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.
| 351. |
Which of the following is used for primary crushing of very hard lumpy materials ? |
| A. | Toothed roll crusher |
| B. | Gyratory crusher |
| C. | Ball mill |
| D. | Tube mill |
| Answer» C. Ball mill | |
| 352. |
__________ mill is not a revolving mill. |
| A. | Pebble |
| B. | Compartment |
| C. | Cage |
| D. | Tube |
| Answer» D. Tube | |
| 353. |
A filter press is |
| A. | a batch filter. |
| B. | not suitable, if the liquid is the main product. |
| C. | having prohibitively high maintenance cost. |
| D. | not suitable for wide range of materials under varying operating conditions of cake thickness and pressure. |
| Answer» B. not suitable, if the liquid is the main product. | |
| 354. |
Maximum size reduction in a fluid energy mill is achieved by |
| A. | compression |
| B. | interparticle attrition |
| C. | cutting |
| D. | impact |
| Answer» C. cutting | |
| 355. |
Grindability of a material does not depend upon its |
| A. | elasticity |
| B. | hardness |
| C. | toughness |
| D. | size |
| Answer» E. | |
| 356. |
During agitation of liquids, power consumption during laminar flow is not proportional to the |
| A. | density of the liquid |
| B. | viscosity of the liquid |
| C. | cube of impeller diameters |
| D. | square of rotational speed. |
| Answer» B. viscosity of the liquid | |
| 357. |
Size reduction of asbestos and mica is done by |
| A. | hammer mills |
| B. | rod mills |
| C. | gyratory crushers |
| D. | crushing rolls |
| Answer» B. rod mills | |
| 358. |
Colloidal mills are used for __________ grinding. |
| A. | coarse |
| B. | intermediate |
| C. | fine |
| D. | ultrafine |
| Answer» E. | |
| 359. |
The filtrate flow rate in constant pressure filtration |
| A. | continuously increases. |
| B. | continuously decreases. |
| C. | remains constant throughout. |
| D. | may increase or decrease ; depends on the pressure. |
| Answer» C. remains constant throughout. | |
| 360. |
For spheres, volume shape factor is given by |
| A. | π(=A/D2) |
| B. | 2π(=2A/D2) |
| C. | π/6(=V/D3) |
| D. | AD/V |
| Answer» D. AD/V | |
| 361. |
Traces of solids are removed from, liquid in a |
| A. | classifier |
| B. | clarifier |
| C. | sparkler filter |
| D. | rotary vacuum filter |
| Answer» C. sparkler filter | |
| 362. |
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 | |
| 363. |
Flow of filtrate through the cake in a plate and frame filter press is best described by the __________ equation. |
| A. | Kozney-Karman |
| B. | Hagen-Poiseulle's |
| C. | Fanning's |
| D. | Kremser |
| Answer» B. Hagen-Poiseulle's | |
| 364. |
A fluid energy mill is used for |
| A. | cutting |
| B. | grinding |
| C. | ultragrinding |
| D. | crushing |
| Answer» D. crushing | |
| 365. |
Close circuit grinding by a ball mill with air sweeping employs a |
| A. | classifier. |
| B. | cyclone separator between mill & classifier. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 366. |
Which of the following mechanical conveyors does not come under the division 'carriers' ? |
| A. | Belt conveyor |
| B. | Bucket elevator |
| C. | Screw conveyor |
| D. | Apron conveyor. |
| Answer» D. Apron conveyor. | |
| 367. |
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 | |
| 368. |
Use of 'grinding aids' is done in __________ grinding. |
| A. | dry |
| B. | wet |
| C. | ultrafine |
| D. | intermediate |
| Answer» B. wet | |
| 369. |
The opening of a 200 mesh screen (Taylor series) is |
| A. | 0.0074 cm |
| B. | 0.0074 mm |
| C. | 0.0047 cm |
| D. | 74 mili-microns |
| Answer» B. 0.0074 mm | |
| 370. |
200 mesh seive size corresponds to __________ microns. |
| A. | 24 |
| B. | 74 |
| C. | 154 |
| D. | 200 |
| Answer» C. 154 | |
| 371. |
