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 348 of 350
- A. Absolute
- B. Gauge
- C. Absolute as well as gauge
- D. dynamic
Explanation: A barometer measures atmospheric pressure relative to a perfect vacuum, so its reading is absolute pressure.
Correct answer: Absolute- A. Flux density
- B. Current
- C. Light intensity
- D. Voltage
Explanation: Photoelectric transducers detect a change in light intensity and convert it into an electrical signal such as current or voltage.
Correct answer: Light intensity- A. Ice (F.P) and steam (B.P)
- B. Oxygen and sulphur (B.P)
- C. Antimony and silver (F.P)
- D. Zinc (B.P) and mercury (F.P)
Explanation: The listed international temperature fixed points include mercury's freezing point, along with zinc's boiling point, so the pair in option…
Correct answer: Zinc (B.P) and mercury (F.P)- A. Sinusoidal
- B. Step
- C. Ramp
- D. Impulse
Explanation: Bode plots are obtained from the steady-state response to sinusoidal inputs over a range of frequencies.
Correct answer: Sinusoidal6945. In a single tank system, the transfer function of _____________ to inlet flow rate is 1/(TS+1)?
- A. Level
- B. Outlet flow rate
- C. Both A. & B.
- D. Neither A. nor B.
Explanation: For a single tank, the outlet-flow response to inlet-flow changes has the first-order form 1/(τs+1).
Correct answer: Outlet flow rate6946. Identify an unbounded input from inputs whose transfer functions are given below______________?
- A. 1
- B. 1/S
- C. 1/S2
- D. 1/(S2 + 1)
Explanation: The transform 1/s² represents a ramp input, whose magnitude increases indefinitely with time, making it unbounded.
Correct answer: 1/S2- A. s/(Ts + 1)
- B. 1/Ts
- C. 1/(Ts + 1)
- D. None of these
Explanation: A standard first-order system has a single time constant and transfer function 1/(Ts+1), assuming unit steady-state gain.
Correct answer: 1/(Ts + 1)- A. Accounting for the tube expansion
- B. Increasing the diameter of the tube
- C. Using steel tube in place of glass tube
- D. Filling nitrogen under pressure in the stem
Explanation: Pressurising the stem with nitrogen raises mercury's boiling point and prevents the column from breaking down at higher temperatures.
Correct answer: Filling nitrogen under pressure in the stem- A. 0
- B. ½
- C. 1
- D. 2
Explanation: For a unit step, the output is Y(s)=G(s)/s, so the initial value is lim[sY(s)] as s approaches infinity, which equals lim[(s+1)/(2s+1)] =…
Correct answer: ½- A. 63.2
- B. 87.5
- C. 95
- D. 100
Explanation: In controller response terminology, stabilising or settling time is conventionally specified as the time to reach about 95% of the final…
Correct answer: 95- A. Ultra pure metals
- B. Nickel-chromium alloys
- C. Iron-copper alloys
- D. Metal oxides
Explanation: Thermistors are temperature-sensitive semiconductor resistors commonly manufactured from sintered metal oxides such as oxides of…
Correct answer: Metal oxides- A. Global radiation
- B. Beam radiation
- C. Bright sunshine period
- D. None of these
Explanation: A pyranometer measures total or global solar radiation received on a surface, including both direct beam and diffuse sky radiation.
Correct answer: Global radiation- A. Kc(1 + TS)
- B. Kc[1 + (1/TS)]
- C. Kc/(1 + TS)
- D. Kc/[1 + (s/T)]
Explanation: A proportional plus reset controller combines proportional action with integral action, giving Gc(s)=Kc[1+1/(Ts)].
Correct answer: Kc[1 + (1/TS)]- A. Inside a pressure vessel
- B. Of an object without coming in contact with it
- C. Of liquid oxygen
- D. Of moving objects at high temperature
Explanation: Liquid oxygen is comparatively transparent to the radiation used by ordinary radiation thermometers, so the instrument may detect…
Correct answer: Of liquid oxygen- A. Iron-constantan
- B. Chromel-alumel
- C. Platinum-platinum/rhodium
- D. Copper-constantan
Explanation: Copper-constantan thermocouples have the narrowest useful range among these choices, typically extending only to roughly 350 to 400°C.
Correct answer: Copper-constantan- A. 961.93
- B. 630.74
- C. 1064.43
- D. 1261.93
Explanation: The antimony fixed point is 630.74°C, defined by equilibrium between solid and liquid antimony at standard atmospheric pressure.
Correct answer: 630.74- A. Combustion space in boilers
- B. Molten slag flowing out of blast furnace
- C. Hot blast (air) from stoves
- D. Rotary limestone calcination kiln
Explanation: A radiation or optical pyrometer requires sufficient emitted radiation from the target, whereas hot air is essentially non-luminous and…
Correct answer: Hot blast (air) from stoves- A. 100
- B. 250
- C. 350
- D. 750
Explanation: Mercury boils at about 357°C, so a mercury thermometer is commonly used up to approximately 350°C.
Correct answer: 350- A. > 100
- B. < 0
- C. 0-100
- D. > 50
Explanation: A constant-volume nitrogen thermometer uses the pressure of nitrogen as an indication of temperature and is suitable for temperatures…
Correct answer: > 100- A. 100
- B. 75
- C. 25
- D. 0
Explanation: An on-off controller has only two output states and changes state abruptly at the set point, corresponding to an ideal proportional…
Correct answer: 0