Free Fluid Flow Operations MCQs with Answers
909 Fluid Flow 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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909 questions · page 33 of 46
- A. Much more than that for fully open globe valves
- B. Much less (say 2% than that for fully open globe valves)
- C. Around 7
- D. Both B. and C.
Explanation: A fully open gate valve offers very little flow resistance, with an equivalent length-to-diameter ratio of roughly 7, far below that of a…
Correct answer: Both B. and C.- A. 50-75
- B. 25-50
- C. 200-250
- D. 750-1000
Explanation: Flooding in a packed tower is commonly associated with a sharp rise in pressure drop, typically about 50–75 mm water column per metre of…
Correct answer: 50-75- A. 500-1500
- B. 5-10
- C. 50-150
- D. 1500-2500
Explanation: Bag filters normally operate with a pressure drop of roughly 50–150 mm water gauge, which increases as dust accumulates on the filter…
Correct answer: 50-150- A. 10
- B. 25
- C. 75
- D. 300
Explanation: A fully open globe valve has a large resistance because the flow changes direction and passes through a restricted, tortuous passage.
Correct answer: 300645. Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is ___________________?
- A. Less
- B. More
- C. Same
- D. Either A. or B.; depends upon the I.D. of the pipe
Explanation: For the same nominal pipe size, schedule 80 has a greater wall thickness and smaller internal diameter than schedule 40.
Correct answer: Less- A. Absorbing the contraction/expansion of pipeline due to temperature changes
- B. Prevention of fluid leakage around moving parts
- C. Facilitating smooth opening and closing of a valve
- D. Reducing the resistance of fluid flow
Explanation: A stuffing box surrounds a moving valve stem or shaft and uses packing to restrict leakage along the moving part.
Correct answer: Prevention of fluid leakage around moving parts- A. (1.2)3/2
- B. (1.2)3/5
- C. (1.2)5/3
- D. (1.2)2/3
Explanation: In fully turbulent mixing, power varies as N³D⁵ when the power number is constant.
Correct answer: (1.2)5/3- A. f = 16/NRe
- B. 5
- C. f = 0.22 NRe
- D. f = 0.04/(NRe)0.16
- E. f = 25/NRe
Explanation: For turbulent flow in a hydraulically smooth or new pipe, an empirical relation is f ≈ 0.04/Re⁰·¹⁶, with the exact coefficient depending…
Correct answer: f = 0.04/(NRe)0.16- A. Both A. & B.
- B. Lowest surface area requirement for a given volume
- C. Higher structural strength
- D. None of these
Explanation: A circular section provides high structural strength because pressure stresses are distributed uniformly, and it also gives the least wall…
Correct answer: Both A. & B.- A. Low viscosity liquids (< 200 poise)
- B. Large diameter tanks
- C. High viscosity liquids (> 600 poise)
- D. None of these
Explanation: Baffles are mainly needed to prevent swirling and improve mixing in low-viscosity liquids.
Correct answer: High viscosity liquids (> 600 poise)- A. Waste steam
- B. Destroy itself of acceleration wear due to rapid recycling
- C. None of these
- D. Back up condensate and cause water hammer in steam line
Explanation: An undersized steam trap cannot discharge condensate at the required rate, so condensate accumulates in the line.
Correct answer: Back up condensate and cause water hammer in steam line- A. 5 to 10
- B. 55 to 75
- C. 40 to 50
- D. 15 to 30
Explanation: A propeller is a small-diameter, high-speed agitator, typically about 15 to 30% of the tank diameter.
Correct answer: 15 to 30- A. 0.1-0.12
- B. 0.4-0.5
- C. 0.45-0.6
- D. 0.2-0.45
Explanation: Tank baffles are commonly sized with a width of approximately 0.1 to 0.12 times the tank diameter.
Correct answer: 0.1-0.12- A. 1 to 5
- B. 20 to 100
- C. 500 to 750
- D. 1000 to 2000
Explanation: Paddle agitators are large, slow-speed impellers used mainly for blending and gentle mixing, typically operating around 20 to 100 rpm.
Correct answer: 20 to 100- A. Increase or decrease depending on the nature of the dust
- B. Decrease
- C. Remain unaffected
- D. Increase
Explanation: For a fixed particle size, a higher cyclone pressure drop usually means higher gas inlet velocity, which increases centrifugal force and…
Correct answer: Increase- A. 0.3 to 0.5 d
- B. 0.1 to 0.2 d
- C. 0.65 to 0.85 d
- D. 0.95 d
Explanation: A turbine agitator generally has an impeller diameter around 0.3 to 0.5 times the tank diameter.
Correct answer: 0.3 to 0.5 d- A. A/P
- B. 4 A/P
- C. 4 P/A
- D. √A
Explanation: For a non-circular channel, the hydraulic or equivalent diameter is defined as D_e = 4A/P, where P is the wetted perimeter.
Correct answer: 4 A/P- A. Pressure drop across the cake & filter medium
- B. Cake & filter medium resistance
- C. All A., B. and C.
- D. Area of filtering surface & the viscosity of filtrate
Explanation: From the filtration equation, rate increases with pressure drop and filtering area, but decreases with cake resistance, medium resistance…
Correct answer: All A., B. and C.- A. Disc compensator
- B. Union
- C. Flange
- D. Elbow
Explanation: An elbow is a pipe fitting designed to turn a pipeline, commonly through 45° or 90°.
Correct answer: Elbow- A. 0.25 to 4
- B. 0.25 to 8
- C. 1 to 5
- D. 1 to 12
Explanation: Plate and frame filter presses use frames of different depths to provide the required cake capacity, commonly ranging from about 0.25 to 8…
Correct answer: 0.25 to 8