MCQOPTIONS
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MCQOPTIONS
This section includes 398 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 251. |
_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.$? |
| A. | Primary |
| B. | Secondary |
| C. | Fine |
| D. | Ultrafine |
| Answer» D. Ultrafine | |
| 252. |
_Vibrating screens have capacity in the range of __________ tons/ft² .mm mesh size.$? |
| A. | 0.2 to 0.8 |
| B. | 5 to 25 |
| C. | 50 to 100 |
| D. | 100 to 250 |
| Answer» B. 5 to 25 | |
| 253. |
_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$? |
| A. | 0.90 μm/s |
| B. | 1 μm/s |
| C. | 22.1 μm/s |
| D. | 0.02 μm/s |
| Answer» C. 22.1 ≈í¬∫m/s | |
| 254. |
_In a roll crusher, both the rolls$? |
| A. | Have the same diameter |
| B. | Are rotated towards each other |
| C. | Run either at the same or different speeds |
| D. | All of the above |
| Answer» E. | |
| 255. |
_As particle size is reduced$? |
| A. | Screening becomes progressively more difficult |
| B. | Screening becomes progressively easier |
| C. | Capacity and effectiveness of the screen is increased |
| D. | None of these |
| Answer» B. Screening becomes progressively easier | |
| 256. |
_Apron conveyors are used for$? |
| 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 | |
| 257. |
_The main size reduction operation in ultrafine grinders is$? |
| A. | Cutting |
| B. | Attrition |
| C. | Compression |
| D. | Impact |
| Answer» C. Compression | |
| 258. |
_A tube mill as compared to a ball mill$? |
| 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 of the above |
| Answer» E. | |
| 259. |
_The energy consumed by a ball mill depends on$? |
| A. | Its speed |
| B. | Its ball load |
| C. | The density of the material being ground |
| D. | All of the above |
| Answer» E. | |
| 260. |
_For transporting pasty material, one will use a/an$? |
| A. | Apron conveyor |
| B. | Belt conveyor |
| C. | Screw colaveyor |
| D. | Bucket elevator |
| Answer» D. Bucket elevator | |
| 261. |
_Fluid medium used in the classification technique of mineral beneficiation is$? |
| A. | Air |
| B. | Water |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 262. |
_Activators are those chemicals which help buoying up one mineral in preference to the other in the froth floatation process. Which of the following is an activator?$? |
| A. | Cresylic acid |
| B. | Copper sulphate |
| C. | Calcium carbonate |
| D. | Sodium carbonate |
| Answer» C. Calcium carbonate | |
| 263. |
_To produce talcum powder, use$? |
| A. | Ball mill |
| B. | Hammer mill |
| C. | Jet mill |
| D. | Pin mill |
| Answer» B. Hammer mill | |
| 264. |
___________ conveyor is the most suitable for long distance transportation of cold, non-abrasive granular/irregular shape/fine materials.$? |
| A. | Bucket |
| B. | Belt |
| C. | Screw |
| D. | Apron |
| Answer» C. Screw | |
| 265. |
_Screen efficiency is$? |
| A. | Recovery/rejection |
| B. | Recovery |
| C. | Rejection |
| D. | None of these |
| Answer» E. | |
| 266. |
_Use of 'grinding aids' is done in __________ grinding.$? |
| A. | Dry |
| B. | Wet |
| C. | Ultrafine |
| D. | Intermediate |
| Answer» B. Wet | |
| 267. |
_Arrange the following size reduction equipment in the decreasing order of the average particle size produced by each of them.$? |
| A. | Jaw crusher, Ball mill, Fluid energy mill |
| B. | Ball mill, Jaw crusher, Fluid energy mill |
| C. | Fluid energy mill, Jaw crusher, Ball mill |
| D. | Fluid energy mill, Ball mill, Jaw crusher |
| Answer» B. Ball mill, Jaw crusher, Fluid energy mill | |
| 268. |
_Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of$? |
