MCQOPTIONS
Saved Bookmarks
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.
| 2101. |
Stacked packing compared to dumped packing |
| A. | provides poorer contact between the fluids. |
| B. | gives lower pressure drop. |
| C. | both (a) and (b). |
| D. | gives higher pressure drop. |
| Answer» D. gives higher pressure drop. | |
| 2102. |
In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at __________ reflux. |
| A. | total |
| B. | minimum |
| C. | operating |
| D. | maximum permissible |
| Answer» B. minimum | |
| 2103. |
Dryer widely used in a textile industry is __________ dryer. |
| A. | festoon |
| B. | cylinder |
| C. | conveyor |
| D. | tunnel |
| Answer» D. tunnel | |
| 2104. |
Air at a particular humidity is heated in a furnace. The new dew point |
| A. | decreases |
| B. | increases |
| C. | depends on the extent of heating |
| D. | remain unchanged |
| Answer» C. depends on the extent of heating | |
| 2105. |
The vapour pressure exerted by the moisture contained in a wet solid depends upon the |
| A. | nature of the moisture. |
| B. | temperature. |
| C. | nature of the solid. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 2106. |
For contacting a highly soluble gas with a liquid |
| A. | bubble the gas through liquid. |
| B. | spray the liquid on gas stream. |
| C. | either (a) or (b) would suffice. |
| D. | none of these. |
| Answer» B. spray the liquid on gas stream. | |
| 2107. |
During drying operation, it is easier to remove the __________ moisture. |
| A. | equilibrium |
| B. | critical |
| C. | unbound |
| D. | bound |
| Answer» D. bound | |
| 2108. |
With increase in solvent rate, the number of transfer units, NtoG, for a fixed degree of absorption from a fixed amount of gas |
| A. | increases |
| B. | decreases |
| C. | decreases linearly |
| D. | remains unaffected |
| Answer» C. decreases linearly | |
| 2109. |
In a packed tower, the value of HETP equals HTUOG, when the equilibrium and the operating lines are (where, HETP = height equivalant to a theoretical plate HTUOG = overall gas phase height of a transfer unit) |
| A. | straight |
| B. | parallel |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 2110. |
Ion exchange process is similar to |
| A. | absorption |
| B. | adsorption |
| C. | extraction |
| D. | leaching |
| Answer» C. extraction | |
| 2111. |
A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state, |
| A. | composition of vapors and that of liquid do not vary throughout the column. |
| B. | reboiler load and condenser load are minimum. |
| C. | the top and bottom compositions are unchanged with and without total reflux. |
| D. | the top and bottom compositions correspond to the maximum enrichment available. |
| Answer» E. | |
| 2112. |
The temperature to which a vapour gas mixture must be cooled (at varying humidity) to become saturated is called the __________ temperature. |
| A. | dew point |
| B. | wet bulb |
| C. | dry bulb |
| D. | none of these |
| Answer» E. | |
| 2113. |
Entrainer used in azeotropic distillation should |
| A. | form a low boiling azeotrope with one of the constituents of the mixture. |
| B. | form a new azeotrope of low relative volatility with one of the constituents of the mixture. |
| C. | have high latent heat of vaporisation. |
| D. | have high viscosity to provide high tray efficiency. |
| Answer» B. form a new azeotrope of low relative volatility with one of the constituents of the mixture. | |
| 2114. |
In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because |
| A. | temperature is less. |
| B. | total pressure is less. |
| C. | mixing of steam with the material being vaporised is not so intimate as to result in equilibrium condition. |
| D. | saturated steam is used for steam distillation. |
| Answer» D. saturated steam is used for steam distillation. | |
| 2115. |
For which of the following unit operations, Lewis number is of significance ? |
| A. | Adsorption |
| B. | Binary distillation |
| C. | Gas absorption |
| D. | Humidification |
| Answer» E. | |
| 2116. |
Heat load in a cooling tower |
| A. | means the amount of heat thrown away (KCal/hr.) by the cooling tower. |
| B. | is equal to the number of kg, of water circulated times the cooling range. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 2117. |
In case of absorption with exothermic reaction, for fluids having |
