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.
| 501. |
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 | |
| 502. |
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. | |
| 503. |
For sizing of fine materials, the most suitable equipment is a |
| A. | trommel |
| B. | grizzly |
| C. | shaking screen |
| D. | vibrating screen |
| Answer» E. | |
| 504. |
Which of the following oxides is not present in hematite iron ore? |
| A. | Titanium oxide |
| B. | Calcium oxide |
| C. | Cobalt oxide |
| D. | Manganese oxide |
| Answer» D. Manganese oxide | |
| 505. |
The reduction ratio for fine grinders is |
| A. | 43743 |
| B. | 44105 |
| C. | 20-40 |
| D. | as high as 100 |
| Answer» E. | |
| 506. |
Ribbon blenders are exclusively meant for |
| A. | blending miscible liquids. |
| B. | non-flowing powder and thin pastes. |
| C. | bath mixing. |
| D. | continuous mixing. |
| Answer» C. bath mixing. | |
| 507. |
The capacity of a gyratory crusher is __________ that of a jaw crusher with the same gape, handling the same feed & for the same product size range. |
| A. | same as |
| B. | 2.5 times |
| C. | 5 times |
| D. | 10 times |
| Answer» C. 5 times | |
| 508. |
Sulphuric acid mist is arrested by using a __________ scrubber. |
| A. | packed wet |
| B. | hollow wet |
| C. | venturi |
| D. | co-current |
| Answer» D. co-current | |
| 509. |
Basic slag is not ground in |
| A. | jaw crushers |
| B. | ball mills |
| C. | compartment mills |
| D. | tube mills |
| Answer» B. ball mills | |
| 510. |
Mixing of plastic solids is generally facilitated by |
| A. | dispersion |
| B. | mastication |
| C. | kneading |
| D. | none of these |
| Answer» D. none of these | |
| 511. |
Which of the following relationships between co-efficinet of friction (μ) between rock & roll and a (half of the angle of nip) of the particle to be crushed is correct ? |
| A. | μ > tan α |
| B. | μ ≥ tan α |
| C. | μ > tan 2α |
| D. | μ ≤ tan α |
| Answer» C. Œº > tan 2Œ± | |
| 512. |
Critical Speed (Nc) of a ball mill is given by(where R1 and R2 are radii of ball mill and the ball respectively). |
| A. | |
| B. | |
| C. | |
| D. | |
| Answer» C. | |
| 513. |
rpm of a trommel at critical speed is given by (where, D = Diameter of trommel in ft) |
| A. | |
| B. | |
| C. | |
| D. | 76.75 D |
| Answer» C. | |
| 514. |
Trommels separate a mixture of particles depending on their |
| A. | size |
| B. | density |
| C. | wettability |
| D. | electrical & magnetic properties |
| Answer» B. density | |
| 515. |
The inlet pressure in a constant rate filtration |
| A. | increases continuously |
| B. | decreases gradually |
| C. | remains constant |
| D. | none of these |
| Answer» B. decreases gradually | |
| 516. |
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 | |
| 517. |
__________ mills fall in the category of tumbling mills, |
| A. | Ball and pebble |
| B. | Rod and tube |
| C. | Compartment |
| D. | all (a), (b) & (c) |
| Answer» E. | |
| 518. |
Screen capacity is expressed in terms of |
| A. | tons/hr |
| B. | tons/ft2 |
| C. | both (a) & (b) |
| D. | tons/hr-ft2 |
| Answer» E. | |
| 519. |
Metallic wire mesh is used as a filtering medium for the separation of dust from dust laden gas in case of a/an |
| A. | air filter |
| B. | bag filter |
| C. | venturi scrubber |
| D. | hydrocyclones |
| Answer» B. bag filter | |
| 520. |
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 | |
| 521. |
According to Bond crushing law, the work required to form particle of size 'D' from very large feed is (where (S/V)p and (S/V)f are surface to volume ratio of the product and feed respectively). |
| A. | (S/V)p |
| B. | (S/V)p |
| C. | (S/V)2p |
| D. | (S/V)f |
| Answer» C. (S/V)2p | |
| 522. |
Limestone is normally crushed in a |
| A. | roll crusher |
| B. | hammer crusher |
| C. | ball mill |
| D. | tube mill |
| Answer» C. ball mill | |
| 523. |
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. | |
| 524. |
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. | |
| 525. |
The capacity of a pneumatic conveying system depends upon the |
| A. | bulk density of materials. |
| B. | pressure of the conveying air. |
| C. | diameter of the conveying line. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 526. |
Fick's law relates to |
| A. | energy consumption |
| B. | final particle size |
| C. | feed size |
| D. | none of these |
| Answer» B. final particle size | |
| 527. |
