MCQOPTIONS
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MCQOPTIONS
This section includes 908 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 651. |
Which of the following factors affect the pressure drop in a co-current gas-liquid absorption packed tower ? |
| A. | Size, shape, orientation and surface of the packing particles. |
| B. | Density and viscosity of fluids. |
| C. | Fluid flow rates. |
| D. | All (a), (b) and (c). |
| Answer» E. | |
| 652. |
Safety valves are provided in chemical equipments to guard against excessive |
| A. | temperature |
| B. | pressure/pressure fluctuation |
| C. | turbulence |
| D. | noise |
| Answer» C. turbulence | |
| 653. |
In a shell and tube heat exchanger, tube side __________ of the mass velocity. |
| A. | heat transfer co-efficient is proportional to 0.8th power |
| B. | pressure drop is proportional to the square |
| C. | both 'a' & 'b' |
| D. | neither 'a' nor 'b' |
| Answer» D. neither 'a' nor 'b' | |
| 654. |
Diameter of bubble caps used in high pressure columns is __________ as compared to that used in identical vacuum columns. |
| A. | less |
| B. | more |
| C. | same |
| D. | either (a) or (b); no generalisation can be made |
| Answer» C. same | |
| 655. |
__________ strain is measured using a 'strain rosetter'. |
| A. | Volumetric |
| B. | Shear |
| C. | Linear |
| D. | none of these |
| Answer» D. none of these | |
| 656. |
A forced circulation long tube vertical evaporator as compared to the natural circulation evaporator |
| A. | is economical in operation. |
| B. | employs high velocity, high heat transfer rate and less heating surface requirement. |
| C. | employs a centrifugal pump placed between external downtake from vapor drum and inlet to tube bundle. |
| D. | both (b) & (c). |
| Answer» E. | |
| 657. |
Which of the following factors determine the amount of entrainment in a distillation column ? |
| A. | Plate spacing. |
| B. | Depth of liquid above the bubble cap slots. |
| C. | Vapour velocity in the volume between the plates. |
| D. | All (a), (b) and (c). |
| Answer» E. | |
| 658. |
The ratio of tube length to shell diameter in case of liquid shell and tube heat exchanger ranges from |
| A. | 2 to 3 |
| B. | 3 to 5 |
| C. | 4 to 8 |
| D. | 6 to 12 |
| Answer» D. 6 to 12 | |
| 659. |
The ratio of down take area to cross-sectional area of the tube, for calendria type evaporator ranges from |
| A. | 0.5 to 1 |
| B. | 1 to 1.5 |
| C. | 1.5 to 2 |
| D. | 2 to 2.5 |
| Answer» B. 1 to 1.5 | |
| 660. |
The normal range of velocity of water in pipes is __________ m/sec. |
| A. | 0.1-0.5 |
| B. | 43497 |
| C. | 18537 |
| D. | 15-30 |
| Answer» C. 18537 | |
| 661. |
The most common standard size of bubble caps used in industrial operation is |
| A. | 1" dia cap with 0.5" dia riser. |
| B. | 6" dia cap with 4" dia riser. |
| C. | 8" dia cap with 1" dia riser. |
| D. | 4" dia cap with 8" dia riser. |
| Answer» C. 8" dia cap with 1" dia riser. | |
| 662. |
In packed towers provided with saddle packing, liquid redistributors are positioned at every __________ times column diameter or 6 metres whichever is less. |
| A. | 43526 |
| B. | 43682 |
| C. | 42278 |
| D. | 20-25 |
| Answer» C. 42278 | |
| 663. |
Minimum baffle spacing recommended in a shell and tube heat exchanger is equal to |
| A. | 5 cms |
| B. | 40% of the I.D. of the shell |
| C. | 25 cms |
| D. | I.D. of the shell |
| Answer» B. 40% of the I.D. of the shell | |
| 664. |
Diameter of rivet hole (d, mm) and the plate thickness (t, mm) are related by Unwin's formula as |
| A. | d = 1.1 t |
| B. | d = 1.6 t |
| C. | d = 1.5 t |
| D. | 3t |
| Answer» C. d = 1.5 t | |
| 665. |
In a distillation column, the minimum residence time for liquid in the downspout is about __________ seconds. |
| A. | 1 |
| B. | 8 |
| C. | 80 |
| D. | 180 |
| Answer» C. 80 | |
| 666. |
With increase in the reflux ratio for a fixed production from a continuous binary distillation column, the __________ decreases. |
| A. | fixed charges initially |
| B. | running cost of cooling water for condenser |
| C. | vapour & liquid load both |
| D. | running cost of steam for reboiler |
| Answer» B. running cost of cooling water for condenser | |
| 667. |
Pick out the wrong statement pertaining to the comparative evaluation of performance of the packed tower and the plate tower. |
| A. | Plate tower is perferred, if interstage cooling is required to remove heats of reaction or solution. |
| B. | Plate tower is preferred over packed tower, if the operation involves liquids containing dispersed solids. |
