MCQOPTIONS
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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.
| 451. |
Size reduction does not occur due to compression in case of |
| A. | rod mills |
| B. | gyratory crushers |
| C. | jaw crushers |
| D. | smooth roll crushers |
| Answer» B. gyratory crushers | |
| 452. |
For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a |
| A. | Buhrstone mill |
| B. | ball mill |
| C. | crushing rolls |
| D. | hammer mill |
| Answer» B. ball mill | |
| 453. |
__________ baffles are provided in ball mills. |
| A. | Horizontal |
| B. | No |
| C. | Only two |
| D. | None of these |
| Answer» B. No | |
| 454. |
Rittinger number which designates the new surface prduced per unit of mechanical energy absorbed by the material being crushed, depends on the |
| A. | state or manner of application of the crushing force. |
| B. | ultimate strength of the material. |
| C. | elastic constant of the material. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 455. |
Which of the following is the most suitable for cleaning of fine coal dust (<0.5 mm) ? |
| A. | Trough washer |
| B. | Baum jig washer |
| C. | Spiral separator |
| D. | Froth floatation |
| Answer» E. | |
| 456. |
Sizing of very fine particles of the order of 5 to 10 microns is done by elutriation, which is a __________ operation. |
| A. | clarification |
| B. | sedimentation |
| C. | flocculation |
| D. | classification |
| Answer» E. | |
| 457. |
Which of the following screens has the maximum capacity ? |
| A. | Grizzlies |
| B. | Trommels |
| C. | Shaking screen |
| D. | Vibrating screen |
| Answer» E. | |
| 458. |
Range of compressibility co-efficient of the commercial compressible cake obtained in filtration operation is |
| A. | 0.01 to 0.1 |
| B. | 0.1 to 0.3 |
| C. | 0.2 to 0.8 |
| D. | 0.2 to 0.4 |
| Answer» D. 0.2 to 0.4 | |
| 459. |
In bag filters, filter fabrics are never made of |
| A. | metallic wire woven mesh |
| B. | polyester fibres |
| C. | cotton fibres |
| D. | nylon fibres |
| Answer» B. polyester fibres | |
| 460. |
The operating speed of a ball mill should be __________ the critical speed. |
| A. | less than |
| B. | much more than |
| C. | at least equal to |
| D. | slightly more than |
| Answer» B. much more than | |
| 461. |
For transporting pasty material, one will use a/an |
| A. | apron conveyor |
| B. | belt conveyor |
| C. | screw colaveyor |
| D. | bucket elevator |
| Answer» D. bucket elevator | |
| 462. |
Which of the following is not a part of the Blake jaw crusher? |
| A. | Hanger |
| B. | Check plates |
| C. | Toggles |
| D. | Pitman |
| Answer» B. Check plates | |
| 463. |
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 ‚àù NRe |
| B. | Np ‚àù NRe |
| C. | Np ‚Üí constant |
| D. | Np ‚àù 1/NRe |
| Answer» E. | |
| 464. |
Cartridge filters are termed as 'edge' filters, because of the fact that the |
| A. | disks have very sharp edge. |
| B. | solids are not deposited at the edge of the disk. |
| C. | bulk of the solids are removed at the periphery of the disks. |
| D. | none of these. |
| Answer» D. none of these. | |
| 465. |
Which of the following conveyors cannot be recommended for transportation of abrasive materials ? |
| A. | Belt conveyor |
| B. | Apron conveyor |
| C. | Flight conveyor |
| D. | Chain conveyor |
| Answer» D. Chain conveyor | |
| 466. |
The porosity of a compressible cake is |
| A. | minimum at the filter medium. |
| B. | minimum at the upstream face. |
| C. | maximum at the filter medium. |
| D. | same throughout the thickness of cake. |
| Answer» B. minimum at the upstream face. | |
| 467. |
In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of __________ crushing. |
| A. | primary |
| B. | secondary |
| C. | fine |
| D. | ultrafine |
| Answer» D. ultrafine | |
| 468. |
Froth floatation is the most suitable for treating |
| A. | iron ores |
| B. | sulphide ores |
| C. | quartzite |
| D. | none of these |
| Answer» C. quartzite | |
| 469. |
Ore concentration by jigging is based on the difference in the __________ of the particles. |
| A. | specific gravities |
| B. | wettability |
| C. | shape |
| D. | none of these |
| Answer» B. wettability | |
| 470. |
What is the reduction ratio in a fine crushing operation having following feed and product sizes? |
| A. | 0.5 |
| B. | 2 |
| C. | 5 |
| D. | 10 |
| Answer» C. 5 | |
| 471. |
Which of the following is not categorised as a "mechanical operation" ? |
| A. | Agitation |
| B. | Filtration |
| C. | Size enlargement |
| D. | Humidification |
| Answer» E. | |
| 472. |
Rittinger's number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger's number of a material indicates its |
| A. | easier grindability |
| B. | poor grindability |
| C. | high power consumption in grinding |
| D. | none of these |
| Answer» B. poor grindability | |
| 473. |
For raschig rings, the sphericity is |
| A. | 0.5 |
| B. | 1 |
| C. | <1 |
| D. | 3 |
| Answer» D. 3 | |
| 474. |
Which of the following is a pressure filter ? |
| A. | Leaf filter (Moore filter). |
| B. | Plate and flame filter. |
| C. | Rotary drum filter. |
| D. | Sand filter. |
| Answer» C. Rotary drum filter. | |
| 475. |
Solid particles of different densities are separated by |
