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.
| 351. |
%_A 'rupture disc' is provided in chemical equipments as an accessory meant for_% |
| A. | Relieving excess pressure |
| B. | Creating turbulence |
| C. | Enhancing mixing rate |
| D. | Avoiding vortex formation |
| Answer» B. Creating turbulence | |
| 352. |
%_In a shell and tube heat exchanger, triangular pitch arrangement as compared to square pitch arrangement_% |
| A. | Results in higher shell side pressure drop |
| B. | Can accomodate less number of tubes for a given shell diameter |
| C. | Facilitates easier shell side cleaning; hence is more suitable for handling high dirt factor shell side fluid |
| D. | Creates relatively lower turbulence on the shell side resulting in lower shell side heat transfer co-efficient |
| Answer» B. Can accomodate less number of tubes for a given shell diameter | |
| 353. |
%_Tube wall thickness depends on the cor-rosiveness of the fluids and their operating pressure & temperature and is specified by Birmingham wire gauge (B.W.G)-a number which varies from 8 to 18 with the numbers 14 and 16 being more commonly used. Outside diameter of tubes varies from about 15 to 50 mm; however a tube of less than __________ mm outside diameter is generally not recommended for fouling fluids._% |
| A. | 16 |
| B. | 19 |
| C. | 28 |
| D. | 38 |
| Answer» C. 28 | |
| 354. |
_ Floating head heat exchangers are used for the$? |
| A. | Heat transfer between corrosive fluids |
| B. | Cases where temperature difference between the shell and the tubes is more (>50°C) |
| C. | Co-current heat transfer systems |
| D. | Counter-current heat transfer systems |
| Answer» C. Co-current heat transfer systems | |
| 355. |
_ Number of evaporators which can be used in service in a multiple effect evaporation system is limited by the$? |
| A. | Practical limit reached, due to low heat transfer rate because of inadequate temperature difference |
| B. | Economic limit reached, when the plant cost exceeds the saving of steam |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 356. |
_ 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.$? |
| A. | 5 to 10 |
| B. | 15 to 30 |
| C. | 40 to 50 |
| D. | 55 to 75 |
| Answer» C. 40 to 50 | |
| 357. |
_ Cylindrical storage tanks used for the storage of volatile liquids (e.g., naphtha) have __________ roofs.$? |
| A. | Conical |
| B. | Flat |
| C. | Floating |
| D. | Fixed |
| Answer» D. Fixed | |
| 358. |
_ In a shell and tube heat exchanger, tube side __________ of the mass velocity.$? |
| A. | Heat transfer co-efficient is proportional to 0.8th power |
| B. | Pressure drop is proportional to the square |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 359. |
_ A cylindrical storage tank can have a self supported conical roof,$? |
| A. | If its diameter is less than 15-20metres |
| B. | If its diameter is more than 50 meters |
| C. | If the thickness of the roof is more than that of the cylindrical shell |
| D. | Irrespective of its diameter |
| Answer» B. If its diameter is more than 50 meters | |
| 360. |
_ Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about __________ kcal/hr.m².°C.$? |
| A. | 1250 |
| B. | 2500 |
| C. | 7500 |
| D. | 15000 |
| Answer» D. 15000 | |
| 361. |
_ Baffles may be eliminated for$? |
| A. | Low viscosity liquids (< 200 poise) |
| B. | High viscosity liquids (> 600 poise) |
| C. | Large diameter tanks |
| D. | None of these |
| Answer» C. Large diameter tanks | |
| 362. |
_ __________ closure is the weakest enclosure for cylindrical vessels.$? |
| A. | Hemispherical |
| B. | Torispherical |
| C. | Conical or flat plate |
| D. | Elliptical |
| Answer» D. Elliptical | |
| 363. |
_ For annular flow of a fluid, the ratio of the equivalent diameter for pressure drop calculation to the equivalent diameter for heat transfer calculation is$? |
