Description : Weeping in a distillation column (A) Increases tray efficiency (B) Provides large interfacial surface for mass transfer (C) Results due to very high gas velocity (D) Results due to very low gas velocity
Last Answer : (D) Results due to very low gas velocity
Description : To get high tray efficiency (A) Interfacial surface between liquid and gas phase should be large (B) Time of contact between the two phases should be less (C) Gas velocity should be very low (D) Liquid entrainment should be severe
Last Answer : (A) Interfacial surface between liquid and gas phase should be large
Description : Flooding in a column results due to (A) High pressure drop (B) Low pressure drop (C) Low velocity of the liquid (D) High temperature
Last Answer : (A) High pressure drop
Description : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these
Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments
Description : Back-trapping in a distillation column (A) Increases tray efficiency (B) Decreases tray efficiency (C) Reduces pressure drop (D) Is desirable, as it provides improved vapour-liquid contact
Last Answer : (B) Decreases tray efficiency
Description : Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is __________ the liquid head available in the downcomer. (A) Less than (B) More than (C) Same as (D) Very much less
Last Answer : (B) More than
Description : Priming in a distillation column (A) Results from very low gas velocity (B) Is desirable from point efficiency consideration (C) Is characterised by the presence of foam throughout the space between trays (D) Reduces the overall pressure drop
Last Answer : (C) Is characterised by the presence of foam throughout the space between trays
Description : 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 ... (C) Have high latent heat of vaporisation (D) Have high viscosity to provide high tray efficiency
Last Answer : (A) Form a low boiling azeotrope with one of the constituents of the mixture
Description : For absorbers, high pressure drop results in (A) Increased efficiency (B) Decreased efficiency (C) High operating cost (D) Better gas liquid contact
Last Answer : (C) High operating cost
Description : Momentum transfer in laminar flow of fluids results due to the (A) Viscosity (B) Density (C) Velocity gradient (D) None of these
Last Answer : (C) Velocity gradient
Description : When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids? (A) At high fluid velocity (B) At low velocity (C) When fluid flows past a smooth surface (D) None of these
Last Answer : (A) At high fluid velocity
Description : In extractive distillation, solvent is (A) Added to alter the relative volatility of the mixture (B) Of high volatility (C) Present in overhead stream (D) Of high viscosity to give high tray efficiency
Last Answer : (A) Added to alter the relative volatility of the mixture
Description : In distillation columns, the number of bubble caps per tray primarily depends upon the (A) Allowable liquid velocity (B) Allowable gas velocity (C) Allowable gas and liquid velocities
Last Answer : (C) Allowable gas and liquid velocities
Description : Flooding in a distillation column is detected by a sharp (A) Increase in Murphree plate efficiency (B) Decrease in pressure drop (C) Decrease in liquid hold up in the column (D) Increase in pressure drop
Last Answer : (D) Increase in pressure drop
Description : Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low ... Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers
Last Answer : (A) Mechanical agitation is required, if the system has low interfacial tension
Description : Which one of the following statements is correct ? (a) Dynamic viscosity is the property of a fluid which is not in motion (b) Surface energy is a fluid property giving rise to the phenomenon ... results from the action of very high pressure (d) Real fluids have lower viscosity than ideal fluids
Last Answer : (d) Real fluids have lower viscosity than ideal fluids
Description : Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the ... (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity
Last Answer : (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity
Description : Operating velocity in a packed tower is usually __________ the flooding velocity. (A) Half (B) Twice (C) Equal to (D) More than
Last Answer : (A) Half
Description : In an absorption column, the flooding velocity for random packing is __________ that for stacked/regular packing. (A) Greater than (B) Smaller than (C) Equal to (D) Either (A), or (B); depends on the type of packing
Last Answer : (B) Smaller than
Description : 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
Last Answer : (C) Both (A) and (B)
Description : Batch tray dryers suffers from the disadvantage of (A) High maintenance cost (B) Non-uniform & low production rate (C) High labour cost & low heat economy (D) All 'a', 'b' & 'c'
Last Answer : (C) High labour cost & low heat economy
Description : Isotropic turbulence occurs (A) Where there is no velocity gradient (B) At higher temperatures (C) Only in Newtonian fluids (D) None of these
Last Answer : (A) Where there is no velocity gradient
Description : For flow of fluids through packed bed, the superficial velocity is (A) Less than the average velocity through channels (B) More than the average velocity through channels (C) Dependent on the pressure drop across the bed (D) Same as the average velocity through channels
Last Answer : (A) Less than the average velocity through channels
Description : For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ
Last Answer : (B) 1/μ
Description : Pick out the correct statement pertaining to transition/ entrance length in fluid flow. (A) The length of entrance region of pipe, in which full development of fluid flow takes place such that velocity profile does not change ... pipe of diameter 'd' is equal to 50 D (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : . __________ column is preferred to be used, when a high liquid hold up is required in a reactor for gas-liquid reaction. (A) Packed (B) Bubble (C) Spray (D) Tray
Last Answer : (B) Bubble
Description : When a high liquid hold up is required in a reactor for gas liquid reaction, use __________ column. (A) Packed (B) Spray (C) Tray (D) Bubble
Last Answer : (D) Bubble
Description : Which one of the following statements is incorrect? (a) The principle of countercurrent flow facilitates efficient respiration in gills of fishes. (b) The residual air in lungs slightly decreases the ... in birds. (d) In insects, circulating body fluids serve to distribute oxygen to tissues.
