All Free Chemical Engineering MCQs with Answers
Every Chemical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
6,983 questions · page 342 of 350
- A. Large area but small mass
- B. High thermal conductivity
- C. Small specific heat
- D. All A , B & C
Explanation: Fast thermometer response requires a large heat-transfer area, low bulb thermal mass, high thermal conductivity, and low specific heat.
Correct answer: All A , B & C- A. Differential float type manometer
- B. Simple float
- C. Glass gauge
- D. None of these
Explanation: An autoclave operates under pressure, so its liquid level is commonly inferred from the pressure difference across the liquid column using…
Correct answer: Differential float type manometer- A. Reproducibility
- B. Fidelity
- C. Dead zone
- D. Sensitivity
Explanation: Fidelity is a dynamic characteristic because it describes how closely an instrument reproduces a changing input over time.
Correct answer: Fidelity- A. First order system
- B. Second order system
- C. Transportation lag
- D. None of these
Explanation: A pure transportation lag only delays a sinusoidal signal and does not change its amplitude, so its amplitude ratio is one.
Correct answer: Transportation lag6825. Which of following error integral is considered as the best criterion in controller settings ?
- A. ∫0 ∞ |e| dt
- B. ∫0 ∞ |e2| dt
- C. None of these
- D. ∫0 ∞ e2 dt
Explanation: The integral of squared error, ISE, heavily penalises large errors and is a widely used criterion for controller tuning.
Correct answer: ∫0 ∞ e2 dt- A. Oxygen in
- B. Carbon dioxide in
- C. Carbon monoxide in
- D. Temperature of
Explanation: A zirconia probe measures oxygen by producing an electrical signal related to the oxygen partial-pressure difference across its…
Correct answer: Oxygen in- A. Specially designed thermocouple
- B. Optical pyrometer
- C. Radiation pyrometer
- D. None of these
Explanation: A radiation pyrometer determines high temperature from the thermal radiation emitted by the hot body, making it suitable for temperatures…
Correct answer: Radiation pyrometer- A. Response
- B. Tine lag
- C. Dynamic error
- D. Drift
Explanation: Drift is a static characteristic because it describes a gradual change in instrument output when the measured input remains constant.
Correct answer: Drift- A. The maximum
- B. The minimum
- C. Both maximum and the minimum
- D. Nothing about the
Explanation: The process degree of freedom gives the number of independent variables that can be controlled, so it sets the maximum number of…
Correct answer: The maximum- A. Polarimeter
- B. CO2 analyser
- C. Spectrometer
- D. Chromatograph
Explanation: A thermal-conductivity gas analyser infers composition from the change in heat conduction of the gas mixture, and it is commonly used for…
Correct answer: CO2 analyser- A. Radiation pyrometer
- B. Optical pyrometer
- C. Resistance pyrometer
- D. Infra red pyrometer
Explanation: A resistance pyrometer is a contact instrument because its sensing element must be placed in contact with the body whose temperature is…
Correct answer: Resistance pyrometer- A. Mercury in glass thermometer with covering
- B. None of these
- C. Pressure gauge with one bellow, two tubes and a tank
- D. Bare mercury in glass thermometer
Explanation: A bare mercury-in-glass thermometer is normally treated as a first-order instrument, since its bulb temperature follows the surroundings…
Correct answer: Bare mercury in glass thermometer- A. Very high pressure
- B. High vacuum
- C. Liquid level under pressure
- D. Liquid level at atmospheric pressure
Explanation: A Pirani gauge measures very low pressures by relating the heat loss from a heated filament to the gas pressure, so it is used for…
Correct answer: High vacuum- A. Humidity of air
- B. % CO2 in flue gas
- C. % O2 in flue gas
- D. Speed of a submarine
Explanation: A zirconia probe develops an electrochemical voltage related to the difference in oxygen partial pressure, so it is used to determine…
Correct answer: % O2 in flue gas- A. Vapor pressure
- B. Constant volume gas
- C. Mercury in glass
- D. Bimetallic
Explanation: A mercury-in-glass thermometer works because mercury expands in volume when heated and rises through a calibrated capillary.
Correct answer: Mercury in glass- A. Transportation lag
- B. None of these
- C. Second order system
- D. First order system
Explanation: For a first-order system, the sinusoidal amplitude ratio is 1 divided by the square root of 1 plus the squared frequency time constant, so…
Correct answer: First order system- A. Mcleod
- B. Pirani
- C. Ionisation
- D. None of these
Explanation: A pressure of 0.01 psi absolute is about 0.52 mmHg, which lies in the low-pressure range commonly measured by a McLeod gauge.
Correct answer: Mcleod- A. Melting
- B. Both A. & B.
- C. Boiling
- D. Neither A. nor B.
Explanation: Temperature instruments are commonly calibrated against reproducible fixed points such as the melting or freezing point and the boiling…
Correct answer: Both A. & B.- A. Sling psychrometer
- B. Hair-hygrometer
- C. Weighing
- D. High resistance Wheatstone bridge circuit
Explanation: In continuous paper-moisture measurement, water changes the electrical resistance of the paper, and a high-resistance Wheatstone bridge…
Correct answer: High resistance Wheatstone bridge circuit- A. CO2 percentage in the flue gas
- B. Specific gravity of petrofuels
- C. Composition of an alloy
- D. O2 percentage in the flue gas
Explanation: Carbon dioxide has a thermal conductivity sufficiently different from the major gases in flue gas for a thermal-conductivity analyser to…
Correct answer: CO2 percentage in the flue gas