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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 6151. |
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 | |
| 6152. |
Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines ? |
| A. | Compartment mill |
| B. | Rod mill |
| C. | Pebble mill |
| D. | Tube mill. |
| Answer» C. Pebble mill | |
| 6153. |
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. | |
| 6154. |
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. | |
| 6155. |
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 | |
| 6156. |
Use of 'grinding aids' is done in __________ grinding. |
| A. | dry |
| B. | wet |
| C. | ultrafine |
| D. | intermediate |
| Answer» B. wet | |
| 6157. |
Which of the following is the most suitable filter for separation of abrasive solids suspended in a corrosive liquid ? |
| A. | Sand bed filter |
| B. | Plate and frame filter press |
| C. | Vacuum filter |
| D. | Batch basket centrifuge. |
| Answer» D. Batch basket centrifuge. | |
| 6158. |
All resistances during washing of cake |
| A. | increases |
| B. | decreases |
| C. | remain constant |
| D. | none of these |
| Answer» D. none of these | |
| 6159. |
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) | |
| 6160. |
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 (a), (b) and (c). |
| Answer» E. | |
| 6161. |
Tube mill compared to ball mill |
| A. | produces finer products. |
| B. | is long in comparison with its diameter. |
| C. | uses smaller balls. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 6162. |
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. | <img src="/_files/images/chemical-engineering/mechanical-operations/120-344-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/mechanical-operations/120-344-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/mechanical-operations/120-344-3.png"> |
| D. | <img src="/_files/images/chemical-engineering/mechanical-operations/120-344-4.png"> |
| Answer» B. <img src="/_files/images/chemical-engineering/mechanical-operations/120-344-2.png"> | |
| 6163. |
For the preliminary breaking of hard rock, we use a |
| A. | gyratory crusher |
| B. | ball mill |
| C. | tube mill |
| D. | squirrel-cage disintegrator |
| Answer» B. ball mill | |
| 6164. |
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 | |
| 6165. |
A screen is said to be blinded, when the |
| A. | oversizes are present in undersize fraction. |
| B. | undersizes are retained in oversize fraction. |
| C. | screen is plugged with solid particles. |
| D. | screen capacity is abruptly increased. |
| Answer» D. screen capacity is abruptly increased. | |
| 6166. |
What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls ? |
| A. | 0.5 |
| B. | 1.0 |
| C. | 2.76 |
| D. | 0.66 |
| Answer» E. | |
| 6167. |
Separation of solid suspended in liquid into a supernatant clear liquid and a denser slurry employs a process termed as the |
| A. | coagulation |
| B. | flocculation |
| C. | sedimentation |
| D. | clarification |
| Answer» D. clarification | |
| 6168. |
Ultrafine grinders operate principally by |
| A. | slow compression |
| B. | impact |
| C. | attrition |
| D. | cutting action |
| Answer» D. cutting action | |
| 6169. |
Half the angle of nip, ( ), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively). |
| A. | <img src="/_files/images/chemical-engineering/mechanical-operations/105-119-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/mechanical-operations/105-119-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/mechanical-operations/105-119-3.png"> |
| D. | <img src="/_files/images/chemical-engineering/mechanical-operations/105-119-4.png"> |
| Answer» C. <img src="/_files/images/chemical-engineering/mechanical-operations/105-119-3.png"> | |
| 6170. |
Which of the following comes in the category of primary crusher for hard and tough stone ? |
| A. | Jaw crusher |
| B. | Cone crusher |
| C. | Gyratory crusher |
| D. | None of these |
| Answer» B. Cone crusher | |
| 6171. |
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 | |
| 6172. |
Filtration rate through a filter cake is proportional to (where, S = filtering surface R = specific cake resistance = viscosity of the filtrate) |
| A. | <i>S</i> |
| B. | 1/ |
| C. | <i>R</i> |
| D. | 1/ |
| E. | all (a), (b) & (c) |
| Answer» E. all (a), (b) & (c) | |
| 6173. |
Which one is a filter aid ? |
| A. | Convas fabric |
| B. | Diatomaceous earth |
| C. | Calcined lime |
| D. | None of these |
| Answer» C. Calcined lime | |
| 6174. |
To remove dirt from the flowing fluid, we use a |
| A. | coagulant |
| B. | gravity settler |
| C. | strains |
| D. | clarifier |
| Answer» D. clarifier | |
| 6175. |
Which of the following crushers can be considered as a combination of a jaw crusher and a roller crusher ? |
| A. | Rod mill |
