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.
| 401. |
__Bracket supports are the most suitable for supporting __________ vessels.__ |
| A. | Thick walled vertical |
| B. | Horizontal |
| C. | Thin shperical (e.g. Horton sphere) |
| D. | None of these |
| Answer» B. Horizontal | |
| 402. |
__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. | |
| 403. |
__The circumferential (hoop) stress in a thin walled cylinderical vessel under internal pressure is__ |
| A. | pd/2t |
| B. | pd/4t |
| C. | pd/t |
| D. | pd/3t |
| Answer» B. pd/4t | |
| 404. |
__Pick out the wrong statement pertaining to shell and tube heat exchanger.__ |
| A. | Clearance between shell & baffles and between tube & baffles should be minimum to avoid by-passing of the fluid, but it should be enough to permit the removal of tube bundle |
| B. | Baffles are supported independently of the tubes by tie rods and positioned by spacers |
| C. | Tie rods are fixed at one end in the tube sheet by making blind holes and the minimum number of tie rods is 4 with at least 10 mm diameter |
| D. | Bracket supports are used for horizontal shell, while saddle support is used for vertical shell |
| Answer» E. | |
| 405. |
__Heat transfer co-efficient for a horizontal condenser as compared to a vertical condenser operating under similar conditions is__ |
| A. | Same |
| B. | Less |
| C. | About 3 times |
| D. | About 0.33 times |
| Answer» D. About 0.33 times | |
| 406. |
__Optimum reflux ratio in a continuous distillation column is determined by the__ |
| A. | Maximum permissible vapour velocity |
| B. | Flooding limit of the column |
| C. | Total cost consideration (fixed cost of the column plus the cooling water & steam cost) |
| D. | None of these |
| Answer» D. None of these | |
| 407. |
__For a cylinderical vessel of moderate height, the weld joint efficiency for joints parallel to the cylinderical axis is given as 1.0, while for joints along the girth (circumference) it is given as 0.8. In calculating the shell wall thickness using code formula for an internally pressurised cylinderical vessel, what value of weld joint efficiency should be used?__ |
| A. | 0.8 |
| B. | 0.9 |
| C. | 1.0 |
| D. | (0.8)0.5 |
| Answer» B. 0.9 | |
| 408. |
__Low pressure steam (with saturation temperature between 105 to 120°C) is usually used in the vacuum evaporators, which normally employ a vacuum of about __________ mm Hg (referred to a 760 mm mercury barometer).__ |
| A. | 250 |
| B. | 450 |
| C. | 650 |
| D. | 750 |
| Answer» D. 750 | |
| 409. |
__The thermal stress in a metallic bar does not depend upon the__ |
| A. | Changes in temperature |
| B. | Cross-sectional area |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» C. Both A & B | |
| 410. |
__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 | |
| 411. |
__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 | |
| 412. |
__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 | |
| 413. |
__Normal screwed fittings are used for pipes upto a diameter of __________ inches.__ |
| A. | 1.5 |
| B. | 3 |
| C. | 5 |
| D. | 7 |
| Answer» C. 5 | |
| 414. |
__In which of the following evaporators, steam is fed inside the tube while the liquor is outside the tube?__ |
| A. | Long tube vertical evaporator |
| B. | Short tube vertical evaporator |
| C. | Horizontal tube evaporator |
| D. | None of these |
| Answer» D. None of these | |
| 415. |
__For storing hazardous chemicals in large storage tanks, the minimum safe distance between the two tanks should range between __________ times the tank diameter.__ |
| A. | 1 to 1.5 |
| B. | 2.5 to 3.5 |
| C. | 4 to 5 |
| D. | 6 to 8 |
| Answer» B. 2.5 to 3.5 | |
| 416. |
__Le/D for fully open globe value may be around__ |
| A. | 10 |
| B. | 25 |
| C. | 75 |
| D. | 300 |
| Answer» E. | |
| 417. |
__The minimum baffle height should be__ |
| A. | Equal to the impeller diameter |
| B. | Twice the impeller diameter |
| C. | Twice the tank diameter |
| D. | 3/4 of the tank height |
| Answer» C. Twice the tank diameter | |
| 418. |
__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 | |
| 419. |
_A/an __________ is used for changing the direction of a pipeline.$? |
| A. | Elbow |
| B. | Union |
| C. | Flange |
