MCQOPTIONS
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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 5101. |
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. | |
| 5102. |
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. | |
| 5103. |
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. | |
| 5104. |
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. | |
| 5105. |
The minimum tray spacing in distillation column of diameter less than 3 ft is normally __________ inches. |
| A. | 6 |
| B. | 18 |
| C. | 24 |
| D. | 34 |
| Answer» B. 18 | |
| 5106. |
Oxygen carrying pipelines in chemical industries are coloured with __________ colour. |
| A. | yellow |
| B. | black |
| C. | blue |
| D. | red |
| Answer» D. red | |
| 5107. |
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 | |
| 5108. |
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. | |
| 5109. |
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 | |
| 5110. |
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. | |
| 5111. |
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 | |
| 5112. |
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 | |
| 5113. |
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 | |
| 5114. |
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 | |
| 5115. |
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. | |
| 5116. |
In the case of a shell and tube heat exchanger, the logarithmic mean temperature difference |
| A. | is always less than arithmetic average value. |
| B. | is always more than arithmetic mean value and the geometric mean value. |
| C. | is always less than arithmetic mean value, but more than geometric mean value. |
| D. | may be either more or less than geometric mean and arithmetic mean value depending upon whether the flow of stream is co-current or counter-current. |
| Answer» B. is always more than arithmetic mean value and the geometric mean value. | |
| 5117. |
In a distillation column, minimum clearance to be maintained betweeen the overflow weir and the last row of the bubble caps is __________ cms. |
| A. | 2.5 |
| B. | 7.5 |
| C. | 15 |
| D. | 20 |
| Answer» C. 15 | |
| 5118. |
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 | |
| 5119. |
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. | |
| 5120. |
In case of a shell and tube heat exchanger, the effect of L/D on inside film heat transfer co-efficient (hi) vanishes after a Reynold number of |
| A. | 1000 |
| B. | 3000 |
| C. | 5000 |
| D. | 10000 |
| Answer» E. | |
| 5121. |
Equivalent diameter for heat transfer calculation for a duct of square cross-section having each side as 'd' will be |
| A. | <i>d</i> |
| B. | <span class="root"><i>d</i></span> |
| C. | <span class="root">2 <i>d</i></span> |
| D. | <span class="root">2<i>d</i></span> |
| Answer» B. <span class="root"><i>d</i></span> | |
| 5122. |
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) |
| E. | <sup>0.5</sup> |
| Answer» B. 0.9 | |
| 5123. |
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 | |
| 5124. |
Bubble cap plate column is |
| A. | a finite stage contactor. |
| B. | used only for distillation, not for absorption. |
| C. | a differential stage contactor. |
| D. | a continuous contactor. |
| Answer» B. used only for distillation, not for absorption. | |
| 5125. |
In seive plate column, holes are drilled or punched in sizes ranging from 2.5 to 12 mm (5 mm being widely used). The hole pitch is normally __________ times the hole diameter to give the required hole area. |
| A. | 0.5 to 1.5 |
| B. | 2.5 to 4.0 |
| C. | 5 to 10 |
| D. | 10 to 15 |
| Answer» C. 5 to 10 | |
| 5126. |
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. | |
| 5127. |
Which tube arrangement in a heat exchanger would facilitate highest heat transfer rate ? |
| A. | Triangular pitch. |
| B. | Square pitch. |
| C. | Diagonal square pitch. |
| D. | Heat transfer rate is independent of tube arrangement. |
| Answer» B. Square pitch. | |
| 5128. |
In case of 1.5" heat exchanger tubes, the inside flow area __________ with decrease in BWG. |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | none of these |
| Answer» C. remains same | |
| 5129. |
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 | |
| 5130. |
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. | 1 - 3 |
| Answer» C. 0.5 - 1.0 | |
| 5131. |
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 | |
| 5132. |
__________ of water makes it a widely used coolant in heat exchangers. |
| A. | Low corrosiveness |
| B. | Low dirt factor |
| C. | High specific heat |
| D. | Low viscosity |
| Answer» D. Low viscosity | |
| 5133. |
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. | |
| 5134. |
A high vapour velocity is required for high plate efficiency in a seive plate coloumn. The satisfactory value of operating vapor velocity for design purpose in seive plate column is about __________ percent of the flooding velocity. |
| A. | 45 |
| B. | 60 |
| C. | 80 |
| D. | 95 |
| Answer» D. 95 | |
| 5135. |
Baffle width is normally taken as __________ times the tank diameter. |
| A. | 0.1-0.12 |
| B. | 0.4-0.5 |
| C. | 0.45-0.6 |
| D. | 0.2-0.45 |
| Answer» B. 0.4-0.5 | |
| 5136. |
A cylinderical pressure vessel of volume 6 m3 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. | |
| 5137. |
Which of the following packing materials provides for maximum mass transfer ? |
| A. | Lessig rings. |
| B. | Raschig rings. |
| C. | Cross-partition rings. |
| D. | All give the same value. |
| Answer» D. All give the same value. | |
| 5138. |
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 | |
| 5139. |
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 | |
| 5140. |
The thickness of segmental baffles (25 -35% cut truncated plates usually) is generally __________ the tube wall thickness. |
| A. | equal to |
| B. | twice |
| C. | four times |
| D. | half |
| Answer» C. four times | |
| 5141. |
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 | |
| 5142. |
For given number of passes, pitch & tube diameter, the maximum number of tubes that can be accommodated in a shell of tripled inside diameter will be __________ times. |
| A. | about 9 |
| B. | considerably more than 9 |
| C. | considerably less than 9 |
| D. | about 3 |
| Answer» C. considerably less than 9 | |
| 5143. |
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 | |
| 5144. |
__________ 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 | |
| 5145. |
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 | |
| 5146. |
Lap joints are preferred for plates having thickness __________ mm. |
| A. | < 12.5 |
| B. | > 3 |
| C. | > 5 |
| D. | 5-10 |
| Answer» C. > 5 | |
| 5147. |
Skirt support is the most suitable for supporting __________ vessels. |
| A. | small horizontal |
| B. | large horizontal |
| C. | tall vertical |
| D. | thick walled |
| Answer» D. thick walled | |
| 5148. |
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. | |
| 5149. |
For high pressure process equipments/vessels, the connected nozzle should be |
| A. | welded |
| B. | screwed |
| C. | flanged |
| D. | brazed |
| Answer» D. brazed | |
| 5150. |
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. | |