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.
| 551. |
The thickness of heat transfer plates used in the plate type heat exchanger ranges from __________ mm, pressed in a single piece provided with grooves & corrugations. |
| A. | 0.3 to 0.8 |
| B. | 1.25 to 3.125 |
| C. | 3.5 to 7.0 |
| D. | 43807 |
| Answer» C. 3.5 to 7.0 | |
| 552. |
Overall tray efficiency of a distillation column is the ratio of the number of |
| A. | overall gas transfer units to the number of ideal trays required. |
| B. | ideal trays required to the number of real trays required. |
| C. | real trays required to the number of ideal trays required. |
| D. | none of these. |
| Answer» C. real trays required to the number of ideal trays required. | |
| 553. |
For high pressure process equipments/vessels, the connected nozzle should be |
| A. | welded |
| B. | screwed |
| C. | flanged |
| D. | brazed |
| Answer» D. brazed | |
| 554. |
Large process vessels operating under extreme temperature and pressure conditions are normally clad/ lined with materials like stainless steel, aluminium, nickel & its alloys, copper & its alloys and titanium. The cladding thickness is generally about __________ percent of the total thickness. |
| A. | 1 to 5 |
| B. | 10 to 20 |
| C. | 30 to 40 |
| D. | 40 to 50 |
| Answer» C. 30 to 40 | |
| 555. |
Fouling factor must be included in the calculation of over all design heat transfer coefficient, when the liquid |
| A. | containing suspended solids flows at low velocity. |
| B. | containing suspended solids flows at high velocity. |
| C. | is highly viscous. |
| D. | is of high specific gravity. |
| Answer» B. containing suspended solids flows at high velocity. | |
| 556. |
Hole diameter of the seive trays in the distillation column ranges from __________ mm. |
| A. | lto3 |
| B. | 4 to 8 |
| C. | 3 to 12.5 |
| D. | 12.5 to 18.5 |
| Answer» D. 12.5 to 18.5 | |
| 557. |
The length of straight rectangular weir used on cross-flow trays is generally __________ the column diameter. |
| A. | 0.6-0.8 times |
| B. | equal to |
| C. | twice |
| D. | 2 ft irrespective of (for column > 3 ft diameter) |
| Answer» B. equal to | |
| 558. |
Thin spherical shells subjected to internal pressure, develop __________ stresses. |
| A. | radial |
| B. | circumferential |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» B. circumferential | |
| 559. |
Bubble cap diameter used for the distillation column having diameter ranging from 1.5 to 4.5 metres is about __________ mm. |
| A. | 10 |
| B. | 50 |
| C. | 100 |
| D. | 150 |
| Answer» D. 150 | |
| 560. |
Weep holes provided in the plates of a distillation column |
| A. | facilitate draining out liquid from a tray when the unit is not in operation. |
| B. | are normally located near the overflow weir so that any delivery of liquid during operation follows approximately the same path as the overflow fluid. |
| C. | must be large enough (usually 1/4" to 5/8" dia) to prevent plugging but should not deliver excessive amount of fluid during operation. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 561. |
__________ liquor is best handled in a long tube vertical evaporator. |
| A. | Foamy |
| B. | Scaling |
| C. | Viscous |
| D. | Salting |
| Answer» B. Scaling | |
| 562. |
Of the pressure vessels, with same thickness but different diameters, which one withstands higher pressure ? |
| A. | Larger dia vessel. |
| B. | Smaller dia vessel. |
| C. | Larger dia long vessel. |
| D. | Strength of the vessel is same irrespective of the diameter. |
| Answer» C. Larger dia long vessel. | |
| 563. |
In a thin cylindrical shell, the hoop stress is __________ stress. |
| A. | radial |
| B. | circumferential tensile |
| C. | compressive |
| D. | longitudinal |
| Answer» C. compressive | |
| 564. |
The force due to wind load acting on a tall vessel depends upon its |
| A. | shape. |
| B. | outside diameter. |
| C. | height. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 565. |
In a __________ rivetted joint, the rivets in the various rows are opposite to each other. |
| A. | zig-zag |
| B. | chain |
| C. | diamond |
| D. | none of these |
| Answer» C. diamond | |
| 566. |
A certain pressure vessel manufacturer avoids doing reinforcements calculations for openings by always providing a reinforcing pad extending upto double the diameter of the opening and of the same material and thickness as that of the shell wall. If area compensation is accepted as a code guideline, his approach leads to safe design |
| A. | only if the opening is on spherical vessel. |
| B. | only if the opening is on a vertical cylinderical vessel. |
| C. | only if the opening is on a horizontal cylinderical vessel. |
| D. | irrespective of the shape of the vessel. |
