MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
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.
| 101. |
The specific surface of spherical particles is given by (where D and ρ are diameter and density of particle). |
| A. | 6/D.p |
| B. | 2/D.p |
| C. | 4/D.p |
| D. | 12/D.p |
| Answer» B. 2/D.p | |
| 102. |
Which of the following screens has the maximum capacity? |
| A. | Grizzlies |
| B. | Trommels |
| C. | Shaking screen |
| D. | Vibrating screen |
| Answer» E. | |
| 103. |
The reduction ratio for grinders is defined as(where, Df and Dp are average diameters of feed and product respectively). |
| A. | Df/Dp |
| B. | Dp/Df |
| C. | Df - Dp |
| D. | None of these |
| Answer» B. Dp/Df | |
| 104. |
Which of the following is not an industrial screening equipment? |
| A. | Sharpies centrifuge |
| B. | Vibrating screen |
| C. | Grizzly |
| D. | Trommel |
| Answer» B. Vibrating screen | |
| 105. |
Which of the following relationships between co-efficinet of friction (μ) between rock & roll and a (half of the angle of nip) of the particle to be crushed is correct ? |
| A. | Μ > tan α |
| B. | Μ ≥ tan α |
| C. | Μ > tan 2α |
| D. | Μ ≤ tan α |
| Answer» C. Μ > tan 2α | |
| 106. |
Filtrate flow rate in case of a rotary drum vacuum filter (in which Rm < < Rc) is proportional to __________ and the cycle time (where, μ = filtrate viscosity Rm = filter medium resistance Rc = cake resistance ). |
| A. | √μ |
| B. | 1/√μ |
| C. | 1/μ |
| D. | 1/μ² |
| Answer» C. 1/μ | |
| 107. |
The resistance offered by the filter used in a bag filter is proportional to (where, c = dust concentration, and s = particle size ) |
| A. | C/s |
| B. | S/c |
| C. | S . c |
| D. | 1/s . c |
| Answer» B. S/c | |
| 108. |
Which of the following is a batch sedimentation equipment? |
| A. | Dust catcher |
| B. | Filter thickener |
| C. | Dry cyclone separator |
| D. | Rotary sprayer scrubber |
| Answer» C. Dry cyclone separator | |
| 109. |
Size reduction of moulding powders, waxes, resins & gums are done in a __________ mill. |
| A. | Cage |
| B. | Hammer |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 110. |
A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is |
| A. | 0.90 μm/s |
| B. | 1 μm/s |
| C. | 22.1 μm/s |
| D. | 0.02 μm/s |
| Answer» C. 22.1 μm/s | |
| 111. |
In case of a hammer crusher, the |
| A. | Feed may be highly abrasive (Moh's scale >5) |
| B. | Minimum product size is 3 mm |
| C. | Maximum feed size may be 50 mm |
| D. | Rotor shaft carrying hammers can be vertical or horizontal |
| Answer» E. | |
| 112. |
The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μrn is |
| A. | 6.35 kWh/ton |
| B. | 9.0 kWh/ton |
| C. | 18 kWh/ton |
| D. | 25.4 kWh/ton |
| Answer» D. 25.4 kWh/ton | |
| 113. |
The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area, m² V = rising velocity of fluid, m/sec.S = percentage of solids in the suspension by volume.ρ = density of solids, kg/m³) |
| A. | 3.6 AVS.ρ |
| B. | 3.6 A.V.ρ |
| C. | 3.6 A.S. ρ |
| D. | 3.6 AVS/ρ |
| Answer» B. 3.6 A.V.ρ | |
| 114. |
Vibrating screens have capacity in the range of __________ tons/ft² .mm mesh size. |
| A. | 0.2 to 0.8 |
| B. | 5 to 25 |
| C. | 50 to 100 |
| D. | 100 to 250 |
| Answer» B. 5 to 25 | |
| 115. |
The specific surface of sherical particles is proportional to (where, Dp = diameter of particle). |
| A. | D²p |
| B. | Dp |
| C. | 1/Dp |
| D. | 1/D²p |
| Answer» D. 1/D²p | |
| 116. |
The specific cake resistance for incompressible sludges is (where ΔP = pressure drop over cake) |
| A. | ∝ ΔP |
| B. | ∝ 1/ ΔP |
| C. | ∝ √ΔP |
| D. | Independent of ΔP |
| Answer» E. | |
| 117. |
For a turbine agitated and baffled tank, operating at low Reynold's number (based on impeller diameter), the power number (Np) varies with NRe as |
| A. | Np ∝ NRe |
| B. | Np ∝ √NRe |
| C. | Np → constant |
| D. | Np ∝ 1/NRe |
| Answer» E. | |
| 118. |
