This is an MCQ-based quiz on the topic of Mass Transfer and Diffusion.
This includes the following topics:-
Steady-state, Ordinary Molecular Diffusion
Steady and Unsteady State Mass Transfer Through Stationary Media
Mass Transfer in Laminar Flow
Mass Transfer in Turbulent Flow
Two Film Theory and Overall Mass Transfer Coefficients
Start Quiz
Which of the following is most true?
Na = kcA(cai – ca)
Na = kcAΔc
Na = kcA(cai – ca)mean
Na = kcA(cai – ca)log mean
What is the correct formula for nusselt’s number?
hµ/k
hρ/k
hL/k
hΔTL/k
What is the physical significance of nusselt’s number?
Ratio of convective heat transfer to conductive heat transfer
Ratio of convective heat transfer to conductive heat transfer
Ratio of total heat transfer to conductive heat transfer
Ratio of total transfer to convective heat transfer
Which of the following is true about prandtl’s number?
Npr = Cpµ/k
Npr = Cpk/µ
Npr = Cvµ/k
Npr = Cpµ
Prandtl’s number is the ratio of which two quantities?
Momentum conductivity and thermal conductivity
Coefficient of convection to thermal conductivity
Momentum diffusivity and thermal diffusivity
Interfacial force and viscous force
The equation of motion for the liquid film in fully developed laminar flow in y-direction is:
µd2uy/dx2 + ρg =0
µd2uy/dy2 + ρg =0
µd2uy/dz2 + ρg =0
µd2uy/dx2 = 0
Which two forces is the reynold’s number a ratio of?
Gravitational force and interfacial force
Interfacial force and viscous force
Thermal conductivity and electrical conductivity
Conduction and convection
What value of Reynold’s number is obtained with water?
8
16
25
50
What value of reynold’s number represents a laminar flow?
3
2500
5000
78
Which of the following reynold’s number represents a turbulent flow?
500
700
2500
6000
Which of the following is present in turbulent flow mass transfer?
Slow mass transfer
Less mass transfer
Eddy currents
Eddy diffusion
What is the physical significance of drag coefficient?
It is drag force divided by projected area and velocity head
It is the ratio of pipe wall shear stress and velocity head
It is the ratio of inertial forces to viscous force
It is the ratio of inertial force to surface tension force
What is the physical significance of weber number?
It is drag force divided by projected area and velocity head
It is the ratio of pipe wall shear stress and velocity head
It is the ratio of inertial forces to viscous force
It is the ratio of inertial force to surface tension force
What is the physical significance of lewis number?
It is the ratio of bulk transfer mass and molecular diffusion
It is the ratio of thermal diffusivity to mass diffusivity
It is the ratio of conductive mass transfer to molecular diffusion
It is the ratio of mass transfer to mass capacity
Which of the following is correct about Reynold’s number?
3 less than re less than 1200
3 less than re less than 1600
25 less than re less than 1200
8 less than re less than 1200