| Answer» E. | |
| 567. |
What is the value of 'q' for saturated vapor feed to a distillation column ?(where q = fraction of the feed stream that is liquid.) |
| A. | 0 |
| B. | 1 |
| C. | <0 |
| D. | > 1 |
| Answer» B. 1 | |
| 568. |
Shortest distance between two tubes is |
| A. | called tube pitch. |
| B. | called tube clearance. |
| C. | more in case of triangular pitch as compared to square pitch of tube layout. |
| D. | none of these. |
| Answer» C. more in case of triangular pitch as compared to square pitch of tube layout. | |
| 569. |
Lap joints are preferred for plates having thickness __________ mm. |
| A. | < 12.5 |
| B. | > 3 |
| C. | > 5 |
| D. | 43743 |
| Answer» C. > 5 | |
| 570. |
In the design of a shell and tube heat exchanger, the corrosion allowance |
| A. | need not be provided for non-pressure parts like tie rods, spacers, baffles, supports etc. |
| B. | for carbon steel and cast iron pressure parts is 1.5 mm (except for tubes) and for severe conditions it is 3 mm. |
| C. | for internal cover and tube sheet is provided on both the sides. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 571. |
Compensation against openings in process vessels for giving inlet and outlet connections, for providing sight glasses and manholes etc. is provided for strength and rigidity. The most efficient type of compensation is of __________ type. |
| A. | nozzle or rim |
| B. | flared out |
| C. | fluid in |
| D. | ring plate |
| Answer» B. flared out | |
| 572. |
Equivalent diameter for heat transfer calculation for a duct of square cross-section having each side as 'd' will be |
| A. | d |
| B. | d |
| C. | 2πd |
| D. | 2d |
| Answer» B. d | |
| 573. |
For identical operating conditions, the pressure drop over __________ tray is the highest out of the following. |
| A. | sieve |
| B. | valve |
| C. | counterflow |
| D. | bubble cap |
| Answer» E. | |
| 574. |
The LMTD correction factor (FT) is applied in __________ heat exchangers. |
| A. | 1-1 cocurrent |
| B. | double pipe |
| C. | all multipass |
| D. | all (involving liquid/liquid heat transfer) |
| Answer» D. all (involving liquid/liquid heat transfer) | |
| 575. |
A/an __________ is used for changing the direction of a pipeline. |
| A. | elbow |
| B. | union |
| C. | flange |
| D. | disc compensator |
| Answer» B. union | |
| 576. |
Height of the flights in the rotary drier is in the range of |
| A. | 0.08 to 0.12 d |
| B. | 0.02 to 0.05 d |
| C. | 0.2 to 0.5 d |
| D. | 0.5 to 0.6 d |
| Answer» B. 0.02 to 0.05 d | |
| 577. |
Ponchon Savarit method is based on the use of enthalpy concentration diagram, which contains the bubble point curve (saturated liquid curve), dew point curve (saturated vapour curve) and equilibrium tie lines. As compared to McCabe-Thiele's method, this method |
| A. | is more accurate in finding the number of equilibrium stages. |
| B. | accounts for the enthalpy changes in the process. |
| C. | facilitates direct calculation of heat load on reboiler & condenser from, the diagram used in this method. |
| D. | all 'a', 'b' & 'c'. |
| Answer» E. | |
| 578. |
Vertical condenser is advantageous to the horizontal condenser from operation point of view, when |
| A. | hydrostatic head is required for refluxing the condensate. |
| B. | only the function of condensation is to be carried out. |
| C. | sub cooling of condensate is desired. |
| D. | both the functions of condensation & sub cooling are carried out in a single unit. |
| Answer» E. | |
| 579. |
If 'D' is the inside diameter of the shell of a shell and tube heat exchanger, then the baffle spacing is usually in the range of |
| A. | D/2 or minimum 2" to 5D. |
| B. | D/5 or minimum 2" to 5D. |
| C. | D/5 or minimum 2" to D. |
| D. | none of these. |
| Answer» C. D/5 or minimum 2" to D. | |
| 580. |
The diameter of a propeller agitator used in agitation tank ranges from __________ percent of the tank diameter and its peripherial speed is normally 300 to 500 metres/minute. |
| A. | 5 to 10 |
| B. | 15 to 30 |
| C. | 40 to 50 |
| D. | 55 to 75 |
| Answer» C. 40 to 50 | |
| 581. |
In shell and tube heat exchangers, straight tie rods are used to |
| A. | hold baffle in space. |
| B. | fix the tubes in position. |
| C. | account for thermal strain. |
| D. | none of these. |
| Answer» B. fix the tubes in position. | |
| 582. |
The clearance between two tubes in a shell and tube heat exchanger is known as 'ligament', whose minimum value is __________ the outside diameter of the tube, but in no case it should be less than 4.5 mm. |
| A. | equal to |
| B. | half |
| C. | one fourth |
| D. | three fourth |
| Answer» D. three fourth | |
| 583. |
What is the slope of the operating line in the stripping section of a distillation column ? |
| A. | 0 |
