Chemical Engineering - Fluid Mechanics - Discussion

Discussion Forum : Fluid Mechanics - Section 1 (Q.No. 26)
26.
A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke's law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity
same as that of A.
one fourth as that of A.
twice as that of A.
four times as that of A.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
22 comments Page 2 of 3.

Manoj said:   8 years ago
No the answer is (1/4) A.
v = R2
v = (2d)2
v = 4d2.
Now, v is doubled so,
2v = 8d2.
Hence v = (1/4) d2.

Yadav said:   7 years ago
D is the correct option.

Mangesh said:   7 years ago
@Manoj.

Diameter = 2* radius.

Not; Radius = 2* diameter.

Zeeshanulhaq said:   6 years ago
At low Reynolds number settling velocity is proportional to square of dp, then d is answer. While for very low or very high Reynolds velocity is proportional to underroot dp.

Bashir said:   5 years ago
D is the right option.

Vicky said:   3 years ago
Vt proportional d^2.

So, option D is right.

Dharmendra Kumar tadav said:   3 years ago
The Correct answer is D.

Yash said:   3 years ago
Yes, D is correct, in the stokes region, settling velocity varies (D)^ (2).

Solving gives Vb= 4* Va.

DAN said:   3 years ago
Anyone, please explain the right answer.

Abhay kumar Pandey said:   3 years ago
Settling velocity is directly proportional to the diameter of the particle (having an increasing trend).


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