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.Management Sciences
Category: Mass Transfer
Mass transfer co-efficient varies as DAB 0.5, according to the _______________ theory?
A. Film
B. Surface renewal
C. Penetration
D. None of these
Mass transfer co-efficient is directly proportional to DAB according to the _____________ theory?
A. Film
B. Penetration
C. Surface-renewal
D. None of these
The cooling effect in a cooling tower cannot be increased by_____________________?
A. Increasing the air velocity over the wet surfaces
B. Reducing the humidity of entering air
C. Lowering the barometric pressure
D. None of these
Drying operation under vacuum is carried out to __________________?
A. Dry those materials which have very high unbound moisture content
B. Reduce drying temperature
C. Increase drying temperature
D. Dry materials having high bound moisture content
Water-ethyl alcohol solution can be concentrated (in respect of alcohol concentration) by ________________ distillation?
A. Atmospheric
B. Vacuum
C. High pressure
D. None of these
Pick out the correct statement?
A. Diffusivity decreases with increase in temperature
B. Diffusivity increases with increase in molecular weight
C. Diffusivity increases with the size of the individual molecule
D. None of these
Which of the following provides maximum contact surface for a liquid-vapour system ?
A. Packed tower
B. Bubble-cap plate column
C. Sieve-plate column
D. Wetted wall column
Pick out the correct statement ?
A. In case of liquid-liquid extraction, no separation is possible, if the selectivity of the solvent
used is unity
B. With increase in temperature, the selectivity of the solvent used in solvent extraction
decreases
C. The selectivity of solvent used in solvent extraction is unity at the plait point
D. All A., B. and C.
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. Remain unaffected
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