# Mass Transfer Questions and Answers – Convective Mass Transfer

This set of Heat Transfer Multiple Choice Questions & Answers (MCQs) focuses on “Convective Mass Transfer”.

1. 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. 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. 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. 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. 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.
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6. 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. 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. 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. 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. Which number forms the connecting link between the temperature and concentration profiles?
a) Prandtl number
b) Schmidt number
c) Fourier number
d) Lewis number

Explanation: When Lewis number is equal to unity, these two profiles are identical.

Sanfoundry Global Education & Learning Series – Heat Transfer.

To practice all areas of Heat Transfer, here is complete set of 1000+ Multiple Choice Questions and Answers.