Which of the following is not categorised as a "mechanical operation"? |
| A. | Agitation |
| B. | Filtration |
| C. | Size enlargement |
| D. | Humidification |
| Answer» E. | |
| 119. |
During the washing of cake |
| A. | all the resistances are constant. |
| B. | filter medium resistance increases. |
| C. | filter medium resistance decreases. |
| D. | cake resistance decreases. |
| Answer» B. filter medium resistance increases. | |
| 120. |
Mesh indicates the number of holes per |
| A. | square inch |
| B. | linear inch |
| C. | square foot |
| D. | linear foot |
| Answer» C. square foot | |
| 121. |
Which of the following is a coarse crusher? |
| A. | Smooth roll crusher |
| B. | Toothed roll crusher |
| C. | Gyratory crusher |
| D. | Tube mill |
| Answer» D. Tube mill | |
| 122. |
The most suitable equipment for the transportation of 200 mesh size particles is a |
| A. | bucket elevator |
| B. | pneumatic conveyor |
| C. | screw conveyor |
| D. | belt conveyor |
| Answer» C. screw conveyor | |
| 123. |
Paddle agitator |
| A. | is suitable for mixing low viscosity liquids. |
| B. | produces axial flow. |
| C. | moves at very high speed. |
| D. | none of these. |
| Answer» B. produces axial flow. | |
| 124. |
__________ are used for the separation of coarse particles from a slurry of fine particles. |
| A. | Thickeners |
| B. | Classifiers |
| C. | Hydrocyclones |
| D. | Decanters |
| Answer» C. Hydrocyclones | |
| 125. |
To remove very small amount of tiny solid impurities from liquid, we use a |
| A. | pressure filter |
| B. | vacuum filter |
| C. | centrifugal filter |
| D. | coagulant |
| Answer» E. | |
| 126. |
Activators are those chemicals which help buoying up one mineral in preference to the other in the froth floatation process. Which of the following is an activator? |
| A. | Cresylic acid |
| B. | Copper sulphate |
| C. | Calcium carbonate |
| D. | Sodium carbonate |
| Answer» C. Calcium carbonate | |
| 127. |
Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines ? |
| A. | Compartment mill |
| B. | Rod mill |
| C. | Pebble mill |
| D. | Tube mill. |
| Answer» C. Pebble mill | |
| 128. |
A centrifugal filtration unit operating at a rotational speed of w has inner surface of the liquid (density ρL) located at a radial distance R from the axis of rotation. The thickness of the liquid film is δ and no cake is formed. The initial pressure drop during filtration is$ |
| A. | w2 . R2 . ρL |
| B. | w2 . δ2 . ρL |
| C. | w2 . δρL (2R + δ) |
| D. | w2 . R . ρL(R + 2δ) |
| Answer» D. w2 . R . œÅL(R + 2Œ¥) | |
| 129. |
Separation of particles of various sizes, shapes and densities by allowing them to settle in a fluid is called |
| A. | classification |
| B. | froth floatation |
| C. | thickening |
| D. | clarification |
| Answer» B. froth floatation | |
| 130. |
Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with __________ to get the same for dry grinding. |
| A. | 1 |
| B. | 0.5 |
| C. | 1.34 |
| D. | 4.34 |
| Answer» D. 4.34 | |
| 131. |
Which of the following is not accomplished by agitation of liquids in agitators? |
| A. | Dispersing gas in liquid. |
| B. | Blending of immiscible liquids. |
| C. | Dispersing immiscible liquid in form of emulsion. |
| D. | Suspending solid particles. |
| Answer» C. Dispersing immiscible liquid in form of emulsion. | |
| 132. |
Fibrous material is broken by a |
| A. | rollcrusher |
| B. | squirrel-cage disintegrator |
| C. | ball mill |
| D. | tube mill |
| Answer» C. ball mill | |
| 133. |
Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripherial velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πN.D where, N = speed of the rolls in rotation per second (rps) D = diameter of rolls, m)$ |
| A. | 3.6 V.W.Dr.ρ |
| B. | 3.6 V.W. ρ |
| C. | 3.6 W.Dr.ρ |
| D. | 3.6 V.W.Dr/ρ |
| Answer» B. 3.6 V.W. œÅ | |
| 134. |
A tube mill as compared to a ball mill |
