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 205 of 350
- A. For which shear & deformation are related as T = μ (∂u/∂y)
- B. Which needs a minimum shear, before it starts deforming
- C. Which follows Newton's law of motion
- D. None of these
Explanation: A Newtonian fluid has shear stress directly proportional to the velocity gradient, τ = μ(∂u/∂y), with constant viscosity at fixed…
Correct answer: For which shear & deformation are related as T = μ (∂u/∂y)- A. 0.5
- B. 2
- C. 4
- D. 1
Explanation: For geometrically similar centrifugal-pump operation, power varies with the cube of speed, P ∝ N³.
Correct answer: 0.5- A. Inertial stress to drag stress
- B. Drag stress to inertial stress
- C. Inertial stress to gravitational stress
- D. Gravitational stress to drag stress
Explanation: The power number compares the power or drag effect required for agitation with the inertial effect, and is written as Np = P/(ρN³D⁵).
Correct answer: Drag stress to inertial stress- A. 10
- B. 100
- C. 1000
- D. 10000
Explanation: The ram-to-plunger area ratio is (10/1)^2 = 100. A 10-ton load equals 10,000 kgf, so the plunger force is 10,000/100 = 100 kgf.
Correct answer: 100- A. 1
- B. > 3
- C. 50
- D. < 0.3
Explanation: Gas compressibility effects are usually negligible when the Mach number is below about 0.3, because pressure disturbances travel much…
Correct answer: < 0.3- A. High capacity at low heads
- B. High capacity at high heads
- C. Low capacity at high heads
- D. Low capacity at low heads
Explanation: Propeller pumps are axial-flow machines designed to move a large volume of liquid against a relatively small head.
Correct answer: High capacity at low heads- A. Two
- B. Three
- C. Four
- D. Eight
Explanation: The hydraulic diameter is defined as D_h = 4A/P, where A is the flow area and P is the wetted perimeter.
Correct answer: Four- A. Shear stress to gravitational stress
- B. Drag stress to shear stress
- C. Inertial stress to shear stress
- D. Inertial stress to gravitational stress
Explanation: The Froude number compares inertial effects with gravitational effects, commonly written as Fr = V/√(gL).
Correct answer: Inertial stress to gravitational stress- A. Fixed in space in steady flow
- B. Always the path of particle
- C. Drawn normal to the velocity vector at every point
- D. A line connecting the mid points of flow cross-section
Explanation: In steady flow, the velocity field does not change with time, so streamlines remain fixed in space.
Correct answer: Fixed in space in steady flow- A. Single stage centrifugal pump
- B. Duplex/triplex reciprocating pump
- C. Screw pump
- D. Gear pump
Explanation: Duplex or triplex reciprocating pumps are positive-displacement pumps capable of delivering crude oil from wells against substantial…
Correct answer: Duplex/triplex reciprocating pump- A. Viscosity of the liquid
- B. Depth of immersion of the body
- C. Weight of the liquid displaced
- D. Surface tension of the liquid
Explanation: Archimedes’ principle states that buoyant force equals the weight of the liquid displaced by the submerged portion of the body.
Correct answer: Weight of the liquid displaced- A. Specific gravity of the liquid
- B. Suction lift
- C. Discharge head
- D. All A., B. and C.
Explanation: For a given flow rate, pump power is proportional to specific gravity multiplied by the total head.
Correct answer: All A., B. and C.- A. Brings about no further reduction of
- B. Increases
- C. Decreases
- D. None of these
Explanation: Once a pipe is hydraulically smooth, the roughness elements are buried within the viscous sublayer, so reducing roughness further does not…
Correct answer: Brings about no further reduction of- A. ft-lb/sec
- B. ft-lb/ft3
- C. ft-lbf/lb
- D. ft-lbf/sec
Explanation: Velocity head is v²/2g, which has the dimensions of length. In British engineering units, ft-lbf/lb reduces to ft, so option c is correct.
Correct answer: ft-lbf/lb- A. Fluid characteristics
- B. Particle size
- C. Neither A. nor B.
- D. Both A. and B.
Explanation: Fluidised-bed behaviour is governed by both the fluid properties, such as density and viscosity, and particle characteristics, especially…
Correct answer: Both A. and B.- A. M2/sec
- B. N/m2. sec
- C. Kg. sec/m
- D. None of these
Explanation: Kinematic viscosity is dynamic viscosity divided by density, giving SI units of m²/s.
Correct answer: M2/sec- A. 39.6y
- B. 48y
- C. 49.2y
- D. 58y
Explanation: The centroid is 5 ft below the oil surface because the 4-ft inclined length has a vertical rise of 2 ft from its lower edge at 6 ft depth.
Correct answer: 48y- A. 64/NRe,P
- B. 16/NRe,P
- C. 24/NRe,P
- D. 48/NRe,P
Explanation: For spherical particles in the Stokes-law range, the drag coefficient varies inversely with particle Reynolds number and is given by C_D =…
Correct answer: 24/NRe,P- A. Speed of
- B. Diameter of
- C. All A., B. and C.
- D. Fluid velocity leaving
Explanation: The theoretical centrifugal-pump head follows Euler’s pump equation and depends on impeller speed, impeller diameter, and the velocity…
Correct answer: All A., B. and C.4100. In area meter (e.g., Rotameter), with increase in the fluid flow rate, the___________________?
- A. Pressure drop increases linearly
- B. None of these
- C. Area through which fluid flows does not vary
- D. Pressure drop is almost constant
Explanation: A rotameter operates at an approximately constant pressure drop, while the float rises to increase the annular flow area as flow rate…
Correct answer: Pressure drop is almost constant