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 14 of 46
- A. Relief
- B. Three/four way
- C. Directional control
- D. Pressure reducing
Explanation: A foot valve prevents liquid in the suction line from flowing back when the pump stops, so it acts as a one-way or directional-control…
Correct answer: Directional control- A. Capacity varies directly with
- B. Head varies as the square of
- C. Horsepower varies as the cube of
- D. All A., B. and C.
Explanation: The centrifugal-pump affinity laws for constant speed give Q ∝ D, H ∝ D², and power ∝ D³, where D is impeller diameter.
Correct answer: All A., B. and C.- A. Relative roughness
- B. Friction co-efficient for flows at equal Reynold number
- C. Absolute roughness
- D. All A., B. & C.
Explanation: Hydraulic roughness is compared by the friction coefficient obtained at the same Reynolds number, since this captures the pipe's…
Correct answer: Friction co-efficient for flows at equal Reynold number- A. Parabolic
- B. Flat
- C. Parabolic near the wall and flat in the middle
- D. Flat near the wall and parabolic in the middle
Explanation: A Bingham plastic fluid has a yield stress, producing an unsheared plug in the central region where velocity is nearly flat.
Correct answer: Parabolic near the wall and flat in the middle- A. None of these
- B. Blower
- C. Acid egg
- D. Jet pump
Explanation: A jet pump uses a high-velocity motive fluid to transfer momentum to and entrain another fluid, thereby moving it.
Correct answer: Jet pump266. Steady fluid flow occurs, when the derivative of flow variables satisfy the following condition.
- A. ∂/∂t = 0
- B. ∂/∂s = 0
- C. ∂/∂s = constant
- D. ∂/∂t = constant
Explanation: Steady flow means that flow variables at a fixed position do not change with time, so their time derivative is zero, ∂/∂t = 0.
Correct answer: ∂/∂t = 0267. Schedule number of a pipe, which is a measure of its wall thickness, is given by ________________?
- A. 100 P'/S
- B. 1000 P'/S
- C. 1000 S/P'
- D. 10000 P'/S
Explanation: The pipe schedule number is commonly calculated as 1000 times the design pressure divided by the allowable stress, or 1000P′/S.
Correct answer: 1000 P'/S- A. M is above G
- B. M is below G
- C. M & G coincide
- D. None of these
Explanation: A floating body is unstable when the metacentre lies below its centre of gravity, M below G, giving a negative metacentric height.
Correct answer: M is below G- A. 4000
- B. 2100
- C. 1500
- D. 3000
Explanation: For pipe flow, laminar flow is generally limited to Reynolds numbers below about 2100; above this value, transition begins.
Correct answer: 2100- A. Von-Karman equation
- B. Colebrook formula
- C. Fanning equation
- D. None of these
Explanation: With the usual notation interpreted as f⁻¹ᐟ² = 4.07 logₑ(NRe√f) − 0.6, this is the von Kármán relation for turbulent flow in smooth pipes.
Correct answer: Von-Karman equation- A. 10 KPa
- B. 20 KPa
- C. 30 KPa
- D. 40 KPa
Explanation: For a Bingham fluid, wall stress equals yield stress plus viscous stress: τ = τ₀ + μ(du/dy).
Correct answer: 20 KPa- A. Average flow velocity
- B. Pressure at a point
- C. Velocity at a point in the flow
- D. Pressure difference in pipe flow
Explanation: A Prandtl-Pitot tube compares stagnation and static pressure to determine the local fluid velocity at the probe position.
Correct answer: Velocity at a point in the flow- A. MLT
- B. MLT-1
- C. ML-1T
- D. ML-1T-1
Explanation: Dynamic viscosity follows τ = μ(du/dy), so its dimensions are stress divided by rate of strain: (ML⁻¹T⁻²)/T⁻¹ = ML⁻¹T⁻¹.
Correct answer: ML-1T-1- A. Inside diameter
- B. Outside diameter
- C. Thickness
- D. None of these
Explanation: For a given nominal pipe size, the outside diameter is standardized, while the inside diameter changes with the schedule because wall…
Correct answer: Outside diameter- A. 0.64
- B. 1.65
- C. 0.32
- D. 0.94
Explanation: The coefficient of contraction is the vena-contracta area divided by the orifice area: Cc = (40/50)^2 = 0.64.
Correct answer: 0.64- A. Vs/Dp2
- B. Vs2/Dp2
- C. Vs2/Dp3
- D. Vs/Dp3
Explanation: In the laminar packed-bed region, the viscous term of the Ergun equation gives pressure drop proportional to μVs/Dp².
Correct answer: Vs/Dp2- A. More diameter compared to orifice diameter
- B. Minimum liquid cross-section
- C. Minimum velocity of fluid stream
- D. None of these
Explanation: The vena contracta is the point where the jet has its smallest cross-sectional area after passing through the orifice, so its diameter is…
Correct answer: Minimum liquid cross-section- A. m/N. sec
- B. N/m2
- C. m2 /sec
- D. kg/m. sec
Explanation: Dynamic viscosity has SI units Pa·s, which are equivalent to N·s/m² and kg/(m·s). Therefore kg/(m·sec) is the correct form.
Correct answer: kg/m. sec- A. More than
- B. Same as
- C. Less than
- D. Data insufficient, cannot be predicted
Explanation: An orifice meter causes greater permanent pressure loss because the abrupt contraction and expansion produce flow separation and…
Correct answer: More than- A. Air at room temperature
- B. Water at room temperature
- C. Oxygen at room temperature
- D. Nitrogen at room temperature
Explanation: Liquids are far less compressible than gases because their molecules are already closely packed.
Correct answer: Water at room temperature