Indiabix - Process Control and Instrumentation Flashcards by Cherilyn Caseros

Which of the following is an undesirable dynamic characteristic of an instrument?
A. Reproducibility
B. Dead zone
C. Time lag
D. Static error

C. Time lag

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Which of the following is not the triple point of water?
A. 32°R
B. 273°K
C. 492°R
D. 32°F

A. 32°R

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Pick out the one which is a first order instrument.
A. Mercury in glass thermometer (without any
covering or air gap).
B. Bare metallic thermometer.
C. Bare vapor pressure thermometer.
D. All (a), (b) and (c).

D. All (a), (b) and (c).

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Load cells are used for the measurement of
A. stress
B. weight
C. strain
D. velocity

B. weight

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Which of the following is the dynamic characteristics of an
instrument?
A. Reproducibility
B. Sensitivity
C. Dead zone
D. Fidelity

D. Fidelity

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Pick out the wrong statement.
A. O2, NO and NO2 exhibit paramagnetic properties
as a result of unpaired electrons.
B. CO2 is the strongest paramagnetic gas.
C. Paramagnetic susceptibility of gases decreases with temperature.
D. Paramagnetic susceptibility of gases permits the measurement of their concentration.

B. CO2 is the strongest paramagnetic gas.

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The __________ of a vapor pressure thermometer is a functioning element.
A. pointer
B. bourdon tube
C. bulb
D. none of these

A. pointer

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A negative gain margin expressed in decibels means a/an __________ system.
A. stable
B. unstable
C. critically damped
D. none of these

B. unstable

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Thermistor, which has high temperature co-efficient of resistivity, is used as the sensing element in resistance thermometer. It is a/an
A. insulator
B. conductor
C. solid semi-conductor
D. liquid semi-conductor

C. solid semi-conductor

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Flapper nozzle is used in a/an __________ controller.
A. electronic
B. hydraulic
C. pneumatic
D. none of these

C. pneumatic

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Typical specifications for design stipulates the gain margin and phase margin to be respectively
A. > 1.7 and > 30°
B. < 1.7 and > 30°
C. < 1.7 and < 30°
D. > 1.7 and < 30°

A. > 1.7 and > 30°

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Working principle of radiation pyrometer is based on the
A. Wien’s law
B. Kirchoffs law
C. Stefan-Boltzman law
D. Seebeck effect

C. Stefan-Boltzman law

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Which of the following relates the emf. generated in a single homogeneous wire to the temperature difference ?
A. Peltier effect
B. Thomson effect
C. Seebeck effect
D. none of these

B. Thomson effect

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Dilute wine was used as a thermometric liquid initially to develop temperature scale. First emperical temperature scale developed was the __________ scale.
A. Kelvin
B. Centigrade
C. Fahrenheit
D. Reaumer

C. Fahrenheit

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In a single tank system, the transfer function of level to
inlet flow rate is
A. R/TS
B. R/(TS + 1)
C. l(TS + l)
D. 1/TS

B. R/(TS + 1)

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Which of the following is a desirable characteristic of an instrument ?
A. High drift
B. High fidelity
C. High measuring lag
D. Poor reproducibility

B. High fidelity

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The operation of a rotameter is based on
A. variable flow area.
B. rotation of a turbine.
C. pressure drop across a nozzle.
D. pressure at a stagnation point.

A. variable flow area.

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The temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured by a/an
__________ thermocouple.
A. chromel-alumel
B. iron-constantan
C. platinum-platinum/rhodium
D. none of these.

B. iron-constantan

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Instrumentation in a plant offers the advantage of
A. greater safety of operation
B. better quality of product
C. greater operation economy
D. all (a), (b) and (c

D. all (a), (b) and (c

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Which of the following temperature measuring instruments need not touch the object whose temperature is being measured ?
A. Radiation/infrared pyrometer
B. Filled system thermometer
C. Mercury in glass thermometer
D. Thermo electric pyrometer

A. Radiation/infrared pyrometer

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Thermal conductivity measurement comprises the working principle of a
A. CO2 analyser
B. polarimeter
C. spectrometer
D. chromatograph

A. CO2 analyser

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Response of a system to a sinusoidal input is called __________ response.
A. impluse
B. unit step
C. frequency
D. none of these

C. frequency

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The closed loop pole of a stable second order system could be
A. both real and positive.
B. complex conjugate with positive real parts.
C. both real and negative.
D. one real positive and the other real negative.

C. both real and negative.

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Smoke density of the flue gas going out of the chimney is measured by a
A. polarograph
B. thermal conductivity meter
C. photo electric cell
D. chromatograph

C. photo electric cell

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Transfer function of transportation lag is
A. eTS
B. e-TS
C. 1/(Ts+1)
D. none of these

B. e-TS

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Temperature measuring instruments are standardised mostly with __________ points of pure substances.
A. melting
B. boiling
C. both (a) & (b)
D. neither (a) nor (b)

C. both (a) & (b)

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Pick out the first order system from among the following.
A. Damped vibrator.
B. Mercury in glass thermometer kept in boiling water.
C. Interacting system of two tanks in series.
D. Non-interacting system of two tanks in series.

B. Mercury in glass thermometer kept in boiling water.

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The maximum service temperature for fibre glass used as thermocouple wire insulation material is __________ °C.
A. 250
B. 500
C. 750
D. 1000

B. 500

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Which of the following controllers has the least maximum
deviation?
A. P-controller
B. P-I controller
C. P-I-D controller
D. P-D controller

D. P-D controller

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Volumetric expansion is the working principle of the __________ thermometers.
A. mercury in glass
B. constant volume gas
C. vapor pressure
D. bimetallic

A. mercury in glass

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Which of the following measurements can be made by the measurement of emf ?
A. pH value
B. Degree of hydrolysis
C. Composition of complex ions
D. All (a), (b) & (c)

D. All (a), (b) & (c)

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A magnetic flowmeter is
A. based on the principle of Faraday’s law.
B. capable of measuring the flow rate of slurries and electrolytes.
C. based on the linear relationship between the fluid flow rate and the induced voltage.
D. all (a), (b) and (c).

D. all (a), (b) and (c).

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Zirconia probe is used for the continuous measurment of __________ flue gases going out of the furnace.
A. oxygen in
B. carbon dioxide in
C. carbon monoxide in
D. temperature of

A. oxygen in

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Strain gage pressure transducers are used to measure __________ pressures.
A. gage as well as vacuum
B. absolute as well as differential
C. both (a) and (b)
D. neither (a) nor (b)

C. both (a) and (b)

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Compositional analysis of __________ is done using mass spectrometer.
A. an isotope
B. natural gas
C. a solid
D. an alloy

A. an isotope

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The function of a transducer is to
A. modify the input signal.
B. amplify the input signal.
C. convert the primary signal into a more useful quantity, usually an electric impulse.

