Category: Mass Transfer

A. Lewis number
B. Schmidt number
C. Prandtl number
D. Sherwood number

A. Size of component molecules are not equal
B. Attractive forces between like and unlike molecules in the solution are approximately equal
C. Component molecules are non-polar
D. Chemical combination or molecular association between unlike molecules takes place in the
formation of solution

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

A. Cylinder
B. Rotary
C. Spray
D. Fluidised bed

A. Natural draft cooling tower
B. Induced draft cooling tower
C. Spray chamber
D. None of these

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

A. μ
B. 1/μ
C. √μ
D. μ2

A. In the McCabe-Thiele diagram for binary distillation, vertical feed line represents saturated
liquid feed and horizontal feed line represents saturated vapour feed
B. In small columns, local efficiency is larger than Murphree efficiency; in large columns local
efficiency is smaller than Murphree efficiency
C. For Laminar flow over a plate of length L, the local mass transfer co-efficient at a distance L
from the leading edge is 1.5 × 10-2m/s. Then the average mass transfer co-efficient for the
plate is 2 × 10-2m/s
D. The concentration and hydrodynamic boundary layers over a flat plate are of equal thickness,
if Schmidt number is equal to unity

A. Small sizes
B. Multi-component distillation
C. High pressure operation
D. Vacuum distillation

A. Decreases
B. Increases
C. Remains unchanged
D. None of these