Free Mass Transfer Operations MCQs with Answers
669 Mass Transfer Operations MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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669 questions · page 34 of 34
- A. 130
- B. 180
- C. 230
- D. 250
Explanation: Using ln(D₂/D₁) = (E/R)(1/T₁ − 1/T₂), the data give E ≈ 230 kJ/mol. The very large increase in diffusivity over this temperature interval…
Correct answer: 230- A. Both B & C
- B. Dew point remains constant
- C. Dry bulb & wet bulb temperature increases
- D. Relative humidity increases
Explanation: Sensible heating adds heat without adding or removing moisture, so the humidity ratio and dew point remain constant.
Correct answer: Both B & C- A. Dew point
- B. Wet bulb
- C. Dry bulb
- D. None of these
Explanation: In adiabatic saturation, evaporation occurs without external heat transfer, so the air approaches saturation at essentially constant…
Correct answer: Wet bulb- A. Kerosene
- B. Water
- C. Sodium stearate
- D. Lime water
Explanation: Sodium stearate forms a soap-like lubricating film that reduces friction between the die and the steel wire during drawing.
Correct answer: Sodium stearate- A. Venturi scrubber
- B. Packed column
- C. Bubble cap plate column
- D. Wetted wall column
Explanation: A venturi scrubber injects and atomizes liquid into a high-velocity gas stream, producing liquid dispersion as fine droplets.
Correct answer: Venturi scrubber- A. 100
- B. 0
- C. 50
- D. None of these
Explanation: At 100% relative humidity, the air is saturated and no evaporation occurs from the wet bulb, so wet-bulb and dry-bulb temperatures become…
Correct answer: 100- A. Dry bulb
- B. Dew point
- C. Wet bulb
- D. None of these
Explanation: A psychrometer directly measures dry-bulb and wet-bulb temperatures; the dew-point temperature is calculated from these readings and the…
Correct answer: Dew point668. The dew point of moist air becomes ____________________ with decrease in its relative humidity ?
- A. More than the dry bulb temperature
- B. More than the wet bulb temperature
- C. Less than the wet bulb temperature
- D. Equal to wet bulb temperature
Explanation: At a fixed dry-bulb temperature, lowering relative humidity lowers the water-vapour partial pressure and hence the dew-point temperature.
Correct answer: Less than the wet bulb temperature- A. Specific humidity
- B. Dry bulb temperature
- C. Relative humidity
- D. Wet bulb temperature
Explanation: During adiabatic evaporative cooling, sensible heat is converted into latent heat, so the wet-bulb temperature remains approximately…
Correct answer: Wet bulb temperature