C. convert the primary signal into a more useful quantity, usually an electric impulse.

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Nichol’s chart deals with
A. A.R. vs. phase lag of first order.
B. A.R. vs. phase lag of second order.
C. closed loop values vs. open loop values.
D. frequency response values of controllers.

C. closed loop values vs. open loop values.

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Which of the following thermocouples will give the highest output for the same value of hot and cold junction temperature ?
A. Platinum-platinum + rhodium.
B. Iron-constantan.
C. Chromel-constantan.
D. All will give the same output.

C. Chromel-constantan.

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A proportional controller with a gain of Kc is used to control a first order process. The offset will increase, if
A. Kc is reduced.
B. Kc is increased.
C. integral control action is introduced.
D. derivative control action is introduced.

A. Kc is reduced.

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__________ is undesirable in thermocouples used in
industries,
A. Linear relation of emf to temperature
B. Corrosion resistance
C. Oxidation resistance
D. Non-linear relation of emf to temperature

D. Non-linear relation of emf to temperature

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Select the correct statement from the following.
A. The frequency response of a pure capacity process is unbounded.
B. The phase lag of a pure time delay system
decreases with increasing frequency.
C. The amplitude ratio of a pure capacity process is inversely proportional to frequency.
D. The amplitude ratio of a pure time delay system increases with frequency.

C. The amplitude ratio of a pure capacity process is inversely proportional to frequency.

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For an input forcing function, X(t) = 2t2, the Laplace transform of this function is
A. 2/s2
B. 4/s2
C. 2/s3
D. 4/s3

D. 4/s3

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Continuous shell temperature measurement in a liquid-liquid heat exchanger is done by a
A. thermocouple
B. reistance thermometer
C. mercury in glass thermometer
D. vapor pressure thermometer

A. thermocouple

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The __________ of a vapor pressure thermometer is a secondary element.
A. pointer
B. Bourdon tube
C. bulb
D. none ofthese

B. Bourdon tube

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Emf developed by a thermocouple, while measuring a temperature of 600°C is about 5.5 mV. The type of
thermocouple used is
A. chromel-alumel
B. iron-constantan
C. platinum-platinum+rhodium
D. either (a), (b) or (c)

C. platinum-platinum+rhodium

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Which of the following relates the absorption & evolution of heat at the junctions of a thermocouple to the current flow in the circuit?
A. Seebeck effect
B. Peltier effect
C. Joule heating effect
D. Thomson effect

B. Peltier effect

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The second order system with the transfer function 4/(s2+2s+4) has a damping ratio of
A. 2.0
B. 0.5
C. 1.0
D. 4.0

B. 0.5

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In a shell and tube heat exchanger, the flow rate of heating/cooling fluid is the __________ variable.
A. load
B. controlled
C. manipulated
D. none of these

C. manipulated

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A non-linear chemical system is exemplified by a/an
A. isothermal CSTR
B. mixer
C. non-isothermal CSTR
D. none of these

C. non-isothermal CSTR

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The frequency response of a first order system, has a phase shift with lower and upper bounds given by
A. - ∞, π/2
B. -π/2, π/2
C. -π/2, 0
D. 0, π/2

D. 0, π/2

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Gas chromatography is used for the measurement of
A. temperature
B. pressure
C. concentration
D. flow rate

C. concentration

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Which of the following thermocouples can measure the maximum temperature ?
A. Platinum-rhodium
B. Tungsten-molybdenum
C. Chromel-alumel
D. Iron-constantan

B. Tungsten-molybdenum

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Radiation pyrometers as compared to thermocouples
A. has a slower speed of response.
B. can measure higher temperature.
C. can’t measure the temperature of moving objects.
D. is more affected by corrosive atmosphere

B. can measure higher temperature.

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Liquid flow rate in a small channel is best measured by a/an
A. weir
B. pitot tube
C. vane meter
D. venturimeter

B. pitot tube

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Specific gravity of a liquid can not be measured by a/an
A. anemometer
B. specific gravity bottle
C. pycnometer
D. hydrometer

A. anemometer

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__________ temperature scale assigns 0° to the ‘ice
point’ and 80° to the ‘steam point’.
A. Celcius
B. Rankine
C. Reumur
D. Farenhite

C. Reumur

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Dead zone is the
A. same as time constant.
B. same as transportation lag.
C. maximum change in the variable that does not change the reading of the instrument.
D. none of these.

C. maximum change in the variable that does not change the reading of the instrument.

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Which of the following thermometers is not suitable for distant reading up to 60 metres?
A. Vapor pressure thermometer
B. Mercury in glass thermometer
C. Constant volume gas thermometer
D. Resistance thermometer

B. Mercury in glass thermometer

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Degree to which an instrument indicates the changes in measured variable without dynamic error is called its
A. speed of response
B. reproducibility
C. fidelity
D. static characteristics

C. fidelity

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Thermistors are made of
A. ultra pure metals
B. metal oxides
C. iron-copper alloys
D. nickel-chromium alloys

B. metal oxides

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A barometer measures the __________ pressure.
A. absolute
B. gauge
C. absolute as well as gauge
D. dynamic

A. absolute

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Humidity of air can be determined by a
A. chromatograph
B. sling psychrometer
C. mass spectrometer
D. polarimeter

B. sling psychrometer

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Thermocouple in a thermal well behaves as a true
A. first order system.
B. second order system (overdamped).
C. multiple first order system.
D. second order system (underdamped).

C. multiple first order system.

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The transfer function for a P-D controller is
A. Kc(1+τD s)
B. Kc(1 +1/τD s)
C. Kc τD s
D. Kc/τD s

A. Kc(1+τD s)

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Bode diagram is a plot of
A. log (AR) vs. log (f) and (Φ) vs. log (f).
B. log (AR) vs. f and log Φ vs.f.
C. AR vs. log (f) and Φ vs. log (f).
D. none of these.

A. log (AR) vs. log (f) and (Φ) vs. log (f).

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Working principle of disappearing filament type optical pyrometer is based on the
A. Wien’s law
B. Seebeck effect
C. Kirchoff’s law
D. Peltier effect

A. Wien’s law

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Strain gage uses an electrical conductor wire, which when elastically stretched increases in length and reduces in diameter. Both these dimensional changes result in __________ in the electrical resistance of the wire.
A. no change
B. decrease
C. increase
D. exponential decrease

C. increase

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Pick out the wrong statement
A. Proportional controller is normally used for level control in industrial applications.
B. CSTR can be considered as a distributed parameter system.
C. Distributed parameter approach gives partial differential equation.
D. Non-linear behaviour is exemplified by an on-off controller.