| D. | Disc compensator |
| Answer» B. Union | |
| 420. |
_Smaller sized packings are generally dumped to the packed columns, and the large ones of size greater than __________ mm are stacked individually, which provides better control over bed porosity and offers lower gas pressure drop.$? |
| A. | 25 |
| B. | 50 |
| C. | 75 |
| D. | 150 |
| Answer» D. 150 | |
| 421. |
_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.$? |
| A. | Working |
| B. | Damaging |
| C. | Allowable |
| D. | None of these |
| Answer» C. Allowable | |
| 422. |
_In inclined long tube vertical evaporators, the tubes are inclined at an angle of$? |
| A. | 15° |
| B. | 90° |
| C. | 45° |
| D. | 60° |
| Answer» D. 60¬¨‚àû | |
| 423. |
_A cylinderical pressure vessel of volume 6 πm³ has to be designed to withstand a maximum internal pressure of 10 atm. The allowable design stress of the material is 125N/mm² and corrosion allowance is 2 mm. The thickness of the vessel for a length/diameter ratio of 3 will be close to$? |
| A. | 5 mm |
| B. | 6 mm |
| C. | 8 mm |
| D. | 10 mm |
| Answer» E. | |
| 424. |
_Which of the following factors determine the amount of entrainment in a distillation column?$? |
| A. | Plate spacing |
| B. | Depth of liquid above the bubble cap slots |
| C. | Vapour velocity in the volume between the plates |
| D. | All of the above |
| Answer» E. | |
| 425. |
_Steam is preferred to be used as a heating medium in heat exchangers, because of its$? |
| A. | Low cost |
| B. | High latent heat |
| C. | Non-corrosive condensate |
| D. | High film co-efficient |
| Answer» C. Non-corrosive condensate | |
| 426. |
_When one of the fluids is highly corrosive and has fouling tendency, it should$? |
| 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 | |
| 427. |
_Smoker's equation for the calculation of number of equilibrium stages in a continuous binary distillation column is used, when the$? |
| A. | Relative volatility is close to one (e.g., separation of close boiling isomers) |
| B. | Feed is not at its bubble point |
| C. | Number of equilibrium stages in only stripping section is to be calculated |
| D. | Number of equilibrium stages required is likely to be very small |
| Answer» B. Feed is not at its bubble point | |
| 428. |
_Scale up problem in design based on the similarity concept takes into account __________ similarity.$? |
| A. | Geometrical |
| B. | Kinematic |
| C. | Dynamic |
| D. | All of the above |
| Answer» E. | |
| 429. |
_In the design of a shell and tube heat exchanger, the corrosion allowance$? |
| A. | Need not be provided for non-pressure parts like tie rods, spacers, baffles, supports etc |
| B. | For carbon steel and cast iron pressure parts is 1.5 mm (except for tubes) and for severe conditions it is 3 mm |
| C. | For internal cover and tube sheet is provided on both the sides |
| D. | All of the above |
| Answer» E. | |
| 430. |
_Baffle spacing is generally __________ the I.D. of the shell.$? |
| A. | More than |
| B. | Not greater than |
| C. | Not less than one fifth of |
| D. | Both B and C |
| Answer» E. | |
| 431. |
_The absorption factor is defined as (where, S‚ÇÅ = slope of the equilibrium curve, S‚ÇÇ = slope of the operating line)$? |
| A. | S‚ÇÅ/S‚ÇÇ |
| B. | S‚ÇÅ.S‚ÇÇ |
| C. | S‚ÇÇ/S‚ÇÅ |
| D. | 1/S‚ÇÅ.S‚ÇÇ |
| Answer» B. S‚Äö√á√Ö.S‚Äö√á√á | |
| 432. |
_Where does the maximum tensile strength occur in a thick cylindrical vessel subjected to internal pressure?$? |
| A. | At the inner surface |
| B. | At the mid thickness of the cylindrical wall |
| C. | At the outer surface |
| D. | None of these |
| Answer» B. At the mid thickness of the cylindrical wall | |
| 433. |
_Diameter of the seive tray column is determined by the$? |
| A. | Lower limit of vapour velocity |
| B. | Upper limit of the vapour velocity |
| C. | Hole diameter of the seive tray |
| D. | Height of the plate spacing |
| Answer» C. Hole diameter of the seive tray | |
| 434. |
_Cylindrical pressure vessels in horizontal condition is generally supported on a __________ support.$? |
| A. | Lug |
| B. | Skirt |
| C. | Saddle |
| D. | Guy wire |
| Answer» D. Guy wire | |
| 435. |
_Fouling factor must be included in the calculation of over all design heat transfer coefficient, when the liquid$? |