The power number for a stirred tank becomes constant at high Reynolds number. In this limit, the variation of power input with impeller rotational speed (N) is proportional to |
| A. | N° |
| B. | N1 |
| C. | N2 |
| D. | N3 |
| Answer» D. N3 | |
| 372. |
A belt conveyor used for the transportation of materials can |
| A. | run upto 1 km. |
| B. | travel at a speed upto 300 metres/minute. |
| C. | handle materials upto 5000 tons/hr. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 373. |
In screen analysis, the notation +5 mm/-10 mm means particles passing through |
| A. | 10 mm screen and retained on 5 mm screen. |
| B. | 5 mm screen and retained on 10 mm screen. |
| C. | both 5 mm and 10 mm screens. |
| D. | neither 5 mm nor 10 mm screen. |
| Answer» B. 5 mm screen and retained on 10 mm screen. | |
| 374. |
General mechanism of size reduction in intermediate and fine grinder is by |
| A. | cutting action. |
| B. | compression. |
| C. | compression and tearing. |
| D. | impact and attrition. |
| Answer» E. | |
| 375. |
The specific cake resistance for compressible sludges is a function of the pressure drop |
| A. | over cake |
| B. | over medium |
| C. | overall |
| D. | none of these |
| Answer» B. over medium | |
| 376. |
As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms ) |
| A. | LS |
| B. | 93 LS |
| C. | 250 LS |
| D. | LS |
| Answer» C. 250 LS | |
| 377. |
Which of the following equations is Rittinger's crushing law ? (where P = power required by the machine, m = feed rate, k = a constant = volume surface mean diameter of feed & product respectively.) |
| A. | P/m = K/Dp |
| B. | P/m = K . ln |
| C. | P/m = K . |
| D. | none of these. |
| Answer» D. none of these. | |
| 378. |
A straight line is obtained on plotting reciprocal of filtration rate vs. the volume of filtrate for __________ flow of filtrate. |
| A. | compressible cakes and laminar |
| B. | incompressible cake and laminar |
| C. | compressible cake and turbulent |
| D. | incompressible cake and turbulent |
| Answer» C. compressible cake and turbulent | |
| 379. |
Size reduction of moulding powders, waxes, resins & gums are done in a __________ mill. |
| A. | cage |
| B. | hammer |
| C. | both (a) & (b) |
| D. | id) neither (a) nor (b) |
| Answer» D. id) neither (a) nor (b) | |
| 380. |
Which of the follwoing mechanical conveyors does not come under the division 'scrapers' ? |
| A. | Ribbon conveyor |
| B. | Flight conveyor |
| C. | Bucket elevators |
| D. | Drag conveyor. |
| Answer» D. Drag conveyor. | |
| 381. |
Dry powdery solid materials are transported by a __________ conveyor. |
| A. | belt |
| B. | bucket |
| C. | screw |
| D. | none of these |
| Answer» D. none of these | |
| 382. |
Which of the following minerals is not subjected to magnetic separation method? |
| A. | Rutile |
| B. | Galena |
| C. | Chromite |
| D. | Siderite |
| Answer» C. Chromite | |
| 383. |
__________ mills are termed as disintegrators. |
| A. | Cage |
| B. | Compartment |
| C. | Pebble |
| D. | All tumbling |
| Answer» B. Compartment | |
| 384. |
During agitation of liquids, the |
| A. | Froude number is independent for the curves between power number and Reynolds number in baffled system. |
| B. | Power number becomes independent of impellers Reynolds number at high Reynolds number, but is dependent on the geometry of the impeller. |
| C. | Froude number is used to account for the effect of surface (e.g., the centre vortex) on the power number. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 385. |
For crushing of solids, the Rittinger's law states that the work required for crushing is proportional to |
| A. | the new surface created. |
| B. | the size reduction ratio. |
| C. | the change in volume due to crushing. |
| D. | none of these. |
| Answer» B. the size reduction ratio. | |
| 386. |
Energy consumption in a crusher decreases with increase in the |
