chemical engineering process control and instrumentation MCQs – Page 11

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 Review each marked answer and report any item that may be outdated or unclear.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
201. Paramagnetism method is not used for the composition determination of ______________ in gases?
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A. Carbon dioxide

B. Oxides of nitrogen

C. Oxygen

D. Any of these

202. The experimental response of the controlled variable y(t) for a step change of magnitude P in the manipulated variable x(t) is shown below: The appropriate transfer function of the process is_________________?
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A. (Q/R) e-TdS/(Q/P) (S + 1)

B. (Q/P) e-TdS/(Q/R) (S + 1)

C. (Q/P) e-(Q/R)S/(TdS + 1)

D. (Q/R) e-(P/Q)S/(TdS + 1)

203. The term analogous to the electrical current in a thermal system is the_________________?
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A. Temperature difference

B. Heat content in the system

C. Heat flow rate

D. None of these

204. Load cells are used for the measurement of __________________?
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A. Weight

B. Velocity

C. Stress

D. Strain

205. Number of poles in a system with transfer function 1/(s2 + 2s2 + 1) is ________________?
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A. 1

B. 3

C. 2

D. 5

206. Which of the following thermocouples will give the highest output for the same value of hot and cold junction temperature ?
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A. Platinum-platinum + rhodium

B. Iron-constantan

C. All will give the same output

D. Chromel-constantan
207. The open loop transfer function of a process is K [{(s + 1) (s + 4)}/{(s + 2) (s + 3)}]. In the root locus diagram, the poles will be at ___________________?
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A. 2, 3

B. -2, -3

C. 1, 4

D. -1, -4

208. Pyrometry refers to the measurement of temperature_________________?
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A. Directly

B. Which is of higher magnitude

C. With the mercurial thermometer upto 350C

D. All A., B. & C.

209. Response of a linear control system for a change in set point is called __________________?
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A. Transient response

B. Servo problem

C. Regulator problem

D. Frequency response

210. On-off controllers are normally used for________________?
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A. None of these

B. Flow rate changes

C. Temperature changes

D. Low loads
211. 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 ________________?
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A. Air

B. A metal powder or graphite

C. Mercury

D. Oil

212. Flow rate of those fluids which are insensitive to changes in their density, viscosity or flow velocity profile can be best measured by a ________________?
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A. Magnetic flowmeter

B. Turbine flowmeter

C. Flow nozzle type flowmeter

D. Pitot tube

213. Which of the following fluid flow measuring devices can measure the largest flow rate ?
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A. Orificemeter

B. Weir

C. Rotameter

D. V-notch

214. In an exothermic chemical reactor, the manipulated variable is the flow rate of_______________?
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A. Product

B. Reactants

C. Coolant

D. None of these

215. For an input forcing function, X(t) = 2t2, the Laplace transform of this function is________________?
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A. 4/s2

B. 2/s2

C. 4/s3

D. 2/s3

216. The open loop transfer function of a control system is KR/(1 + TS). This represents ______________?
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A. A second order system

B. Dead time system

C. A first order time lag

D. A first order system
217. Which of the following can measure temperatures in the range of 20 to 300C ?
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A. None of these

B. Vapor pressure thermometer

C. Resistance thermometer

D. Mercury in glass thermometer

218. In a single tank system, the transfer function of level to inlet flow rate is__________________?
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A. R/(TS + 1)

B. 1/TS

C. R/TS

D. None of these

219. What is the Laplace transform of impulse input having magnitude X? ?
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A. 1/X

B. 1

C. X

D. X2

220. Emf developed by a thermocouple while measuring a temperature of 400C is 22 mV. The type of thermocouple used is ___________________?
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A. Platinum-rhodium

B. Iron-constantan

C. Chromel-alumel

D. Platinum-platinum + rhodium