chemical engineering process control and instrumentation MCQs – Page 3

Practise multiple-choice questions from chemical engineering process control and instrumentation for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering process control and instrumentation Mcqs
41. The initial value (t = 0) of the unit step response of the transfer function [(s + 1)/(2s + 1)] is__________________?
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A. 0

B.

C. 2

D. 1

42. Temperature of _____________ cannot be measured by an optical or radiation pyrometer?
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A. Rotary limestone calcination kiln

B. Combustion space in boilers

C. Molten slag flowing out of blast furnace

D. Hot blast (air) from stoves
43. Relationship between absorption/evolution of heat at the thermocouple junctions and the current flow in the circuit is given by _____________ effect?
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A. Thomson

B. Seebeck

C. None of these

D. Peltier
44. Radiation thermometer cannot measure the temperature ___________________?
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A. Of liquid oxygen

B. Inside a pressure vessel

C. Of an object without coming in contact with it

D. Of moving objects at high temperature

45. Zirconia probe is used for the continuous measurement of ______________ flue gases going out of the furnace?
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A. Oxygen in

B. Temperature of

C. Carbon monoxide in

D. Carbon dioxide in

46. The root locus method, a pole of a transfer function G(s) is the value of s for which G(s) approaches ___________________?
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A. ?

B. 1

C. -1

D. 0

47. Liquid levels in autoclaves are measured by ________________?
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A. None of these

B. Differential float type manometer

C. Simple float

D. Glass gauge

48. When the damping co-efficient (?) is unity, the system is __________________?
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A. Underdamped

B. Critically damped

C. Overdamped

D. Highly fluctuating

49. Optical activity of a solution can be determined using a ___________________?
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A. Dilatometer

B. Polarograph

C. Polarimeter

D. Refractometer

50. Specific conductance is defined as the reciprocal of resistance in ohms of 1c.c. of liquid at a specified temperature. Its value for distilled water is about ______________ micro mho/cm3?
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A. 100

B. 50

C. 1

D. 10

51. Thermal conductivity cell is the primary element of a/an _____________ analyser?
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A. Oxygen

B. Carbon dioxide

C. Carbon monoxide

D. Sulphur dioxide

52. Phase lag of the sinusoidal response of a first order system is _________________?
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A. 30

B. 120

C. 180

D. 90
53. 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______________?
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A. -90

B. -45

C. -180

D. 45

54. Measurement of sub-zero Celsius temperature in industry is done most commonly by __________________?
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A. Thermocouples

B. Gas thermometers

C. Resistance thermometers

D. Bi-metallic thermometers

55. Range of hydrogen gas constant volume thermometer is _____________ C?
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A. -10 to 20

B. 400 1000

C. 0 to 100

D. 100 500

56. If response of a control system is to be free of offset and oscillation, the most suitable controller is_________________?
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A. Proportional-integral (PI) controller

B. Proportional controller

C. Proportional-derivative (PD) controller

D. Proportional integral-derivative (PID) controller
57. Flow rate measurement of hostile acids and alkalis can be most suitably done by a/an ________________?
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A. Hot wire anemometer

B. Venturimeter

C. Orificemeter

D. Magnetic flow meter
58. Which of the following is never used as an element of industrial resistance thermometer ?
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A. Nickel

B. 30% iron + 70% nickel

C. Copper

D. Lead
59. Water is flowing through a series of four tanks and getting heated as shown in figure. It is desired to design a cascade control scheme for controlling the temperature of water leaving the tank 4 as there is a disturbance in the temperature of a second stream entering the tank 2. Select the best place to take the secondary measurement for the second loop?
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A. Tank 2

B. Tank 3

C. Tank 1

D. Tank 4

60. Typical specifications for design stipulates the gain margin and phase margin to be respectively__________________?
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A. 30

B. > 1.7 and > 30

C. < 1.7 and 1.7 and < 30