chemical engineering process control and instrumentation Mcqs
101. Which of the following is not the triple point of water ?
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A. 273K

B. 32R

C. 32F

D. 492R

102. Positioning controllers are used for _______________?
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A. Low loads

B. Temperature changes

C. Flow rate changes

D. High loads
103. Which of the following judges the accuracy of an instrument ?
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A. Static error

B. Drift

C. Dead zone

D. None of these

104. The ____________ of a vapor pressure thermometer is a secondary element ?
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A. Pointer

B. None of these

C. Bulb

D. Bourdon tube
105. Mercury manometer (U-tube type) exemplifies a ______________ order system?
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A. Zero

B. Third

C. First

D. Second
106. Humidity of air can be determined by a__________________?
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A. Sling psychrometer

B. Chromatograph

C. Polarimeter

D. Mass spectrometer

107. Minute depression of freezing point of a liquid solvent on addition of a solid solute can be best measured by a________________?
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A. Dilatometer

B. Mercury thermometer

C. Beckman thermometer

D. Bimetallic thermometer

108. The deflection of the free end of the bimetallic strips in a bimetallic thermometer with temperature is nearly__________________?
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A. Non-linear

B. Linear

C. Parabolic

D. Hyperbolic

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

B. Solid semi-conductor

C. Conductor

D. Insulator

110. The thermal emf-temperature relationship of most thermocouples is_________________?
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A. Parabolic

B. Linear

C. Exponential

D. Square root

111. Mcleod gauge measures the _____________ pressure?
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A. Very high

B. Positive

C. Sub-atmospheric

D. Atmospheric

112. Non-metallic diaphragm used as pressure sensor in instruments is generally made of__________________?
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A. Bakelite

B. Synthetic rubber

C. Teflon

D. Thick paper

113. Process degree of freedom indicates _______________ number of controllers to be used?
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A. The maximum

B. The minimum

C. Both maximum and the minimum

D. Nothing about the

114. Emf developed by a thermocouple, while measuring a temperature of 600C is about 5.5 mV. The type of thermocouple used is_______________?
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A. Chromel-alumel

B. Iron-constantan

C. Platinum-platinum + rhodium

D. Either A., B. or C.

115. 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 ?
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A. Methyl alcohol

B. Carbon-tetrachloride

C. Water

D. Mercury
116. Flame photometry is used for the determination of compositional analysis of_______________?
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A. Solids

B. Isotopes

C. Alkali metals

D. Natural gas

117. Which of the following is not a composition measuring instrument ?
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A. Thermal conductivity cell

B. Hot wire anemometer

C. Polarograph

D. Mass spectrometer

118. Liquid argon level in a pressurised storage tank (at 3 kg/cm2) is measured by a/an ____________________?
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A. External float gage

B. Differential pressure gage

C. None of these

D. Gage glass

119. Starting temperature of optical radiation pyrometer is ______________ C?
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A. 1500

B. 400

C. 1200

D. 800
120. Stroboscope is used for the measurement of _________________?
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A. Liquid level under pressure

B. Frequency of light

C. Depression of freezing point

D. Rpm of a flywheel
121. Which of the following is not suitable for measuring the temperature of a red hot object in the range of 800 1600C ?
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A. Radiation pyrometer

B. Thermocouples

C. Optical pyrometer

D. Photoelectric pyrometer

122. Specific gravity of a liquid cannot be measured by a/an __________________?
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A. Pycnometer

B. Specific gravity bottle

C. Hydrometer

D. Anemometer
123. Composition of natural gas is determined by the_________________?
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A. Haldane apparatus

B. Mass spectrometer

C. Chromatograph

D. Both B. and C.
124. The term analogous to voltage in a single tank system is the_______________?
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A. Level of liquid

B. Heat content of the system

C. Flow rate

D. Liquid volume in the tank

125. Nichols chart deals with __________________?
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A. A.R. vs. phase lag of first order

B. Closed loop values vs. open loop values

C. Frequency response values of controllers

D. A.R. vs. phase lag of second order

126. Pick out the wrong statement ?
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A. Paramagnetic susceptibility of gases permits the measurement of their concentration