| A. | filters |
| B. | thickness |
| C. | cyclones |
| D. | sorting classifier |
| Answer» E. | |
| 476. |
Gelatinous solid (which plug the septum) can be filtered by a __________ filter. |
| A. | sparkler |
| B. | plate and frame |
| C. | vacuum leaf |
| D. | precoat |
| Answer» E. | |
| 477. |
Gravity settling process is not involved in the working of a |
| A. | hydrocyclone |
| B. | classifier |
| C. | dorr-thickener |
| D. | sedimentation tank |
| Answer» B. classifier | |
| 478. |
Diatomaceous earth is a/an |
| A. | explosive |
| B. | filter aid |
| C. | filter medium |
| D. | catalyst |
| Answer» C. filter medium | |
| 479. |
A propeller agitator |
| A. | produces mainly axial flow. |
| B. | is used for mixing high viscosity pastes. |
| C. | runs at very slow speed (2 rpm). |
| D. | all (a), (b) and (c) |
| Answer» B. is used for mixing high viscosity pastes. | |
| 480. |
Separation of materials into products based on the difference of their sizes is called |
| A. | sizing |
| B. | sorting |
| C. | classification |
| D. | flocculation |
| Answer» B. sorting | |
| 481. |
Maximum size reduction in a ball mill is done by the, __________ action. |
| A. | attrition |
| B. | compression |
| C. | impact |
| D. | cutting |
| Answer» D. cutting | |
| 482. |
The main size reduction operation in ultrafine grinders is |
| A. | cutting |
| B. | attrition |
| C. | compression |
| D. | impact |
| Answer» C. compression | |
| 483. |
Which of the following is not an ultrafine grinder (colloid mill)? |
| A. | Micronizers |
| B. | Agitated mills and fluid energy mills |
| C. | Toothed roll crusher |
| D. | Hammer mills with internal classification |
| Answer» D. Hammer mills with internal classification | |
| 484. |
To produce talcum powder, use |
| A. | ball mill |
| B. | hammer mill |
| C. | jet mill |
| D. | pin mill |
| Answer» B. hammer mill | |
| 485. |
In a ball mill, the volume occupied by the balls (when the mill is stopped) is about __________ percent of the volume of the mill. |
| A. | 35 |
| B. | 50 |
| C. | 70 |
| D. | 85 |
| Answer» C. 70 | |
| 486. |
200 mesh screen means 200 openings per |
| A. | cm2 |
| B. | cm |
| C. | inch |
| D. | inch2 |
| Answer» D. inch2 | |
| 487. |
Mixing mechanism employed in a pan mixer is by |
| A. | mulling |
| B. | kneading |
| C. | dispersion |
| D. | none of these |
| Answer» B. kneading | |
| 488. |
Gizzlies are used for separating __________ solids. |
| A. | coarse |
| B. | fine |
| C. | any size |
| D. | none of these |
| Answer» C. any size | |
| 489. |
A widely used size reduction equipment for __________ is Bradford breaker. |
| A. | talc |
| B. | coal |
| C. | iron core |
| D. | wheat |
| Answer» C. iron core | |
| 490. |
Use of grinding aids results in the |
| A. | enhanced production rate. |
| B. | finer products. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» E. | |
| 491. |
Which of the following must be stored in silos and not in open yard ? |
| A. | Coke breeze |
| B. | High V.M. bituminous coal |
| C. | Sand |
| D. | None of these |
| Answer» C. Sand | |
| 492. |
The filter medium resistance is controlled by |
| A. | pressure drop alone |
| B. | flow rate alone |
| C. | both pressure drop and flow rate |
| D. | cake thickness |
| Answer» D. cake thickness | |
| 493. |
Chance process is used for the |
| A. | cleaning of coal. |
| B. | concentration of iron ore. |
| C. | concentration of pyrites. |
| D. | water treatment |
| Answer» B. concentration of iron ore. | |
| 494. |
Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake & reducing the cake resistance during filtration. Filter aid is |
| A. | added to the feed slurry. |
| B. | precoated on the filter medium prior to filtration. |
| C. | separated from the cake by dissolving solids or by burning it off. |
| D. | all 'a', 'b'&'c'. |
| Answer» E. | |
| 495. |
Filter aid is used to |
| A. | increase the rate of filtration. |
| B. | decrease the pressure drop. |
| C. | increase the porosity of the cake. |
| D. | act as a support base for the septum. |
| Answer» D. act as a support base for the septum. | |
| 496. |
__________ is the most commonly used 'filter aid'. |
| A. | Diatomaceous earth |
| B. | Fuller's earth |
| C. | Vermiculite |
| D. | Semi-plastic clay |
| Answer» B. Fuller's earth | |
| 497. |
Width and speed of a conveyor belt depends upon the __________ of the material. |
| A. | lump size |
| B. | bulk density |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 498. |
Apron conveyors are used for |
| A. | heavy loads & short runs. |
| B. | small loads & long runs. |
| C. | heavy loads & long runs. |
| D. | none of these. |
| Answer» B. small loads & long runs. | |
| 499. |
A suspension of glass beads in ethylene glycol has a hindered settling velocity of 1.7 mm/s, while the terminal settling velocity of a single glass bead in ethylene glycol is 17 mm/s. If the Richardson-Zaki hindered settling index is 4.5, the volume fraction of solids in the suspension is |
| A. | 0.1 |
| B. | 0.4 |
| C. | 0.6 |
| D. | none of these |
| Answer» D. none of these | |
| 500. |
Sedimentation on commercial scale occurs in |
| A. | classifiers |
| B. | thickeners |
| C. | rotary drum filters |
| D. | cyclones |
| Answer» D. cyclones | |