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 25 of 46

  • A. Having high viscosities
  • B. Moving at low velocities
  • C. Both A. & B.
  • D. Neither A. nor B.

Explanation: For high-viscosity fluids or very low velocities, viscous effects spread well beyond a thin boundary layer and can influence the entire…

Correct answer: Both A. & B.
  • A. None of these
  • B. Turbulent
  • C. Steady
  • D. Irrotational

Explanation: A velocity potential exists when the flow is irrotational, meaning the curl of the velocity field is zero.

Correct answer: Irrotational
  • A. Rotameter
  • B. Orificemeter
  • C. Anemometer
  • D. Venturimeter

Explanation: A rotameter is a variable-area meter: the float position changes the annular flow area until the pressure force and weight balance.

Correct answer: Rotameter
  • A. Fanning equation
  • B. Blake-Plummer equation
  • C. Hagen-Poiseuille equation
  • D. Kozeny-Carman equation

Explanation: At very large packed-bed Reynolds numbers, inertial losses dominate viscous losses, so the pressure drop varies approximately with the…

Correct answer: Blake-Plummer equation
  • A. Length is shorter
  • B. Throat diameter is more
  • C. Sudden expansion of flow in the downstream occurs
  • D. Distance between the throat and the inlet is more

Explanation: A flow nozzle has a comparatively abrupt discharge and therefore produces a sudden expansion downstream, causing greater eddy and…

Correct answer: Sudden expansion of flow in the downstream occurs
  • A. Globe valve
  • B. Plug-cock
  • C. Check valve
  • D. Gate valve

Explanation: Gate valves provide a relatively unobstructed passage and are economical in large pipe sizes, so they are commonly selected above about 2…

Correct answer: Gate valve
  • A. 1
  • B. 1.5
  • C. 2
  • D. 2.5

Explanation: Laminar flow between parallel plates has a parabolic velocity profile, with maximum velocity at the mid-plane.

Correct answer: 1.5
  • A. 90° and 80°
  • B. 45° and 60°
  • C. 40° and 140°
  • D. 20° and 120°

Explanation: In a double-acting reciprocating pump, the air vessel supplies or receives flow during much of the cycle, but its flow becomes zero at the…

Correct answer: 40° and 140°
  • A. T-joint
  • B. 90°bend
  • C. 45° elbow
  • D. Union

Explanation: A union has a comparatively small change in flow direction and cross-sectional area, so its minor-loss coefficient is lower than those of…

Correct answer: Union
  • A. Bell and spigot joint
  • B. Welding
  • C. Soldering
  • D. Flanges

Explanation: Glass pipes are commonly connected with bell-and-spigot joints, using a packing or sealing material to accommodate the rigid, brittle…

Correct answer: Bell and spigot joint
  • A. Q1/Q2
  • B. (Q2 - Q1)/Q2
  • C. (Q2 - Q1)/Q1
  • D. Q2/Q1

Explanation: Slip is the loss of discharge relative to the theoretical discharge, so percentage slip is 100 times (Q2 − Q1)/Q2.

Correct answer: (Q2 - Q1)/Q2
  • A. Geometrical similarity only
  • B. All geometrical, dynamic and kinematic similarity
  • C. Both geometrical and dynamic similarity
  • D. Dynamic similarity only

Explanation: Reliable agitator scale-up requires geometrical similarity along with dynamic and kinematic similarity so that the flow pattern and force…

Correct answer: All geometrical, dynamic and kinematic similarity
  • A. Is independent of the area of flow
  • B. Is constant
  • C. Decreases in the downstream direction
  • D. Increases in the downstream direction

Explanation: For subsonic compressible flow in a pipeline, friction causes the fluid to accelerate downstream toward sonic conditions, so its velocity…

Correct answer: Increases in the downstream direction
  • A. Energy is constant along a stream line, but may vary across stream lines
  • B. Energy is constant throughout the fluid
  • C. Velocity is constant along a stream line
  • D. None of these

Explanation: Bernoulli's equation expresses conservation of mechanical energy along a streamline for steady, ideal, inviscid flow.

Correct answer: Energy is constant along a stream line, but may vary across stream lines
  • A. I, II, III
  • B. II, III, V
  • C. I, II, V
  • D. II, IV, V

Explanation: Newton's second law and continuity apply to fluid motion, while an impermeable boundary cannot be penetrated, giving the normal-velocity…

Correct answer: II, III, V
  • A. Compress air
  • B. Lift compressed air
  • C. Lift water from a well by using compressed air
  • D. Lift air under negative pressure

Explanation: An air-lift pump injects compressed air into a liquid column, reducing its average density so the water rises through the delivery pipe.

Correct answer: Lift water from a well by using compressed air
  • A. Increase
  • B. Data insufficient to predict
  • C. Remain same
  • D. Decrease

Explanation: At the same flow rate and pump head, power is proportional to the liquid's specific weight.

Correct answer: Decrease
  • A. Inertial
  • B. Gravity
  • C. Viscous
  • D. None of these

Explanation: The pressure coefficient compares pressure forces with inertial forces, typically written as pressure difference divided by one-half…

Correct answer: Inertial
  • A. Diameter
  • B. Colour
  • C. Altitude
  • D. None of these

Explanation: Industrial pipelines are commonly identified by colour coding, which allows the conveyed liquid or gas and its hazard category to be…

Correct answer: Colour
  • A. None of these
  • B. Slurries
  • C. Viscous mass
  • D. Higher pressure

Explanation: Plunger pumps are positive-displacement pumps selected when high pressure is required, especially at relatively low flow rates.

Correct answer: Higher pressure