| A. | size of the product (at constant feed size). |
| B. | capacity of the crushing machine. |
| C. | size of feed (at constant reduction ratio). |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 387. |
Which of the following parts of a jaw crusher is subjected to maximum wear and tear during its operation ? |
| A. | Check plates |
| B. | Jaw plates |
| C. | Toggles |
| D. | Crush shaft |
| Answer» C. Toggles | |
| 388. |
The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the |
| A. | venturi atomiser |
| B. | gravity settling chamber |
| C. | electro-static precipitator |
| D. | cyclone separator |
| Answer» D. cyclone separator | |
| 389. |
For a sphere falling in the constant drag co-efficient regime, its terminal velocity depends on its diameter (d) as |
| A. | d |
| B. | d |
| C. | d2 |
| D. | 1/d |
| Answer» D. 1/d | |
| 390. |
Ultracentrifuges running at speeds upto 100000 rpm is normally used for the |
| A. | separation of isotopes based on their density or molecular weights difference. |
| B. | concentration of rubber latex. |
| C. | separation of cream from milk. |
| D. | dewaxing of lubricating oil. |
| Answer» B. concentration of rubber latex. | |
| 391. |
Ultra centrifuges are used for the separation of __________ solid particles. |
| A. | coarse |
| B. | fine |
| C. | colloidal |
| D. | dissolved |
| Answer» D. dissolved | |
| 392. |
With increase in drum speed, in a rotary drum filter, the filtration rate |
| A. | increases |
| B. | increases linearly |
| C. | decreases |
| D. | is not affected |
| Answer» B. increases linearly | |
| 393. |
Separation of a suspension or slurry into a supernatant clear liquid (free from particles) and a thick sludge containing a high concentration of solid is called |
| A. | classification |
| B. | sedimentation |
| C. | clarification |
| D. | decantation |
| Answer» C. clarification | |
| 394. |
Driving force in case of filtration by a centrifuge is the |
| A. | speed of the centrifuge. |
| B. | centrifugal pressure exerted by the liquid. |
| C. | narrow diameter of the vessel. |
| D. | formation of highly porous cake. |
| Answer» C. narrow diameter of the vessel. | |
| 395. |
__________ mill is normally used for grinding of talc. |
| A. | Tube |
| B. | Compartment |
| C. | Ring-roll |
| D. | Pebble |
| Answer» D. Pebble | |
| 396. |
Higher is the mesh number, smaller will be the aperture size of the screen. It means that the aperture size of a 200 mesh screen will be smaller than that of 20 mesh screen. This is valid for |
| A. | British standard screens. |
| B. | German standard screens (DIN 1171) etc. |
| C. | American standard screens (ASTM and Tyler standard screens). |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 397. |
Cake resistance is |
| A. | important in the beginning of filtration. |
| B. | decreased with the time of filtration. |
| C. | independent of pressure drop. |
| D. | none of these. |
| Answer» E. | |
| 398. |
Where the density difference of the two liquid phase to be separated is very small (as in milk cream separator), the most suitable separator is a |
| A. | disc bowl centrifuge. |
| B. | sharpies supercentrifuge. |
| C. | batch basket centrifuge. |
| D. | sparkler filter. |
| Answer» B. sharpies supercentrifuge. | |
| 399. |
Handling of ashes and similar materials can be done best by a __________ conveyor. |
| A. | flight |
| B. | drag or slat |
| C. | belt |
| D. | ribbon. |
| Answer» C. belt | |
| 400. |
At low Reynold's number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied: Po = ρ/ρN3 D5 : Power number Re = ρ N D2/μ: Reynold's number N is the impeller rotational speed, and D is the impeller diameter.$ |
| A. | Po ‚àù Re-1.0 |
| B. | Po ‚àù Re0.0 |
| C. | Po ‚àù Re0.5 |
| D. | Po ‚àù Re1.0 |
| Answer» C. Po ‚àù Re0.5 | |