| A. | Containing suspended solids flows at low velocity |
| B. | Containing suspended solids flows at high velocity |
| C. | Is highly viscous |
| D. | Is of high specific gravity |
| Answer» B. Containing suspended solids flows at high velocity | |
| 436. |
_Column support for the roof of cylindrical storage tank must be provided for$? |
| A. | Small diameter tanks |
| B. | Large diameter tanks |
| C. | Small diameter tall tanks |
| D. | All of the above |
| Answer» C. Small diameter tall tanks | |
| 437. |
_The value of fouling factor depends upon the$? |
| A. | Characteristic of process fluid |
| B. | Velocity of process fluid containing suspended solids |
| C. | Suspended solids in the fluid |
| D. | All of the above |
| Answer» E. | |
| 438. |
_Vertical storage vessels are never supported by __________ support.$? |
| A. | Bracket |
| B. | Saddle |
| C. | Skirt |
| D. | Lug |
| Answer» C. Skirt | |
| 439. |
_Pressure drop due to pipe fittings can be estimated by the equation, ΔP/p = 4f.Le/D.V2/2gc, where, Le = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and D = diameter of the fitting. The value of Le/D (dimensionless) for 45° elbow and 180° close return bends would be respectively around$? |
| A. | 5 and 10 |
| B. | 45 and 75 |
| C. | 180 and 300 |
| D. | 300 and 500 |
| Answer» C. 180 and 300 | |
| 440. |
___________ strain is measured using a 'strain rosetter'.$? |
| A. | Volumetric |
| B. | Shear |
| C. | Linear |
| D. | None of these |
| Answer» D. None of these | |
| 441. |
_In hydrostatic testing of welded pipe (for leakage, strength etc.) the ratio of minimum hydrostatic test pressure to internal design pressure is around$? |
| A. | 0.5 |
| B. | 1.5 |
| C. | 2.5 |
| D. | 3.5 |
| Answer» C. 2.5 | |
| 442. |
_The normal range of velocity of steam in pipes is __________ m/sec.$? |
| A. | 0.1-0.5 |
| B. | 1-5 |
| C. | 10-20 |
| D. | 80-100 |
| Answer» E. | |
| 443. |
_Vertical condenser is advantageous to the horizontal condenser from operation point of view, when$? |
| A. | Hydrostatic head is required for refluxing the condensate |
| B. | Only the function of condensation is to be carried out |
| C. | Sub cooling of condensate is desired |
| D. | Both the functions of condensation & sub cooling are carried out in a single unit |
| Answer» E. | |
| 444. |
_An increase in the liquid resistance to interphase mass transfer and a resultant reduction in plate efficiency is caused by$? |
| A. | An increase in liquid viscosity |
| B. | An increase in relatived volatility for rectification columns |
| C. | Decrease in gas solubility for absorbers |
| D. | All of the above |
| Answer» E. | |
| 445. |
_In a shell and tube heat exchanger, the overall heat transfer co-efficient is proportional to the tube side (volumetric flow rate)0.8. This is valid, only when the ratio of the tube side film resistance to the total resistance is almost equal to$? |
| A. | ‚à û |
| B. | 1 |
| C. | 20.8 |
| D. | 2 |
| Answer» C. 20.8 | |
| 446. |
_A binary liquid azeotropic mixture has boiling point lower than either of the components, when it shows __________ deviation from Raoult's Law.$? |
| A. | Positive |
| B. | Negative |
| C. | No |
| D. | None of these |
| Answer» B. Negative | |
| 447. |
_Maximum size of the raschig rings used in a packed tower is about __________ of the coloumn diameter.$? |
| A. | 1/10th |
| B. | 1/20th |
| C. | 1/30th |
| D. | 1/50th |
| Answer» D. 1/50th | |
| 448. |
_In a double pipe (concentric) heat exchanger, the hydraulic radius for heat transfer (for a fluid flowing through the annulus) would be$? |
| A. | Same as that for fluid flow |
| B. | Less than that for fluid flow |
| C. | More than that for fluid flow |
| D. | D‚ÇÇ - D‚ÇÅ (D‚ÇÅ and D‚ÇÇ are I.D. of inner and outer pipes respectively) |
| Answer» D. D‚Äö√á√á - D‚Äö√á√Ö (D‚Äö√á√Ö and D‚Äö√á√á are I.D. of inner and outer pipes respectively) | |
| 449. |
_The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio is$? |
| A. | 0 |
| B. | ‚à û |
| C. | 1 |
| D. | Minimum |
| Answer» C. 1 | |
| 450. |
_In shell and tube heat exchangers, straight tie rods are used to$? |
| 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 | |