Explore topic-wise MCQs in Chemical Engineering.

This section includes 552 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.

401.

During filtration operation, the filtrate encounters the resistance of the

A. filter medium.
B. cake.
C. channel carrying the slurry to the upstream side of the cake and filtrate away from the filter medium.
D. all (a), (b) and (c)
Answer» E.
402.

As particle size is reduced

A. screening becomes progressively more difficult.
B. screening becomes progressively easier.
C. capacity and effectiveness of the screen is increased.
D. none of these.
Answer» B. screening becomes progressively easier.
403.

A cottrel precipitator makes use of the __________ for dusty air cleaning.

A. electric spark
B. corrona discharge
C. alternating current
D. none of these.
Answer» C. alternating current
404.

Which of the following is the most suitable for handling fibrous and dense slurries ?

A. Propeller agitator
B. Cone type agitator
C. Turbine agitator
D. Radial propeller agitator
Answer» C. Turbine agitator
405.

Which of the following clay mixing devices is vacuum operated for deairation of clay?

A. Banbery mixer
B. Pug mill
C. Muller-mixer
D. None of these
Answer» C. Muller-mixer
406.

__________ conveyors are also called scrapers.

A. Apron
B. Screw
C. Helical flight
D. both (b) & (c)
Answer» E.
407.

Carbon black is pulverised in a

A. hammer crusher
B. ball mill
C. roll crusher
D. gyratory crusher
Answer» C. roll crusher
408.

Length/diameter ratio of a ball mill is

A. 1.5
B. 1
C. < 1
D. > 1
Answer» D. > 1
409.

Pine oil and cresylic acid are used as __________ in the froth floatation process.

A. frother
B. collector
C. depressor
D. conditioner
Answer» B. collector
410.

Size reduction of the __________ can be suitably done by ball mills, crushing rolls and rod mills.

A. metalliferrous ores
B. non-metallic ores
C. basic slags
D. asbestos & mica
Answer» B. non-metallic ores
411.

Separation of solid suspended in liquid into a supernatant clear liquid and a denser slurry employs a process termed as the

A. coagulation
B. flocculation
C. sedimentation
D. clarification
Answer» D. clarification
412.

In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the __________ crushing.

A. secondary
B. fine
C. primary
D. ultrafine
Answer» D. ultrafine
413.

The capacity of a belt conveyor depends upon two factors. If one is the cross-section of the load, the other is the __________ of the belt.

A. speed
B. thickness
C. length
D. none of these
Answer» B. thickness
414.

__________ balls capable of grinding the feed in a ball mill gives the maximum efficiency.

A. Cast iron
B. Minimum size
C. Maximum size
D. Elliptical
Answer» C. Maximum size
415.

Size reduction of ice and gypsum can be accomplished suitably by a __________ crusher.

A. Blake jaw
B. toothed roll
C. gyratory
D. none of these.
Answer» C. gyratory
416.

Cement clinker is reduced to fine size by a

A. roll crusher
B. ball mill
C. tube mill
D. hammer mill
Answer» D. hammer mill
417.

In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is

A. 4
B. 43556
C. 1
D. 43497
Answer» C. 1
418.

Ball mills and tube mills with flint or porcelain balls are used for size reduction of

A. asbestos
B. rubber
C. non-metallic ores
D. limestone
Answer» D. limestone
419.

Bucket elevators are not suitable for the vertical lifting of __________ materials.

A. fine (e.g. - 200 mesh size coal)
B. sticky (e.g. clay paste)
C. small lumpy (e.g. grains and sand)
D. free flowing
Answer» C. small lumpy (e.g. grains and sand)
420.

For classification of potable (drinking) water, we use a __________ filter.

A. gravity sand
B. plate and frame
C. vacuum leaf
D. rotary vacuum
Answer» B. plate and frame
421.

For a non-spherical particle, the sphericity

A. is defined as the ratio of surface area of a sphere having the same volume as the particle to the actual surface area of the particle.
B. has the dimension of length.
C. is always less than 1.
D. is the ratio of volume of a sphere having the same surface area as the particle to the actual volume of the particle.
Answer» B. has the dimension of length.
422.

Which of the following achieves the least reduction ratio for a given feed size?

A. Jaw crusher
B. Roll crusher
C. Cone crusher
D. Gyratory crusher
Answer» C. Cone crusher
423.

Tabular bowl centrifuges as compared to disk bowl centrifuges

A. operate at higher speed.
B. employ bowl of larger diameter.
C. can not be operated under pressure/vacuum.
D. can't be used for separation of fine suspended solids from a liquid.
Answer» B. employ bowl of larger diameter.
424.

Dust collection efficiency of electrostatic precipitator can be as high as 99.9%. Maximum temperature and pressure of dust laden gas that can be cleaned in an electrostatic precipitator is respectively.

