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 4 of 46
- A. Produces only radial current
- B. Is effective over wide range of viscosities
- C. Produces only tangential current
- D. Does not produce tangential current
Explanation: A turbine impeller can generate both radial and tangential circulation, so the options claiming only one type of current are false.
Correct answer: Is effective over wide range of viscosities- A. 0.5
- B. 0.67
- C. 1
- D. 2
Explanation: The laminar pipe-flow profile is parabolic, with the centreline velocity equal to twice the mean velocity.
Correct answer: 2- A. Always inversely proportional to the Reynolds number
- B. Not dimensionless
- C. Not dependent on the roughness of the pipe
- D. None of these
Explanation: The friction factor is dimensionless and depends on Reynolds number and, in turbulent flow, relative pipe roughness.
Correct answer: None of these- A. Electrical conductivity
- B. Thermal conductivity
- C. Specific gravity
- D. Electrical resistivity
Explanation: Magnetic flowmeters require the flowing liquid to conduct electricity so the induced voltage can be detected.
Correct answer: Electrical conductivity- A. Centrifugal
- B. Mixed flow
- C. Axial flow
- D. None of these
Explanation: Pump specific speed rises as the pump handles greater flow relative to its head, progressing from centrifugal to mixed-flow and then…
Correct answer: Axial flow- A. 2
- B. 1
- C. > 1
- D. < 1
Explanation: Liquid metals have very low Prandtl numbers, meaning thermal diffusivity is much greater than momentum diffusivity.
Correct answer: < 1- A. Bingham plastic
- B. Newtonian
- C. Pseudo plastic
- D. Dilatent
Explanation: Sewage sludge generally behaves as a Bingham plastic: it requires a yield stress before it flows and then shows a roughly linear…
Correct answer: Bingham plastic- A. 15
- B. 55
- C. 155
- D. 1050
Explanation: At room temperature, water has a viscosity of about 1 cP, while air has about 0.018 cP.
Correct answer: 55- A. Centrifugal
- B. Reciprocating
- C. Impulse
- D. Parallel cylinder
Explanation: A hydraulic ram uses the water-hammer effect: suddenly stopped flowing water creates an impulse pressure that lifts a portion of the…
Correct answer: Impulse- A. All A., B. and C.
- B. Pressure
- C. Total energy
- D. Flow velocity
Explanation: At a stagnation point, the local fluid velocity becomes zero, while the pressure reaches a maximum relative to the flowing stream.
Correct answer: Flow velocity- A. Pipe becomes smoother with use
- B. Absolute roughness increases linearly with time
- C. Absolute roughness decreases with time
- D. Friction factor increases linearly with time
Explanation: Corrosion and deposition during pipe ageing increase the internal absolute roughness, which generally raises frictional resistance.
Correct answer: Absolute roughness increases linearly with time- A. < 2100
- B. > 2.5
- C. < 0.1
- D. < 500
Explanation: Creeping flow requires viscous forces to dominate strongly over inertia; for a sphere this is commonly represented by a particle Reynolds…
Correct answer: < 0.1- A. Gage
- B. Atmospheric
- C. Absolute
- D. Small differential
Explanation: The elongated liquid column in an inclined manometer produces a larger readable displacement for a small pressure difference.
Correct answer: Small differential- A. Rotameter
- B. Pitot tube
- C. Venturimeter
- D. None of these
Explanation: Venturimeters and Pitot tubes determine flow conditions from changes in pressure head or velocity head.
Correct answer: Rotameter- A. As square of
- B. As cube of
- C. Directly as
- D. None of these
Explanation: The fan affinity laws state that, at constant wheel diameter, flow varies as N, pressure or head as N², and power as N³.
Correct answer: As cube of- A. Discharge and overall efficiency
- B. Volume swept by piston for one complete revolution and the pressure in the cylinder
- C. Angle swept by the crank pin at any instant and the discharge
- D. None of these
Explanation: An indicator diagram records cylinder pressure against piston displacement, which can be expressed as the volume swept by the piston.
Correct answer: Volume swept by piston for one complete revolution and the pressure in the cylinder- A. 33:3
- B. 50
- C. 66.6
- D. 88.8
Explanation: For transmission through a pipe, friction loss increases with flow and the useful head is the total head minus this loss.
Correct answer: 66.6- A. 25.61 kPa
- B. 11.77 kPa
- C. 14.86 kPa
- D. 21.13 kPa
Explanation: At incipient fluidisation, the pressure drop balances the submerged bed weight: ΔP = (1 − ε)ρs gL.
Correct answer: 11.77 kPa- A. Q∝N2 : H∝N3 : P∝N
- B. Q∝N : H∝N2 : P∝N3
- C. Q∝N : H∝N3 : P∝N2
- D. Q∝N3 : H∝N : P∝N2
Explanation: The centrifugal-pump affinity laws for a fixed impeller diameter are Q ∝ N, H ∝ N², and P ∝ N³.
Correct answer: Q∝N : H∝N2 : P∝N3- A. Inverse
- B. Second power
- C. Square root
- D. First power
Explanation: In Newton’s-law flow, drag is proportional to d²v², while particle weight is proportional to d³.
Correct answer: Square root