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 349 of 350
- A. Point velocity
- B. Flow rate
- C. Vacuum
- D. Pressure
Explanation: A McLeod gauge measures very low absolute pressures, commonly expressed as vacuum in microns of mercury.
Correct answer: Vacuum- A. Polarimeter
- B. Polarograph
- C. Spectrometer
- D. Refractometer
Explanation: A refractometer determines composition or concentration from the refractive index, which changes with the angle of refraction.
Correct answer: Refractometer- A. Volumetric expansion
- B. Increase of thermal conductivity
- C. Increase of pressure
- D. Differential linear expansion
Explanation: Mercury expands appreciably and nearly uniformly in volume when heated, causing it to rise in the narrow thermometer capillary.
Correct answer: Volumetric expansion- A. 1/(1 + GH)
- B. G/(1 + GH)
- C. H/(1 + GH)
- D. G/(1 - GH)
Explanation: For a standard negative-feedback loop, the closed-loop transfer function is the forward-path gain divided by one plus the loop gain: C/R =…
Correct answer: G/(1 + GH)- A. 0.0001
- B. 0.001
- C. 0.01
- D. 0.1
Explanation: One micron of mercury is 0.001 mm Hg because the prefix micro means one-thousandth in this pressure convention.
Correct answer: 0.0016966. The time constant of a first order process with resistance R and capacitance C is__________________?
- A. R + C
- B. R - C
- C. 1/RC
- D. RC
Explanation: A first-order system reaches about 63.2% of its final response after one time constant, and its resistance-capacitance model gives this…
Correct answer: RC- A. Both A. & B.
- B. An element which senses optical input and delivers thermal output
- C. Used for the measurement of thermal radiation
- D. Neither A. nor B.
Explanation: A bolometer detects radiant or optical energy through the heating it produces, so it is used for measuring thermal radiation and acts as…
Correct answer: Both A. & B.- A. Alumel
- B. Duralumin
- C. Constantan
- D. Rhodium
Explanation: Alumel, rhodium and constantan are used in thermocouple alloys or elements.
Correct answer: Duralumin- A. Voltage sensitive null
- B. None of these
- C. Current sensitive deflected
- D. Voltage sensitive deflected
Explanation: Dynamic strain measurement requires a deflection-type Wheatstone bridge, whose output voltage changes with strain and is measured…
Correct answer: Voltage sensitive deflected- A. Passive
- B. Active
- C. Capacitive
- D. None of these
Explanation: An LVDT needs an external AC excitation source to produce its output signal, so it is a passive transducer.
Correct answer: Passive- A. Compact & rugged construction with an accuracy of 0.1 to 1%
- B. All A, B & C
- C. Provision of thermal compensation and is hermetically sealed
- D. No moving parts and incurs negligible deflection under load
Explanation: A practical load cell is compact and rugged, has no significant moving parts, and is commonly temperature-compensated and hermetically…
Correct answer: All A, B & C6972. The following thermocouple may be used for measuring temperature upto 1873°K__________________?
- A. Chromel-alumel
- B. Copper-constantan
- C. Platinum-platinum rhodium
- D. Iron-constantan
Explanation: A platinum-platinum-rhodium thermocouple, commonly Type R or Type S, is suitable for very high temperatures approaching 1873 K.
Correct answer: Platinum-platinum rhodium- A. The continuous adjustment of the set point index of an automatic control loop by a primary(master) controller
- B. Used when changes in process conditions cause serious upsets in the controlled variable
- C. Useful to control flow from temperature
- D. All A, B & C
Explanation: In cascade control, a primary controller continuously changes the set point of a secondary controller.
Correct answer: All A, B & C- A. Frequency
- B. Amplitude
- C. Damping
- D. None of these
Explanation: A Lissajous figure compares an unknown periodic signal with a reference signal, allowing the frequency ratio to be found from the plotted…
Correct answer: Frequency- A. Linear variable differential transducer (LVDT)
- B. Shaft encoder
- C. Stroboscope
- D. Tachometer
Explanation: A shaft encoder converts angular position or rotation into electrical pulses or coded signals, allowing direct measurement of angular…
Correct answer: Shaft encoder- A. Capacitance
- B. Resistance
- C. None of these
- D. Mutual inductance
Explanation: An LVDT has a movable ferromagnetic core that changes the mutual inductance between its primary and secondary coils.
Correct answer: Mutual inductance- A. Final control element
- B. On-off control
- C. Floating control action
- D. None of these
Explanation: The final control element receives the controller output and physically changes the manipulated variable, such as a valve changing fluid…
Correct answer: Final control element- A. Derivative time
- B. Deviation
- C. Error ratio
- D. Differential gap
Explanation: Deviation is the instantaneous difference between the set point and the controlled variable, with its sign depending on the convention…
Correct answer: Deviation- A. Steel
- B. Copper
- C. Aluminium
- D. Brass
Explanation: Copper conducts heat much better than steel, aluminium, or brass, so the thermal well reaches the gas temperature with less temperature…
Correct answer: Copper- A. Gamma rays
- B. Microwaves
- C. A beam of coherent light
- D. A beam of white light
Explanation: A laser uses stimulated emission to generate light waves having a fixed phase relationship, giving a coherent beam.
Correct answer: A beam of coherent light