B. CSTR can be considered as a distributed parameter system.

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Range of hydrogen gas constant volume themometer is __________ °C.
A. -10 to 20
B. 0 to 100
C. 100 - 500
D. 400 - 1000

B. 0 to 100

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The initial value (t=0) of the unit step response of the transfer function [(s + 1)/(2s + 1)] is
A. 0
B. 1/2
C. 1
D. 2

B. 1/2

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The __________ of a vapor pressure thermometer is a primary element.
A. pointer
B. Bourdon tube
C. bulb
D. none of these

C. bulb

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The time constant of a first order process with resistance
R and capacitance C is
A. R + C
B. R - C
C. RC
D. 1/RC

C. RC

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A sinusoidal variation in the input passing through a linear first order system
A. becomes more oscillatory (frequency increases).
B. becomes less oscillatory (frequency decreases).
C. gets amplified (magnitude increases).
D. gets attenuated (magnitude decreases).

D. gets attenuated (magnitude decreases).

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Nitrogen gas constant volume thermometer is suitable for measuring a temperature of __________ °C.
A. 0-100
B. < 0
C. > 100.
D. > 50

C. > 100.

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Pick out the most suitable instrument for measuring temperature in the range of-40 to 425°C.
A. mercury thermometer
B. bimetallic thermometer
C. radiation pyrometer
D. none of these

B. bimetallic thermometer

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Accurate temperature measurement performance of a radiation pyrometer cannot be affected, if the
A. enhancement or attentuation of redia-tion occurs in the sighting path.
B. object and surrounding are at almost the same temperature.
C. object has varying emissivity.
D. object is transparent.

B. object and surrounding are at almost the same temperature.

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Relationship between absorption/evolution of heat at the thermocouple junctions and the current flow in the circuit is given by __________ effect.
A. Peltier
B. Thomson
C. Seebeck
D. none of these

A. Peltier

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Configuration of Bourdon spring tube is never made of __________ shape.
A. circular
B. semi-circular
C. helical
D. spiral

A. circular

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Thermodynamic celsius scale of temperature measurement is
A. defined on the basis of melting point of ice and evaporation temperature of water vapor.
B. defined on the basis of melting point of ice and condensation temperature of water vapor.
C. having an interval of 100° between ice point to steam point.
D. both (b) and (c)

D. both (b) and (c)

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According to Bode stability criterian, a system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at frequency for which phase lag is
A. 0°
B. 45°
C. 90°
D. 180°

D. 180°

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In a closed loop system, the process to be controlled is an integrating process with transfer function l/2s. The controller proposed to be used in an integral controller with transfer function 1/T1s. When a step change in set point is applied to such a closed loop system, the controlled variable will exhibit
A. overdamped response.
B. underdamped response.
C. undamped response.
D. unstable response.

B. underdamped response.

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Measurement of pressure in ammonia reactor is done by
A. Bourdon gauge
B. U-tube manometer
C. Inclined tube manometer
D. Pirani guage

A. Bourdon gauge

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The fluid used in hydraulic controller is
A. water
B. steam
C. air
D. oil

D. oil

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Flow rate of a river is measured by a/an
A. pitot tube
B. vane meter
C. kennison nozzle
D. open weir

B. vane meter

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Which of the following thermocouple materials does not contain nickel?
A. Alumel
B. Chromel
C. Constantan
D. None of these.

D. None of these.

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Flow rate of those fluids which are insensitive to changes in their density, viscosity or flow velocity profile can be best measured by a
A. magnetic flowmeter
B. pitot tube
C. flow nozzle type flowmeter
D. turbine flowmeter

A. magnetic flowmeter

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Identify an unbounded input from inputs whose transfer functions are given below
A. 1
B. 1/S
C. 1/S2
D. 1/(S2 + 1)

C. 1/S2

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“A control system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at
the crossover frequency.” This is __________ criterion.
A. Bode stability
B. Nyquist
C. Routh stability
D. none of these

A. Bode stability

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Feed forward controller accounts for the __________ changes.
A. set point
B. load
C. both (a) & (b)
D. neither (a) nor (b)

B. load

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Which thermocouple can be used to measure a temperature of around 1400°C ?
A. Copper-constantan
B. Aluminium-chromel
C. Platinum-platinum+rhodium
D. None of these

C. Platinum-platinum+rhodium

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Which of the following filled system expansion thermometer has the capability to measure the lowest
temperature ?
A. Mercury in glass thermometer
B. Mercury in steel thermometer
C. Alcohol in glass thermometer
D. Fused metal (Na or K) in steel thermometer

C. Alcohol in glass thermometer

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Concentration of sugar solution can be determined by the
A. polarimetry
B. flame photometry
C. emission spectroscopy
D. oscillometry

A. polarimetry

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In a single tank system, the transfer function of __________ to inlet flow rate is 1/TS+1.
A. outlet flow rate
B. level
C. both (a) & (b)
D. neither (a) nor (b)

A. outlet flow rate

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Which of the following can not measure a temperature of 1600°C ?
A. Platinum resistance thermometer
B. Thermocouple
C. Photo-electric pyrometer
D. Radiation pyrometer

A. Platinum resistance thermometer

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The temperature range for which copper resistance thermometer can be used is __________ °C
A. 0 to 150
B. -200 to 150
C. 350 to 750
D. 500 to 900

B. -200 to 150

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Paramagnetism method is not used for the composition determination of __________ in gases.
A. oxygen
B. oxides of nitrogen
C. carbon dioxide
D. any of these

C. carbon dioxide

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An amplitude ratio of 0.1 corresponds to __________ decibels.
A. 20
B. -20
C. 10
D. -10

B. -20

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For increased speed of response of an expansion pressure spring thermometer, the thermometer bulb should have a
A. large area but small mass.
B. high thermal conductivity.
C. small specific heat.
D. all’a’, ‘b’ & ‘c’.

