MCQOPTIONS
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MCQOPTIONS
This section includes 362 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. |
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 | |
| 252. |
For coarse reduction of hard solids, use ____________________? |
| A. | Impact |
| B. | Attrition |
| C. | Compression |
| D. | Cutting |
| Answer» D. Cutting | |
| 253. |
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 | |
| 254. |
For achieving maximum capacity of the ball mill, the ball charge should be equal to about ______________ percent of the ball mill volume? |
| A. | 10 |
| B. | 25 |
| C. | 50 |
| D. | 75 |
| Answer» D. 75 | |
| 255. |
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. | |
| 256. |
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 | |
| 257. |
For a non-spherical particle, the sphericity__________________? |
| A. | Is defined as the ratio of surface area of a sphere having the same volume as the particle to the actual surface area of the particle |
| B. | Has the dimension of length |
| C. | Is always less than 1 |
| D. | Is the ratio of volume of a sphere having the same surface area as the particle to the actual volume of the particle |
| Answer» B. Has the dimension of length | |
| 258. |
For a cyclone of diameter 0.2 m with a tangential velocity of 15 m/s at the wall, the separation factor is__________________? |
| A. | 2250 |
| B. | 1125 |
| C. | 460 |
| D. | 230 |
| Answer» E. | |
| 259. |
Fluid medium used in the classification technique of mineral beneficiation is_________________? |
| A. | Air |
| B. | Water |
| C. | Either A. or B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 260. |
Fluid energy mill comes in the category of________________? |
| A. | Grinder |
| B. | Crusher |
| C. | Cutter |
| D. | Ultrafine grinder |
| Answer» E. | |
| 261. |
Flow of filtrate through the cake in a plate and frame filter press is best described by the ______________ equation? |
| A. | Kozeny-Carman |
| B. | Hagen-Poiseuille’s |
| C. | Fanning’s |
| D. | Kremser |
| Answer» B. Hagen-Poiseuille’s | |
| 262. |
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 | |
| 263. |
Filtration should be stopped in a filter press, if the_________________? |
| A. | Cake becomes very dense |
| B. | Liquor stops flowing out to the discharge |
| C. | Filtration pressure rises suddenly |
| D. | Both B. & C. |
| Answer» E. | |
| 264. |
Filtration rate through a filter cake is proportional to (where, S = filtering surface R = specific cake resistance μ = viscosity of the filtrate) ? |
| A. | S |
| B. | 1/R |
| C. | 1/μ |
| D. | All A., B. & C. |
| Answer» E. | |
| 265. |
Filtration rate does not depend upon the________________? |
| A. | Pressure drop & area of filtering surface |
| B. | Resistance of the cake & the septum |
| C. | Properties of the cake & the filtrate |
| D. | None of these |
| Answer» E. | |
| 266. |
Filtration operation carried out by continuous increase of the inlet pressure of slurry, is called the _____________ filtration? |
| A. | Constant rate |
| B. | Varying pressure |
| C. | Varying rate |
| D. | Constant pressure |
| Answer» B. Varying pressure | |
| 267. |
Filtration of water in a paper mill is done by a/an _______________ filter? |
| A. | Open sand |
| B. | Plate and frame |
| C. | Vacuum leaf |
| D. | Sparkler |
| Answer» B. Plate and frame | |
| 268. |
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 | |
| 269. |
Filtration capacity of a rotary drum vacuum filter depends upon the_______________? |
| A. | Cake thickness |
| B. | Characteristics of the feed slurry |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 270. |
Filter medium resistance is important during the ______________ of filtration? |
| A. | Early stages |
| B. | Final stages |
| C. | Entire process |
| D. | None of these |
| Answer» B. Final stages | |
| 271. |
Filter medium resistance is that offered by the__________________? |
| A. | Filter cloth |
| B. | Embedded particles in the septum |
| C. | Filter cloth and the embedded particle collectively |
| D. | None of these |
| Answer» D. None of these | |
| 272. |
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. | Pre-coated 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. | |
| 273. |
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 | |
| 274. |
Fick’s law relates to_________________? |
| A. | Energy consumption |
| B. | Final particle size |
| C. | Feed size |
| D. | None of these |
| Answer» B. Final particle size | |
| 275. |
Fibrous material is broken by a__________________? |
| A. | Roll-crusher |
| B. | Squirrel-cage disintegrator |
| C. | Ball mill |
| D. | Tube mill |
| Answer» C. Ball mill | |
| 276. |
Feed size of ≥ 25 cms can be accepted by _______________________? |
| A. | Ball mill |
| B. | Rod mill |
| C. | Fluid energy mill |
| D. | Jaw crusher |
| Answer» E. | |
| 277. |
Equivalent diameter of a particle is the diameter of the sphere having the same __________________? |
