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.
| 201. |
In case of a hammer crusher ? |
| A. | Crushing takes place by impact breaking |
| B. | Maximum acceptable feed size is 30 cms |
| C. | Reduction ratio can be varied by adjusting the distance from cage to hammers |
| D. | All A., B. and C. |
| Answer» E. | |
| 202. |
In case of a hammer crusher, the final product size depends on the____________________? |
| A. | Feed rate |
| B. | Rotor speed |
| C. | Clearance between hammer & grinding plates |
| D. | All A., B. and C. |
| Answer» E. | |
| 203. |
In case of a ball mill ? |
| A. | Coarse feed requires a larger ball |
| B. | Fine feed requires a larger ball |
| C. | Operating speed should be more than the critical speed |
| D. | None of these |
| Answer» B. Fine feed requires a larger ball | |
| 204. |
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 | |
| 205. |
In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the ________________ crushing? |
| A. | Secondary |
| B. | Fine |
| C. | Primary |
| D. | Ultrafine |
| Answer» D. Ultrafine | |
| 206. |
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 | |
| 207. |
In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the _____________ crushing? |
| A. | Primary |
| B. | Secondary |
| C. | Fine |
| D. | Ultrafine |
| Answer» C. Fine | |
| 208. |
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. | |
| 209. |
In a roll crusher, the specific power consumption and the production rate is affected by the_________________? |
| A. | Reduction ratio |
| B. | Differential roll speed |
| C. | Both A. and B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 210. |
In a mixer, the quantity, (v. L/D) is termed as __________ number (where, v = longitudinal velocity of material, L = length of the mixer, D = diffusivity in axial mixing) ? |
| A. | Weber |
| B. | Peclet |
| C. | Brinkman |
| D. | Schmidt |
| Answer» C. Brinkman | |
| 211. |
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. | |
| 212. |
In a ball mill, the volume occupied by the balls (when the mill is stopped) is about _______________ percent of the volume of the mill? |
| A. | 35 |
| B. | 50 |
| C. | 70 |
| D. | 85 |
| Answer» C. 70 | |
| 213. |
If radius of a batch basket centrifuge is halved & the r.p.m. is doubled, then the_________________? |
| A. | Linear speed of the basket is doubled |
| B. | Linear speed of the basket is halved |
| C. | Centrifugal force is doubled |
| D. | Capacity of centrifuge is increased |
| Answer» D. Capacity of centrifuge is increased | |
| 214. |
If dp is the equivalent diameter of a non-spherical particle, Vp its volume and sp its surface area, then its sphericity is φs is defined by________________? |
| A. | φs = 6 Vp/dpsp |
| B. | φs = Vp/dpsp |
| C. | φs = 6 dpSp/Vp |
| D. | φs = dpSp/Vp |
| Answer» B. φs = Vp/dpsp | |
| 215. |
If a force greater than that of gravity is used to separate solids & fluids of different densities, the process is termed as the __________________? |
| A. | Sedimentation |
| B. | Flocculation |
| C. | Dispersion |
| D. | Centrifugation |
| Answer» E. | |
| 216. |
Hot, lumpy & abrasive materials are best transported by using a/an ___________ conveyor ? |
| A. | Apron |
| B. | Belt |
| C. | Screw |
| D. | Flight |
| Answer» B. Belt | |
| 217. |
Horsepower required for a roll crusher is directly proportional to its__________________? |
| A. | Reduction ratio |
| B. | Capacity |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 218. |
Highly viscous liquids & pastes are agitated by________________? |
| A. | Propellers |
| B. | Turbine agitators |
| C. | Multiple blade paddles |
| D. | None of these |
| Answer» D. None of these | |
| 219. |
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. | |
| 220. |
Helical screw agitator is used for________________? |
| A. | Mixing highly viscous pastes |
| B. | Blending immiscible liquids |
| C. | Mixing liquids at very high temperature (> 250 °C) |
| D. | None of these |
| Answer» B. Blending immiscible liquids | |
| 221. |
Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The clearance between the tank bottom and the bottom most impeller should be about (where, D = impeller diameter) ? |
| A. | 0.5 D |
| B. | D |
| C. | 1.5 D |
| D. | 2 D |
| Answer» C. 1.5 D | |
| 222. |
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 | |
| 223. |
Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively) ? |
| A. | cos α = (dr + dp)/(dr + df) |
| B. | cos α = (dr + df)/(dr + dp) |
| C. | tan α = (dr + dp)/(dr + df) |
| D. | sin α = (dr + dp)/(dr + df) |
| Answer» B. cos α = (dr + df)/(dr + dp) | |
