# Mass Transfer MCQ’s – Convective Mass Transfer

1 - Question

The mass transfer by convection can take place under how many conditions?
a) 1
b) 2
c) 3
d) 4
Explanation: Free or forced conditions.

2 - Question

Lewis number is given by
a) 4 α/D
b) 3 α/D
c) 2 α/D
d) α/D
Explanation: It forms the connecting link between the temperature and concentration profiles.

3 - Question

Prandtl number is given by
a) V/α
b) 2 V/α
c) 3 V/α
d) 4 V/α
Explanation: It is related to velocity and temperature profiles.

4 - Question

Schmidt number is given by
a) 2 V/D
b) D/V
c) V/D
d) 2 D/V
Explanation: It is related to velocity and concentration profiles.

5 - Question

Sherwood number is given by
a) 3/2 h m L/D
b) ½ h m L/D
c) 3 h m L/D
d) h m L/D
Explanation: It is a non-dimensional mass transfer number.

6 - Question

The solution for velocity, concentration and temperature boundary layers will be same if
a) Prandtl number = Schmidt number= Lewis number
b) Prandtl number = 2 Schmidt number= Lewis number
c) Prandtl number = Schmidt number= 2 Lewis number
d) 2 Prandtl number = Schmidt number= Lewis number
Explanation: All the three boundary layers must coincide.

7 - Question

Convective mass transfer involves the transportation of material between a boundary surface and a moving fluid or between two immiscible fluids. It is prescribed by the relation
a) 2 h m (d C B)
b) ½ h m (d C B)
c) h m (d C B)
d) 3/2 h m (d C B)
Explanation: It is equal to m/A = h m (d C B).

8 - Question

Which number forms the connecting link between the velocity and temperature profiles?
a) Fourier number
b) Prandtl number
c) Stanton number
d) Biot number
Explanation: These profiles become identical when Prandtl number is equal to one.

9 - Question

Which number forms the connecting link between the velocity and concentration profiles?
a) Schmidt number
b) Reynolds number
c) Stanton number
d) Fourier number
Explanation: These profiles become identical when Schmidt number is equal to one.

10 - Question

Which number forms the connecting link between the temperature and concentration profiles?
a) Prandtl number
b) Schmidt number
c) Fourier number
d) Lewis number