1) In case of an unsaturated mixture of gas and vapor, the percentage saturation is __________________ its relative saturation? a. Lower than b. Higher than c. Equal to d. Either A. or B., depends on the mixture composition
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2) At __________________ reflux, theoretical number of plates in a distillation coloumn is calculated using Fenske-Underwood equation? a. Operating b. Total c. Minimum d. Maximum permissible
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3) In physical terms, Schmidt number means _________________? a. Thermal diffusivity/mass diffusivity b. Thermal diffusivity/momentum diffusivity c. Momentum diffusivity/mass diffusivity d. Mass diffusivity/thermal diffusivity
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4) Unit operation involved in the prilling of urea is_____________________? a. Evaporation b. Drying c. Crystallisation d. Both B. and C.
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5) Degree of freedom for leaching and solvent extraction process is_____________________? a. 0 b. 1 c. 2 d. 3
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6) With increase in temperature, the solubility of gases in liquids, at fixed pressure____________________? a. Increases b. Decreases c. Remain same d. Either A. or B., depends on the system
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7) The equipment used in the extraction of highly corrosive radioactive liquids is_______________________? a. Pulse column b. Spray column c. Mixer settler d. Baffle tower
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8) Tea percolation employs___________________________? a. Liquid-liquid extraction b. Leaching c. Absorption d. None of these
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9) When the solvent dissolves very little of solute, then__________________________? a. Solvent of low latent heat of vaporisation should be used b. Solvent of low freezing point should be used c. Large quantity of solvent is required to extract the solute d. Very small quantity of solvent is required
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10) Bollman extractor___________________? a. Is a static bed leaching equipment b. Is used for extraction of oil from oilseed c. Is a centrifugal extractor d. Employs only counter-current extraction
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11) In case of absorption, both the operating and equilibrium lines will be straight for______________? a. Isothermal operation b. Dilute solutions c. Dilute solutions and isothermal operation d. None of these
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12) The most economical range of absorption factor is____________________? a. 0 to 0.5 b. 0 to 3 c. 1.25 to 2 d. 5 to 15
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13) In the constant rate period of the rate of drying curve for batch drying,_________________? a. Cracks develop on the surface of the solid b. Rate of drying decreases abruptly c. Surface evaporation of unbound moisture occurs d. None of these
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14) 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
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15) Rose oil is extracted from rose leaves using ____________ distillation? a. High pressure b. Low pressure c. Extractive d. Steam
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16) The value of NA/(NA + NB), for steady state equimolal counter diffusion of two gases ‘A’ and ‘B’ is____________? a. 1 b. ∞ c. 0.5 d. 2
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17) Which of the following is not a unit of mass transfer co-efficient ? a. Moles transferred/ [(time) (area) (mole fraction)] b. Moles transferred/ [(time) (area) (mass A/mass B)] c. Moles transferred/ [(time) (area) (pressure)] d. None of these
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18) Dry bulb temperature of the gas is _____________ the wet bulb temperature? a. Less than b. More than c. Equal to d. None of these
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19) The equilibrium liquid composition compared to the vapor composition in case of________________?
Azeotropic mixture is a. More b. Less c. Same d. Either more or less; depends on the system
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20) Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled_________________? a. And humidified b. And dehumidified with increase in wet bulb temperature c. At the same relative humidity d. And dehumidified with decrease in wet bulb temperature
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21) The value of Lewis number (Le = Sc/Pr) for air-water vapour system is around_________________? a. 1 b. 0.24 c. 3.97 d. 600
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22) Dew point of an air-water vapor mixture_________________? a. Decreases with decrease in pressure b. At constant humidity & total pressure is fixed c. Corresponding to any point on the humidity chart is obtained by projecting a line through this point parallel to the temperature axis and to the satur d. All A , B. & C.
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23) The relation, Sc = Pr = 1, is valid, when the mechanism of ______________ transfer is same? a. Heat and mass b. Mass and momentum c. Heat and momentum d. Heat, momentum and mass
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24) McCabe-Thiele method________________? a. Uses molal units for material and energy balance b. Uses weight fractions to express liquid and vapour composition c. Can use any type of units d. Is more accurate than Ponchon-Savarit method
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25) If the path of liquid across the plate is very long as in case of large diameter tower, Murphree efficiency can be _______________ percent? a. 100 b. > 100 c. < 100 d. None of these
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26) If the specific heats of a gas and a vapor are 0.2KJ/Kg.°K and 1.5 KJ/Kg.°K respectively, and the humidity is 0.01; the humid heat in KJ/°Kg. is________________? a. 0.31 b. 0.107 c. 0.017 d. 0.215
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27) In case of ______________ distillation, a solvent is added to alter the relative volatility of the mixture to be separated? a. Molecular b. Azeotropic c. Extractive d. Flash
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28) Moisture contained by a substance in excess of the equilibrium moisture is called the _______________ moisture? a. Unbound b. Free c. Critical d. Bound
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29) Hypersorption refers to a ________________ process? a. Fixed bed absorption b. Moving bed absorption c. Fixed bed adsorption d. Moving bed adsorption
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30) In case of liquids, the binary diffusivity is proportional to (where, T = temperature) _____________________? a. T b. √T c. T2 d. 1/T
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31) The relative saturation of an unsaturated mixture of gas and vapor is independent of the___________________? a. Nature of the vapor b. Temperature of the mixture c. Composition of the mixture d. None of these
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32) Advantage of continuous drying over batch drying is that the_____________________? a. Drying cost per unit weight of dried product is less b. Product with more uniform moisture content is produced c. Equipment size required is smaller d. All A , B. & C.
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33) An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively. The humidity of air sample expressed as kg of water vapour/kg of dry air is__________________? a. 0.048 b. 0.079 c. 0.122 d. 0.152
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34) For an absorber, both equilibrium and operating line will be straight for _______________________? a. Concentrated solution and non-isothermal operation b. Dilute solution and non-isothermal operation c. Dilute solution and isothermal operation d. Concentrated solution and isothermal operation
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35) Penetration model (theory) for mass transfer was enunciated by _____________________? a. Danckwerts b. Toor and Marcello c. Higbie d. Kissinevskii
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36) Milk is dried usually in a __________________ dryer? a. Freeze b. Spray c. Tray d. Rotary
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37) Unit of molal diffusivity is____________________? a. cm2/sec gm . mole b. gm moles/cm2 . sec c. gm moles/cm. sec d. gm moles/cm2. sec
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38) In case of non-ideal gases and liquids, the molal diffusivity ________________? a. Varies inversely as the pressure b. Varies directly as the pressure c. Is independent of pressure d. Is equal to the volumetric diffusivity
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39) Which of the following is a suitable absorbent for removal of H2S from natural gas ? a. Vetrocoke solution b. Monoethanolamine (MEA) c. Dilute d. Hot water
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40) Humid volume is the total volume in m3 of 1 kg of _____________________? a. Vapour laden gas at 1 atm. and room temperature b. Gas plus its accompanying vapour at 1 atm. and room temperature c. Gas plus its accompanying vapour at 1 atm. and gas temperature d. Vapour laden gas at 1 atm. and gas temperature
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