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.
| 601. |
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 | |
| 602. |
Hold up of material in a operating rotary drier is in the range of |
| A. | 0.05 to 0.15 |
| B. | 0.25 to 0.50 |
| C. | 0.5 to 0.8 |
| D. | 0.8 to 0.9 |
| Answer» B. 0.25 to 0.50 | |
| 603. |
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. | |
| 604. |
The safe height (h) to diameter (d) ratio (i.e., h/d) for liquid/petro fuel storage tank of capacity more than 45 kilolitres is less than |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 3.5 |
| Answer» B. 2 | |
| 605. |
The equivalent diameter for fluid flow through a channel of constant non-circular cross section of area 'A' is given by (where, P = perimeter of the channel in contact with the fluid) |
| A. | 4 A/P |
| B. | A/P |
| C. | 4 P/A |
| D. | A |
| Answer» B. A/P | |
| 606. |
The dust collection efficiency of electrostatic precipitator increases with increase in the |
| A. | gas flow rate. |
| B. | electrode area. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» C. both (a) & (b). | |
| 607. |
Which of the following is the most common type of baffle used in industrial shell and tube heat exchanger ? |
| A. | 75% cut segmental baffle. |
| B. | 25% cut segmental baffle. |
| C. | Orifice baffle. |
| D. | Disk and doughnut baffle. |
| Answer» C. Orifice baffle. | |
| 608. |
Pick out the wrong statement about routing of fluids in a shell and tube heat exchanger. |
| A. | The corrosive and fouling fluid should be preferably routed through the tubes. |
| B. | The viscous fluid should be routed through the shell side. |
| C. | Lower flow rate fluid should be routed through the shell side. |
| D. | Higher pressure fluid stream should be routed through the shell side. |
| Answer» E. | |
| 609. |
Typical static submergence for bubble cap plate column operating at atmospheric pressure may be around |
| A. | 2.5" |
| B. | 0.5" |
| C. | 5" |
| D. | 50% of the plate spacing |
| Answer» C. 5" | |
| 610. |
Reflux ratio variation in a distillation column is between |
| A. | zero and infinity |
| B. | zero and one |
| C. | minimum and infinity |
| D. | none of these |
| Answer» D. none of these | |
| 611. |
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. | D2 - D1 (D1 and D2 are I.D. of inner and outer pipes respectively). |
| Answer» D. D2 - D1 (D1 and D2 are I.D. of inner and outer pipes respectively). | |
| 612. |
A minimum clearance of about __________ mm is maintained between the distillation column wall and the bubble cap. |
| A. | 19 |
| B. | 38 |
| C. | 76 |
| D. | 95 |
| Answer» C. 76 | |
| 613. |
"A claming section" before the liquid flows into the downcomer is privided to |
| A. | permit release of entrained vapour in the liquid. |
| B. | reduce the discharge fluctuation. |
| C. | ensure better vapour-liquid contact. |
| D. | cool the liquid before it flows down. |
| Answer» B. reduce the discharge fluctuation. | |
| 614. |
In case of plain carbon steel, butt welded joints are used for shell plate thickness ≤ __________ cms.$ |
| A. | 1.2 |
| B. | 0.5 |
| C. | 3.8 |
| D. | 6.8 |
| Answer» D. 6.8 | |
| 615. |
The ratio of lateral strain to linear strain is termed as the |
| A. | Poisson's ratio |
| B. | bulk modulus |
| C. | modulus of elasticity |
| D. | shear modulus |
| Answer» B. bulk modulus | |
| 616. |
__________ closure is the weakest enclosure for cylindrical vessels. |
| A. | Hemispherical |
| B. | Torispherical |
| C. | Conical or flat plate |
| D. | Elliptical |
| Answer» D. Elliptical | |
| 617. |
__________ head is the most economical for cylindrical vessels designed for operating at high pressure (> 15 atm.). |
| A. | Hemispherical |
| B. | Dished |
| C. | Ellipsoidal |
| D. | Conical |
| Answer» D. Conical | |
| 618. |
for fully open gate valves would be |
| A. | much more than that for fully open globe valves. |
| B. | much less (say 2% than that for fully open globe valves). |
| C. | around 7. |
| D. | both (b) and (c). |
| Answer» E. | |
| 619. |
Lug support is meant for supporting __________ vessels. |
| A. | large horizontal cylindrical |
| B. | tall but empty |
| C. | small |
| D. | thick walled tall |
| Answer» D. thick walled tall | |
| 620. |
The distance between the centre of a rivet hole to the nearest edge of the plate is called |
| A. | pitch |
| B. | margin |
| C. | back pitch |
| D. | none of these |
| Answer» C. back pitch | |
| 621. |
In a shell and tube heat exchanger, the clearance of the tube is generally |
| A. | not less than one-fourth of the tube diameter or 3/16". |
| B. | more than the tube diameter. |
| C. | equal to the tube diameter. |
| D. | more in case of triangular pitch as compared to the square pitch tube layout. |
| Answer» B. more than the tube diameter. | |
| 622. |
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. | |
| 623. |
__________ shapedroof is the most commonly used roof for cylinderical storage tanks. |
| A. | Conical |
| B. | Flat |
| C. | Dome |
| D. | Umbrella |
| Answer» B. Flat | |
| 624. |
In a shell and tube heat exchanger, the shortest centre to centre distance between the adjacent tubes is |
| A. | called tube pitch. |
| B. | called tube clearance. |
| C. | always less than the diameter of the tube. |
| D. | none of these. |
| Answer» B. called tube clearance. | |
| 625. |
A pipe is generally made of circular cross-section, because a circular cross-section has the |