D. all’a’, ‘b’ & ‘c’.

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Pressure of 0.0001 absolute psi can be measured by __________ gauge.
A. Mcloid
B. Pirani
C. thermocouple
D. none of these

A. Mcloid

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Pirani gauge is used for the measurement of
A. very high pressure.
B. high vacuum.
C. liquid level under pressure.
D. liquid level at atmospheric pressure

B. high vacuum.

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The __________ of the fluid contained in the temperature
sensing element (i.e., bulb) of filled system thermometers
changes with change in temperature.
A. pressure
B. volume
C. viscosity
D. all (a), (b) and (c

D. all (a), (b) and (c

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__________ thermometer can not measure sub-zero (<
0° C) temperature,
A. Mercury in glass
B. Bimetallic
C. Vapor pressure
D. Resistance

B. Bimetallic

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Starting temperature of optical radiation pyrometer is __________ °C.
A. 800
B. 400
C. 1200
D. 1500

A. 800

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Liquid argon level in a pressurised storage tank (at 3 kg/cm2 ) is measured by a/an
A. gage glass
B. external float gage
C. differential pressure gage
D. none of these

C. differential pressure gage

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Which of the systems having following transfer functions is stable?
A. 1/(s2+ 2)
B. 1/(s2-2s + 3)
C. 1/(s2 + 2s + 2)
D. exp(-20s)/(s2 + 2s-l)

C. 1/(s2 + 2s + 2)

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What is the dynamic error in a critically damped second order instrument for a ramp input (At) ?
A. 0.5 AT
B. 2 AT
C. AT
D. 1.5 AT

B. 2 AT

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The deflection of the free end of the bimetallic strips in a bimetallic thermometer with temperature is nearly
A. linear
B. non-linear
C. parabolic
D. hyperbolic

A. linear

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Alphatron measures pressure __________ microns.
A. < 1
B. < 3
C. > 3
D. < 0.1

C. > 3

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What is the ratio of output amplitude to input amplitude for a sinusoidal forcing function in a first order system ?
A. 1
B. >1
C. < 1
D. none of these

C. < 1

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The term analogous to the electrical current in a thermal system is the
A. temperature difference
B. heat flow rate
C. heat content in the system
D. none of these

B. heat flow rate

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Reset rate is the another term used for __________ time.
A. dead
B. integral
C. derivative
D. none of these

B. integral

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Continuous measurement of moisture in paper is done by
A. sling psychrometer
B. hair-hygrometer.
C. weighing.
D. high resistance Wheatstone’s bridge circuit.

D. high resistance Wheatstone’s bridge circuit.

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Psychrometer determines the
A. humidity of gases
B. moisture content of solids
C. water of crystallisation
D. hygroscopic nature of solids

A. humidity of gases

A mercury barometer measures the __________ pressure.
A. atmospheric
B. gauge
C. vacuum
D. absolute

A. atmospheric

Positioning controllers are used for
A. low loads
B. temperature changes
C. high loads
D. flow rate changes

C. high loads

The amplitude ratio for the sinusoidal response of a __________ is 1.
A. first order system
B. second order system
C. transportation lag
D. none of these

C. transportation lag

The response of two tanks of same size and resistance in series is
A. under damped
B. critically damped
C. over damped
D. none of the above

B. critically damped

The amplitude ratio for the sinusoidal response of __________ is < 1.
A. transportation lag
B. first order system
C. second order system
D. none of these

B. first order system

Which of the following is a ‘contact’ pyrometer ?
A. resistance pyrometer
B. optical pyrometer
C. radiation pyrometer
D. infra red pyrometer

A. resistance pyrometer

Which of the following is not a speed measuring instrument ?
A. Psychrometer
B. Stroboscope
C. Tachometer
D. All (a), (b) and (c)

A. Psychrometer

Measurement of sub-zero Celcius temperature in industry is done most commonly by
A. thermocouples
B. resistance thermometers
C. gas thermometers
D. bi-metallic thermometers

B. resistance thermometers

Use of I-control along with P-control facilitates
A. elimination of offset
B. reduction of offset
C. reduction of stability time
D. none of these

A. elimination of offset

Turbine flow meters are suitable for
A. very limited flow ranges.
B. cryogenic flow measurements.
C. aerospace and in air borne applications.
D. both (b) and (c).

D. both (b) and (c).

Liquid discharge from a tank or reservoir can not be measured by
A. orificemeters
B. weirs
C. mouthpieces
D. notches

A. orificemeters

Which of the following is not a mechanical pressure sensing element ?
A. Bellows
B. Diaphragm
C. Bourdon tube
D. U-tube

D. U-tube

__________ are analysed using a polarograph.
A. Isotonic solutions
B. Solids
C. Liquids
D. Gases

B. Solids

Which of the following judges the accuracy of an instrument ?
A. Dead zone
B. Drift
C. Static error
D. None of these

C. Static error

On-off controllers are normally used for
A. low loads
B. temperature changes
C. flow rate changes
D. none of these

A. low loads

Magnetic flowmeters are generally not used for the velocity/flow measurement of hydrocarbons due to their
A. low thermal conductivity.
B. low electrical conductivity.
C. high viscosity index.
D. low flash point.

B. low electrical conductivity.

Pressure of 0.01 psi (absolute) can be measured by __________ gauge.
A. ionisation
B. Pirani
C. Mcloid
D. none of these

C. Mcloid

Which of the following controllers has maximum offset ?
A. P-controller
B. P-I controller
C. P-D controller
D. P-I-D controller

A. P-controller

High temperature of around 2000°C of incandescent gas mantles is measured by a/an
A. specially designed thermocouple.
B. optical pyrometer.
C. radiation pyrometer.
D. none of these.

C. radiation pyrometer.

Which of the following does not figure in the list of seven
substances selected for international temperature scale ?
A. Ice (F.P) and steam (B.P)
B. Oxygen and sulphur (B.P)
C. Antimony and silver (F.P)
D. Zinc (B.P) and mercury (F.P)

D. Zinc (B.P) and mercury (F.P)

A constant volume gas thermometer employing__________ is used to measure sub-zero (i.e., < 0° C) temperature.
A. helium
B. hydrogen
C. nitrogen
D. none of these

A. helium

pH meter has
A. one cell
B. two cells
C. three cells
D. no cell

B. two cells

Routh test
A. criterion provides information about the actual location of roots.
B. cannot be used to test the stability of a control system containing transportation lag.
C. criterion is not applicable to systems with polynomial characteristic equation.
D. can not determine as to how many roots of the characteristics equation have positive real roots.

B. cannot be used to test the stability of a control system containing transportation lag.

When a bare thermocouple is covered by a protective sheath, the response becomes
A. faster and oscillatory.
B. faster and non-oscillatory.
C. slower and oscillatory.
D. slower and non-oscillatory.

