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.
Last updated
909 questions · page 24 of 46
- A. Circular
- B. Rectangular
- C. Triangular
- D. Trapezoidal
Explanation: The standard sharp-crested weir forms include rectangular, triangular or V-notch, and trapezoidal sections.
Correct answer: Circular- A. One, which obeys Newton's law of viscosity
- B. Frictionless & incompressible
- C. Highly viscous
- D. None of these
Explanation: An ideal fluid is modeled as having zero viscosity, so it is frictionless, and constant density, so it is incompressible.
Correct answer: Frictionless & incompressible- A. Paddle
- B. Turbine
- C. Propeller
- D. All A., B. and C.
Explanation: A propeller is the standard axial-flow impeller because it moves fluid mainly parallel to the impeller shaft.
Correct answer: Propeller- A. Water surface
- B. None of these
- C. Centre of buoyancy
- D. Centre of gravity
Explanation: Metacentric height is the vertical distance between the metacentre and the centre of gravity.
Correct answer: Centre of gravity- A. Pseudo-plastic
- B. Rheopectic
- C. Thixotropic
- D. Dilatant
Explanation: Paints and enamels commonly show pseudoplastic behaviour, meaning their apparent viscosity decreases as shear rate increases, making them…
Correct answer: Pseudo-plastic- A. 2
- B. 4
- C. 8
- D. 5.5
Explanation: For geometrically similar centrifugal pumps, head varies as the square of speed: H₂/H₁ = (N₂/N₁)².
Correct answer: 2- A. 4
- B. 2100-4000
- C. 4000
- D. ∞
Explanation: The Reynolds number is Re = ρvD/μ, and an ideal fluid has zero viscosity, μ = 0.
Correct answer: ∞- A. V/Vmax = (x/r)1/7
- B. V/Vmax = (r/x)1/7
- C. V/Vmax = (x.r)1/7
- D. None of these
Explanation: The one-seventh power law gives V/Vmax = (x/r)^(1/7) when x is the distance from the pipe wall and r is the pipe radius.
Correct answer: V/Vmax = (x/r)1/7- A. Longer, if Metacentric height is increased
- B. None of these
- C. Dependent on the buoyant forces only
- D. Independent of the Metacentric height
Explanation: For small oscillations of a floating body, the period varies approximately as T ∝ 1/√(GM), so increasing metacentric height makes the…
Correct answer: None of these- A. Newtonian
- B. Dilatant
- C. Pseudo-plastic
Explanation: For steady laminar flow of a Newtonian fluid, the Hagen–Poiseuille relation gives Q ∝ D⁴ at fixed pressure drop and length.
Correct answer: Newtonian- A. 4
- B. > 12.5
- C. < 10
Explanation: Capillary rise or depression becomes negligible when the manometer tube is sufficiently large, conventionally above about 12.5 mm in…
Correct answer: > 12.5- A. Circulation around the body is essentially required
- B. The body should be stream lined
- C. The body should be bluff body
- D. The main stream velocity must approach the velocity of sound in that fluid medium
Explanation: Lift is associated with a pressure difference produced by circulation around the body, as in the circulation theory of lift.
Correct answer: Circulation around the body is essentially required- A. Reduction of pressure below vapour pressure
- B. Adverse pressure gradient
- C. Reduction of pressure gradient to zero
- D. Reduction of boundary layer thickness to zero
Explanation: An adverse pressure gradient means pressure increases in the direction of flow, slowing the boundary-layer fluid until it can reverse near…
Correct answer: Adverse pressure gradient- A. Angular velocity
- B. None of these
- C. Specific volume
- D. Fanning friction factor
Explanation: The Fanning friction factor is a ratio of wall shear stress to dynamic pressure, so its units cancel.
Correct answer: Fanning friction factor475. The distribution of shear stress in a stream of fluid in a circular tube is_____________________?
- A. Linear with radius for both laminar & turbulent flow
- B. Linear with radius for laminar flow only
- C. Linear with radius for turbulent flow only
- D. Parabolic with radius for both laminar & turbulent flow
Explanation: A momentum balance on a circular tube gives shear stress proportional to the distance from the tube axis, regardless of whether the flow…
Correct answer: Linear with radius for both laminar & turbulent flow476. The ratio of actual discharge to theoretical discharge through an orifice is equal to______________?
- A. Cc . Cv
- B. Cc . Cd
- C. Cv . Cd
- D. Cd/Cv
Explanation: The discharge coefficient is defined as actual discharge divided by theoretical discharge, so the ratio is Cd.
Correct answer: Cc . Cv- A. Placed farther from the wall
- B. Near each other
- C. Not affected by other particles and the wall
- D. None of these
Explanation: Hindered settling occurs at sufficiently high particle concentration that neighbouring particles interfere with one another and displace…
Correct answer: Near each other- A. Normal
- B. Convective
- C. Local
- D. Tangential
Explanation: The local acceleration is caused by the time variation of velocity at a fixed position, so it represents the unsteady nature of flow.
Correct answer: Local- A. Cv . Va
- B. Cc . √(2gH)
- C. Cd . √(2gH)
- D. Cv . √(2gH)
Explanation: At the vena contracta, the actual velocity equals the ideal theoretical velocity multiplied by the coefficient of velocity, giving…
Correct answer: Cv . √(2gH)- A. Manometer
- B. Pitot tube
- C. Rotameter
- D. None of these
Explanation: A Pitot tube is suitable for high-velocity gas streams because it measures the stagnation pressure and hence the local velocity from the…
Correct answer: Pitot tube