Q.1

Which of the following judges the accuracy of an instrument ?

  • Dead zone
  • Drift
  • Static error
  • None of these
Q.2

The characteristic equation for the control system with a closed loop transfer function G1/1 + G2 is given by 1 + G2 =The characteristic equation for the control system

  • depends only upon the open loop transfer function.
  • determines its stability.
  • is the same for set point or load changes.
  • all 'a', 'b' & 'c'
Q.3

Alphatron measures pressure __________ microns.

  • < 1
  • < 3
  • > 3
  • < 0.1
Q.4

Reset rate is the another term used for __________ time.

  • dead
  • integral
  • derivative
  • none of these
Q.5

Emf developed by a thermocouple while measuring a temperature of 400°C ismV. The type of thermocouple used is

  • chromel-alumel
  • iron-constantan
  • platinum-rhodium
  • platinum-platinum+rhyodium
Q.6

Volumetric expansion is the working principle of the __________ thermometers.

  • mercury in glass
  • constant volume gas
  • vapor pressure
  • bimetallic
Q.7

Working principle of disappearing filament type optical pyrometer is based on the

  • Wien's law
  • Seebeck effect
  • Kirchoff's law
  • Peltier effect
Q.8

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.

  • no change
  • decrease
  • increase
  • exponential decrease
Q.9

Which of the following is a 'contact' pyrometer ?

  • resistance pyrometer
  • optical pyrometer
  • radiation pyrometer
  • infra red pyrometer
Q.10

Liquid discharge from a tank or reservoir can not be measured by

  • orificemeters
  • weirs
  • mouthpieces
  • notches
Q.11

A first order system with a time constant of 1 min is subjected to frequency response analysis. At an input frequency of 1 radian/min, the phase shift is

  • 45°
  • -90°
  • -180°
  • -45°
Q.12

Bode diagram are generated from output response of the system subjected to which of the following input?

  • Impulse
  • Step
  • Ramp
  • Sinusoidal
Q.13

Which of the following is not a differential pressure flow meter ?

  • Rotameter
  • Flow nozzle
  • Orificemeter
  • Venturimeter
Q.14

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 ?

  • Water
  • Mercury
  • Methyl alcohal
  • Carbon-tetrachloride
Q.15

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

  • air
  • a metal powder or graphite
  • oil
  • mercury
Q.16

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 ?

  • CO2
  • N2
  • O2
  • CO
Q.17

Continuous shell temperature measurement in a liquid-liquid heat exchanger is done by a

  • thermocouple
  • reistance thermometer
  • mercury in glass thermometer
  • vapor pressure thermometer
Q.18

An aneroid barometer measures the __________ pressure.

  • atmospheric
  • absolute
  • vacuum
  • gage
Q.19

Stability of a control system containing a transportation lag can be best analysed by

  • Routh test
  • root locus methods
  • frequency response methods
  • none of these
Q.20

Stabilising time for the controllers is the time required for the response to reach __________ percent of its ultimate value.

  • 63.2
  • 87.5
  • 95
  • 100
Q.21

Which thermocouple can be used to measure a temperature of around 1400°C ?

  • Copper-constantan
  • Aluminium-chromel
  • Platinum-platinum+rhodium
  • None of these
Q.22

Temperature measurement by optical pyrometer is done above __________ point, which is 1063°C.

  • antimony
  • gold
  • silver
  • nickel
Q.23

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

  • overdamped response.
  • underdamped response.
  • undamped response.
  • unstable response.
Q.24

Dead zone is the

  • same as time constant.
  • same as transportation lag.
  • maximum change in the variable that does not change the reading of the instrument.
  • none of these.
Q.25

Which of the following thermocouple materials does not contain nickel ?