Last Answer : (b) The residual air in lungs slightly decreases the efficiency of respiration in mammals.
Description : Dams are designed to reduce flooding by ____________. a) Protecting river banks from erosion b) Providing storage for flood water c) Increasing the downstream velocity of flood water ‘ d) Trapping sediment behind the dam so it can't be deposited downstream
Last Answer : b) Providing storage for flood water
Description : Channelization of streams is designed to reduce flooding by ___________. a) Speeding the passage of floodwaters b) Reducing bank erosion c) Slowing down river velocity so as to reduce damage d) Increase the meandering of streams
Last Answer : a) Speeding the passage of floodwaters
Description : Dams are designed to reduce flooding by _______________. a) Protecting river banks from erosion b) Providing storage for flood water c) Increasing the downstream velocity of flood water d) Trapping sediment behind the dam so it can't be deposited downstream
Description : Extremely large or small volumes of fluids are generally best routed through the shell side of a shell and tube heat exchanger, because of the (A) Less corrosion problems (B) Flexibility possible in the baffle arrangement (C) Low pressure drop (D) High heat transfer co-efficient
Last Answer : (B) Flexibility possible in the baffle arrangement
Description : The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids (A) Having high viscosities (B) Moving at low velocities (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : Dengue fever is transmitted primarily by a. contact with body fluids. b. contaminated water and food. c. arthropods. d. None of the above( A-C) is correct.
Last Answer : d. None of the above( A-C) is correct.
Description : Low viscosity absorbent is preferred for reasons of (A) Rapid absorption rates and good heat transfer characteristics (B) Improved flooding characteristics (C) Low pressure drop on pumping (D) All (A), (B) and (C)
Description : A single fixed pulley is used to draw water from a well because – (1) efficiency is 100% (2) velocity ratio is low (3) mechanical advantage is high (4) force is applied in a convenient direction
Last Answer : (4) force is applied in a convenient direction Explanation: A single fixed pulley is used to lift a load upwards by applying efforts downward's. The load and effort move equal distance but in opposite ... apply effort in downward direction. They are used on flag-poles and to draw water from a well.
Description : A single fixed pulley is used to draw water from a well because (1) efficiency is 100% (2) velocity ratio is low (3) mechanical advantage is high (4) force is applied in a convenient direction
Last Answer : force is applied in a convenient direction
Description : Minimum possible diameter of a packed column is decided mainly bythe (A) Flooding (B) Gas viscosity (C) Liquid density (D) Liquid hold up
Last Answer : (A) Flooding
Description : Under conditions of flooding in packed tower, the gas pressure drop (A) Decreases rapidly (B) Increases rapidly (C) Remain constant (D) Is maximum
Last Answer : (D) Is maximum
Description : Pick out the correct statement. (A) For identical gas flow rates, less pressure drop occurs through a plate tower than through a packed tower (B) Plate column can handle greater liquid loads without flooding than packed ... duty, plate columns weigh less than packed columns (D) All (A), (B) and (C)
Description : Which of the following equipments is not used for gas dispersion? (A) Agitated vessels (B) Bubble cap tray towers (C) Perforated sieve tray towers (D) Spray towers
Last Answer : (D) Spray towers
Description : Out of the following gas-liquid contacting devices, for a given set of operating conditions, gas pressure drop is the least in __________ tower. (A) Wetted wall (B) Bubble cap (C) Perforated tray (D) Packed
Last Answer : (A) Wetted wall
Description : __________ column is used in gas absorption process. (A) Wetted wall (B) Sieve/perforated tray (C) Bubble cap (D) Packed
Last Answer : (D) Packed
Description : Which of the following gas-liquid contacting devices incurs the least pressure drop for a particular duty? (A) Grid tray tower (B) Perforated tray tower (C) Wetted wall tower (D) Bubble cap tower
Last Answer : (D) Bubble cap tower
Description : Dust collection efficiency of a cyclone separator depends upon its (A) Diameter (B) Inlet gas velocity (C) Overall height (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : In a Rankine cycle, regeneration results in higher efficiency because (a) Pressure inside the boiler increases [GATE-2003] (b) Heat is added before steam enters the low pressure turbine (c) ... temperature of heat addition in the boiler increases (d) Total work delivered by the turbine increases
Last Answer : (c) Average temperature of heat addition in the boiler increases
Description : Umf is the minimum fluidisation velocity for a bed of particles. An increase in the superficial gas velocity from 2 Umf to 2.5 Umf results in (all velocities are smaller than the entrainment velocity of the particles ... (A) Drag on particles (B) Drag on column walls (C) Bed height (D) Bed voidage
Last Answer : (C) Bed height
Description : Explain how global warming can lead to the flooding of low lying areas.
Last Answer : Global warming will cause the ice caps at the Poles to melt which in turn will cause the sea level to rise, thus causing a change in weather patterns: more flooding will occur in the lowlying parts of the world.
Description : measures oxygen and temperature of the flue gas. a) Fuel efficiency monitor. b) Combustion analyzer. c) Contact thermometer. d) Infrared thermometer.
Last Answer : Combustion analyzer
Description : Pick out the wrong statement. (A) Critical moisture content is not a property of the material itself (B) A sharp increase in pressure drop gives an indication of the flooding in a ... unity (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum
Last Answer : (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum