chemical engineering mechanical operations MCQs – Page 19

Practise multiple-choice questions from chemical engineering mechanical operations for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering mechanical operations Mcqs

361. As the product becomes finer, the energy required for grinding___________________?
0

A. Is 1.5 times that for coarser grinding

B. Decreases

C. Is same as for coarser grinding

D. Increases

362. For crushing of solids, the Rittingers law states that the work required for crushing is proportional to __________________?
0

A. The new surface created

B. None of these

C. The change in volume due to crushing

D. The size reduction ratio

363. For the transportation of ultrafine particles, the equipment used is a ____________ conveyor?
0

A. Pneumatic

B. None of these

C. Belt

D. Screw

364. The resistance offered by the filter used in a bag filter is proportional to (where, c = dust concentration, and s = particle size)?
0

A. s . c

B. 1/s . c

C. s/c

D. c/s

365. The process opposite to dispersion is termed as the___________________?
0

A. Flocculation

B. Filtration

C. Sedimentation

D. None of these

366. A centrifugal filtration unit operating at a rotational speed of w has inner surface of the liquid (density ?L) located at a radial distance R from the axis of rotation. The thickness of the liquid film is ? and no cake is formed. The initial pressure drop during filtration is ___________________?
0

A. w2 . ??L (2R + ?)

B. w2 . ?2 . ?L

C. w2 . R . ?L(R + 2?)

D. w2 . R2 . ?L

367. Which of the following is not accomplished by agitation of liquids in agitators ?
0

A. Dispersing gas in liquid

B. Suspending solid particles

C. Dispersing immiscible liquid in form of emulsion

D. Blending of immiscible liquids

368. The reduction ratio for fine grinders is_____________?
0

A. As high as 100

B. 20-Oct

C. 20-40

D. 10-May

369. Filter medium resistance is that offered by the__________________?
0

A. Embedded particles in the septum

B. Filter cloth

C. Filter cloth and the embedded particle collectively

D. None of these

370. For the preliminary breaking of hard rock, we use a____________________?
0

A. Squirrel-cage disintegrator

B. Ball mill

C. Gyratory crusher

D. Tube mill

371. Which of the following is not a revolving/tumbling mill used for size reduction ?
0

A. Pebble mill

B. Rod mill

C. Compartment mill

D. Cage mill

372. A widely used size reduction equipment for ______________ is Bradford breaker?
0

A. Iron core

B. Wheat

C. Talc

D. Coal

373. In a roll crusher, both the rolls_________________?
0

A. All A., B. and C.

B. Run either at the same or different speeds

C. Are rotated towards each other

D. Have the same diameter

374. Which of the following mechanical conveyors does not come under the division scrapers? ?
0

A. Drag conveyor

B. Bucket elevators

C. Ribbon conveyor

D. Flight conveyor

375. All resistances during washing of cake _____________________?
0

A. None of these

B. Increases

C. Remain constant

D. Decreases

376. Colloidal mills are used for ______________ grinding?
0

A. Intermediate

B. Fine

C. Ultrafine

D. Coarse

377. For spheres, the specific surface shape factor is given by___________________?
0

A. AD/V

B. A/V

C. ?(AD/V)

D. D/V

378. In closed circuit grinding as compared to open circuit grinding, the_________________?
0

A. Operation is economical

B. Production rate at a given limiting size is lower

C. Specific surface of product is more

D. Product has lesser size uniformity

379. Size reduction of the ______________ can be suitably done by ball mills, crushing rolls and rod mills?
0

A. Metalliferous ores

B. Non-metallic ores

C. Basic slags

D. Asbestos & mica

380. _____________ conveyors are also called scrapers?
0

A. Apron

B. Screw

C. Helical flight

D. Both B. & C.

Previous Next

Showing 361 to 380 of 445 mcqs