B. CO2 is the strongest paramagnetic gas

C. O2, NO and NO2 exhibit paramagnetic properties as a result of unpaired electrons

D. Paramagnetic susceptibility of gases decreases with temperature

127. Which is the strongest paramagnetic gas ?
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A. NO

B. NO2

C. CO2

D. O2
128. Volumetric expansion is the working principle of the ______________ thermometers?
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A. Vapor pressure

B. Constant volume gas

C. Bimetallic

D. Mercury in glass
129. Working principle of radiation pyrometer is based on the ________________?
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A. Wiens law

B. Kirchoffs law

C. Stefan-Boltzmann law

D. Seebeck effect

130. An aneroid barometer measures the _____________ pressure?
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A. Absolute

B. Vacuum

C. Gage

D. Atmospheric

131. Bimetal strips are not used in________________?
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A. Relays for opening & closing of electrical circuits

B. Thermostats

C. Bimetallic thermometers

D. Thermocouples
132. Thermal wells used in temperature measurements should have __________________?
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A. Polished surface

B. High transmissivity of radiation

C. Low emissivity

D. Very thick walls

133. The unit of time constant of a system is the same as that of___________________?
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A. (Time)-1

B. None of these

C. Time

D. Velocity

134. Which of the systems having the following transfer function is stable ?
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A. 1/(S2 + 2)

B. 1/(S2 + 2S + 2)

C. exp (-20 S)/(S2 + 2S 1)

D. 1/(S2 2S + 3)

135. Flapper nozzle is used in a/an ______________ controller?
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A. None of these

B. Electronic

C. Hydraulic

D. Pneumatic
136. Which of the following is not a second order instrument ?
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A. Mercury in glass thermometer with covering

B. Bare mercury in glass thermometer

C. None of these

D. Pressure gauge with one bellow, two tubes and a tank

137. Which of the following is not a differential pressure flow meter ?
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A. Orificemeter

B. Rotameter

C. Flow nozzle

D. Venturimeter

138. A pyrheliometer is an instrument used for measuring the_________________?
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A. None of these

B. Bright sunshine period

C. Diffuse radiation

D. Beam radiation
139. Stalagmometer is used for the measurement of__________________?
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A. Kinematic viscosity

B. Surface tension

C. Refractive index

D. Optical activity

140. 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 ?
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A. Brass

B. Nickel

C. Invar

D. Chromel

141. Which of the following is an undesirable dynamic characteristic of an instrument ?
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A. Static error

B. Dead zone

C. Time lag

D. Reproducibility

142. The pressure sensing element of elastic type pressure gauge is never made in the form of a_________________?
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A. Diaphragm

B. Bellow

C. Strip

D. Bourdon tube

143. Which of the following relates the emf. generated in a single homogeneous wire to the temperature difference ?
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A. Seebeck effect

B. Peltier effect

C. None of these

D. Thomson effect
144. The function of a transducer is to _______________ ?
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A. Convert the primary signal into a more useful quantity, usually an electric impulse

B. Modify the input signal

C. Amplify the input signal

D. Codify/decodify the input signal

145. Operating range of a temperature measuring instrument is 800 to 1600C. It could be a/an _____________ pyrometer?
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A. Photoelectric

B. None of these

C. Optical

D. Radiation

146. Ordinary mercury in glass thermometer is used for measuring temperature upto 120C. 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?
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A. 250

B. 700

C. 550

D. 350

147. Stability of a control system containing a transportation lag can be best analysed by_______________?
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A. Frequency response methods

B. None of these

C. Routh test

D. Root locus methods

148. The offset introduced by proportional controller with gain Kc in response of first order system can be reduced by ____________________?
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A. None of the above

B. Reducing value of Kc

C. Introducing integral control

D. Introducing derivative control

149. Pressure of 0.01 psi (absolute) can be measured by ______________ gauge?
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A. Pirani

B. None of these

C. Mcleod

D. Ionisation

150. Continuous measurement of moisture in paper is done by_______________?
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A. Sling psychrometer

B. High resistance Wheatstone bridge circuit

C. Weighing

D. Hair-hygrometer