| 224. |
Gyratory crushers compared to the reciprocating jaw crushers__________________? |
| A. | Have greater capacity per unit of discharge area |
| B. | Crush intermittently |
| C. | Are less suitable for coarse materials |
| D. | Have less steady power consumption |
| Answer» B. Crush intermittently | |
| 225. |
Gummy & sticky materials like molasses, sugar etc. are best transported/handled by using a ______________ conveyor? |
| A. | Drag |
| B. | Ribbon |
| C. | Screw |
| D. | Slat |
| Answer» C. Screw | |
| 226. |
Grizzlies are used for separating _____________ solids? |
| A. | Coarse |
| B. | Fine |
| C. | Any size |
| D. | None of these |
| Answer» C. Any size | |
| 227. |
Grinding efficiency of a ball mill is of the order of _______________ percent? |
| A. | 1-5 |
| B. | 40-50 |
| C. | 75-80 |
| D. | 90-95 |
| Answer» B. 40-50 | |
| 228. |
Grinding characteristic of a material is given by its___________________? |
| A. | HGI |
| B. | Angle of repose |
| C. | Shatter index |
| D. | Abrasion index |
| Answer» B. Angle of repose | |
| 229. |
Grindability of a material does not depend upon its_____________________? |
| A. | Elasticity |
| B. | Hardness |
| C. | Toughness |
| D. | Size |
| Answer» E. | |
| 230. |
Gravity settling process is not involved in the working of a________________? |
| A. | Hydrocyclone |
| B. | Classifier |
| C. | Dorr-thickener |
| D. | Sedimentation tank |
| Answer» B. Classifier | |
| 231. |
Gravity stamp mill is meant for the ___________________ crushing? |
| A. | Primary |
| B. | Intermediate |
| C. | Fine |
| D. | Ultrafine |
| Answer» D. Ultrafine | |
| 232. |
Gold ore concentration is mostly done using___________________? |
| A. | Jigging |
| B. | Tabling |
| C. | Froth floatation |
| D. | Elutriation |
| Answer» C. Froth floatation | |
| 233. |
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. | |
| 234. |
General crushing equation is given by d(P/m) = -K (dD̅ S/D̅ n S). Bond’s crushing law is obtained by solving this equation for n = _____________ and feed of infinite size? |
| A. | 1 |
| B. | 1.5 |
| C. | 2 |
| D. | 2.5 |
| Answer» C. 2 | |
| 235. |
Gelatinous solid (which plug the septum) can be filtered by a _____________ filter? |
| A. | Sparkler |
| B. | Plate and frame |
| C. | Vacuum leaf |
| D. | Pre-coat |
| Answer» E. | |
| 236. |
Froth floatation is the most suitable for treating ____________________? |
| A. | Iron ores |
| B. | Sulphide ores |
| C. | Quartzite |
| D. | None of these |
| Answer» C. Quartzite | |
| 237. |
For transporting pasty material, one will use a/an__________________? |
| A. | Apron conveyor |
| B. | Belt conveyor |
| C. | Screw conveyor |
| D. | Bucket elevator |
| Answer» D. Bucket elevator | |
| 238. |
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 | |
| 239. |
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 | |
| 240. |
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 | |
| 241. |
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. | AD/V |
| D. | None of these |
| Answer» B. π/6 = (V/D3) | |
| 242. |
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 | |
| 243. |
For sizing of fine materials, the most suitable equipment is a____________________? |
| A. | Trommel |
| B. | Grizzly |
| C. | Shaking screen |
| D. | Vibrating screen |
| Answer» E. | |
| 244. |
For separation of sugar solution from settled out mud, we use a ___________________ filter? |
| A. | Sparkler |
| B. | Plate and frame |
| C. | Centrifugal |
| D. | Rotary drum vacuum |
| Answer» D. Rotary drum vacuum | |
| 245. |
For removal of very small amounts of precipitate from large volume of water, the most suitable filter is the ______________ filter? |
| A. | Plate & frame |
| B. | Shell & leaf |
| C. | Sand |
| D. | Rotary vacuum |
| Answer» D. Rotary vacuum | |
| 246. |
For raschig rings, the sphericity is_____________________? |
| A. | 0.5 |
| B. | 1 |
| C. | < 1 |
| D. | √3 |
| Answer» D. √3 | |
| 247. |
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 | |
| 248. |
For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a__________________? |
| A. | Buhrstone mill |
| B. | Ball mill |
| C. | Crushing rolls |
| D. | Hammer mill |
| Answer» B. Ball mill | |
| 249. |
For efficient grinding, ball mills must be operated__________________? |
| A. | At a speed less than the critical speed |
| B. | At a speed more than the critical speed |
| C. | At a speed equal to the critical speed |
| D. | With minimum possible small balls |
| Answer» B. At a speed more than the critical speed | |
| 250. |
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 | |