| C. | The total weight of a dry plate tower is usually much more than that of a dry packed tower designed for the same duty. |
| D. | In operations involving large temperature changes. (e.g. distillation), plate towers are preferred over packed towers as the packing may be crushed due to large temperature changes. |
| Answer» D. In operations involving large temperature changes. (e.g. distillation), plate towers are preferred over packed towers as the packing may be crushed due to large temperature changes. | |
| 668. |
Flanges are connected to pipes by |
| A. | screwing |
| B. | welding |
| C. | brazing |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 669. |
In a multiple effect evaporator system having 'n' effects, the amount of water evaporated per unit surface area in approximately equal to __________ times that in a single effect. |
| A. | 'n'th |
| B. | (1/n)th |
| C. | 0.5 nth |
| D. | 1.5 nth |
| Answer» C. 0.5 nth | |
| 670. |
In a bag filter, the pressure drop increases directly as the |
| A. | density of the gas, but is independent of the viscosity of the gas. |
| B. | density of the gas and inversely as viscosity of the gas. |
| C. | viscosity of the gas and inversely as density of the gas. |
| D. | none of these. |
| Answer» C. viscosity of the gas and inversely as density of the gas. | |
| 671. |
The ideal size of round bubble caps to be used in industrial distillation column having a diameter of 3-6 metres is __________ cms. |
| A. | 5 |
| B. | 15 |
| C. | 7.5 |
| D. | 50 |
| Answer» C. 7.5 | |
| 672. |
Which of the following is used to set the diameter of the distillation column ? |
| A. | Number of theorectical plates. |
| B. | Static submergence. |
| C. | Allowable vapour velocity. |
| D. | Length of straight rectangular weir on cross-flow tray. |
| Answer» D. Length of straight rectangular weir on cross-flow tray. | |
| 673. |
Which of the following packing materials provides for maximum mass transfer ? |
| A. | Lessig rings. |
| B. | Raschig rings. |
| C. | Cross-partition rings. |
| D. | All give the same value. |
| Answer» D. All give the same value. | |
| 674. |
Most of the storage vessels/tanks are made cylindrical, because of the fact that a cylinder |
| A. | has greater structural strength. |
| B. | is easy to fabricate. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 675. |
To avoid the tearing off the plate of an edge, the margin (i.e., the minimum distance from the centre of the rivet hole to the nearest edge of the plate) should be equal to |
| A. | 0.5 d |
| B. | d |
| C. | 1.5 d |
| D. | 2.5 d |
| Answer» D. 2.5 d | |
| 676. |
An adequate clearance between the tray and the shell wall of a distillation column is provided to |
| A. | drain the liquid from the tray when the unit is not in operation. |
| B. | allow for thermal expansion and facilitate installation. |
| C. | avoid back-trapping. |
| D. | none of these. |
| Answer» C. avoid back-trapping. | |
| 677. |
The minimum shell thickness for tank ≤ 15 metres diameter is limited to __________ mm, for reasons of elastic stability.$ |
| A. | 2 |
| B. | 5 |
| C. | 10 |
| D. | 15 |
| Answer» C. 10 | |
| 678. |
Pressure differential maintained across a continuous rotary vacuum filter is in the range of __________ mm Hg column. |
| A. | 50 to 100 |
| B. | 100 to 150 |
| C. | 250 to 500 |
| D. | 600 to 700 |
| Answer» D. 600 to 700 | |
| 679. |
for couplings and unions would be |
| A. | 60 |
| B. | 200 |
| C. | 350 |
| D. | negligible |
| Answer» E. | |
| 680. |
Wind load consideration in the design of a support can be neglected, when the vessel is |
| A. | tall (say 30 metres), but is full of liquid. |
| B. | tall but empty. |
| C. | short (< 2 m) and housed indoor. |
| D. | none of these. |
| Answer» D. none of these. | |
| 681. |
For a cylinderical internally pressurised vessel, which of the following closure types would withstand highest pressure, if each closure is of the same material and thickness ? |
| A. | hemispherical |
| B. | ellipsoidal (2 : 1) |
| C. | conical |
| D. | flat plate |
| Answer» C. conical | |
| 682. |
When one of the fluids is highly corrosive and has fouling tendency, it should |
| A. | preferably flow inside the tube for its easier internal cleaning. |
| B. | perferably flow outside the tube. |
| C. | flow at a very slow velocity. |
| D. | flow outside the tube, when the flow is counter-current and inside the tube when the flow is co-current. |
| Answer» B. perferably flow outside the tube. | |
