Q.1

In Bode plot, Φ vs ω is plotted on a/an __________ graph paper.

  • log-log
  • ordinary
  • semi-log
  • triangular
Q.2

With increase in temperature, the electrical conductivity of the platinum used in the resistance thermometer

  • increases
  • decreases
  • remains constant
  • increases exponentially
Q.3

A magnetic flowmeter is

  • based on the principle of Faraday's law.
  • capable of measuring the flow rate of slurries and electrolytes.
  • based on the linear relationship between the fluid flow rate and the induced voltage.
  • all (a), (b) and (c).
Q.4

Zirconia probe is used for the continuous measurment of __________ flue gases going out of the furnace.

  • oxygen in
  • carbon dioxide in
  • carbon monoxide in
  • temperature of
Q.5

Which of the following can measure temperatures in the range of -to 300°C ?

  • Mercury in glass thermometer
  • Vapor pressure thermometer
  • Resistance thermometer
  • None of these.
Q.6

A manometer measures the __________ pressure.

  • atmospheric
  • absolute
  • gauge
  • none of these
Q.7

Phase lag of the sinusoidal response of a first order system is

  • 120°
  • 30°
  • 180°
  • 90°
Q.8

Continuous measurement of moisture content of paper in paper industry is done by measuring the

  • thermal conductivity through the paper
  • electrical resistance through the paper
  • magnetic susceptibility
  • none of these
Q.9

Ordinary mercury in glass thermometer is used for measuring temperature upto 120°C. However, for measuring higher temperature upto __________ °C, thermometer is made by filling nitrogen under pressure above the mercury, which stops the evaporation of mercury and reduces the chance of broken thread of mercury.

  • 250
  • 350
  • 550
  • 700
Q.10

Phase margin is equal to

  • 180° - phase lag
  • phase lag - 180°
  • phase lag + 180°
  • phase lag + 90°
Q.11

Platinum resistance thermometer is the international standard for temperature measurement between

  • triple point of hydrogen and freezing point of antimony
  • 13.81°K to 903.9°K
  • both (a) and (b)
  • neither (a) nor (b)
Q.12

A first order system with unity gain and time constant τ is subjected to a sinusoidal input of frequency w = 1/τ. The amplitude ratio for this system is

  • 1
  • 0.5
  • 1/2
  • 0.25
Q.13

Stroboscope is used for the measurement of

  • rpm of a flywheel
  • frequency of light
  • depression of freezing point
  • liquid level under pressure
Q.14

The pressure sensing element of elastic type pressure gauge is never made in the form of a

  • bellow
  • diaphragm
  • strip
  • Bourdon tube
Q.15

Strain gage pressure transducers are used to measure __________ pressures.

  • gage as well as vacuum
  • absolute as well as differential
  • both (a) and (b)
  • neither (a) nor (b)
Q.16

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

  • filling nitrogen under pressure in the stem.
  • increasing the diameter of the tube.
  • using steel tube in place of glass tube.
  • accounting for the tube expansion.
Q.17

Thermal well made of __________ gives the fastest speed of response, while measuring temperature by thermocouples.

  • steel
  • vycor (a glass)
  • nichrome
  • inconel
Q.18

Mercury thermometer is commonly used for low temperature measruement. The freezing point and boiling point of mercury are respectively __________ °C.

  • - 39 and 350
  • - 51 and 439
  • - 79 and 395
  • - 10 and 425
Q.19

Mcleoid gauge is used to measure the

  • point velocity
  • flow rate
  • vacuum
  • pressure
Q.20

Minute depression of freezing point of a liquid solvent on addition of a solid solute can be best measured by a

  • Beckman thermometer
  • dilatometer
  • mercury thermometer
  • bimetallic thermometer
Q.21

Which of the following thermocouples has the least temperature measurement range?

  • Copper-constantan
  • Chromel-alumel
  • Platinum-platinum/rhodium
  • Iron-constantan
Q.22

In Bode plot, Φ vs ω is plotted on a/an __________ graph paper.

  • log-log
  • ordinary
  • semi-log
  • triangular
Q.23

Mcleoid gauge is used to measure the

  • point velocity
  • flow rate
  • vacuum
  • pressure
Q.24

Which of the following can measure temperatures in the range of -to 300°C ?

  • Mercury in glass thermometer
  • Vapor pressure thermometer
  • Resistance thermometer
  • None of these.
Q.25

The root locus plot of the roots of the characteristics equation of a closed loop system having the open loop transfer function will have a definite num-ber of loci for variation of K from 0 to ∞. The number of loci is

  • 1
  • 3
  • 4
  • 2
Q.26

Pick out the symbol for "locally mounted instrument" in instrumentation diagram.