| A. | Pr = Sc; percentage change in heat and mass transfer flux will be the same for a given change in the degree of turbulence. |
| B. | Pr = Sc = 1; total mass, momentum and thermal diffusivity will be the same. |
| C. | both (a) and (b) |
| D. | Pr = Sc ; there won't be any change in heat and mass transfer flux with changes in degree of turbulence. |
| Answer» D. Pr = Sc ; there won't be any change in heat and mass transfer flux with changes in degree of turbulence. | |
| 2118. |
Detergent solution is dried to a powder in a |
| A. | spray dryer |
| B. | spouted bed dryer |
| C. | tunnel dryer |
| D. | pan open to atmosphere |
| Answer» B. spouted bed dryer | |
| 2119. |
Which of the following mixtures does not form an azeotrope at atmosheric pressure? |
| A. | Water-alcohol |
| B. | Methyl alcohol-acetone |
| C. | Butyl acetate-water |
| D. | None of these |
| Answer» E. | |
| 2120. |
During bottling of cold drinks (e.g. Pepsi), the main resistance to mass transfer for the absorption of carbon dioxide in water lies in the |
| A. | gas film |
| B. | liquid film |
| C. | liquid-gas interface |
| D. | none of these |
| Answer» C. liquid-gas interface | |
| 2121. |
For continuous drying of grannular or crystalline material, the dryer used is the __________ dryer. |
| A. | tunnel |
| B. | tray |
| C. | rotary |
| D. | none of these |
| Answer» D. none of these | |
| 2122. |
When adsorption hysteresis is observed, the desorption equilibrium pressure is __________ that obtained by adsorption. |
| A. | always lower than |
| B. | always higher than |
| C. | same as |
| D. | dependent on the system; can be either lower or higher than |
| Answer» B. always higher than | |
| 2123. |
Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called the __________ temperature. |
| A. | dry-bulb |
| B. | wet-bulb |
| C. | dew point |
| D. | adiabatic saturation |
| Answer» C. dew point | |
| 2124. |
The Reynolds number of the liquid was increased 100 fold for a laminar falling film used for gas-liquid contacting. Assuming penetrating theory is applicable, the fold increase in the mass transfer co-efficient (Kc) for the same sytem is |
| A. | 100 |
| B. | 10 |
| C. | 5 |
| D. | 1 |
| Answer» C. 5 | |
| 2125. |
The slope of 9-line is determined by the |
| A. | reflux ratio |
| B. | plate efficiency to be achieved |
| C. | thermal condition of the feed |
| D. | relative volatility. |
| Answer» D. relative volatility. | |
| 2126. |
In steam distillation, the |
| A. | temperature is 100 C. |
| B. | temperature is more than 100 C. |
| C. | product must be immiscible with water. |
| D. | temperature is higher than the boiling point of either component. |
| Answer» D. temperature is higher than the boiling point of either component. | |
| 2127. |
Which of the following can be calculated theoretically using steam table and Dalton's law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known ? |
| A. | Dew point |
| B. | Humidity ratio |
| C. | Wet bulb temperature |
| D. | None of these |
| Answer» D. None of these | |
| 2128. |
The relative volatility of a binary mixture at constant temperature __________ the total pressure. |
| A. | decreases with increase in |
| B. | increases with increase in |
| C. | is independent of |
| D. | none of these |
| Answer» B. increases with increase in | |
| 2129. |
Tower diameter may be decreased by |
| A. | using higher reflux ratio. |
| B. | use of increased tray spacing. |
| C. | increasing the liquid flow rate. |
| D. | increasing the vapour flow rate. |
| Answer» C. increasing the liquid flow rate. | |
| 2130. |
Rayleigh's equation applies to __________ distillation. |
| A. | continuous |
| B. | steam |
| C. | differential |
| D. | flash |
| Answer» D. flash | |
| 2131. |
Which of the following is considered equivalent to one theoretical stage in Mc-Cabe Thiele's method ? |
| A. | Partial condenser |
| B. | Total condenser |
| C. | Reboiler |
| D. | Both (b) and (c) |
| Answer» E. | |
| 2132. |
Which of the following is directly concerned with psychrometry ? |
| A. | Lewis reltionship |
| B. | Galileo number |
| C. | Weber number |
| D. | Dean number |
| Answer» B. Galileo number | |
| 2133. |
Plate efficiency in a distillation column is reduced due to the __________ of liquid. |
| A. | entrainment |
| B. | foaming |
| C. | weeping & dumping |