| A. | Bronze |
| B. | Stainless steel |
| C. | Flint or porcelain |
| D. | Concrete |
| Answer» D. Concrete | |
| 269. |
_Molten ammonium nitrate is mixed with ground limestone in fertilizer plant in a$? |
| A. | Pug mill |
| B. | Mixer-extruder |
| C. | Banbury mixer |
| D. | Muller mixer |
| Answer» B. Mixer-extruder | |
| 270. |
_Reciprocating screens are normally inclined at an angle of 5° with the horizontal and employ gyratory motion at feed end & reciprocating motion at the discharge end. They are not suitable for the screening of the$? |
| A. | Light metal powder down upto 4 meshsize |
| B. | Dry chemicals |
| C. | Heavy tonnages of rocks or gravel |
| D. | Powdered food & granular materials |
| Answer» D. Powdered food & granular materials | |
| 271. |
_Float and sink test determines the possibility of cleaning of coal by a process based on the$? |
| A. | Gravity separation |
| B. | Wettability |
| C. | Particle shape |
| D. | None of these |
| Answer» B. Wettability | |
| 272. |
_Optimum ratio of operating speed to critical speed of a trommel is$? |
| A. | 0.33-0.45 |
| B. | 1.33-1.45 |
| C. | 0.5-2 |
| D. | 1.5-2.5 |
| Answer» B. 1.33-1.45 | |
| 273. |
_With increase in the pressure drop across the cake, the specific cake resistance for the compressible sludge$? |
| A. | Increases |
| B. | Decreases |
| C. | Remains constant |
| D. | Increases linearly |
| Answer» B. Decreases | |
| 274. |
_Filtrate flow rate in case of a rotary drum vacuum filter (in which Rm < < Rc) is proportional to __________ and the cycle time (where, μ = filtrate viscosity Rm = filter medium resistance Rc = cake resistance ).$? |
| A. | ‚à öŒº |
| B. | 1/‚à öŒº |
| C. | 1/μ |
| D. | 1/μ² |
| Answer» C. 1/≈í¬∫ | |
| 275. |
_Paddle agitator$? |
| A. | Is suitable for mixing low viscosity liquids |
| B. | Produces axial flow |
| C. | Moves at very high speed |
| D. | None of these |
| Answer» B. Produces axial flow | |
| 276. |
_Xanthates are used in the froth floatation process as a/an$? |
| A. | Conditioner |
| B. | Frother |
| C. | Collector |
| D. | Activator |
| Answer» D. Activator | |
| 277. |
_There is practically no alternative/competitor to __________ in the beneficiation treatment of sulphide ores.$? |
| A. | Classification |
| B. | Tabling |
| C. | Jigging |
| D. | Froth floatation |
| Answer» E. | |
| 278. |
_Which of the following is used for primary crushing of very hard lumpy materials?$? |
| A. | Toothed roll crusher |
| B. | Gyratory crusher |
| C. | Ball mill |
| D. | Tube mill |
| Answer» C. Ball mill | |
| 279. |
_Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed?$? |
| A. | Wet grinding in low viscous suspension |
| B. | Wet grinding in high viscous suspension |
| C. | Dry grinding of large particles (upto 1.25 cms) |
| D. | Dry grindng of large particles in un-baffed mills |
| Answer» E. | |
| 280. |
_Feed size of ‚â• 25 cms can be accepted by$? |
| A. | Ball mill |
| B. | Rod mill |
| C. | Fluid energy mill |
| D. | Jaw crusher |
| Answer» E. | |
| 281. |
_Which of the following mineral dressing operations is termed as 'comminution'?$? |
| A. | Panning |
| B. | Spiralling |
| C. | Tabling |
| D. | None of these |
| Answer» E. | |
| 282. |
_For classification of potable (drinking) water, we use a __________ filter.$? |
| A. | Gravity sand |
| B. | Plate and frame |
| C. | Vacuum leaf |
| D. | Rotary vacuum |
| Answer» B. Plate and frame | |
| 283. |
_Which of the following may prove unsuitable for filtering volatile liquids?$? |
| A. | Pressure filter |
| B. | Gravity filter |
| C. | Centrifugal filter |
| D. | Vacuum filter |
| Answer» E. | |
