chemical engineering MCQs – Page 129

Practise multiple-choice questions from chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs
2561. A centrifugal filtration unit operating at a rotational speed of w has inner surface of the liquid (density ?L) located at a radial distance R from the axis of rotation. The thickness of the liquid film is ? and no cake is formed. The initial pressure drop during filtration is ___________________?
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A. w2 . ?2 . ?L

B. w2 . ??L (2R + ?)

C. w2 . R2 . ?L

D. w2 . R . ?L(R + 2?)

2562. _____________ mills are termed as disintegrators?
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A. Compartment

B. Pebble

C. Cage

D. All tumbling

2563. For raschig rings, the sphericity is_____________________?
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A. 0.5

B. 1

C. < 1

D. ?3

2564. Capacity of flight conveyor in tons/hr is given by (where, W & D = width and depth of flight respectively in metre V = speed of the conveyor, metre/second ? = bulk density of material, kg/m3) ?
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A. 3.6 W.D.V.?

B. 3.6 D.V.?

C. 3.6 W.D.V

D. 3.6 W.V.?

2565. For a cyclone of diameter 0.2 m with a tangential velocity of 15 m/s at the wall, the separation factor is__________________?
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A. 2250

B. 1125

C. 230

D. 460

2566. For the preliminary breaking of hard rock, we use a____________________?
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A. Gyratory crusher

B. Squirrel-cage disintegrator

C. Ball mill

D. Tube mill

2567. A _____________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end?
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A. Pebble

B. Rod

C. Tube

D. Compartment
2568. Separation of solid particles based on their densities is called_________________?
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A. Sizing

B. Sorting

C. Dispersion

D. Clarification

2569. Gold ore concentration is mostly done using___________________?
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A. Froth floatation

B. Jigging

C. Tabling

D. Elutriation

2570. Separation of materials into products based on the difference of their sizes is called___________________?
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A. Flocculation

B. Sorting

C. Classification

D. Sizing
2571. Size reduction mechanism used in Jaw crushers is__________________?
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A. Impact

B. Attrition

C. Cutting

D. Compression
2572. Supporting legs of a plate and frame filter is normally made of________________?
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A. Wooden plank

B. Stainless steel

C. High speed steel

D. Cast iron
2573. Apron conveyors are used for ___________________ ?
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A. None of these

B. Heavy loads & long runs

C. Small loads & long runs

D. Heavy loads & short runs
2574. Volume change for unimolecular type first order reaction as shown in the bellow figure, increases _____________ with time?
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A. Parabolically

B. Exponentially

C. Linearly

D. Logarithmically

2575. For the transportation of ultrafine particles, the equipment used is a ____________ conveyor?
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A. None of these

B. Screw

C. Pneumatic

D. Belt

2576. Ball mills and tube mills with flint or porcelain balls are used for size reduction of_______________?
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A. Limestone

B. Rubber

C. Asbestos

D. Non-metallic ores
2577. Mechanical conveyors which push the material along an endless trough or tube are called scrappers. Which of the following conveying equipments comes under the category of scrappers? ?
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A. Bucket conveyor

B. Flight conveyor

C. Screw conveyor

D. Both B. and C.
2578. Work index is defined as the_________________?
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A. product passes through a 100 micron screen</strong>

B. Energy needed to crush one ton of feed to 100 microns

C. Gross energy (kWh/ton of feed) needed to reduce very large feed to such a size that 80% of

D. ses a 200 mesh screen

E. Energy (kWh/ton of feed) needed to crush small feed to such a size that 80% of the product

F. Energy needed to crush one tonne of feed to 200 microns

2579. Colloid mills achieve size reduction mainly by___________________?
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A. Attrition

B. Impact

C. Cutting

D. Compression

2580. 200 mesh screen means 200 openings per_____________________?
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A. cm

B. inch

C. cm2

D. inch2