The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = _________________?

Related Mcqs:

1. NSc/NPr is called the______________________?

   A. Psychrometric ratio
   B. Lewis number
   C. Sherwood number
   D. Stanton number

2. If mass diffusivity in a mixture is equal to the thermal diffusivity, then the Lewis number is____________________

   A. 0
   B. 1
   C. 1

3. According to Chilton-Colburn analogy for mass transfer, NSt.NSc 2/3 is equal to_________________?

   A. f
   B. f/2
   C. 2f
   D. 1/f

4. (NRe . NSc) is termed in mass transfer operation as the ______________ number?

   A. Stanton
   B. Sherwood
   C. Peclet
   D. None of these

5. (NSh/NRe.NSc) is termed in mass transfer operation as the __________________________?

   A. Stanton number
   B. Peclet number
   C. Thermal diffusivity
   D. Momentum diffusivity

6. Mass transfer co-efficient ‘K’ according to penetration theory varies with mass diffusivity as____________________?

   A. D0.5
   B. D
   C. 1/D
   D. D1.5

7. According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity) ?

   A. D
   B. D2
   C. D0.5
   D. 1/D

8. The diffusivity, DAB (for component A diffusing in B) is equal to the diffusivity DBA (for component B diffusing in A) for a binary mixture of________________?

   A. Newtonian liquids
   B. Non-Newtonian liquids
   C. Ideal gases
   D. Real gases

9. A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)) ?

   A. M(Xo – XF)
   B. M(Xo/XF)
   C. M ln(Xo/XF)
   D. MXo ln(Xo/XF)

10. A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids))_____________?

    A. M(Xo – XF)
    B. M(Xo/XF)
    C. M ln(Xo/XF)
    D. MXo ln(Xo/XF)