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.
| 301. |
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 | |
| 302. |
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 (a), (b) and (c). |
| Answer» E. | |
| 303. |
In a grinding operation, the limiting particle size is the size of the __________ particle in the sample. |
| A. | smallest |
| B. | largest |
| C. | either (a) or (b) |
| D. | neither (a) nor (b) |
| Answer» E. | |
| 304. |
Which of the following is not a wet classifier ? |
| A. | Sharpies supercentrifuge |
| B. | Hydrocyclones |
| C. | Dorr Oliver rake classifier |
| D. | None of these |
| Answer» E. | |
| 305. |
The ratio of the area of openings in one screen (Taylor series) to that of the openings in the next smaller screen is |
| A. | 1.5 |
| B. | 1 |
| C. | 2 |
| D. | none of these |
| Answer» E. | |
| 306. |
In case of grinding in a ball mill |
| A. | wet grinding achieves a finer product size than dry grinding. |
| B. | its capacity decreases with increasing fineness of the products. |
| C. | grinding cost and power requirement increases with increasing fineness of the products. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 307. |
Toothed roll crushers achieve size reduction by |
| A. | tearing (shear) and compression. |
| B. | impact and attrition. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 308. |
The maximum slope of a belt conveyor can be |
| A. | 15° |
| B. | 30° |
| C. | 45° |
| D. | 60° |
| Answer» C. 45¬∞ | |
| 309. |
The work index in Bond's law for crushing of solids has the following dimensions |
| A. | no units (dimensionless) |
| B. | kWh/ton |
| C. | kW/ton |
| D. | kWh.m1/2/ton |
| Answer» C. kW/ton | |
| 310. |
The critical speed of a trommel (N) is related to its dia (D) as |
| A. | N ‚àù |
| B. | N ‚àù D |
| C. | N ‚àù D |
| D. | N ‚àù |
| Answer» B. N ‚àù D | |
| 311. |
Run of mine (ROM) coal is crushed by a __________ for use in domestic ovens. |
| A. | jaw crusher |
| B. | hammer crusher |
| C. | ball mill |
| D. | tube mill |
| Answer» C. ball mill | |
| 312. |
Use of baffles in agitators help in minimising the __________ tendency. |
| A. | swirling |
| B. | vortexing |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 313. |
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 | |
| 314. |
In the cyclone separator used for separation of dust from dust laden gas, the gas |
| A. | enters the cyclone from the top. |
| B. | is admitted tangentially at high velocity. |
| C. | develops a helical motion inside the chamber. |
| D. | both (b) and (c). |
| Answer» E. | |
| 315. |
Kick's law assumes that the energy required for size reduction is proportional to the logarithm of the ratio between the initial and the final diameters. The unit of Kick's constant is |
| A. | kW. sec/kg |
| B. | kWh/kg |
| C. | kWh/sec. kg |
| D. | kg/sec. |
| Answer» B. kWh/kg | |
| 316. |
The study on washability of coal is done by using the __________ technique. |
| A. | tabling |
| B. | elutriation |
| C. | heavy media separation |
| D. | none of these |
| Answer» D. none of these | |
| 317. |
Which of the following is a fine crusher? |
| A. | Blake jaw crusher |
| B. | Gyratory crusher |
| C. | Toothed roll crusher |
| D. | Dodge jaw crusher |
| Answer» D. Dodge jaw crusher | |
| 318. |
Tank filter (e.g., Nutsch filter) is |
| A. | a high pressure filter. |
| B. | a continuous filter. |
| C. | used for small scale filtration work. |
| D. | a leaf filter. |
| Answer» D. a leaf filter. | |
| 319. |
For the transportation of ultrafine particles, the equipment used is a........conveyor. |
| A. | belt |
| B. | pneumatic |
| C. | screw |
| D. | none of these |
| Answer» C. screw | |
| 320. |
The process by which fine solids is removed from liquids is termed as |
| A. | decantation |
| B. | flocculation |
| C. | sedimentation |
| D. | classification |
| Answer» D. classification | |
| 321. |
Which of the following terminology is not used for size reduction of materials to fine sizes or powders? |
| A. | Comminution |
| B. | Dispersion |
| C. | Pulverisation |
| D. | Compression |
| Answer» E. | |
| 322. |
Sauter mean diameter is the same as the __________ mean diameter. |
| A. | mass |
| B. | arithmetic |
| C. | volume-surface |
| D. | geometric |
| Answer» D. geometric | |
| 323. |
Which of the following crushing laws is most accurately applicable to the fine grinding of materials ? |
| A. | Bond's crushing law |
| B. | Kick's law |
| C. | Rittinger's law |
| D. | None of these. |
| Answer» D. None of these. | |
| 324. |
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 | |
| 325. |
__________ is the most suitable for compounding rubber and plastic solids. |
| A. | Banbery mixer |
| B. | Pan mixer |
| C. | Pug mill |
| D. | Charge can mixer |
| Answer» B. Pan mixer | |
| 326. |
The crushed material received for separation is called feed or |
| A. | tailing |
| B. | heading |
| C. | concentrate |
| D. | middling |
| Answer» C. concentrate | |
| 327. |
Moisture can be removed from lubricating oil using |
| A. | tubular centrifuge |
| B. | clarifier |
| C. | sparkler filter |
| D. | vacuum leaf filter |
| Answer» B. clarifier | |
| 328. |