D. slower and non-oscillatory.

What is the normal percentage of rhodium in platinum +
rhodium element used in the thermocouple ?
A. 0.1
B. 3
C. 13
D. 29

C. 13

Bode diagram are generated from output response of the system subjected to which of the following input?
A. Impulse
B. Step
C. Ramp
D. Sinusoidal

D. Sinusoidal

Helium gas constant volume thermometer is suitable for
the measurement of a temperature of __________ °C.
A. < 100
B. < 0
C. > 0
D. > 800

B. < 0

Which of the following thermocouples is the most suitable for measuring a temperature of about 1600°C in an oxidizing atmosphere ?
A. Platinum-platinum + rhodium
B. Iron-constantan
C. Copper-constantan
D. Chromel-alumel

A. Platinum-platinum + rhodium

Mercury thermometer can be used to measure the temperature up to __________ °C.
A. 100
B. 250
C. 350
D. 750

C. 350

Vapour actuated pressure spring thermometer does not require ambient temperature compensation. Ambient temperature compensation is provided in gas or liquid expansion pressure spring thermometer by
A. making the volume of thermometer bulb as large
as conveniently possible.
B. reducing the volume of the capillary to a
minimum.
C. reducing the volume of the receiving element to a
minimum.
D. all ‘a’, ‘b’ & ‘c’

D. all ‘a’, ‘b’ & ‘c’

Working principle of mercury in glass thermometer is based on volumetric expansion of mercury with increase in temperature. Which of the following undergoes minimum volumetric expansion for a given temperature change ?
A. Water
B. Mercury
C. Methyl alcohal
D. Carbon-tetrachloride

B. Mercury

Which of the following is not a differential pressure flow meter?
A. Rotameter
B. Flow nozzle
C. Orificemeter
D. Venturimeter

A. Rotameter

Bourdon gauges are used for measuring pressure (kg/cm2 )
A. < atmospheric
B. > 2 (gauge)
C. < 2 (gauge)
D. > 10 (absolute)

B. > 2 (gauge)

A photo electric device in which the resistance of the
metal is directly proportional to the light striking on it, is
known as photo-conductive cell. Photoelectric
transducers are used for the measurement of those
parameters, which can be used to produce variation in
A. light intensity
B. current
C. flux density
D. voltage

A. light intensity

An aneroid barometer measures the __________ pressure.
A. atmospheric
B. absolute
C. vacuum
D. gage

B. absolute

A typical example of a physical system with under
damped characteristic is a
A. U-tube manometer.
B. spring loaded diaphragm valve.
C. CSTR with first order reaction.
D. thermocouple kept immersed in a liquid filled
thermowell

B. spring loaded diaphragm valve.

A bolometer is
A. used for the measurement of thermal radiation.
B. an element which senses optical input and
delivers thermal output.
C. both (a) & (b).
D. neither (a) nor (b).

C. both (a) & (b).

Thermal wells are used in the temperature measurement to
A. guard against corrosive and oxidising action
on thermocouple materials
B. reduce measuring lag.
C. increase the fidelity.
D. increase the sensitivity

A. guard against corrosive and oxidising action

The offset introduced by proportional controller with gain Kc in response of first order system can be reduced by
A. reducing value of Kc.
B. introducing integral control.
C. introducing derivative control.
D. none of the above.

B. introducing integral control.

A system with a double pole at the origin is unstable since the corresponding term in the time domain
A. is a constant.
B. grows exponentially with time.
C. grows linearly with time.
D. decays linearly with time.

C. grows linearly with time.

To increase the speed of response of a pressure spring liquid or gas expansion thermometer, the clearance space between the thermometer bulb and the thermal well should not be filled with
A. air
B. a metal powder or graphite
C. oil
D. mercury

A. air

In an exothermic chemical reactor, the manipulated variable is the flow rate of
A. coolant
B. reactants
C. product
D. none of these

A. coolant

Very low pressure is expressed in microns(μ), which is equal to __________ mm of Hg coloumn (absolute) at 0°C.
A. 0.0001
B. 0.001
C. 0.01
D. 0.1

B. 0.001

Thermal conductivity based continuous flue gas analyser makes use of varying thermal conductivity of the constituents of flue gases. Which of the following constituents of flue gases has the maximum thermal conductivity ?
A. CO2
B. N2
C. O2
D. CO

A. CO2

Emf generated in a thermocouple depends on the temperature
A. of cold junction only.
B. of hot junction only.
C. difference between hot and cold junctions.
D. difference between cold junction and atmospheric temperature.

C. difference between hot and cold junctions.

Working principle of mercury in glass thermometer is based on the __________ of mercury with increase in temperature.
A. increase of pressure
B. increase of thermal conductivity
C. volumetric expansion
D. differential linear expansion

C. volumetric expansion

Radiation thermometer can not measure the temperature
A. inside a pressure vessel.
B. of an object without coming in contact with it.
C. of liquid oxygen.
D. of moving objects at high temperature.

C. of liquid oxygen.

Continuous flue gas analyser makes use of paramagnetic properties of some of its constituents, which move towards the strongest part of the magnetic field thus displacing diamagnetic gases. Which of the following gases is diamagnetic ?
A. CO2
B. O2
C. NO
D. NO2

A. CO2

Temperature measurement by optical pyrometer is done
above __________ point, which is 1063°C.
A. antimony
B. gold
C. silver
D. nickel

B. gold

Dilatometer is used to measure
A. stress
B. strain
C. deflection
D. contraction/expansion due to changes in temperature

D. contraction/expansion due to changes in temperature

Mass spectrometer is used for the composition analysis of
A. alloys
B. solids
C. isotopes
D. none of these

C. isotopes

__________ stability method uses open loop transfer function.
A. Nyquist
B. Mikhalov
C. Ruth
D. none of these

A. Nyquist

A pyranometer is an instrument used for measuring the
A. beam radiation.
B. global radiation.
C. bright sunshine period.
D. none of these.

B. global radiation.

All the thermocouples used for temperature measurement use dissimilar metal
A. strips
B. bars
C. wires
D. beads

C. wires

Composition of alloys can be determined by
A. polarograph
B. chromatograph
C. refractrometer
D. none of these

A. polarograph

Optical activity of a solution can be determined using a
A. polarimeter
B. polarograph
C. dilatometer
D. refractrometer

A. polarimeter

Stability of a control system containing a transportation
lag can be best analysed by
A. Routh test
B. root locus methods
C. frequency response methods
D. none of these

C. frequency response methods

Time constant is the
A. time taken by the controlled variable to reach 63.2% of its full change.
B. same as transportation lag.
C. same as dead time.
D. time required by the measured variable to reach 63.2% of its ultimate change.

A. time taken by the controlled variable to reach 63.2% of its full change.

Stabilising time for the controllers is the time required for the response to reach __________ percent of its ultimate
value.
A. 63.2
B. 87.5
C. 95
D. 100

C. 95

Mercury manometer (U-tube type) exemplifies a __________ order system.
A. zero
B. first
C. second
D. third

C. second

Bode stability method uses __________ loop transfer function.
A. open
B. closed
C. either (a) or (b)
D. neither (a) nor (b)

A. open

Working principle of bimetallic thermometers is difference
in linear co-efficient of thermal expansion of two strips of
different metals welded together. Which of the following
has the maximum thermal co-efficient of linear
expansion?
A. Nickel
B. Brass
C. Chromel
D. Invar

B. Brass

Which of the following is not a second order instrument?
A. Mercury in glass thermometer with covering.
B. Bare mercury in glass thermometer.
C. Pressure gauge with one bellow, two tubes and a
tank
D. None of these.

