Top 550+ Solved Mass Transfer MCQ Questions Answer
Q. Molecular diffusion is caused by the
a. Transfer of molecules from low concentration to high concentration region
b. Thermal energy of the molecules
c. Activation energy of the molecules
d. Potential energy of the molecules
Q. Liquid diffusivity is of the order of __________ cm2 /second.
a. 0.01
b. 0.1
c. 10-5 to 10-6
d. > 1
Q. The diffusivity, DAB (for component A diffusing in B) is equal to the diffusivity DBA (forcomponent B diffusing in A) for a binary mixture of
a. Newtonian liquids
b. Non-Newtonian liquids
c. Ideal gases
d. Real gases
Q. Can a cooling tower cool water below the wet bulb temperature of inlet air?
a. Yes
b. No
c. Yes; but height of cooling tower will be prohibitively high
d. Yes; but the air flow rate should be excessively high
Q. Wetted wall tower experiment determines the
a. Molal diffusivity
b. Volumetric co-efficient
c. Mass transfer co-efficient
d. None of these
Q. Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid).
a. p = P
b. p >>P
c. p < P
d. p << P
Q. If the overall efficiency and Murphree plate efficiency are equal, then both the equilibrium and operating lines are:
a. Straight
b. Parallel
c. Both (A) & (B)
d. Neither (A) nor (B)
Q. JD factor for mass transfer is a function of Reynolds number. Mass transfer by molecular diffusion from a single drop to surrounding still air is given by
a. Nsh = 2
b. Nst = 2
c. Nsc = 2
d. None of these
Q. Molecular sieves are porous
a. Alumina
b. Silica
c. Synthetic zeolites crystals/metal alumino-silicates
d. None of these
Q. Nitrobenzene (boiling point = 210.6°C) is steam distilled at 1 atm pressure. Nitrobenzene will distil off __________ °C.
a. At < 100
b. At > 210.6
c. Between 100 and 210
d. None of these
Q. The adiabatic saturation curve for a vapour-gas mixture is
a. Straight line
b. Slightly concave upward
c. Slightly concave downward
d. None of these
Q. 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
Q. Absorption factor is defined as (where, S1 = slope of the operating line S2 = slope of the equilibrium curve)
a. S2/S1
b. S1/S2
c. S1 - S2
d. S1 × S2