Xanthates are used in the froth floatation process as a/an |
| A. | conditioner |
| B. | frother |
| C. | collector |
| D. | activator |
| Answer» D. activator | |
| 329. |
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 | |
| 330. |
For spheres, the specific surface shape factor is given by |
| A. | AD/V |
| B. | D/V |
| C. | A/V |
| D. | AD/V |
| Answer» B. D/V | |
| 331. |
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) | |
| 332. |
The basic filtration equation is given as where, V is volume of the filtrate ; A is the filtration area, a is specific cake resistance, μ is viscosity of the filtrate, and C is the concentration of the solids in the feed slurry. In a 20 minutes constant rate filtration, 5 m3 of filtrate was obtained. If this is followed by a constant pressure filtration, how much more time in minutes, it will take for another 5 m3 of filtrate to be produced ? Neglect filter medium resistance, Rm ; assume incompressible cake.$ |
| A. | 10 |
| B. | 20 |
| C. | 25 |
| D. | 30 |
| Answer» C. 25 | |
| 333. |
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/Œº | |
| 334. |
Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity ? |
| A. | Sphere |
| B. | Cube |
| C. | Cylinder (L/D = 1) |
| D. | Raschig rings |
| Answer» B. Cube | |
| 335. |
Mixer used for rubber compounding is |
| A. | mixer-extruder |
| B. | banbury internal mixer |
| C. | muller mixer |
| D. | pug mill |
| Answer» C. muller mixer | |
| 336. |
For Indian standard (IS) screens, the mesh number is equal to its aperture size expressed to the nearest deca-micron (0.01 mm). Aperture width of IS screen of mesh number 50 will be approximately __________ microns. |
| A. | 5 |
| B. | 50 |
| C. | 500 |
| D. | 5000 |
| Answer» D. 5000 | |
| 337. |
To get a fine talc powder from its granules, the equipment used is |
| A. | roller crusher |
| B. | ball mill |
| C. | jaw crusher |
| D. | gyratory crusher |
| Answer» C. jaw crusher | |
| 338. |
The term 'angle of nip' is concerned with the operation of the __________ crushers. |
| A. | jaw |
| B. | roll |
| C. | gyratory |
| D. | none of these |
| Answer» C. gyratory | |
| 339. |
__________ mills are termed as impactors. |
| A. | Hammer |
| B. | Cage |
| C. | Rolling-compression |
| D. | none of these |
| Answer» B. Cage | |
| 340. |
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 | |
| 341. |
Particle size range in which dust catcher (gravity settling chamber) works most effectively and efficiently is __________ microns. |
| A. | < 5 |
| B. | 10 to 25 |
| C. | < 74 |
| D. | > 1000 |
| Answer» D. > 1000 | |
| 342. |
Removal of activated carbon from glycerine is done by |
| A. | plate and frame filter |
| B. | rotary vacuum filter |
| C. | batch basket centrifuge |
| D. | none of these |
| Answer» B. rotary vacuum filter | |
| 343. |
Which of the following is not used as a filter medium in case of corrosive liquids ? |
| A. | Nylon |
| B. | Glass cloth |
| C. | Metal cloth of monel or stainless steel |
| D. | Cotton fabric |
| Answer» E. | |
| 344. |
In ball mill operation, the feed size (Df in meters) and the ball diameter (Db in metres) are related as ( where, K = grindability constant (varying from 0.9 to 1.4 in increasing order of hard ness)) |
| A. | Db2 = K.Df |
| B. | Db = K.Df |
| C. | Db3 = K.Df |
| D. | Db2 = K.Df2 |
| Answer» B. Db = K.Df | |
| 345. |
For benefication of iron ore, the most commonly used method is |
| A. | flocculation. |
| B. | froth floatation. |
| C. | jigging & tabling. |
| D. | none of these. |
| Answer» D. none of these. | |
| 346. |
For spheres, the surface shape factor is given by (where, A = area, V = volume, and D = diameter) |
| A. | π(=A/D2) |
| B. | π/6(=V/D3) |
| C. | |
| Answer» B. œÄ/6(=V/D3) | |
| 347. |
Vibrating screens are used for handling large tonnages of materials. The vibrating motion is imparted to the screening surface by means of |
| A. | electromagnets |
| B. | cams or eccentric shafts |
| C. | unblanced fly wheels |
| D. | either (a), (b) or (c). |
| Answer» E. | |
| 348. |
For laminar flow of filtrate through the cake deposited on septum, which of the following will be valid ? |
| A. | Kozney-Karman equation |
| B. | Leva's equation |
| C. | Blake-Plummer equation |
| D. | none of these |
| Answer» B. Leva's equation | |
| 349. |
Mechanical conveyors which push the material along an endless trough or tube are called scrappers. Which of the following conveying equipments comes under the category of 'scrappers' ? |
| A. | Bucket conveyor |
| B. | Flight conveyor |
| C. | Screw conveyor |
| D. | Both (b) and (c) |
| Answer» E. | |
| 350. |
Rittinger's crushing law states that |
| A. | work required to form a particle of any size is proportional to the square of the surface to volume ratio of the product. |
| B. | work required to form a particle of a particular size is proportional to the square root of the surface to volume ratio of the product. |
| C. | work required in crushing is proportional to the new surface created. |
| D. | for a given machine and feed, crushing efficiency is dependent on the size of the feed & product. |
| Answer» D. for a given machine and feed, crushing efficiency is dependent on the size of the feed & product. | |