| A. | D1/(d1 + d2) |
| B. | D2/(d1 + d2) |
| C. | (d1 + d2)/d1 |
| D. | (d1 + d2)/d2 |
| Answer» B. D2/(d1 + d2) | |
| 364. |
_ Generally, elliptical dished heads$? |
| A. | Are manufactured on 2:1 ratio of major to minor axis and is recommended to be used for pressure vessels operating above a pressure of 1.5 MN/m² |
| B. | Resist half the pressure rating compared to hemi spherical head provided on the cylindrical shell of the same thickness and diameter |
| C. | Are approximately as strong as seamless cylindrical shell having the corresponding I.D and O.D |
| D. | All of the above |
| Answer» E. | |
| 365. |
_ The operating pressure drop range in a bag filter is about __________ mm water gauge.$? |
| A. | 50-150 |
| B. | 5-10 |
| C. | 500-1500 |
| D. | 1500-2500 |
| Answer» B. 5-10 | |
| 366. |
_ Which of the following material is seldom used for pressure vessel construction?$? |
| A. | Rimmed still |
| B. | Mild steel |
| C. | Killed steel |
| D. | Semi-killed steel |
| Answer» B. Mild steel | |
| 367. |
_ Most of the storage vessels/tanks are made cylindrical, because of the fact that a cylinder$? |
| A. | Has greater structural strength |
| B. | Is easy to fabricate |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 368. |
_ In case of a continuous distillation column, increase in reflux ratio may result in the$? |
| A. | Lower fixed charges for the column |
| B. | Greater cost for the reboiler heat supply |
| C. | Greater cost for the condenser coolant |
| D. | All of the above |
| Answer» E. | |
| 369. |
_ Tube side heat transfer co-efficient for turbulent flow of liquid through tubes is proportional to$? |
| A. | G0.2 |
| B. | G0.5 |
| C. | G0.8 |
| D. | G1.5 |
| Answer» D. G1.5 | |
| 370. |
_ For turbulent flow (NRe > 2100) of low viscosity fluid (μ > 20cp) in steel pipes, the optimum inside pipe diameter is given by(where, Q = fluid flow rate, ft³/sec.ρ = fluid density, lb/ft³ μ = fluid viscosity, centipoise Di = optimum inside pipe diameter, inches)$? |
| A. | Di, opt = 3.9 Q0.45 ρ0.13 |
| B. | Di, opt = 3.9 Q0.45 . μ0.95 |
| C. | Di, opt = 4.7 Q0.36 . μ3.2ρ0.13 |
| D. | Di, opt = 3 Q0.36 . μ0.88 |
| Answer» B. Di, opt = 3.9 Q0.45 . ≈í¬∫0.95 | |
| 371. |
_ In a distillation column, bubble caps are located on trays with a pitch of __________ times the outside diameter of the caps.$? |
| A. | 1.3 to 2 |
| B. | 1.6 to 2 |
| C. | 2.5 |
| D. | 1.5 to 3 |
| Answer» B. 1.6 to 2 | |
| 372. |
_ Welded joint efficiency in the design of chemical process equipment is taken as$? |
| A. | 0.55 |
| B. | 0.75 |
| C. | 0.85 |
| D. | 0.95 |
| Answer» D. 0.95 | |
| 373. |
_ The retention time of material in a rotary dryer depends upon its$? |
| A. | Rpm |
| B. | Slope & length |
| C. | Flights arrangement |
| D. | All of the above |
| Answer» E. | |
| 374. |
_ Vapor velocity in a distillation column for non-foaming mixture is in the range of __________ times the flooding velocity.$? |
| A. | 0.1 to 0.3 |
| B. | 0.6 to 0.7 |
| C. | 0.85 to 0.95 |
| D. | 1.5 to 2 |
| Answer» C. 0.85 to 0.95 | |
| 375. |
_ Circumferential (hoop) stress in a thin cylindrical vessel under internal pressure is __________ the longitudinal stress.$? |
| A. | Half |
| B. | Equal to |
| C. | Twice |
| D. | Eight times |
| Answer» D. Eight times | |
| 376. |
_ The approximate liquid depth in an agitation tank is equal to (where, d = tank diameter)$? |
| A. | 0.5 d |
| B. | 0.75 d |
| C. | D |
| D. | 2 d |
| Answer» D. 2 d | |
| 377. |
_ Thin spherical shells subjected to internal pressure, develop __________ stresses.$? |
| A. | Radial |
| B. | Circumferential |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» B. Circumferential | |
| 378. |
_ 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.$? |