| A. | Ratio of surface to volume as the actual volume |
| B. | Ratio of volume to surface as the particle |
| C. | Volume as the particle |
| D. | None of these |
| Answer» B. Ratio of volume to surface as the particle | |
| 278. |
Energy requirement (per unit mass of material crushed/ground) is highest for__________________? |
| A. | Jaw crusher |
| B. | Rod mill |
| C. | Ball mill |
| D. | Fluid energy mill |
| Answer» E. | |
| 279. |
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. | |
| 280. |
Energy consumed for crushing one ton of material ranges from ______________ kWh? |
| A. | 0.01 to 0.1 |
| B. | 0.5 to 1.5 |
| C. | 2 to 3.5 |
| D. | 4 to 5 |
| Answer» C. 2 to 3.5 | |
| 281. |
Dust laden air can be purified using a____________________? |
| A. | Cyclone separator |
| B. | Bag filter |
| C. | Gravity settler |
| D. | Tubular centrifuge |
| Answer» B. Bag filter | |
| 282. |
Dust collection efficiency of electrostatic precipitator can be as high as 99.9%. Maximum temperature and pressure of dust laden gas that can be cleaned in an electrostatic precipitator is respectively ? |
| A. | 200°C and 5 atm |
| B. | 1000°C and 10 atm |
| C. | 500°C and 50 atm |
| D. | 1000°C and 500 atm |
| Answer» C. 500°C and 50 atm | |
| 283. |
During washing of filter at the end of constant pressure filtration, the rate of washing equals the rate of filtration___________________? |
| A. | At time zero |
| B. | At the end of filtration |
| C. | When half the filtrate has been obtained |
| D. | At the end of filtration, but decreases with time subsequently |
| Answer» C. When half the filtrate has been obtained | |
| 284. |
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 | |
| 285. |
During size reduction by a jaw crusher, the energy consumed decreases with the__________________? |
| A. | Decreasing size of product at constant size of feed |
| B. | Decreasing machine capacity |
| C. | Increasing size of feed at constant reduction ratio |
| D. | None of these |
| Answer» D. None of these | |
| 286. |
During filtration operation, the filtrate encounters the resistance of the ___________________? |
| A. | Filter medium |
| B. | Cake |
| C. | Channel carrying the slurry to the upstream side of the cake and filtrate away from the filter medium |
| D. | All A., B. and C. |
| Answer» E. | |
| 287. |
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. | |
| 288. |
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 | |
| 289. |
Dry powdery solid materials are transported by a ______________ conveyor? |
| A. | Belt |
| B. | Bucket |
| C. | Screw |
| D. | None of these |
| Answer» D. None of these | |
| 290. |
Dispersion of a gas through liquid is done by using a__________________? |
| A. | Sparger |
| B. | Kneader |
| C. | Masticator |
| D. | None of these |
| Answer» B. Kneader | |
| 291. |
Diatomaceous earth is a/an_________________? |
| A. | Explosive |
| B. | Filter aid |
| C. | Filter medium |
| D. | Catalyst |
| Answer» C. Filter medium | |
| 292. |
Cyclones are used primarily for separating_________________? |
| A. | Solids |
| B. | Solids from fluids |
| C. | Liquids |
| D. | Solids from solids |
| Answer» C. Liquids | |
| 293. |
Cumulative analysis for determining surface is more precise than differential analysis, because of the_______________? |
| A. | Assumption that all particles in a single fraction are equal in size |
| B. | Fact that screening is more effective |
| C. | Assumption that all particles in a single fraction are equal in size, is not needed |
| D. | None of these |
| Answer» D. None of these | |
| 294. |
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 | |
| 295. |
Crushing efficiency of a machine ranges between __________________ percent? |
| A. | 0.1 to 2 |
| B. | 5 to 10 |
| C. | 20 to 25 |
| D. | 50 to 70 |
| Answer» B. 5 to 10 | |
| 296. |
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 | |
| 297. |
Critical speed of rotation, N (in rps – rotation per second) of a trammel is equal to (where, g = acceleration due to gravity = 9.81 m/sec2 and, r = radius of trammel, metre.) ? |
| A. | (1/2π). √(g/r) |
| B. | (1/π). √(g/r) |
| C. | ½ √(g/r) |
| D. | 2π. √(g/r) |
| Answer» B. (1/π). √(g/r) | |
| 298. |
Critical Speed (Nc) of a ball mill is given by (where R1 and R2 are radii of ball mill and the ball respectively) ? |
| A. | Nc = (1/4π). √(g/R1 – R2) |
| B. | Nc = (1/2π). √(g/R1 – R2) |
| C. | Nc = (1/π). √(g/R1 – R2) |
| D. | Nc = (1/2π). √(R1 – R2/g) |
| Answer» C. Nc = (1/π). √(g/R1 – R2) | |
| 299. |
_____________ conveyors are also called scrapers? |
| A. | Apron |
| B. | Screw |
| C. | Helical flight |
| D. | Both B. & C. |
| Answer» E. | |
| 300. |
__________ conveyor is the most suitable for short distance transportation of non-abrasive loose materials like garbage, grain, food wastes etc? |
| A. | Flight |
| B. | Screw |
| C. | Drag |
| D. | Belt |
| Answer» B. Screw | |