A. Sc × Pr
B. Pr × St
C. Sh × Pr
D. St × Sh
Related Mcqs:
- Lewis number (Le) is____________________?
A. Sc × Pr
B. Pr × St
C. Sh × Pr
D. St × Sh - 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 - Schmidt number and Lewis number for pure air at atmospheric conditions are respectively__________________?
A. < 1 and ≈ 1
B. 1 and 0
C. > 1 and ≈ 1
D. 0 and ≈ 1 - Lewis number, which is important in problems involving simultaneous heat and mass transfer, is the ratio of__________________?
A. Mass diffusivity to momentum diffusivity
B. Thermal diffusivity to mass diffusivity
C. Momentum diffusivity to thermal diffusivity
D. None of these - If mass diffusivity in a mixture is equal to the thermal diffusivity, then the Lewis number is____________________
A. 0
B. 1
C. 1 - For which of the following unit operations, Lewis number is of significance ?
A. Adsorption
B. Binary distillation
C. Gas absorption
D. Humidification - A pure drug is administered as a sphere and as a cube. The amount of drug is the same in the two tablets. Assuming that the shape and size do not influence the mass transfer, the ratio of rate of dissolution in water at t = 0 for the cubic to spherical tablet is___________________?
A. 0.54
B. 1.04
C. 1.24
D. 1.94 - As per Gilliland’s equation, the diffusivity is___________________?
A. Directly proportional to ‘T1.5’
B. Inversely proportional to ‘P’
C. Dependent on the molecular volume & molecular weight of components
D. All A , B. & C. - Positive deviation from Raoult’s law means a mixture whose total pressure is___________________?
A. Greater than that computed for ideality
B. Less than that computed for ideality
C. Less than the sum of the vapour pressure of the components
D. None of these - If G = insoluble gas in gas stream and L = non-volatile solvent in liquid stream, then the slope of the operating line for the absorber is___________________?
A. L/G
B. G/L
C. Always < 1
D. None of these