| A. | Molal flow rate of vapour |
| B. | Vapour molecular weight |
| C. | Pressure and temperature |
| D. | All of the above |
| Answer» E. | |
| 379. |
_ The ratio of the largest load in a test to the original cross-sectional area of the test specimen is called the __________ stress.$? |
| A. | Yield point |
| B. | Breaking |
| C. | Ultimate |
| D. | None of these |
| Answer» D. None of these | |
| 380. |
_ A pressure vessel is said to be made of 'thick' shell, if the ratio of its diameter to wall thickness is$? |
| A. | 10 |
| B. | 10 |
| C. | 20 |
| D. | 20 |
| Answer» B. 10 | |
| 381. |
_ Overall mass transfer co-efficient in case of absorption of __________ in water is based on the gas film co-efficient only, as the mass transfer process is gas film (phase) controlling.$? |
| A. | CO‚ÇÇ |
| B. | SO‚ÇÇ |
| C. | NH‚ÇÉ |
| D. | None of these |
| Answer» D. None of these | |
| 382. |
_ __________ liquor is best handled in a long tube vertical evaporator.$? |
| A. | Foamy |
| B. | Scaling |
| C. | Viscous |
| D. | Salting |
| Answer» B. Scaling | |
| 383. |
_ Mc Cable Thiele method used for finding theoretical stages in a distillation column assumes that the$? |
| A. | Sensible heat differences are small, because the temperature changes from tray to tray is small |
| B. | Trouton's rule is applicable |
| C. | Liquid/vapor loading across the column remains constant |
| D. | All of the above |
| Answer» E. | |
| 384. |
_ Pick out the wrong statement pertaining to the comparative evaluation of performance of the packed tower and the plate tower.$? |
| A. | Plate tower is perferred, if interstage cooling is required to remove heats of reaction or solution |
| B. | Plate tower is preferred over packed tower, if the operation involves liquids containing dispersed solids |
| C. | The total weight of a dry plate tower is usually much more than that of a dry packed tower designed for the same duty |
| D. | In operations involving large temperature changes. (e.g. distillation), plate towers are preferred over packed towers as the packing may be crushed due to large temperature changes |
| Answer» D. In operations involving large temperature changes. (e.g. distillation), plate towers are preferred over packed towers as the packing may be crushed due to large temperature changes | |
| 385. |
_ A head comprises of straight flange section, corner torus, section and central dished section. Crown radius and knuckle radius in a head is related respectively to the$? |
| A. | Central dished section and corner torus section |
| B. | Corner torus section and central dished section |
| C. | Central dished section and straight flange section |
| D. | Straight flange section and corner torus section |
| Answer» B. Corner torus section and central dished section | |
| 386. |
_ A forced circulation long tube vertical evaporator as compared to the natural circulation evaporator$? |
| A. | Is economical in operation |
| B. | Employs high velocity, high heat transfer rate and less heating surface requirement |
| C. | Employs a centrifugal pump placed between external downtake from vapor drum and inlet to tube bundle |
| D. | Both B & C |
| Answer» E. | |
| 387. |
_ Accidents in chemical plants are mostly due to$? |
| A. | Inadequate equipment design |
| B. | Faulty operating procedures |
| C. | Improper layout of the equipments |
| D. | Failure of equipments |
| Answer» C. Improper layout of the equipments | |
| 388. |
_ __________ tower is the most suitable gas-liquid contacting device involving highly corrosive fluids.$? |
| A. | Sieve plate |
| B. | Packed |
| C. | Bubble cap plate |
| D. | None of these |
| Answer» C. Bubble cap plate | |
| 389. |
_ The ideal size of round bubble caps to be used in industrial distillation column having a diameter of 3-6 metres is __________ cms.$? |
