Free Chemical Process Principles MCQs with Answers
2,710 Chemical Process Principles 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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- A. Flight
- B. Screw
- C. Drag
- D. Belt
Explanation: Flight conveyors move loose bulk solids over short distances using flights attached to a chain, and they can handle materials such as…
Correct answer: Flight- A. Particle sizes
- B. Terminal velocities
- C. Densities
- D. None of these
Explanation: Differential settling separates particles according to their terminal settling velocities, which depend mainly on particle size, density…
Correct answer: Terminal velocities- A. Roll-crusher
- B. Ball mill
- C. Squirrel-cage disintegrator
- D. Tube mill
Explanation: A squirrel-cage disintegrator is effective for fibrous materials because its rotating impact elements tear and disintegrate the fibres.
Correct answer: Squirrel-cage disintegrator- A. Energy (kWh/ton of feed) needed to crush small feed to such a size that 80% of the product
- B. the product passes through a 100 micron screen
- C. Energy needed to crush one tonne of feed to 200 microns
- D. Gross energy (kWh/ton of feed) needed to reduce very large feed to such a size that 80% of
- E. passes a 200 mesh screen
- F. Energy needed to crush one ton of feed to 100 microns
Explanation: Bond's work index is the gross energy in kWh per tonne required to reduce a very large feed until 80% of the product passes a…
Correct answer: Gross energy (kWh/ton of feed) needed to reduce very large feed to such a size that 80% of- A. Elasticity
- B. Size
- C. Toughness
- D. Hardness
Explanation: Grindability is an intrinsic response of a material and is related to properties such as hardness, toughness, and elasticity.
Correct answer: Size- A. Sizing
- B. Clarification
- C. Sorting
- D. Dispersion
Explanation: Sorting separates solid particles according to a property such as density, whereas sizing separates them according to particle size.
Correct answer: Sorting- A. Hammer crusher
- B. Gyratory crusher
- C. Roll crusher
- D. Ball mill
Explanation: A ball mill provides repeated impact and attrition, making it suitable for pulverising coal to a fine size such as 200 mesh.
Correct answer: Ball mill- A. Dry powders
- B. Lumpy solids and low viscosity liquids
- C. High viscosity liquids
- D. Thick pastes
Explanation: Ribbon blenders are designed mainly for mixing dry powders and other free-flowing solids using helical ribbons.
Correct answer: Dry powders- A. Ratio of discharge opening to feed opening
- B. Ratio of feed opening to discharge opening
- C. Determining factor for minimum dia of the feed and the product
- D. None of these
Explanation: The reduction ratio compares the characteristic feed size with the product or discharge size, so it is represented here by the feed…
Correct answer: Ratio of feed opening to discharge opening- A. Compartment mill
- B. Pebble mill
- C. Cage mill
- D. Rod mill
Explanation: Compartment, pebble, and rod mills are tumbling mills in which the grinding charge revolves with the shell.
Correct answer: Cage mill- A. (S/V)p
- B. (S/V)f
- C. (S/V)2p
- D. √(S/V)p
Explanation: Bond's law makes work proportional to the difference in the reciprocals of the square roots of feed and product sizes.
Correct answer: √(S/V)p- A. Electromagnets
- B. Either A., B. or C.
- C. Unbalanced flywheels
- D. Cams or eccentric shafts
Explanation: Vibratory motion in screens may be produced mechanically by cams or eccentric shafts, dynamically by unbalanced flywheels, or electrically…
Correct answer: Either A., B. or C.- A. m/ρ . Vp
- B. m . ρ/Vp
- C. m . Vp/ρ
- D. Vp/m . ρ
Explanation: The mass of one particle is ρVp, so the number of particles is total mass divided by this particle mass: m/(ρVp).
Correct answer: m/ρ . Vp- A. Slow compression
- B. Impact
- C. Cutting action
- D. Attrition
Explanation: Ultrafine grinding requires very small size reduction and is chiefly achieved by attrition, where particles rub against one another or the…
Correct answer: Attrition- A. Volume-surface
- B. Arithmetic
- C. Mass
- D. Geometric
Explanation: The Sauter mean diameter is defined by equal volume-to-surface-area behavior, so it is also called the volume-surface mean diameter.
Correct answer: Volume-surface- A. Employ a steel shell having L/D ratio of 1.5 to 3.0
- B. All A , B & C
- C. Employ steel rods of 2-12 cms diameter extending over full length of the mill
- D. Is useful for handling sticky materials
Explanation: Rod mills commonly have an L/D ratio of about 1.5 to 3, use long steel rods roughly 2 to 12 cm in diameter, and can handle somewhat sticky…
Correct answer: All A , B & C- A. 5 to 10
- B. 0.1 to 2
- C. 20 to 25
- D. 50 to 70
Explanation: Only a small fraction of the energy supplied to a crusher creates new surface; most is lost through friction, deformation, noise, and…
Correct answer: 0.1 to 2- A. None of these
- B. No
- C. Only two
- D. Horizontal
Explanation: Horizontal baffles or lifter projections are fitted inside ball mills to lift and cascade the balls instead of allowing them to slide…
Correct answer: Horizontal1759. To remove very small amount of tiny solid impurities from liquid, we use a_____________________?
- A. Coagulant
- B. Vacuum filter
- C. Centrifugal filter
- D. Pressure filter
Explanation: When only a small amount of extremely fine solid is dispersed in a liquid, a coagulant is added to aggregate the particles into larger…
Correct answer: Coagulant- A. Crushing takes place by impact breaking
- B. All A., B. and C.
- C. Reduction ratio can be varied by adjusting the distance from cage to hammers
- D. Maximum acceptable feed size is 30 cms
Explanation: A hammer crusher breaks particles primarily by impact. Its feed limit and reduction ratio are controlled by the crusher design, including…
Correct answer: All A., B. and C.