For separation of sugar solution from settled out mud, we use a __________ filter. |
| A. | sparkler |
| B. | plate and frame |
| C. | centrifugal |
| D. | rotary drum vaccum |
| Answer» D. rotary drum vaccum | |
| 528. |
Traces of liquid tar fog present in coke oven gas is separated using |
| A. | electrostatic precipitator |
| B. | cyclone separator |
| C. | strainer |
| D. | none of these |
| Answer» B. cyclone separator | |
| 529. |
Vacuum filter is most suitable for the |
| A. | removal of fines from liquid. |
| B. | liquids having high vapour pressure. |
| C. | liquids of very high viscosity. |
| D. | none of these. |
| Answer» E. | |
| 530. |
In filtration, the use of 'filter aid' helps in |
| A. | reducing the filtration pressure. |
| B. | accelerating the rate of filtration. |
| C. | deplugging the filter medium. |
| D. | enhancing the cake porosity in case of a dense impermeable cake. |
| Answer» D. enhancing the cake porosity in case of a dense impermeable cake. | |
| 531. |
Pick out the material having minimum Rittinger's number. |
| A. | Calcite |
| B. | Pyrite |
| C. | Quartz |
| D. | Galena |
| Answer» D. Galena | |
| 532. |
The unit of specific cake resistance is |
| A. | gm/cm2 |
| B. | cm/gm |
| C. | cm/gm2 |
| D. | gm/gm |
| Answer» B. cm/gm | |
| 533. |
Screen efficiency is |
| A. | recovery/rejection |
| B. | recovery |
| C. | rejection |
| D. | none of these |
| Answer» E. | |
| 534. |
Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of |
| A. | bronze |
| B. | stainless steel |
| C. | flint or porcelain |
| D. | concrete |
| Answer» D. concrete | |
| 535. |
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 | |
| 536. |
Which of the following mineral dressing operations is termed as 'comminution'? |
| A. | Panning |
| B. | Spiralling |
| C. | Tabling |
| D. | None of these |
| Answer» E. | |
| 537. |
Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill ) |
| A. | D |
| B. | 1/D |
| C. | D2.5 |
| D. | 1/D2.5 |
| Answer» D. 1/D2.5 | |
| 538. |
Which of the following gives the crushing energy required to create new surface ? |
| A. | Taggarts rule |
| B. | Fick's law |
| C. | Rittinger's law |
| D. | none of these |
| Answer» D. none of these | |
| 539. |
In continuous filtration (at a constant pressure drop), filtrate flow rate varies inversely as the |
| A. | square root of the velocity. |
| B. | square of the viscosity. |
| C. | filtration time only. |
| D. | washing time only. |
| Answer» B. square of the viscosity. | |
| 540. |
Size reduction of __________ is accomplished in steam heated rollers and roll crushers. |
| A. | resins |
| B. | gums |
| C. | hard rubber |
| D. | waxes |
| Answer» D. waxes | |
| 541. |
To get ultrafine particles, the equipment used is a |
| A. | ball mill |
| B. | rod mill |
| C. | hammer crusher |
| D. | fluid energy mill |
| Answer» E. | |
| 542. |
The distribution given by microscopic analysis of powder is |
| A. | number |
| B. | length |
| C. | area |
| D. | volume |
| Answer» B. length | |
| 543. |
Sphericity of raschig ring (whose length and diameter are equal) is |
| A. | >1 |
| B. | <1 |
| C. | 1 |
| D. | 2 |
| Answer» D. 2 | |
| 544. |
The value of 'angle of nip' is generally about |
| A. | 16° |
| B. | 32° |
| C. | 52° |
| D. | 64° |
| Answer» C. 52¬∞ | |
| 545. |
Out of the following size reduction equipments, the maximum feed size can be accepted by the |
| A. | tube mill |
| B. | ball mill |
| C. | jaw crusher |
| D. | jet pulveriser |
| Answer» D. jet pulveriser | |
| 546. |
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. | |
| 547. |
Two particles are called to be equal settling, if they are having the same. |
| A. | size. |
| B. | specific gravity. |
| C. | terminal velocities in the same fluid & in the same field of force. |
| D. | none of these. |
| Answer» D. none of these. | |
| 548. |
With increase in the capacity of screens, the screen effectiveness |
| A. | remains unchanged |
| B. | increases |
| C. | decreases |
| D. | decreases exponentially |
| Answer» D. decreases exponentially | |
| 549. |
The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μrn is |
| A. | 6.35 kWh/ton |
| B. | 9.0 kWh/ton |
| C. | 18 kWh/ton |
| D. | 25.4 kWh/ton |
| Answer» D. 25.4 kWh/ton | |
| 550. |
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/dp sp |
| B. | Φs = Vp/dp sp |
| C. | Φs = 6 dp Sp/Vp |
| D. | Φs = dp Sp/Vp |
| Answer» B. Œ¶s = Vp/dp sp | |