All Free Chemical Engineering MCQs with Answers
Every Chemical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
6,983 questions · page 214 of 350
- A. 1
- B. 0
- C. < 1
- D. > 1
Explanation: In turbulent pipe flow, pressure drop varies approximately as a power of velocity greater than one, such as ΔP proportional to velocity…
Correct answer: < 1- A. 0.003
- B. 0.01
- C. 0.1
- D. 0.3
Explanation: For a smooth pipe at Reynolds number 10^6, the Fanning friction factor is about 0.0025 to 0.003, using the Blasius-type correlation as an…
Correct answer: 0.003- A. Friction factor is independent of the relative roughness
- B. Laminar film covers the roughness projections
- C. Friction factor depends upon NRe only
- D. Rough and smooth pipes have the same friction factor
Explanation: In the complete turbulence zone, viscous effects are negligible and the friction factor no longer changes appreciably with Reynolds…
Correct answer: Friction factor is independent of the relative roughness- A. 2000
- B. 10
- C. 100
- D. 1000
Explanation: Using Re = ρvD/μ for water, Re ≈ (1000)(0.05)(0.02)/(0.001) = 1000. Thus the nearest option is 1000.
Correct answer: 1000- A. Dependent on the length of the pipe
- B. Independent of Reynolds number
- C. Dependent on Reynolds number
- D. None of these
Explanation: Equivalent length represents the length of straight pipe having the same pressure loss as a fitting, and the loss depends on the flow…
Correct answer: Dependent on Reynolds number- A. Incompressible, frictionless, steady, along a streamline
- B. Uniform, steady, incompressible, along a streamline
- C. Steady, density being pressure dependent, frictionless
- D. None of these
Explanation: Bernoulli's equation in its basic form assumes steady, incompressible, frictionless flow along a streamline.
Correct answer: Incompressible, frictionless, steady, along a streamline- A. Booster service
- B. All A., B. and C.
- C. Pumping industrial wastes
- D. Pumping liquid fertilisers (e.g. liquid NH3)
Explanation: Self-priming centrifugal pumps can evacuate air from the suction line and are therefore useful in booster service, liquid fertiliser…
Correct answer: All A., B. and C.- A. 500
- B. 200
- C. 1000
- D. 750
Explanation: The centrifugal-pump affinity law gives Q proportional to speed when the impeller diameter is unchanged.
Correct answer: 500- A. 4.728
- B. 0.5
- C. 0.622
- D. 0.474
Explanation: Nominal pipe size is not the actual inside diameter, because schedule changes wall thickness.
Correct answer: 0.622- A. Centrifugal
- B. Reciprocating
- C. Gear
- D. Screw
Explanation: Centrifugal pumps are commonly used for slurries because they can handle large flow rates and suspended solids with relatively simple…
Correct answer: Centrifugal- A. Multiplying with density (gm/c.c)
- B. Dividing by density (gm/c.c)
- C. Multiplying with specific gravity
- D. Dividing by specific gravity
Explanation: Kinematic viscosity is related to dynamic viscosity by ν = μ/ρ, so poise is divided by density in g/cm³ to obtain stokes.
Correct answer: Dividing by density (gm/c.c)- A. Thickness only
- B. Outer diameter only
- C. Thickness & outer diameter both
- D. Inner diameter
Explanation: A tube is conventionally identified by its outside diameter and wall thickness, from which the inside diameter can also be calculated.
Correct answer: Thickness & outer diameter both- A. Head loss is the same through each pipe
- B. Discharge is the same through all the pipes
- C. Total head loss is equal to the sum of the head losses through each pipe
- D. None of these
Explanation: Branches connected in parallel have the same pressure drop, and therefore the same head loss between their common junctions.
Correct answer: Head loss is the same through each pipe- A. 0.44
- B. 0.044
- C. 4.4
- D. 44
Explanation: In the Newton or high-Reynolds-number range, the drag coefficient of a smooth spherical particle is approximately 0.44.
Correct answer: 0.44- A. D Δp/8L
- B. D Δp/4L
- C. 8 Vavg/D
- D. 4 Vavg/D
Explanation: For laminar pipe flow, the wall shear rate is the velocity-gradient magnitude at the wall, equal to 8Vavg/D.
Correct answer: 8 Vavg/D- A. Logarithmic
- B. Hyperbolic
- C. Parabolic
- D. Linear
Explanation: The Hagen-Poiseuille velocity profile is u = umax[1 − (d/R)²], so velocity varies parabolically with distance from the centreline.
Correct answer: Parabolic- A. d
- B. d2
- C. d4
- D. d̅ 2
Explanation: In the viscous, low-Reynolds-number part of packed-bed flow, the Ergun relation contains the particle-size dependence 1/d².
Correct answer: d̅ 2- A. Rotameter
- B. Orificemeter
- C. Venturimeter
- D. Flow nozzle
Explanation: A rotameter has a variable-area passage and can measure small gas flow rates with relatively low pressure loss.
Correct answer: Rotameter- A. Shear stress and velocity
- B. Shear stress and rate of angular deformation in a fluid
- C. Velocity gradient and pressure intensity
- D. Pressure gradient and rate of angular deformation
Explanation: Newton's viscosity law states that shear stress is proportional to the rate of angular deformation, equivalently the velocity gradient, in…
Correct answer: Shear stress and rate of angular deformation in a fluid- A. Exponentially decrease
- B. Decrease
- C. Not change
- D. Increase
Explanation: At a fixed volumetric flow rate, supplying more horsepower to a centrifugal compressor allows it to develop a greater pressure rise, so…
Correct answer: Increase