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.
| 701. |
Souders Brown equation given by, , is used for the calculation of the __________ in a continuous distillation column. |
| A. | diameter of the bubble cap column |
| B. | diameter of the seive plate column |
| C. | tray pressure drop |
| D. | residence time in the downcomer for the disengagement of entrained vapour |
| Answer» B. diameter of the seive plate column | |
| 702. |
The LMTD correction factor (FT) is defined as the |
| A. | ratio of true temperature difference to the LMTD. |
| B. | ratio of LMTD to the true temperature difference. |
| C. | differenced of true temperature difference and the LMTD. |
| D. | geometric mean of the true temperature difference and the LMTD. |
| Answer» B. ratio of LMTD to the true temperature difference. | |
| 703. |
Removable connection of tubes to tube sheet is called |
| A. | ferrule |
| B. | socket |
| C. | nipple |
| D. | saddle |
| Answer» B. socket | |
| 704. |
Rotary driers are most economically designed for the number of heat transfer units (HTU) from |
| A. | 0.01 to 1 |
| B. | 1.5 to 2.5 |
| C. | 5 to 10 |
| D. | 10 to 20 |
| Answer» C. 5 to 10 | |
| 705. |
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 tanks irrespective of their heights and diameters. |
| Answer» C. small diameter tall tanks. | |
| 706. |
The ratio of volumes of the mixed reactor to the plug flow reactor (for identical feed composition, flow rate, conversion, and for all positive reaction orders) is always |
| A. | 1 |
| B. | < 1 |
| C. | >1 |
| D. | equal to the order of reaction |
| Answer» D. equal to the order of reaction | |
| 707. |
Which of the following is the best tube material from thermal conductivity point of view alone? |
| A. | Aluminium |
| B. | Stainless steel |
| C. | Copper |
| D. | Carbon steel |
| Answer» D. Carbon steel | |
| 708. |
Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, D = shell diameter ) |
| A. | 0.2 D |
| B. | 0.5 D |
| C. | 0.66 D |
| D. | 0.80 D |
| Answer» B. 0.5 D | |
| 709. |
The type of stress developed in a metallic bar on subjecting it to a change in temperature without allowing it to be deformed is __________ stress. |
| A. | shear |
| B. | tensile |
| C. | compressive |
| D. | thermal |
| Answer» E. | |
| 710. |
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 flow. |
| C. | using split flow, radial flow or cascade flow for column diameter large than 4 ft. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 711. |
In case of saddle packing (e.g., berl and intralox saddles), the maximum size of the packing should not exceed __________ of the column diameter. |
| A. | l/5th |
| B. | l/15th |
| C. | l/30th |
| D. | l/50th |
| Answer» C. l/30th | |
| 712. |
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 | |
| 713. |
Pressure drop per tray in the atmospheric distillation column is about __________ psi. |
| A. | 0.01 - 0.5 |
| B. | 0.07 - 0.12 |
| C. | 0.5 - 1.0 |
| D. | 43525 |
| Answer» C. 0.5 - 1.0 | |
| 714. |
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. | |
| 715. |
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. | |
| 716. |
Normally, the length to diameter ratio of rotary dryers varies form 4 to 10 and for its economic operation, the number of transfer units (NTU) for such dryers varies from |
| A. | 1.5-2.5 |
| B. | 3.5-5.5 |
| C. | 7.5-10.0 |
| D. | 42278 |
| Answer» B. 3.5-5.5 | |
| 717. |
Stage efficiency for packed tower varies with the |
| A. | type & size of packing. |
| B. | fluid rates and fluid properties. |
| C. | operating pressure and column diameter. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 718. |
__________ dished head is the strongest of all. |
| A. | Hemispherical |
| B. | Elliptical |
| C. | Torispherical |
| D. | none of these |
| Answer» B. Elliptical | |
| 719. |
Pick out the wrong statement pertaining to a shell and tube heat exchanger. |
| A. | The minimum value of baffle spacing is 50 mm. |
| B. | The maximum value of baffle spacing is equal to the I.D. of the shell. |
| C. | The maximum unsupported tube span is generally about 75 times tube diameter, but is reduced to about 60 times for aluminium, copper & alloys of these. |
| D. | Disk and doughnut baffle is the most commonly used baffle. |
| Answer» E. | |
| 720. |
Which of the following efficiencies can be greater than 100% ? |
| A. | Overall plate efficiency. |
| B. | Murphree plate efficiency. |
| C. | Point efficiency. |
| D. | None of these. |
| Answer» C. Point efficiency. | |
| 721. |
Maximum acceptable total liquid gradient over a tray is about __________ mm. |
| A. | 5.5 |
| B. | 12.5 |
| C. | 30.5 |
| D. | 45.5 |
| Answer» C. 30.5 | |
| 722. |
Corrosion allowance in the design of pressure vessel/chemical equipment is not necessary, if |
| A. | plain carbon steel and cast iron parts are used. |
| B. | wall thickness is > 30 mm. |
| C. | material of construction is high alloy steel. |
| D. | both(b) & (c). |
| Answer» E. | |
| 723. |
__________ shaped roof is most commonly used for cylindrical tanks. |
| A. | Cone |
| B. | Dome |
| C. | Umbrella |
| D. | Flat |
| Answer» B. Dome | |
| 724. |
