chemical engineering Mcqs
2651. Tank filter (e.g., Nutsche filter) is___________________?
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A. A high pressure filter

B. A continuous filter

C. A leaf filter

D. Used for small scale filtration work
2652. Half the angle of nip, (?), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively) ?
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A. cos ? = (dr + df)/(dr + dp)

B. tan ? = (dr + dp)/(dr + df)

C. cos ? = (dr + dp)/(dr + df)

D. sin ? = (dr + dp)/(dr + df)

2653. A _____________ mixer resembles a ball mill without balls?
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A. Tumbling

B. Pug mill

C. Banbury

D. Pan

2654. Fluid medium used in the classification technique of mineral beneficiation is_________________?
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A. Water

B. Either A. or B.

C. Air

D. Neither A. nor B.

2655. Trommels separate a mixture of particles depending on their_____________________?
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A. Size

B. Density

C. Wettability

D. Electrical & magnetic properties

2656. Horsepower required for a roll crusher is directly proportional to its__________________?
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A. Reduction ratio

B. Capacity

C. Both A. & B.

D. Neither A. nor B.

2657. Mass flow of granular solid (M) through a circular opening of dia, D follows_____________________?
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A. M ? ?D

B. M ? D

C. M ? D3

D. M ? D2

2658. For a non-spherical particle, the sphericity__________________?
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A. Is defined as the ratio of surface area of a sphere having the same volume as the particle to the

B. Is the ratio of volume of a sphere having the same surface area as the particle to the actual

C. ual surface area of the particle</strong>

D. ume of the particle

E. Has the dimension of length

F. Is always less than 1

2659. What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls?
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A. 16

B. 46

C. 32

D. 40

2660. Pine oil and Cresylic acid are used as ______________ in the froth floatation process?
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A. Frother

B. Depressor

C. Conditioner

D. Collector

2661. For spheres, the specific surface shape factor is given by___________________?
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A. A/V

B. AD/V

C. ?(AD/V)

D. D/V

2662. Trommels employ _____________ for screening of materials?
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A. None of these

B. Fibrous cloth

C. Punched plate

D. Woven wire screen

2663. Ore concentration by jigging is based on the difference in the ______________ of the particles?
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A. None of these

B. Shape

C. Wettability

D. Specific gravities
2664. Which of the following parts of a jaw crusher is subjected to maximum wear and tear during its operation ?
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A. Toggles

B. Check plates

C. Crush shaft

D. Jaw plates
2665. _______________ mill is not used for grinding wheat into flour and for milling of cereals & other ?
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A. Pebble

B. etable products.

C. Roller

D. Buhrstone

E. Attrition

2666. _____________ Centrifuge is normally used in sugar mills?
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A. Tubular bowl

B. Disc-bowl

C. Perforated horizontal basket continuous

D. Suspended batch basket
2667. Participation of _______________ is involved in the occurrence of a chemical reaction?
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A. Neutrons

B. Electrons

C. None of these

D. Protons

2668. Pick out the wrong statement ?
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A. Gape is the greatest distance between the crushing surfaces or the jaws

B. Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy

C. The angle of nip (2?) is the angle between roll faces at the level where they will just take hold

D. a particle and draw it in the crushing zone

E. Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the

F. duct

2669. A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 ?m/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is_________________?
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A. 0.02 ?m/s

B. 0.90 ?m/s

C. 1 ?m/s

D. 22.1 ?m/s

2670. The sphericity of a cylinder of 1 mm diameter and length 3 mm is_________________?
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A. 0.5

B. 0.9

C. 0.78

D. 0.6

2671. Handling of ashes and similar materials can be done best by a ______________ conveyor?
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A. Ribbon

B. Belt

C. Flight

D. Drag or slat
2672. Mixer used for rubber compounding is__________________?
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A. mixer-extruder

B. Pug mill

C. Banbury internal mixer

D. Muller mixer

2673. Screen capacity is proportional to (where, S = screen aperture)____________________?
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A. S

B. 1/S

C. ?S

D. S2

2674. Rod mills employed for grinding_________________?
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A. Employ steel rods of 2-12 cms diameter extending over full length of the mill

B. Is useful for handling sticky materials

C. All A , B & C

D. Employ a steel shell having L/D ratio of 1.5 to 3.0

2675. In the cyclone separator used for separation of dust from dust laden gas, the gas ?
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A. Enters the cyclone from the top