| D. | all (a), (b) & (c) |
| Answer» E. | |
| 2134. |
The most efficient cooling tower out of the following is |
| A. | induced draft |
| B. | forced draft |
| C. | natural draft |
| D. | atmospheric |
| Answer» B. forced draft | |
| 2135. |
Sodium bicarbonate is produced during soda ash manufacture using a __________ tower. |
| A. | plate |
| B. | baffle |
| C. | packed |
| D. | none of these |
| Answer» C. packed | |
| 2136. |
Powdery materials can be guarded against caking tendency on storage by |
| A. | providing irregular grain size. |
| B. | providing minimum percentage of voids. |
| C. | having maximum possible points of contact. |
| D. | none of these. |
| Answer» E. | |
| 2137. |
According to Poiseuille's law, the permeability for gas flow through a capillary is proportional to (where, = gas viscosity) |
| A. | |
| B. | 1/ |
| C. | <span class="root"> </span> |
| D. | |
| E. | <sup>2</sup> |
| Answer» C. <span class="root"> </span> | |
| 2138. |
For a binary mixture distillation process, the degree of freedom is 2. However, if the pressure is fixed in this process, the number of independent variables in this process will be |
| A. | 1 |
| B. | 0 |
| C. | 2 |
| D. | 3 |
| Answer» B. 0 | |
| 2139. |
H2S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H2S has to be reduced from 0.05 to 0.001 mole fraction in the gas side. The height of the tower (in metres) corresponding to an operating line given by, y = 5x + 0.001 is |
| A. | 2.0 |
| B. | 1.56 |
| C. | 1.0 |
| D. | 0.56 |
| Answer» B. 1.56 | |
| 2140. |
Packed column distillation is limited to the column __________ metres. |
| A. | height < 6 |
| B. | diameter < 0.6 |
| C. | both (a) & (b) |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 2141. |
For the flow of gases through a capillary, with increase in temperature, the permeability __________ as per Knudsen law. |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | either (a) or (b); depends on the gas |
| Answer» B. decreases | |
| 2142. |
Polar organic compounds are normally used as separating agents for the azeotropic and extractive distillation. Which of the following is the most important factor to be considered for the choice of the separating agent for extractive distillation ? |
| A. | Cost |
| B. | Availability |
| C. | Toxicity |
| D. | Selectivity |
| Answer» E. | |
| 2143. |
As the reflux ratio increases, the slope of the operating line for rectifying section |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | data insufficient, cannot be predicted |
| Answer» B. decreases | |
| 2144. |
For a ternery mixture, in which equilateral triangular co-ordinate is used in leaching and extraction, a __________ of the equilateral triangular co-ordinates. |
| A. | binary mixture is represented by the apex |
| B. | binary mixture is represented by any point inside |
| C. | ternery mixture is represented by the sides |
| D. | pure component is represented by the apex. |
| Answer» E. | |
| 2145. |
Ammonia present in the coke oven gas is removed by washing with |
| A. | caustic solution |
| B. | dilute ammoniacal liquor |
| C. | dilute HCl |
| D. | ethanolamine |
| Answer» C. dilute HCl | |
| 2146. |
With increase in temperature, the leaching rate increases due to |
| A. | decreased liquid viscosity |
| B. | increased diffusivity |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 2147. |
Which of the following processes is not an example of adsorption applied to gaseous separations ? |
| A. | Recovery of valuable solvent vapors from dilute mixture with air and other gases. |
| B. | Dehumidification of air and gas. |
| C. | Removal of objectionable odour and impurities from industrial gases. |
| D. | Decolouration of yellow glycerene. |
| Answer» E. | |
| 2148. |
The critical moisture content in case of drying indicates the __________ rate period. |
| A. | beginning of falling |
| B. | beginning of constant |
| C. | end of falling |
| D. | none of these |
| Answer» B. beginning of constant | |
| 2149. |
In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number. |
| A. | Lewis |
| B. | Grashoff |
| C. | Sherwood |
| D. | none of these |
| Answer» B. Grashoff | |
| 2150. |
Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes ? |
| A. | Packed towers |
| B. | Plate towers |
| C. | Spray towers |
| D. | Wetted wall columns |
| Answer» E. | |