| 284. |
_To remove very small amount of tiny solid impurities from liquid, we use a$? |
| A. | Pressure filter |
| B. | Vacuum filter |
| C. | Centrifugal filter |
| D. | Coagulant |
| Answer» E. | |
| 285. |
_For spheres, the specific surface shape factor is given by$? |
| A. | AD/V |
| B. | D/V |
| C. | A/V |
| D. | ‚à ö(AD/V) |
| Answer» B. D/V | |
| 286. |
_In case of a revolving mill, wet grinding compared to dry grinding$? |
| A. | Requires more energy |
| B. | Has less capacity |
| C. | Complicates handling & classification of the product |
| D. | None of these |
| Answer» E. | |
| 287. |
_According to Bond crushing law, the work required to form particle of size 'D' from very large feed is (where (S/V)p and (S/V)f are surface to volume ratio of the product and feed respectively).$? |
| A. | (S/V)p |
| B. | ‚à ö(S/V)p |
| C. | (S/V)²p |
| D. | (S/V)f |
| Answer» C. (S/V)¬¨‚â§p | |
| 288. |
_At low Reynold's number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied: Po = ρ/ρN3 D5 : Power number Re = ρ N D2/μ: Reynold's number N is the impeller rotational speed, and D is the impeller diameter.$? |
| A. | Po ‚Äö√ √π Re-1.0 |
| B. | Po ‚Äö√ √π Re0.0 |
| C. | Po ‚Äö√ √π Re0.5 |
| D. | Po ‚Äö√ √π Re1.0 |
| Answer» C. Po ‚Äö√ √π Re0.5 | |
| 289. |
___________ mills fall in the category of tumbling mills,$? |
| A. | Ball and pebble |
| B. | Rod and tube |
| C. | Compartment |
| D. | All of the above |
| Answer» E. | |
| 290. |
_Additives used for promoting the floccula-tion of particles is a/an$? |
| A. | Electrolyte |
| B. | Surface active agent |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 291. |
_Moisture can be removed from lubricating oil using$? |
| A. | Tubular centrifuge |
| B. | Clarifier |
| C. | Sparkler filter |
| D. | Vacuum leaf filter |
| Answer» B. Clarifier | |
| 292. |
_Two particles are called to be equal settling, if they are having the same.$? |
| A. | Size |
| B. | Specific gravity |
| C. | Terminal velocities in the same fluid & in the same field of force |
| D. | None of these |
| Answer» D. None of these | |
| 293. |
___________ mills are termed as disintegrators.$? |
| A. | Cage |
| B. | Compartment |
| C. | Pebble |
| D. | All of the above |
| Answer» B. Compartment | |
| 294. |
Sedimentation on commercial scale occurs in$? |
| A. | Classifiers |
| B. | Thickeners |
| C. | Rotary drum filters |
| D. | Cyclones |
| Answer» D. Cyclones | |
| 295. |
Which of the following is the most suitable for cleaning of fine coal dust (<0.5 mm)?$? |
| A. | Trough washer |
| B. | Baum jig washer |
| C. | Spiral separator |
| D. | Froth floatation |
| Answer» E. | |
| 296. |
Fluid energy mill comes in the category of$? |
| A. | Grinder |
| B. | Crusher |
| C. | Cutter |
| D. | Ultrafine grinder |
| Answer» E. | |
| 297. |
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.$? |
| A. | Impact |
| B. | Roll |
| C. | Vibratory |
| D. | None of these |
| Answer» B. Roll | |
| 298. |
The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the$? |
| A. | Venturi atomiser |
| B. | Gravity settling chamber |
| C. | Electro-static precipitator |
| D. | Cyclone separator |
| Answer» D. Cyclone separator | |
| 299. |
Size reduction does not occur due to compression in case of$? |
| A. | Rod mills |
| B. | Gyratory crushers |
| C. | Jaw crushers |
| D. | Smooth roll crushers |
| Answer» B. Gyratory crushers | |
| 300. |
In constant pressure filtration,$? |
| A. | Resistance decreases with time |
| B. | Rate of filtration is constant |
| C. | Rate of filtration increases with time |
| D. | Rate of filtration decreases with time |
| Answer» E. | |