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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- A. Inertial forces to viscous forces
- B. Viscous forces to gravity forces
- C. Viscous forces to inertial forces
- D. Inertial forces to gravity forces
Explanation: Reynolds number compares inertial forces with viscous forces, commonly written as Re = ρvD/μ.
Correct answer: Inertial forces to viscous forces- A. 0.93 to 0.98
- B. 0.58 to 0.8
- C. 0.2 to 0.3
- D. 0.02 to 0.03
Explanation: The discharge coefficient of a standard sharp-edged orifice plate is typically around 0.6, with a practical range close to 0.58 to 0.8…
Correct answer: 0.58 to 0.8- A. Velocity of fluid
- B. Size of pipe
- C. None of these
- D. Length of pipe and number of bends
Explanation: Pressure drop is affected by velocity, pipe size, length, and fittings such as bends.
Correct answer: None of these- A. Hagen and Poiseuille
- B. Reynolds
- C. Pascal
- D. Blake-Plummer
Explanation: Hagen and Poiseuille experimentally established the relationship for laminar flow through a circular tube, now expressed in the…
Correct answer: Hagen and Poiseuille- A. Water
- B. Any liquid
- C. Solids
- D. None of these
Explanation: A cock is a manually operated valve commonly used to start, stop, or regulate liquid flow.
Correct answer: Any liquid- A. Wetted perimeter to flow area
- B. Flow area to square of wetted perimeter
- C. Flow area to wetted perimeter
- D. Square root of flow area to wetted perimeter
Explanation: Hydraulic radius is defined as flow cross-sectional area divided by wetted perimeter, R_h = A/P.
Correct answer: Flow area to wetted perimeter- A. Both B. and C.
- B. Speed of the impeller
- C. Diameter of the impeller
- D. Barometric pressure
Explanation: The maximum suction lift is fundamentally limited by atmospheric pressure, which supplies the pressure head pushing water up into the…
Correct answer: Barometric pressure- A. 7
- B. 700
- C. 7000
- D. 630
Explanation: Using Re = VD/ν gives V = Reν/D = (2100)(0.01)/3 = 7 cm/s. The viscosity ratio is kinematic viscosity, so its given units can be used…
Correct answer: 7- A. Deliver liquid at uniform pressure
- B. Are not subject to air binding
- C. Can handle slurries more efficiently
- D. Can be operated with delivery valve closed
Explanation: A reciprocating pump is a positive-displacement pump and does not normally suffer from air binding in the same way as a centrifugal pump.
Correct answer: Are not subject to air binding- A. 0.75 - 0.90
- B. 0.5 - 0.75
- C. 0.61 - 0.63
- D. 0.35 - 0.55
Explanation: A sharp-edged circular orifice has a discharge coefficient of about 0.61 to 0.63 for the stated beta range.
Correct answer: 0.61 - 0.63- A. Mechanical energy balance in boundary layer
- B. Kinetic energy balance in laminar flow
- C. Mechanical energy balance in turbulent flow
- D. Mechanical energy balance in potential flow
Explanation: Bernoulli's equation is a mechanical-energy balance for steady, incompressible, frictionless flow, commonly represented as potential flow.
Correct answer: Mechanical energy balance in potential flow- A. Shear stress over the cross-section is proportional to the distance from the surface of the pipe
- B. Average flow occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)
- C. volume of circumscribing cylinder
- D. Velocity profile varies hyperbolically and the shear stress remains constant over the crosssection
- E. Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the
Explanation: For laminar flow in a circular pipe, the velocity profile is parabolic, so its solid of revolution is a paraboloid whose volume is half…
Correct answer: Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the- A. Increase the structural strength of the tank
- B. Reduce swirling and vortex formation
- C. Aid in rotational flow
- D. None of these
Explanation: Baffles interrupt tangential fluid motion in a mixing tank, preventing excessive swirling and vortex formation.
Correct answer: Reduce swirling and vortex formation- A. Venturimeter
- B. Orificemeter
- C. Rotameter
- D. Weir
Explanation: A weir measures open-channel flow by relating the upstream liquid head to the discharge over the crest.
Correct answer: Weir- A. 0.01
- B. 0.1
- C. 1
- D. 10
Explanation: Water has a dynamic viscosity of approximately 0.001 Pa.s at room temperature; multiplying by 100 gives 0.1 Pa.s.
Correct answer: 0.1- A. Gravity forces
- B. Turbulent forces
- C. Pressure forces
- D. Viscous forces
Explanation: The Navier-Stokes equation explicitly includes pressure, viscous, and body forces such as gravity.
Correct answer: Turbulent forces- A. 2
- B. 2.828
- C. 5.657
- D. 4
Explanation: For a triangular (V-notch) weir, discharge varies as H^(5/2). Doubling the head therefore multiplies discharge by 2^(5/2) = 5.657.
Correct answer: 5.657- A. Transition
- B. Laminar
- C. Turbulent
- D. Both B. and C.
Explanation: The Fanning friction-factor equation is used for both laminar and turbulent flow, although the friction-factor correlation differs in the…
Correct answer: Both B. and C.- A. Gases
- B. Liquids
- C. Mixture of hydrocarbons
- D. None of these
Explanation: A two-liquid manometer is commonly used to measure small pressure differences in gases because the manometric liquids can provide a…
Correct answer: Gases- A. static
- B. Total
- C. Dynamic
- D. None of these
Explanation: A simple Pitot tube brings the flowing fluid to rest at its opening, converting velocity pressure into stagnation pressure.
Correct answer: Total