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 45 of 46
- A. 5
- B. 10
- C. 20
- D. 40
Explanation: A commonly used approximate upper limit for air velocity in pipelines is about 10 m/s, since higher velocities cause excessive friction…
Correct answer: 10882. Induced draft fans provided in large thermal power plant boilers have __________________ blades?
- A. Forward curved
- B. Backward curved
- C. Double curved
- D. Radial or straight
Explanation: Large induced-draft fans generally use backward-curved blades because they provide good efficiency, stable operation and lower power…
Correct answer: Backward curved- A. Pressure
- B. Viscous
- C. Gravity
- D. Turbulent
Explanation: The Navier-Stokes equation includes pressure, viscous, gravitational and inertial effects, but turbulence is not a separate fundamental…
Correct answer: Turbulent- A. Wet scrubber
- B. Electrostatic precipitator
- C. Bag filter
- D. Gravity settling chamber
Explanation: A wet scrubber removes dust by contacting the gas with liquid and therefore produces a wet slurry or sludge.
Correct answer: Wet scrubber- A. Crusher
- B. wet classifier
- C. Dry classifier
- D. Magnetic separator
Explanation: A hydrocyclone separates particles from a liquid by centrifugal action, with heavier particles moving outward and downward.
Correct answer: wet classifier- A. Fluid density & viscosity
- B. Pipe roughness
- C. Pipe length
- D. Mass flow rate of fluid
Explanation: The Darcy friction factor depends on Reynolds number and relative roughness, not directly on pipe length.
Correct answer: Pipe length- A. Plastic
- B. Steel
- C. Concrete
- D. Cast iron
Explanation: Traditional cast-iron pipe joints are sealed by pouring molten lead into the annular space and then caulking it.
Correct answer: Cast iron- A. Parabolic
- B. Hyperbolic
- C. Straight line
- D. None of these
Explanation: For laminar flow in an open channel, the velocity is zero at the bed and increases to a maximum at the free surface, giving a parabolic…
Correct answer: Parabolic889. Pressure required to increase the density of water by about 1% is ____________________ atmosphere?
- A. 10
- B. 50
- C. 200
- D. 1000
Explanation: Using water's bulk modulus of about 2.2 GPa, a 1% density increase requires roughly 22 MPa, or about 217 atmospheres.
Correct answer: 200- A. Drops down in the tube
- B. Rotates at higher speed
- C. Rotates at lower speed
- D. Rises in the tube
Explanation: A rotameter float rises until the increased upward drag balances its weight and buoyancy at a higher position.
Correct answer: Rises in the tube- A. Carbon tetrachloride
- B. Ethyl alcohol
- C. Glycerol
- D. Ethylene glycol
Explanation: Carbon tetrachloride is a dense, nonvolatile liquid commonly used in manometers for relatively low pressure differences, producing a…
Correct answer: Carbon tetrachloride- A. Shear
- B. Tensile
- C. Compressive
- D. None of these
Explanation: A fluid at rest cannot sustain shear stress because even a small shear force causes continuous deformation.
Correct answer: Shear- A. Froude
- B. Mach
- C. Reynolds
- D. Euler
Explanation: The Mach number is the ratio of inertial force to elastic force, expressed as the ratio of flow velocity to the speed of sound.
Correct answer: Mach- A. Chromatography
- B. Evaporation
- C. Filtration
- D. Fractional distillation
Explanation: Filtration retains solid metal particles on a porous medium while allowing the liquid oil to pass through.
Correct answer: Filtration- A. Watt/m
- B. Joule/m2
- C. Newton/m2
- D. Joule/m
Explanation: Surface tension has units of force per unit length, N/m. Since 1 J=N·m, this is equivalently J/m², making option b correct; J/m is not the…
Correct answer: Joule/m2- A. 1
- B. 10
- C. 25
- D. 50
Explanation: A Venturi meter with a 15° taper has a relatively efficient gradual passage, so its permanent pressure loss is commonly about 10% of the…
Correct answer: 10- A. Greater than
- B. Less than
- C. Equal to
- D. Unpredictable; depends on the bubble size
Explanation: Surface tension produces an excess pressure inside a curved liquid surface, so the pressure inside a bubble or droplet is greater than the…
Correct answer: Less than- A. Collar
- B. Bell and Spigot
- C. Flanged
- D. Expansion
Explanation: A flanged joint can be unbolted easily, making it suitable for temporary cast-iron pipelines that must be dismantled and reassembled…
Correct answer: Flanged- A. High viscosity
- B. Low surface tension
- C. High density
- D. High surface tension
Explanation: Mercury has high surface tension, so cohesive forces pull its surface into the shape with minimum area, producing nearly spherical…
Correct answer: High surface tension- A. Cast iron
- B. Steel
- C. Aluminium
- D. None of these
Explanation: Dry compressed air is commonly used when machining cast iron because liquid coolants can mix with cast-iron dust and create a troublesome…
Correct answer: Cast iron