A. 200°C and 5 atm.
B. 1000°C and 10 atm.
C. 500°C and 50 atm.
D. 1000°C and 500 atm.
Answer» C. 500¬∞C and 50 atm.
425.

Production rate __________ with increased fineness, with a given energy input to the size reduction machine.

A. decreases
B. increases
C. remains unchanged
D. may increase or decrease; depends on the machine
Answer» B. increases
426.

The equivalent diameter of channel of a constant non-circular cross-section of 3 cm by 6 cm will be __________ cms.

A. 20
B. 12
C. 8
D. 2
Answer» E.
427.

The most common filter aid is

A. diatomaceous earth
B. calcium silicate
C. sodium carbonate
D. silica gel
Answer» B. calcium silicate
428.

Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles)$

A. m/ρ . Vp
B. m . ρ/Vp
C. m . Vp/ρ
D. Vp/m . ρ
Answer» B. m . œÅ/Vp
429.

In a roll crusher, both the rolls

A. have the same diameter.
B. are rotated towards each other.
C. run either at the same or different speeds.
D. all (a), (b) and (c).
Answer» E.
430.

A __________ mixer resembles a ball mill without balls.

A. banbery
B. pug mill
C. tumbling
D. pan
Answer» D. pan
431.

__________ centrifuge is normally used in sugar mills.

A. Tubular bowl
B. Disc-bowl
C. Suspended batch basket
D. Perforated horizontal basket continuous
Answer» D. Perforated horizontal basket continuous
432.

Solid particles separation based on the difference in their flow velocities through fluids is termed as the

A. clarification
B. classification
C. elutriation
D. sedimentation
Answer» C. elutriation
433.

A tube mill compared to a ball mill

A. has a higher length/diameter ratio.
B. produces a coarser product.
C. has a higher diameter/length ratio.
D. uses much larger balls.
Answer» B. produces a coarser product.
434.

Stamp mills are generally used for crushing

A. iron ores
B. gold ores
C. talc
D. diamond
Answer» C. talc
435.

Wheat is ground into flour in a

A. hammer crusher
B. roller crusher
C. impact mill
D. fluid energy mill
Answer» C. impact mill
436.

Crushing of mineral particles is accomplished in a 'cage mill', when one or more alloy steel bars are revolved in opposite directions. It is a type of __________ mill.

A. impact
B. roll
C. vibratory
D. none of these
Answer» B. roll
437.

If a force greater than that of gravity is used to separate solids & fluids of different densities, the process is termed as the

A. sedimentation
B. flocculation
C. dispersion
D. centrifugation
Answer» E.
438.

Cyclones are used primarily for separating

A. solids
B. solids from fluids
C. liquids
D. solids from solids
Answer» C. liquids
439.

In closed circuit grinding as compared to open circuit grinding, the

A. specific surface of product is more.
B. product has lesser size uniformity.
C. production rate at a given limiting size is lower.
D. operation is economical.
Answer» E.
440.

In case of a plate and frame filter press, filtrate flow through the cake follows __________ flow.

A. plug
B. turbulent
C. laminar
D. none of these
Answer» D. none of these
441.

__________ mixer is used for devulcanisation of rubber scrap & making water dispersion & rubber solution.

A. Tumbler
B. Banbery
C. Muller
D. Rubbon blender
Answer» C. Muller
442.

Wet grinding in a revolving mill __________ as compared to dry grinding.

A. gives less wear on chamber walls
B. requires more energy
C. increases capacity
D. complicates handling of the product
Answer» D. complicates handling of the product
443.

Filtration rate through a filter cake is proportional to (where, S = filtering surface R = specific cake resistance μ = viscosity of the filtrate)$

A. S
B. 1/R
C. 1/μ
D. all (a), (b) & (c)
Answer» E.
444.

Separation of solid particles based on their densities is called

A. sizing
B. sorting
C. clarification
D. dispersion
Answer» C. clarification
445.

The sphericity of a cylinder of 1 mm diameter and length 3 mm is

A. 0.9
B. 0.78
C. 0.6
D. 0.5
Answer» B. 0.78
446.

A __________ employs a set of screen across a flow channel for the separation of dirt/rust from a flowing liquid stream.

A. thickener
B. classifier
C. strainer
D. clarifier
Answer» D. clarifier
447.

Balls for ball mills are never made of

A. forged/cast steel
B. lead
C. cast iron
D. alloy steel
Answer» C. cast iron
448.

The controlling resistance in a rotary drum vacuum filter is the __________ resistance.

A. piping
B. cake
C. filter medium
D. none of these
Answer» C. filter medium
449.

Pick out the wrong statement pertaining to the roll crushers.

A. Maximum feed size determines the required roll diameter.
B. For hard material's crushing, the reduction ratio should not exceed 4.
C. Both the rolls run necessarily at the same speed.
D. Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced.
Answer» D. Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced.
450.

Soft & non-abrasive materials can be made into fines by

A. attrition
B. compression
C. cutting
D. none of these
Answer» B. compression