Normally, the ratio of the total riser area to the tower cross sectional area (for bubble cap towers of diameter more than 3 ft) is around |
| A. | 0.4-0.6 |
| B. | 0.35-0.75 |
| C. | 0.1-0.2 |
| D. | 0.55-0.85 |
| Answer» D. 0.55-0.85 | |
| 725. |
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 | |
| 726. |
for a Tee (used as elbow, entering branch) would be |
| A. | less than that for Tee (used as elbow, entering run). |
| B. | more than that for Tee (used as elbow, entering run). |
| C. | around 90. |
| D. | both (b) and (c). |
| Answer» E. | |
| 727. |
Saddle supports are used for supporting __________ vessels. |
| A. | horizontal cylinderical |
| B. | tall vertical |
| C. | thick walled vertical |
| D. | thick spherical |
| Answer» B. tall vertical | |
| 728. |
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 | |
| 729. |
High pressure fluid in a shell and tube heat exchanger should preferably be routed through the |
| A. | tubes to avoid the expansion of high pressure shell construction. |
| B. | shell side for smaller total pressure drop. |
| C. | shell side, if the flow is counter-current and tube side if the flow is co-current. |
| D. | shell side for large overall heat transfer co-efficient. |
| Answer» B. shell side for smaller total pressure drop. | |
| 730. |
Normal screwed fittings are used for pipes upto a diameter of __________ inches. |
| A. | 1.5 |
| B. | 3 |
| C. | 5 |
| D. | 7 |
| Answer» C. 5 | |
| 731. |
__________ heat exchanger is also known as 'hair pin type' exchanger, |
| A. | Double pipe |
| B. | Finned |
| C. | Plate type |
| D. | Regenerative |
| Answer» B. Finned | |
| 732. |
Brass valves are usually made for pipe sizes __________ inches. |
| A. | ≤1 |
| B. | ≤2 |
| C. | >2.5 |
| D. | >3.5 |
| Answer» C. >2.5 | |
| 733. |
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. | |
| 734. |
The raio, is normally taken as |
| A. | 0.15-030 |
| B. | 0.5-0.65 |
| C. | 0.75-0.85 |
| D. | 0.60-0.90 |
| Answer» B. 0.5-0.65 | |
| 735. |
The ratio of linear stress to linear strain is termed as the |
| A. | modulus of elasticity |
| B. | modulus of rigidity |
| C. | bulk modulus |
| D. | none of these |
| Answer» B. modulus of rigidity | |
| 736. |
In distillation columns, bubble caps are held in place over trays by |
| A. | rivets |
| B. | a hold down bar |
| C. | bolts |
| D. | both (b) and (c) |
| Answer» E. | |
| 737. |
Excessive liquid gradient on a tray may result in the |
| A. | maldistribution of gas. |
| B. | back trapping. |
| C. | gas blowing beneath cap skit. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 738. |
The normal range of velocity of steam in pipes is __________ m/sec. |
| A. | 0.1-0.5 |
| B. | 43586 |
| C. | 44105 |
| D. | 80-100 |
| Answer» E. | |
| 739. |
In packed towers provided with pall rings liquid redistributors are positioned at heights of every 6 metres or 5-10 times the column diameter, whichever is less. Maximum size of the pall rings should not exceed __________ of the column diameter. |
| A. | 1/10-1/15th |
| B. | 1/5-1/10th |
| C. | 1/20-1/30th |
| D. | 1/2 to 1/4th |
| Answer» B. 1/5-1/10th | |
| 740. |
__________ is the determining factor for the number of bubble caps to be used per tray. |
| A. | Permissible slot velocity |
| B. | Tray diameter |
| C. | Liquid load |
| D. | Vapor load |
| Answer» B. Tray diameter | |
| 741. |
In condenser, the cooling water is passed in the tube side in a pass arrangement, because |
| A. | it reduces heat transfer area. |
| B. | more thinner tubes can be used. |
| C. | pressure drop is reduced. |
| D. | it makes condenser compact. |
| Answer» B. more thinner tubes can be used. | |
| 742. |
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 . Œº0.95 | |
| 743. |
Stress-strain diagram for low carbon steel/mild steel is shown below in the Fig. The point 'A' on the Fig. represents the |
| A. | breaking stress |
| B. | ultimate stress |
| C. | elastic limit |
| D. | yield point |
| Answer» D. yield point | |
| 744. |
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 |
| D. | (0.8)0.5 |
| Answer» B. 0.9 | |
| 745. |
The slope of the feed line in distillation opeartion is given by (where, q = fraction of the feed stream that is liquid.) |
| A. | #NAME? |
| B. | #NAME? |
| C. | #NAME? |
| D. | none of these |
| Answer» C. #NAME? | |
| 746. |
The testing pressure of storage tanks and pressure vessels designed as per Indian standard codes should be about __________ times.the design pressure. |
| A. | 1.5 to 2 |
| B. | 3 to 4 |
| C. | 4 to 5 |
| D. | >5 |
| Answer» B. 3 to 4 | |
| 747. |
In most of the shell and tube heat exchangers, the tube pitch is generally __________ the tube diameter. |
| A. | less than |
| B. | 1.25-1.50 times |
| C. | 2.5 times |
| D. | one-fourth of |
| Answer» C. 2.5 times | |
| 748. |
If a single tube pass heat exchanger is converted to two passes; for the same flow rate, the pressure drop per unit length in tube side will __________ times. |
| A. | increase by 1.8 |
| B. | decrease by 22 |
| C. | increase by 21.6 |
| D. | none of these |
| Answer» D. none of these | |
| 749. |
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 | |
| 750. |
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 | |