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 227 of 350

  • A. Gyratory crusher
  • B. Toothed roll crusher
  • C. Ball mill
  • D. Tube mill

Explanation: A gyratory crusher is designed for primary crushing and can accept large, very hard lumps continuously under compression.

Correct answer: Gyratory crusher
  • A. Belt
  • B. Screw
  • C. Bucket
  • D. None of these

Explanation: Screw conveyors are well suited to moving dry powdery solids over short or moderate distances in an enclosed trough.

Correct answer: Screw
  • A. Apron conveyor
  • B. Belt conveyor
  • C. Screw conveyor
  • D. Pneumatic conveyor

Explanation: A screw conveyor can move sticky or sluggish material because the rotating screw positively pushes it through an enclosed trough.

Correct answer: Screw conveyor
  • A. Different fluids
  • B. Same fluid
  • C. Same field of force
  • D. Both B. and C.

Explanation: Equal-settling particles have the same terminal velocity under the same settling conditions, including the same fluid and field of force.

Correct answer: Both B. and C.
  • A. Ribbed
  • B. Curved
  • C. Plane
  • D. Either A. or B.

Explanation: The working face of a filter-press plate is ribbed, providing drainage channels for the filtrate while the filter cake builds on the…

Correct answer: Ribbed
  • A. Banbury mixer
  • B. Pug mill
  • C. Muller-mixer
  • D. None of these

Explanation: A vacuum pug mill mixes and kneads clay while removing entrained air under vacuum, producing a dense, uniform clay body.

Correct answer: Pug mill
  • A. Remains constant
  • B. Decreases
  • C. Increases
  • D. Increases linearly

Explanation: A compressible cake compacts as pressure drop rises, reducing its void spaces and making fluid flow more difficult.

Correct answer: Increases
  • A. Sparger
  • B. Kneader
  • C. Masticator
  • D. None of these

Explanation: A sparger introduces gas into a liquid through holes or a porous distributor, producing bubbles and gas-liquid contact.

Correct answer: Sparger
  • A. Crush intermittently
  • B. Have greater capacity per unit of discharge area
  • C. Are less suitable for coarse materials
  • D. Have less steady power consumption

Explanation: A gyratory crusher acts continuously, whereas a jaw crusher has a reciprocating, intermittent action.

Correct answer: Have greater capacity per unit of discharge area
  • A. Blake jaw
  • B. Gyratory
  • C. Toothed roll
  • D. None of these

Explanation: Toothed-roll crushers are suitable for relatively soft, tough or friable materials such as ice and gypsum.

Correct answer: Toothed roll
  • A. Thickeners
  • B. Hydrocyclones
  • C. Classifiers
  • D. Decanters

Explanation: Classifiers separate particles according to settling behaviour, allowing coarse particles to be removed from a slurry containing finer…

Correct answer: Classifiers
  • A. 35
  • B. 50
  • C. 70
  • D. 85

Explanation: A ball mill is commonly operated with a ball charge of about 40 to 50% of its internal volume. Thus 50% is the closest standard value.

Correct answer: 50
  • A. Density separation
  • B. Differential wettability
  • C. Size
  • D. Volatile matter content

Explanation: A float-and-sink test divides coal according to its density, so its washability curve evaluates cleaning by density separation.

Correct answer: Density separation
  • A. ½ √(g/r)
  • B. (1/π). √(g/r)
  • C. (1/2π). √(g/r)
  • D. 2π. √(g/r)

Explanation: At critical speed, a particle just remains in circular contact with the trammel wall, giving omega squared r equals g.

Correct answer: (1/2π). √(g/r)
  • A. 1
  • B. 1.5
  • C. 2
  • D. 2.5

Explanation: Bond's law corresponds to an exponent n equal to 1.5 in the general crushing equation.

Correct answer: 1.5
  • A. Plate and frame filter
  • B. Rotary vacuum filter
  • C. Batch basket centrifuge
  • D. None of these

Explanation: Activated carbon is a fine insoluble solid and is removed from glycerine by cake filtration.

Correct answer: Plate and frame filter
  • A. Bag filter
  • B. Electrostatic precipitator
  • C. Cyclone separator
  • D. Wet scrubber

Explanation: Electrostatic precipitators efficiently collect very fine particles, including submicron dust, by electrically charging the particles and…

Correct answer: Electrostatic precipitator
  • A. Concentration of pyrites
  • B. Concentration of iron ore
  • C. Cleaning of coal
  • D. Water treatment

Explanation: The Chance process is a gravity-based coal-washing method that separates clean coal from denser shale and pyrites.

Correct answer: Cleaning of coal
  • A. Constant pressure
  • B. Varying pressure
  • C. Varying rate
  • D. Constant rate

Explanation: When slurry is filtered at a constant rate, the cake resistance increases and the inlet pressure must continuously rise.

Correct answer: Constant rate
  • A. Both A. & B.
  • B. Froude
  • C. Reynold's
  • D. Neither A. nor B.

Explanation: Mixing power depends on both the Reynolds number, which indicates viscous or turbulent flow, and the Froude number, which represents the…

Correct answer: Both A. & B.