chemical engineering MCQs – Page 130

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 Review each marked answer and report any item that may be outdated or unclear.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
2581. The first order series reaction as shown in the bellow figure is conducted in a batch reactor. The initial concentrations of A, B and C (CA0, CB0, CC0 respectively) are all non-zero. The variation of CB with reaction time will not show a maximum, if___________________?
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A. CA0 > CB0

B. k CA0 > k2.CB0

C. CB0 > CA0

D. k2 CB0 > k1 CA0
2582. To remove very small amount of tiny solid impurities from liquid, we use a_____________________?
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A. Pressure filter

B. Vacuum filter

C. Coagulant

D. Centrifugal filter

2583. Balls for ball mills are never made of_________________?
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A. Lead

B. Cast iron

C. Alloy steel

D. Forged/cast steel

2584. Which of the following is not an ultrafine grinder (colloid mill) ?
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A. Agitated mills and fluid energy mills

B. Toothed roll crusher

C. Hammer mills with internal classification

D. Micronizers

2585. Highly viscous liquids & pastes are agitated by________________?
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A. None of these

B. Turbine agitators

C. Propellers

D. Multiple blade paddles
2586. _______________ mill is normally used for grinding of talc?
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A. Compartment

B. Tube

C. Pebble

D. Ring-roll
2587. According to Bond crushing law, the work required to form particle of size D from very large feed is (where (S/V)p and (S/V)f are surface to volume ratio of the product and feed respectively) ?
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A. (S/V)f

B. (S/V)2p

C. ?(S/V)p

D. (S/V)p

2588. For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a__________________?
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A. Buhrstone mill

B. Ball mill

C. Hammer mill

D. Crushing rolls

2589. The reduction ratio for fine grinders is_____________?
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A. 10-May

B. 20-40

C. 20-Oct

D. As high as 100
2590. According to Taggarts rule for selecting between a gyratory crusher and a jaw crusher; the later should be used, if the hourly tonnage to be crushed divided by the square of the gape expressed in cm is less than_______________?
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A. 0.184

B. 0.00184

C. 0.0184

D. 1.84

2591. Ultrafine grinders operate principally by_________________?
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A. Impact

B. Cutting action

C. Slow compression

D. Attrition
2592. Weber number is significant and is concerned with the_________________?
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A. Dispersion of liquid in liquid

B. Suspension of solid in liquid

C. Solid-liquid mixing

D. Liquid-liquid mixing

2593. Two particles are called to be equal settling, if they are having the same ?
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A. Terminal velocities in the same fluid & in the same field of force

B. None of these

C. Size

D. Specific gravity

2594. Gravity settling process is not involved in the working of a________________?
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A. Dorr-thickener

B. Sedimentation tank

C. Classifier

D. Hydrocyclone
2595. The term angle of nip is concerned with the operation of the ____________ crushers?
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A. Jaw

B. Gyratory

C. None of these

D. Roll
2596. Addition of filter aid to the slurry before filtration is done to _______________ of the cake?
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A. Decrease the compressibility co-efficient

B. Increase the compressibility co-efficient

C. Decrease the porosity

D. Increase the porosity
2597. Xanthates are used in the froth floatation process as a/an _______________________?
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A. Conditioner

B. Activator

C. Frother

D. Collector
2598. The operating speed of a ball mill should be ______________ the critical speed?
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A. Much more than

B. At least equal to

C. Less than

D. Slightly more than

2599. Froth floatation is the most suitable for treating ____________________?
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A. Quartzite

B. Iron ores

C. Sulphide ores

D. None of these

2600. If radius of a batch basket centrifuge is halved & the r.p.m. is doubled, then the_________________?
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A. Centrifugal force is doubled

B. Linear speed of the basket is halved

C. Capacity of centrifuge is increased

D. Linear speed of the basket is doubled