  • Alumel
  • Chromel
  • Constantan
  • None of these.
Q.26

The unit step response of the transfer function 1/(s2 + 2s + 3)

  • has a non-zero slope at the origin.
  • has a damped oscillatory characteristics.
  • is overdamped
  • is unstable
Q.27

On-off controllers are normally used for

  • low loads
  • temperature changes
  • flow rate changes
  • none of these
Q.28

Magnetic flowmeters are generally not used for the velocity/flow measurement of hydrocarbons due to their

  • low thermal conductivity.
  • low electrical conductivity.
  • high viscosity index.
  • low flash point.
Q.29

__________ thermometer can not measure sub-zero (<C) temperature,

  • Mercury in glass
  • Bimetallic
  • Vapor pressure
  • Resistance
Q.30

What is the ratio of output amplitude to input amplitude for a sinusoidal forcing function in a first order system ?

  • 1
  • >1
  • < 1
  • none of these
Q.31

Continuous measurement of moisture in paper is done by

  • sling psychrometer.
  • hair-hygrometer.
  • weighing.
  • high resistance Wheatstone's bridge circuit.
Q.32

Bode stability method uses __________ loop transfer function.

  • open
  • closed
  • either (a) or (b)
  • neither (a) nor (b)
Q.33

Which of the following is not a speed measuring instrument ?

  • Psychrometer
  • Stroboscope
  • Tachometer
  • All (a), (b) and (c)
Q.34

__________ stability method uses open loop transfer function.

  • Nyquist
  • Mikhalov
  • Ruth
  • none of these
Q.35

Which of the following thermocouples is the most suitable for measuring a temperature of about 1600°C in an oxidizing atmosphere ?

  • Platinum-platinum + rhodium
  • Iron-constantan
  • Copper-constantan
  • Chromel-alumel
Q.36

Bourdon gauges are used for measuring pressure (kg/cm2 )

  • < atmospheric
  • > 2 (gauge)
  • < 2 (gauge)
  • > 10 (absolute)
Q.37

In an exothermic chemical reactor, the manipulated variable is the flow rate of

  • coolant
  • reactants
  • product
  • none of these
Q.38

Emf generated in a thermocouple depends on the temperature

  • of cold junction only.
  • of hot junction only.
  • difference between hot and cold junctions.
  • difference between cold junction and atmospheric temperature.
Q.39

A bolometer is

  • used for the measurement of thermal radiation.
  • an element which senses optical input and delivers thermal output.
  • both (a) & (b).
  • neither (a) nor (b).
Q.40

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 ?

  • CO2
  • O2
  • NO
  • NO2
Q.41

Psychrometer determines the

  • humidity of gases
  • moisture content of solids
  • water of crystallisation
  • hygroscopic nature of solids
Q.42

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?

  • Nickel
  • Brass
  • Chromel
  • Invar
Q.43

A pyranometer is an instrument used for measuring the

  • beam radiation.
  • global radiation.
  • bright sunshine period.
  • none of these.
Q.44

Mercury thermometer can be used to measure the temperature upto __________ °C.

  • 100
  • 250
  • 350
  • 750
Q.45

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

  • light intensity
  • current
  • flux density
  • voltage
Q.46

Continuous shell temperature measurement in a liquid-liquid heat exchanger is done by a

  • thermocouple
  • reistance thermometer
  • mercury in glass thermometer
  • vapor pressure thermometer
Q.47

Very low pressure is expressed in microns(μ), which is equal to __________ mm of Hg coloumn (absolute) at 0°C.

  • 0.0001
  • 0.001
  • 0.01
  • 0.1
Q.48

Working principle of mercury in glass thermometer is based on the __________ of mercury with increase in temperature.

  • increase of pressure
  • increase of thermal conductivity
  • volumetric expansion
  • differential linear expansion
Q.49

Which of the following thermocouple materials does not contain nickel ?

  • Alumel
  • Chromel
  • Constantan
  • None of these.
Q.50

Thermal wells are used in the temperature measurement to

  • guard against corrosive and oxidising action on thermocouple materials
  • reduce measuring lag.
  • increase the fidelity.
  • increase the sensitivity.
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