B. Bare mercury in glass thermometer.

Small furnace draught is accurately measured by an inclined tube manometer, in which the manometric liquid used most commonly is
A. water
B. carbon tetrachloride
C. paraffin
D. ethylene glycol

C. paraffin

A simple pitot tube measures the
A. average velocity
B. maximum velocity
C. point velocity
D. static pressure

D. static pressure

For a feed back control system to be stable, the
A. roots of the characteristic equation should be real.
B. poles of the closed loop transfer function should lie in the left half of the complex plane.
C. Bode plots of the corresponding open loop
transfer function should monotoni-cally decrease.
D. poles of the closed loop transfer function should
lie in the right half of the complex plane.

B. poles of the closed loop transfer function should lie in the left half of the complex plane.

__________ controller has the maximum stabilising time.
A. P
B. PD
C. PI
D. PID

C. PI

Out of the following temperature measuring instruments,
the measurement accuracy will be minimum for the
A. mercury in glass thermometer.
B. optical pyrometer.
C. iron-constantan thermocouple.
D. alcohol filled thermometer.

B. optical pyrometer.

Stalagmometer is used for the measurement of
A. kinematic viscosity
B. surface tension
C. refractive index
D. optical activity

B. surface tension

The deflection in diaphragm (which is used as pressure sensor in pneumatic and electronic instruments) is dependent on the metal thickness, its diameter (d) and shape & number of corrugations. Its deflection is proportional to
A. d
B. d2
C. d3
D. d4

D. d4

Working principle of radiation pyrometer is based on the
A. Wien’s law
B. Kirchoffs law
C. stefan-Boltzman law
D. Seebeck effect

C. stefan-Boltzman law

Liquid levels in autocalves are measued by
A. simple float
B. differential float type manometer
C. glass gauge
D. none of these

B. differential float type manometer

E.m.f. generated by thermocouples is of the order of
A. millivolts
B. microvolts
C. volts
D. kilo volts

A. millivolts

A pyrheliometer is an instrument used for measuring the
A. bright sunshine period.
B. beam radiation.
C. diffuse radiation.
D. none of these.

B. beam radiation.

Flow rate through an orifice is __________ the pressure differential.
A. proportional to
B. inversely proportional to the square root of
C. proportional to the square root of
D. inversely proportional to the square of

C. proportional to the square root of

Thermistors are used in __________ devices.
A. voltage measuring
B. temperature measuring
C. temperature compensating
D. both(b)&(c)

D. both(b)&(c)

_________ is the static characteristics of an instrument,
A. Response
B. Time lag
C. Drift
D. dynamic error

C. Drift

Phase lag of the frequency response of a second order
system to a sinusoidal forcing function
A. is 30°
B. is 90° at the most
C. approaches 180° asymptotically
D. is 120°

C. approaches 180° asymptotically

Dead zone in an instrument must be less than
__________ percent of the scale.
A. 0.2
B. 1.5
C. 4
D. 8

A. 0.2

Gas analysis is commonly done using the
A. thermal conductivity cell
B. X-ray diffraction
C. mass spectrometer
D. emission spectrometer

A. thermal conductivity cell

Emission spectroscopy is used for
A. solids and metal analysis.
B. determining water purity.
C. determination of CO2 in gases.
D. NOxdetermination.

A. solids and metal analysis.

Thermal conductivity measurement is used for the
determination of
A. O2 percentage in the flue gas.
B. specific gravity of petrofuels.
C. composition of an alloy.
D. CO2 percentage in the flue gas

D. CO2 percentage in the flue gas

Presence of a small amount of water in the organic systems can be determined by the __________ method.
A. electrical conductivity
B. polarimetry
C. emission spectroscopy
D. dielectric constant end loss factor

D. dielectric constant end loss factor

Thermal conductivity cell is the primary element of a/an __________ analyser.
A. oxygen
B. carbon dioxide
C. carbon monoxide
D. sulphur dioxide

B. carbon dioxide

Zirconia probe is used for the measurement of
A. humidity of air.
B. % CO2 in flue gas.
C. % O2 in flue gas.
D. speed of a submarine.

C. % O2 in flue gas.

Characteristic equation is the denominator of __________ loop transfer function.
A. open
B. closed
C. both (a)and (b)
D. neither (a) nor (b)

B. closed

Operating range of a temperature measuring instrument is 800 to 1600°C. It could be a/an __________ pyrometer.
A. radiation
B. optical
C. photoelectric
D. none of these

C. photoelectric

Process degree of freedom indicates __________ number of controllers to be used.
A. the maximum
B. the minimum
C. both maximum and the minimum
D. nothing about the

A. the maximum

__________ type of element is normally not used in the
bimetallic thermometers.
A. Flat spiral
B. Bourdon tube
C. Single helix
D. Multiple helix

B. Bourdon tube

Polarograph is meant for the analysis of
A. gaseous mixture
B. miscible liquids
C. solids
D. isotopes

C. solids

Which of the following fluid flow measuring devices can
measure the largest flow rate ?
A. V-notch
B. Rotameter
C. Orificemeter
D. Weir

D. Weir

Flow rate of sludge is not measured by a/an
A. orificemeter
B. open weir
C. kennison nozzle
D. both(b)&(c)

D. both(b)&(c)

In a shell and tube heat exchanger, the inlet temperature
of heating/cooling fluid is the __________ variable.
A. load
B. manipulated
C. controlled
D. none of these

A. load

Polarisation of light forms the working principle of a
A. polarimeter
B. polarograph
C. chromatograph
D. spectrometer

A. polarimeter

A bimetallic thermometer as compared to industrial mercury in glass thermometer has almost the same
A. temperature measuring range (- 40°C to 450°C).
B. accuracy (± 1% of span).
C. speed of response.
D. all a, b & c.

D. all a, b & c.

Which of the following flow-metering instruments is an areameter ?
A. Venturimeter
B. Rotameter
C. Pitot tube
D. Hot wire anemometer

B. Rotameter

Thermal wells used in temperature measurements should
have
A. very thick walls.
B. low emissivity.
C. polished surface.
D. high transmissivity of radiation.