Q.27

In Bode plot, Φ vs ω is plotted on a/an __________ graph paper.

  • log-log
  • ordinary
  • semi-log
  • triangular
Q.28

The root locus plot of the roots of the characteristics equation of a closed loop system having the open loop transfer function will have a definite num-ber of loci for variation of K from 0 to ∞. The number of loci is

  • 1
  • 3
  • 4
  • 2
Q.29

The transfer function for a PID controller is (where, τ i is the integral (reset) time and τD is the derivative time.)

  • Kc(1 + τis + τD ). s
    383-599-1u.png
    383-599-2.png
    383-599-3.png
Q.30

Which of the following is a desirable characteristic of an instrument ?

  • High drift
  • High fidelity
  • High measuring lag
  • Poor reproducibility
Q.31

Compositional analysis of __________ is done using mass spectrometer.

  • an isotope
  • natural gas
  • a solid
  • an alloy
Q.32

Pick out the wrong statement.

  • O2, NO and NO2 exhibit paramagnetic properties as a result of unpaired electrons.
  • CO2 is the strongest paramagnetic gas.
  • Paramagnetic susceptibility of gases decreases with temperature.
  • Paramagnetic susceptibility of gases permits the measurement of their concentration.
Q.33

The operation of a rotameter is based on

  • variable flow area.
  • rotation of a turbine.
  • pressure drop across a nozzle.
  • pressure at a stagnation point.
Q.34

The temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured by a/an __________ thermocouple.

  • chromel-alumel
  • iron-constantan
  • platinum-platinum/rhodium
  • none of these.
Q.35

The function of a transducer is to

  • modify the input signal.
  • amplify the input signal.
  • convert the primary signal into a more useful quantity, usually an electric impulse.
  • codify/decodify the input signal.
Q.36

Nichol's chart deals with

  • A.R. vs. phase lag of first order.
  • A.R. vs. phase lag of second order.
  • closed loop values vs. open loop values.
  • frequency response values of controllers.
Q.37

The __________ of a vapor pressure thermometer is a functioning element.

  • pointer
  • bourdon tube
  • bulb
  • none of these
Q.38

Temperature measuring instruments are standardised mostly with __________ points of pure substances.

  • melting
  • boiling
  • both (a) & (b)
  • neither (a) nor (b)
Q.39

Instrumentation in a plant offers the advantage of

  • greater safety of operation
  • better quality of product
  • greater operation economy
  • all (a), (b) and (c)
Q.40

Which of the following filled system expansion thermometer has the capability to measure the lowest temperature ?

  • Mercury in glass thermometer
  • Mercury in steel thermometer
  • Alcohol in glass thermometer
  • Fused metal (Na or K) in steel thermometer
Q.41

Which of the following thermocouples will give the highest output for the same value of hot and cold junction temperature ?

  • Platinum-platinum + rhodium.
  • Iron-constantan.
  • Chromel-constantan.
  • All will give the same output.
Q.42

Flow rate of those fluids which are insensitive to changes in their density, viscosity or flow velocity profile can be best measured by a

  • magnetic flowmeter
  • pitot tube
  • flow nozzle type flowmeter
  • turbine flowmeter
Q.43

A sinusoidal variation in the input passing through a linear first order system

  • becomes more oscillatory (frequency increases).
  • becomes less oscillatory (frequency decreases).
  • gets amplified (magnitude increases).
  • gets attenuated (magnitude decreases).
Q.44

Relationship between absorption/evolution of heat at the thermocouple junctions and the current flow in the circuit is given by __________ effect.

  • Peltier
  • Thomson
  • Seebeck
  • none of these
Q.45

Radiation pyrometers as compared to thermocouples

  • has a slower speed of response.
  • can measure higher temperature.
  • can't measure the temperature of moving objects.
  • is more affected by corrosive atmosphere.
Q.46

A negative gain margin expressed in decibels means a/an __________ system.

  • stable
  • unstable
  • critically damped
  • none of these
Q.47

Thermistor, which has high temperature co-efficient of resistivity, is used as the sensing element in resistance thermometer. It is a/an

  • insulator
  • conductor
  • solid semi-conductor
  • liquid semi-conductor
Q.48

Pick out the first order system from among the following.

  • Damped vibrator.
  • Mercury in glass thermometer kept in boiling water.
  • Interacting system of two tanks in series.
  • Non-interacting system of two tanks in series.
Q.49

Thermocouple in a thermal well behaves as a true

  • first order system.
  • second order system (overdamped).
  • multiple first order system.
  • second order system (underdamped).
Q.50

The response of two tanks of same size and resistance in series is

  • under damped
  • critically damped
  • over damped
  • none of the above
0 h : 0 m : 1 s