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