While measuring pure torsion, the strain gauges are bonded to the shaft :->At 450 to the axis of

rotation 201.Windage torque is :->Lowest possible powe r or torque required to turn the rotating parts

and to

over come the bearing friction and othe r Windage losses

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