| B. | ‚àû |
| C. | > 1 |
| D. | < 1 |
| Answer» D. < 1 | |
| 584. |
The distance between the top of the slots and the liquid surface when the static liquid is just ready to flow over the overflow weir is called |
| A. | downcomer liquid seal |
| B. | static submergence |
| C. | skirt clearance |
| D. | none of these |
| Answer» C. skirt clearance | |
| 585. |
Which of the following lengths of heat exchanger tubes are normally not used in practice ? |
| A. | 2.5 metres |
| B. | 6 metres |
| C. | 10 metres |
| D. | 0.5 metre |
| Answer» D. 0.5 metre | |
| 586. |
Rate of filtrate delivery is inversely proportional to the |
| A. | filtering area & the pressure difference driving force. |
| B. | viscosity of filtrate. |
| C. | cake & filter medium resistance. |
| D. | both (a) and (b) |
| Answer» E. | |
| 587. |
Elastic failure of a material occurs, when the tensile stress equals yield strength, yield point or the elastic limit. Also, the elastic failure occurs according to maximum strain theory, when the maximum tensile strain equals (where, σ = yield strength and E = modulus of elasticity)$ |
| A. | E |
| B. | σ |
| C. | σ/E |
| D. | E/σ |
| Answer» D. E/œÉ | |
| 588. |
The units of Young's modulus of elasticity and __________ are the same. |
| A. | strain |
| B. | stress |
| C. | modular ratio |
| D. | none of these |
| Answer» C. modular ratio | |
| 589. |
The maximum liquid gradient over a tray must not exceed |
| A. | 0.5" -1.25". |
| B. | 2"-3.5". |
| C. | 5". |
| D. | half the tray spacing. |
| Answer» B. 2"-3.5". | |
| 590. |
The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio is |
| A. | 0 |
| B. | ‚àû |
| C. | 1 |
| D. | minimum |
| Answer» C. 1 | |
| 591. |
Liquid redistribution should be done in a packed tower packed with raschig rings every 6 metres or __________ times the column diameter, whichever is lower. |
| A. | 2.5-3.0 |
| B. | 5-7.5 |
| C. | 10-12.5 |
| D. | 15-20 |
| Answer» B. 5-7.5 | |
| 592. |
For a cylindrical shell, (subject to the thickness of uppermost course being more than the minimum for diaofthe tank in question), the thickness of the courses of shell |
| A. | decreases upwards. |
| B. | increases upwards. |
| C. | remains same throughout. |
| D. | may decrease or increase upwards depending upon whether vacuum or positive pressure would be maintained inside the shell. |
| Answer» B. increases upwards. | |
| 593. |
Pick out the wrong statement about distillation operation |
| A. | Distillation under vacuum is a substitute for steam distillation. |
| B. | In differential (simple) distillation, the vapour is removed as soon as it is formed without appreciable condensation. |
| C. | In flash (equilibrium) distillation, a definite fraction of liquid is vaporised in such a way that the evolved vapour & residual liquids are in equilibrium with each other. |
| D. | Flash distillation, differential distillation & steam distillation are all continuous distillation processes. |
| Answer» E. | |
| 594. |
Cylindrical pressure vessels in horizontal condition is generally supported on a __________ support. |
| A. | lug |
| B. | skirt |
| C. | saddle |
| D. | guy wire |
| Answer» D. guy wire | |
| 595. |
With increase in temperature drop (in a shell and tube heat exchanger), the LMTD correction factor, FT |
| A. | decreases very rapidly |
| B. | increases very rapidly |
| C. | remains constant |
| D. | increases linearly |
| Answer» B. increases very rapidly | |
| 596. |
Tubes are fixed to the tube sheet (a thick circular metallic plate) by the method of tube rolling and brazing (non-removable) or ferrule connection (removable). Thickness of the tube, sheet is normally __________ the outside diameter of the tube but in no case it should be less than 22 mm (7/8"). |
| A. | half |
| B. | three fourth |
| C. | equal to |
| D. | 1.5 times |
| Answer» D. 1.5 times | |
| 597. |
In actual operation of a bubble cap distillation tower, the __________ at the bottom of the tower is more than that at the top of the tower. |
| A. | molal flow rate of vapour |
| B. | vapour molecular weight |
| C. | pressure and temperature |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 598. |
The ratio for the rate of washing to the final rate of filtration in a washing type of plate and frame filter is |
| A. | 0.25 |
| B. | 0.5 |
| C. | 0.75 |
| D. | 1.25 |
| Answer» B. 0.5 | |
| 599. |
In a continuous distillation column, the optimum reflux ratio ranges from __________ times the minimum reflux ratio. |
| A. | 1.1 to 1.5 |
| B. | 1.6 to 2 |
| C. | 2.2 to 2.6 |
| D. | 2.7 to 3 |
| Answer» B. 1.6 to 2 | |
| 600. |
In case of a 'thin' pressure vessel, the ratio of its diameter to wall thickness is |
| A. | < 10 |
| B. | > 10 |
| C. | > 20 |
| D. | 30 |
| Answer» C. > 20 | |