| 683. |
The absorption factor is defined as (where, S1 = slope of the equilibrium curve, S2 = slope of the operating line) |
| A. | S1/S2 |
| B. | S1.S2 |
| C. | S2/S1 |
| D. | 1/S1.S2 |
| Answer» B. S1.S2 | |
| 684. |
Log mean temperature difference in case of multi-pass shell and tube heat exchanger is always |
| A. | less than arithmetic mean value. |
| B. | more than arithmetic mean value. |
| C. | more than geometric mean value. |
| D. | both(b) & (c). |
| Answer» B. more than arithmetic mean value. | |
| 685. |
Steam is preferred to be used as a heating medium in heat exchangers, because of its |
| A. | low cost. |
| B. | high latent heat. |
| C. | non-corrosive condensate. |
| D. | high film co-efficient. |
| Answer» C. non-corrosive condensate. | |
| 686. |
Circumferential (hoop) stress in a thin cylindrical vessel under internal pressure is __________ the longitudinal stress. |
| A. | half |
| B. | equal to |
| C. | twice |
| D. | eight times |
| Answer» D. eight times | |
| 687. |
Baffle width is normally taken as __________ times the tank diameter. |
| A. | 0.1-0.12 |
| B. | 0.4-0.5 |
| C. | 0.45-0.6 |
| D. | 0.2-0.45 |
| Answer» B. 0.4-0.5 | |
| 688. |
The design stress, which is more than the damaging stress, is the least unit stress that will render a member unfit for service before the end of its normal life. The design stress factor or factor of safety indicates the margin between design stress and the __________ stress. |
| A. | working |
| B. | damaging |
| C. | allowable |
| D. | none of these |
| Answer» C. allowable | |
| 689. |
LMTD correction factor is used in heat exchanger design for |
| A. | double pipe heat exchanger. |
| B. | multipass shell and tube heat exchanger. |
| C. | fouling fluids. |
| D. | counter flow of hot and cold fluids. |
| Answer» C. fouling fluids. | |
| 690. |
The practical representative values of HETP for a number of commercial operations lies within a range of __________ metre. |
| A. | 0.1-0.2 |
| B. | 0.2-0.5 |
| C. | 0.4-0.9 |
| D. | 1.2-1.5 |
| Answer» D. 1.2-1.5 | |
| 691. |
In case of a shell and tube heat exchanger, the effect of L/D on inside film heat transfer co-efficient (hi) vanishes after a Reynold number of |
| A. | 1000 |
| B. | 3000 |
| C. | 5000 |
| D. | 10000 |
| Answer» E. | |
| 692. |
Rivets are generally specified by the |
| A. | head diameter |
| B. | shank diameter |
| C. | overall length |
| D. | none of these |
| Answer» C. overall length | |
| 693. |
Length to diameter ratio of most rotary driers is in the range of |
| A. | 1 to 2 |
| B. | 4 to 10 |
| C. | 10 to 20 |
| D. | 20 to 30 |
| Answer» C. 10 to 20 | |
| 694. |
In a __________ rivetted joint, the number of rivets decreases from the innermost row to the outermost row. |
| A. | chain |
| B. | diamond |
| C. | zig-zag |
| D. | none of these |
| Answer» C. zig-zag | |
| 695. |
Bubble cap tray is the most commonly used tray in large distillation column, because |
| A. | of its flexibility and nearly constant efficiency under varying conditions of operation. |
| B. | it incurs less pressure drop as compared to any other try designed for the same duty. |
| C. | it eliminates the foaming and entrain-ment tendency during operation. |
| D. | none of these. |
| Answer» B. it incurs less pressure drop as compared to any other try designed for the same duty. | |
| 696. |
A perforated plate has holes of diameter dn arranged in a pitch ph. Each hole has a tube of I.D. dt passing through it. The ligament efficiency is given by |
| A. | (ph - dh)/ph |
| B. | (ph - dh . dt/2)/ph |
| C. | (ph - dt)/ph |
| D. | (ph - dh)/dh |
| Answer» D. (ph - dh)/dh | |
| 697. |
Vertical storage vessels are never supported by __________ support. |
| A. | bracket |
| B. | saddle |
| C. | skirt |
| D. | lug |
| Answer» C. skirt | |
| 698. |
Oxygen carrying pipelines in chemical industries are coloured with __________ colour. |
| A. | yellow |
| B. | black |
| C. | blue |
| D. | red |
| Answer» D. red | |
| 699. |
Spherical shaped pressure vessel is considered to be the most ideal, because it can |
| A. | withstand higher pressure for a given metallic shell thickness. |
| B. | be fabricated very easily. |
| C. | be designed without wind load considerations. |
| D. | be supported very easily. |
| Answer» B. be fabricated very easily. | |
| 700. |
Generally, no corrosion allowance in wall thickness of a part is required, if the thickness is more than __________ mm. |
| A. | 10 |
| B. | 20 |
| C. | 30 |
| D. | 5 |
| Answer» D. 5 | |