chemical engineering MCQs – Page 236

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 Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs
4701. Nickel percentage in invar which is an iron-nickel alloy, and is used as a thermocouple material is __________________?
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A. 68

B. 12

C. 54

D. 36
4702. The unit step response of the transfer function 1/(s2 + 2s + 3) _______________________?
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A. Is overdamped

B. Has a damped oscillatory characteristics

C. Has a non-zero slope at the origin

D. Is unstable

4703. Which of the following is never used as an element of industrial resistance thermometer ?
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A. Nickel

B. Lead

C. 30% iron + 70% nickel

D. Copper

4704. Conversion formula for converting amplitude ratio (AR) into decibels is ________________?
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A. Decibel = 20 loge (AR)0.5

B. Decibel = 20 log10 (AR)0.5

C. Decibel = 20 loge (AR)

D. Decibel = 20 log10 (AR)
4705. 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)

4706. Working principle of radiation pyrometer is based on the ________________?
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A. Stefan-Boltzmann law

B. Kirchoffs law

C. Wiens law

D. Seebeck effect

4707. A metal oxide is reduced by heating it in a stream of hydrogen. After complete reduction, it is found that 3.15 gm of the oxide has yielded 1.05 gm of the metal. It may be inferred that the ____________________?
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A. Equivalent weight of the metal is 4

B. Equivalent weight of the metal is 8

C. Atomic weight of the metal is 4

D. Atomic weight of the metal is 2

4708. The initial value (t = 0) of the unit step response of the transfer function [(s + 1)/(2s + 1)] is__________________?
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A.

B. 2

C. 1

D. 0

4709. Refluxing of part of the distillate in a fractionating column is a recycling operation, aimed primarily at_______________?
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A. Heat conservation

B. Yield enhancement

C. Product enrichment

D. None of these

4710. Which of the following relates the emf. generated in a single homogeneous wire to the temperature difference ?
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A. Peltier effect

B. Seebeck effect

C. None of these

D. Thomson effect
4711. A sinusoidal variation in the input passing through a linear first order system _________________?
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A. Becomes less oscillatory (frequency decreases)

B. Gets amplified (magnitude increases)

C. Becomes more oscillatory (frequency increases)

D. Gets attenuated (magnitude decreases)
4712. The unit of Cp in S.I. units is___________________?
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A. W/m.K

B. W/m2.K

C. J/m3. K

D. J/kg.K
4713. The characteristic equation for the control system with a closed loop transfer function G1/1 + G2 is given by 1 + G2 = 0. The characteristic equation for the control system_________________?
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A. All A , B & C.

B. Is the same for set point or load changes

C. Depends only upon the open loop transfer function

D. Determines its stability

4714. A bypass stream in a chemical process is useful, because it___________________?
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A. Facilitates better control of the process

B. Improves the conversion

C. Increases the yield of products

D. None of these

4715. Pressure of 0.01 psi (absolute) can be measured by ______________ gauge?
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A. None of these

B. Ionisation

C. Mcleod

D. Pirani

4716. A mercury barometer measures the _____________ pressure?
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A. Absolute

B. Vacuum

C. Gauge

D. Atmospheric
4717. An aneroid barometer measures the _____________ pressure?
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A. Atmospheric

B. Vacuum

C. Absolute

D. Gage

4718. Thermal wells used in temperature measurements should have __________________?
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A. Low emissivity

B. Very thick walls

C. Polished surface

D. High transmissivity of radiation
4719. Response of a system to a sinusoidal input is called _____________ response?
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A. Unit step

B. Impulse

C. None of these

D. Frequency
4720. A system with a double pole at the origin is unstable since the corresponding term in the time domain________________?
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A. Is a constant

B. Grows linearly with time

C. Decays linearly with time

D. Grows exponentially with time