D. high transmissivity of radiation.

Which is the most suitable instrument for measuring pressure below 3 microns ?
A. Mcleoid gauge
B. Alphatron
C. Ionisation gauge
D. Bourdon guage

C. Ionisation gauge

Non-metallic diaphragm used as pressure sensor in instruments is generally made of
A. teflon
B. synthetic rubber
C. bakelite
D. thick paper

B. synthetic rubber

Photoelectric pyrometers are suitable in the temperature
range of __________ °C.
A. 400-1600
B. 800-1600
C. 800-2500
D. 400-1000

B. 800-1600

Out of the following themocouple wire insulating material, the highest temperature rating is for
A. teflon
B. ceramic fibre
C. asbestos
D. fibre glass

B. ceramic fibre

Routh stability method uses __________ loop transfer
function.
A. open
B. closed
C. either (a) or (b)
D. neither (a) nor (b)

B. closed

Pyrometry refers to the measurement of temperature
A. with the mercurial thermometer upto 350°C.
B. directly.
C. which is of higher magnitude.
D. all (a), (b) & (c).

C. which is of higher magnitude.

Which of the following thermocouples has the widest temperature measurement range ?
A. Iron-constantan
B. Chromel-alumel
C. Copper-constantan
D. Platinum-platinum/rhodium

D. Platinum-platinum/rhodium

Temperature control of an exothermic chemical reaction taking place in a CSTR is done with the help of cooling water flowing in a jacket around the reactor. The types of valve and controller action to be recommended are
A. air to open valve with the controller direct acting.
B. air to close valve with the controller indirect acting.
C. air to open valve with the controller indirect acting.
D. air to close valve with the controller direct acting.

C. air to open valve with the controller indirect acting.

Response of a linear control system for a change in set
point is called
A. frequency response
B. transient response
C. servo problem
D. regulator problem

C. servo problem

Hot wire anemometer is used for the measurement of
A. flow rates of fluids.
B. flow rates of granular solids.
C. very high temperature.
D. thermal conductivity of gases.

A. flow rates of fluids.

“An emf of the order of mV is generated when two solutions of different hydrogen ion concentration are separated by a thin glass wall”. This is the working principle of a
A. pH meter
B. polarimeter
C. chromatograph
D. polarograph

A. pH meter

Bourdon tube is never made of
A. phosphor bronze
B. monel metal
C. stainless steel
D. cast iron

D. cast iron

In a shell and tube heat exchanger, the outlet temperature of heating/cooling fluid is the __________ variable.
A. load
B. manipulated
C. controlled
D. none of these

C. controlled

Mcleoid gauge is used to measure the
A. point velocity
B. flow rate
C. vacuum
D. pressure

C. vacuum

The term analogous to voltage in a single tank system is the
A. heat content of the system.
B. liquid volume in the tank.
C. flow rate.
D. level of liquid.

D. level of liquid.

Thermocouple is suitable for measuring
A. liquid temperatures only.
B. very high temperatures only.
C. very low temperatures only.
D. both high and low temperatures.

D. both high and low temperatures.

Nickel percentage in invar which is an iron-nickel alloy,
and is used as a thermocouple material is
A. 12
B. 36
C. 54
D. 68

B. 36

Bimetal strips are not used in
A. bimetallic thermometers.
B. thermocouples.
C. thermostats.
D. relays for opening & closing of electrical circuits.

B. thermocouples.

When the damping co-efficient (ξ) is unity, the system is
A. Overdamped.
B. Critically damped.
C. Underdamped.
D. Highly fluctuating.

B. Critically damped.

A non-linear system will have __________ steady state values.
A. one
B. more than one
C. two
D. three

B. more than one

Which of the following is not a variable area flow meter ?
A. Piston type meter
B. Rotameter
C. Magnetic flow meter
D. Orifice and tapered plug meter

C. Magnetic flow meter

Silver point temperature is __________ °C.
A. 760.5
B. 860.5
C. 960.5
D. 1060.5

C. 960.5

Sub-zero temperature (< 0°C) can be measured by a constant volume gas thermometer employing
A. helium
B. nitrogen
C. hydrogen
D. none of these

A. helium

With increase in temperature, the electrical conductivity of the platinum used in the resistance thermometer
A. increases
B. decreases
C. remains constant
D. increases exponentially

B. decreases

__________ is an example of distributed parameter system
A. Tubular reactor
B. CSTR
C. On-off controller
D. none of these

A. Tubular reactor

Which of the following is not classified as a thermo electric pyrometer ?
A. Resistance thermometer.
B. Thermocouple.
C. Optical pyrometer (disappearing filament type)
D. Radiation pyrometer

C. Optical pyrometer (disappearing filament type)

Maximum differential pressure in liquid manometer is
__________ psi.
A. 20
B. 30
C. 40
D. 50

B. 30

Flow rate measurement of hostile acids and alkalis can be most suitably done by a/an
A. venturimeter
B. orificemeter
C. magnetic flow meter
D. hot wire anemometer

C. magnetic flow meter

Compositional analysis of flue gas coming out of a furnace in respect of O2 and CO2% can be continuously done by a/an
A. orsat apparatus
B. thermal conductivity cell
C. zirconia probe
D. chromatograph

B. thermal conductivity cell

Thermisters which have a very high temperature coefficient of resistivity belong to the class of solid called
A. dielectrics
B. insulators
C. semi conductors
D. conductors

C. semi conductors

The pressure sensing element of elastic type pressure gauge is never made in the form of a
A. bellow
B. diaphragm
C. strip
D. Bourdon tube

C. strip

Liquid flow rate in an open channel can not be measured by a/an
A. orifice meter
B. cipolletti weir
C. rectangular weir
D. V-notch

A. orifice meter

The unit of ‘time constant’ of a system is the same as that of
A. velocity
B. time
C. (time)-1
D. none of these

B. time

Which of the following filled system expansion thermometers has the lowest positive temperature measurement capability ?
A. Mercury in glass thermometer.
B. Alcohol in glass thermometer.
C. Fused metal (Na or K) in steel thermometer.
D. Nitrogen in steel thermometer.

B. Alcohol in glass thermometer.

Liquid column manometers are used for measuring the pressure __________ kgf/cm2 .
A. > 2(gage)
B. < 3 (gage)
C. < 10 (gage)
D. < atmospheric

B. < 3 (gage)

Cascade control means
A. feed forward control.
B. more than one feed-back loop.
C. on-off control.
D. one feed-back loop.

B. more than one feed-back loop.

The level of a liquid under pressure can be determined using
A. bubbler system
B. differential pressure manometer
C. diaphragm box system
D. air-trap system

B. differential pressure manometer

Temperature measurement range of iron-constantan thermocouple is 0 to 870°C. It can be used to measure sub zero temperature, because at lower temperature
A. emf produced is very low of the order of microvolt.
B. embrittlement of iron occurs.
C. rusting of iron takes place.
D. both (b) and (c).