B. Is admitted tangentially at high velocity

C. Develops a helical motion inside the chamber

D. Both B. and C.
2676. The equivalent diameter of channel of a constant non-circular cross-section of 3 cm by 6 cm will be _______________ cms?
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A. 8

B. 2

C. 12

D. 20

2677. In a mixer, the quantity, (v. L/D) is termed as __________ number (where, v = longitudinal velocity of material, L = length of the mixer, D = diffusivity in axial mixing) ?
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A. Peclet

B. Weber

C. Brinkman

D. Schmidt

2678. Additives used for promoting the flocculation of particles is a/an _____________________?
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A. Electrolyte

B. Surface active agent

C. Both A. & B.

D. Neither A. nor B.

2679. 200 mesh sieve size corresponds to _____________ microns?
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A. 74

B. 200

C. 24

D. 154

2680. For classification of potable (drinking) water, we use a _______________ filter?
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A. Rotary vacuum

B. Vacuum leaf

C. Plate and frame

D. Gravity sand
2681. Which of the following is not a revolving/tumbling mill used for size reduction ?
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A. Compartment mill

B. Rod mill

C. Cage mill

D. Pebble mill

2682. The half life period t of a zero order reaction as shown in the bellow figure, is equal to_________________?
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A. CA0/K

B. 1/K

C. CA0/2K

D. 0.693/K

2683. A first order reaction is to be treated in a series of two mixed reactors. The total volume of the two reactors is minimum, when the reactors are_____________________?
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A. Of different sizes

B. Equal in size

C. Of such size that the ratio of their volumes is < 5

D. None of these

2684. In case of a plate and frame filter press, filtrate flow through the cake follows _______________ flow?
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A. Laminar

B. None of these

C. Turbulent

D. Plug

2685. If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the ________________ diffusion?
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A. Pore

B. None of these

C. Film

D. Ash layer

2686. In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is__________________?
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A. 4

B. 2-Jan

C. 1

D. 1/4
2687. What is the selectivity index, if the grade of tailings & concentrate is the same ?
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A. 0

B. 1

C. ?

D. 0.5

2688. The resistance offered by the filter used in a bag filter is proportional to (where, c = dust concentration, and s = particle size)?
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A. s/c

B. c/s

C. s . c

D. 1/s . c

2689. Metallic wire mesh is used as a filtering medium for the separation of dust from dust laden gas in case of a/an________________?
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A. Venturi scrubber

B. Bag filter

C. Air filter

D. Hydrocyclones

2690. Which of the following comes in the category of primary crusher for hard and tough stone ?
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A. None of these

B. Gyratory crusher

C. Cone crusher

D. Jaw crusher
2691. Semibatch reactor is preferred, when a/an__________________?
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A. A gas is to be reacted with liquid (e.g. hydrogenation of fat)

B. A highly exothermic reaction is to be controlled

C. Undesirable side reaction (at high concentration of one of the reactants) is to be avoided

D. All A., B., and C.
2692. To produce talcum powder, use_____________________?
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A. Pin mill

B. Hammer mill

C. Jet mill

D. Ball mill
2693. Cake resistance is___________________?
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A. None of these

B. Important in the beginning of filtration

C. Decreased with the time of filtration

D. Independent of pressure drop

2694. Which of the following represents the plot of filtrate volume versus time for constant pressure filtration ?
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A. Exponential curve

B. Straight line

C. Hyperbola

D. Parabola
2695. Which of the following is not an industrial screening equipment ?
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A. Vibrating screen

B. Grizzly

C. Sharpies centrifuge

D. Trommel

2696. Mixing of plastic solids is generally facilitated by___________________?
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A. Kneading

B. Dispersion

C. None of these

D. Mastication

2697. The energy required per unit mass to grind limestone particles of very large size to 100 ?m is 12.7 kWh/ton. An estimate (using Bonds law) of the energy to grind the particles from a very large size to 50 ?m is________________?
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A. 18 kWh/ton

B. 9.0 kWh/ton

C. 25.4 kWh/ton

D. 6.35 kWh/ton

2698. Shape factor for a cylinder whose length equals its diameter is_________________?
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A. 0.5

B. 1.5

C. 1

D. 2

2699. Which of the following is the most suitable for handling fibrous and dense slurries ?
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A. Turbine agitator

B. Cone type agitator

C. Radial propeller agitator

D. Propeller agitator

2700. Ficks law relates to_________________?
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A. Final particle size

B. None of these

C. Feed size

D. Energy consumption