| A. | employs smaller balls. |
| B. | gives finer size reduction but consumes more power. |
| C. | has larger length/diameter ratio (>2 as compared to 1 for ball mill). |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 135. |
Gravity stamp mill is meant for the __________ crushing. |
| A. | primary |
| B. | intermediate |
| C. | fine |
| D. | ultrafine |
| Answer» D. ultrafine | |
| 136. |
Crushing efficiency is the ratio of the |
| A. | surface energy created by crushing to the energy absorbed by the solid. |
| B. | energy absorbed by the solid to that fed to the machine. |
| C. | energy fed to the machine to the surface energy created by crushing. |
| D. | energy absorbed by the solid to the surface energy created by crushing. |
| Answer» B. energy absorbed by the solid to that fed to the machine. | |
| 137. |
In case of a ball mill, |
| A. | coarse feed requires a larger ball. |
| B. | fine feed requires a larger ball. |
| C. | operating speed should be more than the critical speed. |
| D. | none of these |
| Answer» B. fine feed requires a larger ball. | |
| 138. |
Size reduction of fibrous materials like wood, asbestos, mica etc. is done by a disintegrator exemplified by the |
| A. | Blake jaw crusher |
| B. | cage mill |
| C. | stamp mill |
| D. | Bradford's breaker |
| Answer» C. stamp mill | |
| 139. |
What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls ? |
| A. | 16° |
| B. | 32° |
| C. | 40° |
| D. | 46° |
| Answer» C. 40¬∞ | |
| 140. |
Which of the following is a continuous filter? |
| A. | Plate and frame filter |
| B. | Cartridge filter |
| C. | Shell and leaf filter |
| D. | None of these |
| Answer» E. | |
| 141. |
Reduction ratio of crushers is the |
| A. | ratio of feed opening to discharge opening. |
| B. | ratio of discharge opening to feed opening. |
| C. | determining factor for minimum dia of the feed and the product. |
| D. | none of these. |
| Answer» B. ratio of discharge opening to feed opening. | |
| 142. |
What is the selectivity index, if the grade of tailings & concentrate is the same ? |
| A. | 0 |
| B. | ‚àû |
| C. | 1 |
| D. | 0.5 |
| Answer» D. 0.5 | |
| 143. |
Which of the following is the most suitable filter for separation of abrasive solids suspended in a corrosive liquid ? |
| A. | Sand bed filter |
| B. | Plate and frame filter press |
| C. | Vacuum filter |
| D. | Batch basket centrifuge. |
| Answer» D. Batch basket centrifuge. | |
| 144. |
Pine oil used in froth floatation technique acts as a/an |
| A. | collector |
| B. | modifier |
| C. | frother |
| D. | activator |
| Answer» D. activator | |
| 145. |
Electrical energy consumed by a jaw crusher is not a function of the |
| A. | average feed size |
| B. | average product size |
| C. | machine capacity |
| D. | none of these |
| Answer» E. | |
| 146. |
According to Taggart's 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 |
| A. | 0.00184 |
| B. | 0.0184 |
| C. | 0.184 |
| D. | 1.84 |
| Answer» C. 0.184 | |
| 147. |
Choke crushing (in case of a Jaw crusher) compared to free crushing |
| A. | results in increased capacity. |
| B. | consumes less power. |
| C. | consumes more power. |
| D. | both (a) and (c). |
| Answer» D. both (a) and (c). | |
| 148. |
The process opposite to 'dispersion' is termed as the |
| A. | flocculation |
| B. | sedimentation |
| C. | filtration |
| D. | none of these. |
| Answer» B. sedimentation | |
| 149. |
Which is a secondary crusher for a hard & tough stone ? |
| A. | Jaw crusher |
| B. | Cone crusher |
| C. | Impact crusher |
| D. | Toothed roll crusher |
| Answer» C. Impact crusher | |
| 150. |
The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area, m2 V = rising velocity of fluid, m/sec.S = percentage of solids in the suspension by volume.ρ = density of solids, kg/m3)$ |
| A. | 3.6 AVS.ρ |
| B. | 3.6 A.V.ρ |
| C. | 3.6 A.S. ρ |
| D. | 3.6 AVS/ρ |
| Answer» B. 3.6 A.V.œÅ | |