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
Discussion:
22 comments Page 1 of 3.
Daniel said:
1 decade ago
This is wrong answer.
Vt is proportional to square of dia.
So if dia is doubled, Vt should be four times not one - fourth of original.
Vt is proportional to square of dia.
So if dia is doubled, Vt should be four times not one - fourth of original.
Lucy said:
1 decade ago
Vt = (g*dp^2*(raup - rauf))/(18*(viscocity)).
Where dp = diameter of particle.
raup = density of particle.
rauf = density of fluid.
Where dp = diameter of particle.
raup = density of particle.
rauf = density of fluid.
G.K said:
1 decade ago
So, from this:
Vt = (g*dp^2*(raup - rauf))/(18*(viscocity)).
VA = (1/4) of VB.
Vt = (g*dp^2*(raup - rauf))/(18*(viscocity)).
VA = (1/4) of VB.
Harika said:
9 years ago
This answer is wrong. It should be four times. That is option d.
Yogi said:
9 years ago
v is proportional to R^2.
V2/V1 = R^2\r^2.
V2/V1 = 20^2/10^2.
V2 = 4 * V1.
So, Answer D.
V2/V1 = R^2\r^2.
V2/V1 = 20^2/10^2.
V2 = 4 * V1.
So, Answer D.
Aswin said:
9 years ago
I agree with @Yogi.
Vivek kumar pal said:
9 years ago
Yes, the correct answer is (d).
Sandy said:
9 years ago
Velocity is inversely proportional to diameter.
Vb/Va= Da^2/Db^2
Vb/Va= 100/400
Vb= 1/4 Va
Vb/Va= Da^2/Db^2
Vb/Va= 100/400
Vb= 1/4 Va
Sandy said:
9 years ago
Am afraid am wrong settling velocity is nothing but terminal velocity, therefore, terminal velocity is directly proportional to diameter square answer should be D if they ask about the only velocity without mentioning terminal velocity then the answer would be B that is Velocity is inversely proportional to diameter square.
Avinash Raj said:
8 years ago
Answer is D. As u is proportional to the square of D.
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