| B. | Fluid energy mill |
| C. | Gyratory crusher |
| D. | Ball mill |
| Answer» D. Ball mill | |
| 6176. |
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 | |
| 6177. |
Trommels are revolving screens which normally operate in the range of __________ rpm. |
| A. | 1 - 2 |
| B. | 15 - 20 |
| C. | 40 - 50 |
| D. | 60 - 75 |
| Answer» C. 40 - 50 | |
| 6178. |
Maximum size reduction in a fluid energy mill is achieved by |
| A. | compression |
| B. | interparticle attrition |
| C. | cutting |
| D. | impact |
| Answer» C. cutting | |
| 6179. |
rpm of a trommel at critical speed is given by (where, D = Diameter of trommel in ft) |
| A. | <img src="/_files/images/chemical-engineering/mechanical-operations/123-387-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/mechanical-operations/123-387-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/mechanical-operations/123-387-3.png"> |
| D. | 76.75 |
| E. | <span class="root"><i>D</i></span> |
| Answer» C. <img src="/_files/images/chemical-engineering/mechanical-operations/123-387-3.png"> | |
| 6180. |
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 | |
| 6181. |
The process opposite to 'dispersion' is termed as the |
| A. | flocculation |
| B. | sedimentation |
| C. | filtration |
| D. | none of these. |
| Answer» B. sedimentation | |
| 6182. |
The cake resistance increases steadily with the time of filtration in a plate and frame filter employing constant __________ filtration. |
| A. | rate |
| B. | pressure |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 6183. |
__________ conveyors are also called scrapers. |
| A. | Apron |
| B. | Screw |
| C. | Helical flight |
| D. | both (b) & (c) |
| Answer» E. | |
| 6184. |
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 | |
| 6185. |
Which of the following is a continuous filter? |
| A. | Plate and frame filter |
| B. | Cartridge filter |
| C. | Shell and leaf filter |
| D. | None of these |
| Answer» E. | |
| 6186. |
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 | |
| 6187. |
Pick out the wrong statement pertaining to the turbine agitator. |
| A. | Recommended peripheral speed for the turbine agitator is 200-250 metres/minute. |
| B. | Pitched blade turbine agitator gives only radial flow with complete absence of the axial flow. |
| C. | Generally, the diameter of the agitator is kept between l/3rd to l/6th of the tank diameter while the blade length is l/4th of agitator diameter (with central disc, it is l/8th of the agitator diameter). |
| D. | Turbine agitator should be located at a height not less than one agitator diameter length from the bottom. If the depth of liquid in the tank is more than twice the agitator diameter, two agitators should be used. |
| Answer» C. Generally, the diameter of the agitator is kept between l/3rd to l/6th of the tank diameter while the blade length is l/4th of agitator diameter (with central disc, it is l/8th of the agitator diameter). | |
| 6188. |
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. | |
| 6189. |
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. | |
| 6190. |
Dry powdery solid materials are transported by a __________ conveyor. |
| A. | belt |
| B. | bucket |
| C. | screw |
| D. | none of these |
| Answer» D. none of these | |
| 6191. |
Fluid energy mill comes in the category of |
| A. | grinder |
| B. | crusher |
| C. | cutter |
| D. | ultrafine grinder |
| Answer» E. | |
| 6192. |
About 2-3 hp, power per gallon of a thin liquid provides vigrous agitation in an agitator. 'Power number' in agitation is given by |
| A. | <img src="/_files/images/chemical-engineering/mechanical-operations/118-323-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/mechanical-operations/118-323-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/mechanical-operations/118-323-3.png"> |
| D. | <img src="/_files/images/chemical-engineering/mechanical-operations/118-323-4.png"> |
| Answer» B. <img src="/_files/images/chemical-engineering/mechanical-operations/118-323-2.png"> | |
| 6193. |
Percentage of drum submerged in the slurry in case of rotary drum filter is |
| A. | 3 |
| B. | 30 |
| C. | 85 |
| D. | 25 |
| Answer» C. 85 | |
| 6194. |
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. | |
| 6195. |
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. | |
| 6196. |
Pick out the material having minimum Rittinger's number. |
| A. | Calcite |
| B. | Pyrite |
| C. | Quartz |
| D. | Galena |
| Answer» D. Galena | |
| 6197. |
__________ mills are termed as impactors. |
| A. | Hammer |
| B. | Cage |
| C. | Rolling-compression |
| D. | none of these |
| Answer» B. Cage | |
| 6198. |
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. | |
| 6199. |
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 | |
| 6200. |
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. | |