D. both (b) and (c).

Which of the following is never used as an element of industrial resistance thermometer ?
A. Lead
B. Nickel
C. Copper
D. 30% iron + 70% nickel

A. Lead

Which of the following shows maximum dip effect (indicating reverse direction of temperature change) ?
A. Mercury thermometer
B. Radiation pyrometer
C. Bimetallic thermometer
D. Thermocouple

A. Mercury thermometer

A stable system is the one
A. for which the output response is bounded for all bounded input.
B. which exhibits an unbounded response to a bounded input
C. which satisfies the conditions for a servo problem.
D. none of these.

A. for which the output response is bounded for all bounded input.

Platinum resistance thermometer can be used upto antimony point which is __________ °C, and is the temperature of equilibrium between solid antimony & liquid antimony at normal atmospheric pressure.
A. 961.93
B. 630.74
C. 1064.43
D. 1261.93

B. 630.74

Change of angle of refraction with composition comprises the working principle of a
A. polarimeter
B. polarograph
C. spectrometer
D. refractrometer

D. refractrometer

Which of the following instruments is not used for measuring sub-zero (<0°) temperatures ?
A. Platinum resistance thermometer
B. Mercury in glass thermometer
C. Vapor pressure thermometer
D. Radiation pyrometer

D. Radiation pyrometer

Flame photometry is used for the determination of compositional analysis of
A. solids
B. alkali metals
C. natural gas
D. isotopes

B. alkali metals

Reference points i.e., ice point and steam point in Reaumer temperature scale are respectively
A. - 273° & 80°
B. 0° & 80°
C. 32° & 460°
D. 32° & 80°

B. 0° & 80°

Which of the following is not a composition measuring instrument ?
A. Thermal conductivity cell
B. Mass spectrometer
C. Polarograph
D. Hot wire anemometer

D. Hot wire anemometer

Platinum resistance thermometer is the international standard for temperature measurement between
A. triple point of hydrogen and freezing point of antimony
B. 13.81°K to 903.9°K
C. both (a) and (b)
D. neither (a) nor (b)

C. both (a) and (b)

On-off control which is a special case of proportional control, has a band width of about __________ percent.
A. 100
B. 75
C. 25
D. 0

D. 0

The thermal emf-temperature relationship of most thermocouples is
A. linear
B. parabolic
C. exponential
D. square root

B. parabolic

Which is the strongest paramagnetic gas?
A. CO2
B. O2
C. NO
D. NO2

B. O2

For measuring the temperature of a red hot furnace, which is the most suitable instrument ?
A. Platinum resistance thermometer
B. Thermocouple
C. Optical pyrometer
D. Bimetallic thermometer

C. Optical pyrometer

Continuous measurement of specific gravity of a liquid is done by
A. hydrometer
B. contact-type electric indicators
C. displacement meter
D. both (a) and (c)

D. both (a) and (c)

Stroboscope is used for the measurement of
A. rpm of a flywheel
B. frequency of light
C. depression of freezing point
D. liquid level under pressure

A. rpm of a flywheel

In second order underdamped system,
A. decay ratio = overshoot
B. decay ratio = (overshoot)2
C. overshoot increases for increasing damping coefficient.
D. large damping co-efficient means smaller damping.

B. decay ratio = (overshoot)2

Dome temperature of blast furnace stove is most accurately measured by a
A. radiation pyrometer.
B. platinum-platinum/rhodium thermocouple.
C. iron-constantan thermocouple.
D. platinum resistance thermometer.

B. platinum-platinum/rhodium thermocouple.

Phase lag of the sinusoidal response of a first order system is
A. 120°
B. 30°
C. 180°
D. 90°

D. 90°

Continuous measurement of moisture content of paper in paper industry is done by measuring the
A. thermal conductivity through the paper
B. electrical resistance through the paper
C. magnetic susceptibility
D. none of these

B. electrical resistance through the paper

Thermal well made of __________ gives the fastest speed of response, while measuring temperature by thermocouples.
A. steel
B. vycor (a glass)
C. nichrome
D. inconel

B. vycor (a glass)

Pick out the wrong statement.
A. There is no transfer lag for a single first order system.
B. Stirred tank with a water jacket exemplifies an interacting system.
C. Transfer lag is a characteristics of all higher order systems (other than first order systems).
D. Transfer lag decreases as the number of stages decreases.

D. Transfer lag decreases as the number of stages decreases.

Working principle of mercury in glass thermometer is
A. volumetric expansion.
B. pressure rise with temperature.
C. linear expansion.
D. none of these.

A. volumetric expansion.

The frequency at which maximum amplitude ratio is attained is called the __________ frequency.
A. corner
B. resonant
C. cross-over
D. natural

B. resonant

If response of a control system is to be free of offset and oscillation, the most suitable controller is
A. proportional controller.
B. proportional-derivative(PD)controller.
C. proportional-integral (PI) controller.
D. proportional integral-derivative (PID)
controller.

D. proportional integral-derivative (PID)
controller.

Conversion formula for converting amplitude ratio (AR)
into decibels is
A. Decibel = 20 log10 (AR)
B. Decibel = 20 loge (AR)
C. Decibel = 20 log10 (AR)0.5
D. Decibel = 20 loge (AR)0.5

A. Decibel = 20 log10 (AR)

A manometer measures the __________ pressure.
A. atmospheric
B. absolute
C. gauge
D. none of these

C. gauge

Normal mercury thermometer can be used to measure a temperature of about 300°C. However, its maximum temperature measurement range can be increased upto about 500°C by
A. filling nitrogen under pressure in the stem.
B. increasing the diameter of the tube.
C. using steel tube in place of glass tube.
D. accounting for the tube expansion.

A. filling nitrogen under pressure in the stem.

Minute depression of freezing point of a liquid solvent on addition of a solid solute can be best measured by a
A. Beckman thermometer
B. dilatometer
C. mercury thermometer
D. bimetallic thermometer

A. Beckman thermometer

Gain margin is equal to the
A. amplitude ratio
B. reciprocal of amplitude ratio
C. gain in P controller
D. gain in P-I controller

B. reciprocal of amplitude ratio

Temperature of molten pig iron (1450°C) and molten slag (1500°C) flowing out of a blast furnace is measured by a/an
A. chromel-alumel thermocouple
B. optical pyrometer
C. radiation pyrometer
D. either (b) or (c)

D. either (b) or (c)

For two non-interacting first order systems connected in series, the overall transfer function is the __________ of the individual transfer functions.
A. product
B. ratio
C. sum
D. difference

A. product

Composition of natural gas is determined by the
A. Haldane apparatus
B. mass spectrometer
C. chromatograph
D. both (b) and (c)

D. both (b) and (c)

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Indiabix - Process Control and Instrumentation Flashcards

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