| A. | higher structural strength. |
| B. | lowest surface area requirement for a given volume. |
| C. | both (a) & (b). |
| D. | none of these. |
| Answer» D. none of these. | |
| 626. |
For pipe flows, head is proportional to __________ at constant capacity (where D = pipe diameter ). |
| A. | 1/D |
| B. | 1/D2 |
| C. | 1/D5 |
| D. | D2 |
| Answer» D. D2 | |
| 627. |
In a cylinderical vessel subjected to internal pressure, the longitudinal stress σL and the circumferential stress, σn are related by$ |
| A. | σh = 2 σL |
| B. | σh = σL |
| C. | σh = σL/2 |
| D. | no relation exists |
| Answer» B. œÉh = œÉL | |
| 628. |
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. | |
| 629. |
The difficulty of liquid distribution in packed towers is accentuated, when the ratio of tower diameter to packing diameter is |
| A. | < 30 |
| B. | < 7 |
| C. | > 7 < 15 |
| D. | > 20 < 50 |
| Answer» C. > 7 < 15 | |
| 630. |
Commercial packed scrubbers are normally designed for a pressure drop range of __________ mm water coloumn per metre of packed height. |
| A. | 43681 |
| B. | 17-34 |
| C. | 52-68 |
| D. | 88-105 |
| Answer» C. 52-68 | |
| 631. |
The wall thickness for a large high pressure pipeline is determined by the consideration of the |
| A. | axial tensile stress in the pipe. |
| B. | forces exerted by static and dynamic action at bends. |
| C. | circumferential pipewall tension. |
| D. | temperature stresses. |
| Answer» D. temperature stresses. | |
| 632. |
Slope of countercurrent flow rotary drier is in the range of __________ meter/metre. |
| A. | 0 to 0.08 |
| B. | 0 to 0.8 |
| C. | 0 to 1.5 |
| D. | 0 to 2.2 |
| Answer» B. 0 to 0.8 | |
| 633. |
Factor of safety (i.e., overdesign factor) in heat transfer equipments is about __________ percent more than the actual/theoretical design factor. |
| A. | 43743 |
| B. | 15-20 |
| C. | 30-35 |
| D. | 35-40 |
| Answer» C. 30-35 | |
| 634. |
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 (a), (b) and (c). |
| Answer» E. | |
| 635. |
In the design of a bag filter, the gas temperature is an important consideration, as it affects the |
| A. | gas density |
| B. | gas viscosity |
| C. | fibre selection |
| D. | all (a), (b) & (c) |
| Answer» E. | |
| 636. |
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 | |
| 637. |
Generally, as the length of the liquid path on a tray is increased beyond 5 ft, the overall column efficiency |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | may increase or decrease depending upon the plate spacing |
| Answer» B. decreases | |
| 638. |
Multiple blade paddle agitator is used for mixing high viscosity liquids/paste in which the paddle diameter is commonly 0.8 times the tank diameter. However, the width of the blade is in the range of __________ times the paddle diameter. |
| A. | 0.1 to 0.25 |
| B. | 0.3 to 0.5 |
| C. | 0.5 to 0.6 |
| D. | 0.65 to 0.80 |
| Answer» B. 0.3 to 0.5 | |
| 639. |
What is the slope of the operating line in the rectifying section of a distillation coloumn ? |
| A. | 0 |
| B. | ‚àû |
| C. | > 1 |
| D. | <1 |
| Answer» E. | |
| 640. |
Filtration rate is affected by the |
| A. | pressure drop across the cake & filter medium. |
| B. | cake & filter medium resistance. |
| C. | area of filtering surface & the viscosity of filtrate. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 641. |
Poisson's ratio of a material is the ratio of unit lateral strain to the unit axial elongation within its elastic limit. The value of Poisson's ratio for structural and pressure vessel steel may be taken as |
| A. | 0.01 |
| B. | 0.3 |
| C. | 0.75 |
| D. | 0.95 |
| Answer» C. 0.75 | |
| 642. |
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 | |
| 643. |
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. | |
| 644. |
In a multipass shell and tube heat exchanger, the problem of differential expansion between the shell and tube passes is taken care of by using a |
| A. | U-bend |
| B. | floating head tube sheet |
| C. | either (a) or (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 645. |
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 (a), (b) and (c). |
| Answer» E. | |
| 646. |
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 | |
| 647. |
Normally, the plate thickness of the bottoms and roofs of vertically cylindrical storage vessels as compared to that of the cylindrical shell is |
| A. | more |
| B. | less |
| C. | same |
| D. | more or less depending upon the pressure & temperature inside the vessel and the nature of the fluid contained therein. |
| Answer» C. same | |
| 648. |
The safe distance of habitation from a hazardous chemical plant (TLV of its product < 1000 ppm) should be about __________ kms. |
| A. | 1 |
| B. | 5 |
| C. | 15 |
| D. | 25 |
| Answer» E. | |
| 649. |
The optimum size ratio for two mixed reactors in series depends on the kinetics of the reaction and the conversion level. For reaction orders more than one, the |
| A. | equal sized reactors are the best. |
| B. | smaller reactor should come first. |
| C. | larger reactor should come first. |
| D. | none of these. |
| Answer» C. larger reactor should come first. | |
| 650. |
In packed absorption tower, onset of flooding usually occurs at a pressure drop of about __________ mm of water column per metre height of packing. |
| A. | 25-50 |
| B. | 50-75 |
| C. | 200-250 |
| D. | 750-1000 |
| Answer» C. 200-250 | |