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 200 of 350
- 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- A. Same as
- B. Larger than
- C. Smaller than
- D. Twice
Explanation: The suction pipe is usually made larger than the discharge pipe to keep suction velocity and entrance losses low, thereby helping satisfy…
Correct answer: Smaller than- A. Discharge
- B. Suction
- C. Suction minus vapor pressure of the liquid at suction temperature
- D. Discharge minus vapor pressure of the liquid at the discharge temperature
Explanation: NPSH available is the suction pressure head plus suction velocity head, measured relative to the liquid vapour-pressure head at suction…
Correct answer: Suction minus vapor pressure of the liquid at suction temperature- A. d4/5
- B. d2/3
- C. √d
- D. d1/3
Explanation: For turbulent flow over a flat plate, the empirical boundary-layer relation gives δ proportional to d^(4/5).
Correct answer: d4/5- A. Viscous
- B. Elastic
- C. Gravity
- D. None of these
Explanation: Mach number compares inertial forces with elastic or compressibility forces, so it becomes important when these effects dominate.
Correct answer: Elastic- A. Inlet pressure low
- B. Outlet pressure low
- C. Inlet pressure high
- D. Outlet pressure high
Explanation: Cavitation occurs when pressure at the pump suction falls below the liquid vapour pressure.
Correct answer: Inlet pressure high- A. 2
- B. 100
- C. 2100
- D. 700
Explanation: Stokes' settling law applies in the creeping-flow range, conventionally stated in many chemical-engineering texts as particle Reynolds…
Correct answer: 2- A. Steady non-uniform
- B. Steady uniform
- C. Unsteady uniform
- D. Unsteady non-uniform
Explanation: Gradually varied flow changes depth and velocity gradually along the channel, so it is non-uniform; the usual classification assumes…
Correct answer: Steady non-uniform3991. In case of supersonic flow of a fluid through pipeline, the 'Mach number' is__________________?
- A. 0
- B. 1
- C. > 1
- D. < 1
Explanation: Mach number is the ratio of flow velocity to the local speed of sound. Supersonic flow has velocity greater than the speed of sound, so…
Correct answer: > 1- A. Size
- B. Roughness
- C. Material density
- D. Wall thickness
Explanation: The schedule number specifies the pipe wall thickness for a given nominal pipe size and material standard.
Correct answer: Wall thickness- A. FL-1
- B. F-1. L
- C. F.L-2
- D. F-2. L
Explanation: Surface tension is force per unit length, so its dimensions are F/L, written as FL⁻¹.
Correct answer: FL-1- A. Decrease
- B. Increase
- C. Remain same
- D. Be quadrupled
Explanation: For laminar pipe flow, pressure drop increases strongly as diameter decreases; at constant flow rate, ΔP is proportional to 1/D⁴.
Correct answer: Increase3995. The exit cone angle in case of a standard Venturimeter is _____________ the entrance cone angle?
- A. Equal to
- B. Greater than
- C. Smaller than
- D. Either A. or B.
Explanation: A Venturimeter uses a gradual converging entrance and a longer, more gradual diffuser exit to reduce flow separation and energy loss.
Correct answer: Smaller than- A. Decreases
- B. Can either increase or decrease; depends on other factors
- C. Remains unaltered
- D. Increases
Explanation: Increasing pump speed generally increases flow velocity and the velocity-related losses at the suction inlet, so the required NPSH rises.
Correct answer: Increases- A. Newtonian
- B. Bingham
- C. Perfect
- D. None of these
Explanation: Newtonian fluids obey Newton's law of viscosity, τ = μ(du/dy), so shear stress is directly proportional to the velocity gradient.
Correct answer: Newtonian- A. Inner
- B. Approximate
- C. Outer
- D. None of these
Explanation: Nominal pipe size is a standardized approximate size rather than a direct, exact measurement of either inner or outer diameter.
Correct answer: Approximate- A. Hyperbolic
- B. Parabolic
- C. Logarithmic
- D. Linear
Explanation: Turbulent mixing produces a relatively flat velocity profile in the central region, while the near-wall profile follows a logarithmic law.
Correct answer: Logarithmic- A. Permanently resists distortion
- B. Continuously expands till it fills any container
- C. Is incompressible
- D. Cannot remain at rest under the action of shear force
Explanation: A fluid cannot sustain a shear force at rest, so even a small persistent shear stress causes continuous deformation.
Correct answer: Cannot remain at rest under the action of shear force