| A. | 5 |
| B. | 15 |
| C. | 7.5 |
| D. | 50 |
| Answer» C. 7.5 | |
| 390. |
_ Back-trapping in a distillation column results due to$? |
| A. | Low gas velocity |
| B. | High gas velocity |
| C. | Excessive liquid gradient over the tray |
| D. | Low reflux ratio |
| Answer» D. Low reflux ratio | |
| 391. |
_ In case of a shell and tube heat exchanger, the minimum shell thickness for carbon steel (inclusive of corrosion allowance) depends on shell diameter and is in the range of __________ mm.$? |
| A. | 3-5 |
| B. | 5-11 |
| C. | 8-15 |
| D. | 12-18 |
| Answer» C. 8-15 | |
| 392. |
_ The ratio of down take area to cross-sectional area of the tube, for calendria type evaporator ranges from$? |
| A. | 0.5 to 1 |
| B. | 1 to 1.5 |
| C. | 1.5 to 2 |
| D. | 2 to 2.5 |
| Answer» B. 1 to 1.5 | |
| 393. |
_ Frame thickness in the plate and frame filter press is normally in the range of __________ inches.$? |
| A. | 0.25 to 4 |
| B. | 0.25 to 8 |
| C. | 1 to 5 |
| D. | 1 to 12 |
| Answer» C. 1 to 5 | |
| 394. |
_ Pick out the wrong statement pertaining to 'Horton sphere' used for the storage of liquid ammonia.$? |
| A. | Diameter of Horton sphere is normally 6 to 25 metres and it is supported by 6 to 12 nos. tubular or rolled section column |
| B. | Thickness of spherical shell is half that of the cylinderical vessel under same operating pressure condition. Besides, the ratio of surface area to volume is less for sphere than any other shape ; hen |
| C. | Horton sphere is used for the storage of gases and volatile liquid at a moderate pressure of 1 to 10 kg/cm² |
| D. | Horton sphere is used for the storage of liquid at sub-zero temperature at very high pressure upto 200 kg/cm² |
| Answer» E. | |
| 395. |
_ Minimum baffle spacing recommended in a shell and tube heat exchanger is equal to$? |
| 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 | |
| 396. |
_ Larger depth of liquid on the trays of a distillation column$? |
| A. | Leads to high tray efficiency |
| B. | Results in higher pressure drop per tray |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 397. |
_ Liquid gradient over a tray can be minimised by$? |
| A. | Providing a higher skirt clearance or a higher weir |
| B. | Decreasing the number of rows of caps through which the liquid flows or by decreasing the velocity of liquid flow past the caps or by reducing the distance along the tray through which the liquid must |
| C. | Using split flow, radial flow or cascade flow for column diameter large than 4 ft |
| D. | All of the above |
| Answer» E. | |
| 398. |
_ Pick out the wrong statement about the design of seive plate column and the bubble cap column.$? |
| A. | The downcomer design and the residence time in the downcomer is almost same for seive plate and bubble cap columns |
| B. | Weir length for a bubble cap plate is the same as that for the seive plate |
| C. | Weir height for a bubble cap plate column is the same as that for a seive plate column |
| D. | Weir height in case of a bubble cap plate ranges from 50 to 150 mm and is higher than the seive plate |
| Answer» D. Weir height in case of a bubble cap plate ranges from 50 to 150 mm and is higher than the seive plate | |
| 399. |
_ Height equivalent to a theoretical plate (HETP) is the height of packing that will give the same separation as one theoretical plate in gas-liquid mass transfer operations like distillation, absorption/stripping and humidification/dehumidification. HETP which is experimentally determined, depends upon the$? |
| A. | Flow rates of each fluid |
| B. | Type and size of packing |
| C. | Concentration of each fluid |
| D. | All of the above |
| Answer» E. | |
| 400. |
__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 | |