Engineering Questions with Answers - Multiple Choice Questions
Separation Processes MCQ’s – Centrifuge Devices for Solid Liquid Separations
1 - Question
What are the two general types of centrifuge devices for solid-liquid separations?
a) Sedimentation centrifuges, filtering centrifuges
b) Sedimentation centrifuges, decantation centrifuges
c) Filtering centrifuges, sintering centrifuges
d) Sedimentation centrifuges, two way centrifuges
View Answer
Answer: a
Explanation: The two general types of centrifuge devices for solid-liquid separations are Sedimentation centrifuges, filtering centrifuges.
2 - Question
What is the use of tubular-bowl centrifuge?
a) To separate soap from oil
b) To separate waste material
c) To separate cells and viruses from broth
d) To separate salts from mixtures
View Answer
Answer: c
Explanation: The tubular-bowl centrifuge is used to separate cells and viruses from broth.
3 - Question
In which industry tubular-bowl centrifuge not used?
a) Food industry
b) Pharma industry
c) Biochemical industry
d) Metallurgical industry
View Answer
Answer: d
Explanation: The tubular-bowl centrifuge is used to separate cells and viruses from broth and hence has no use in the metal industry
4 - Question
When is the basket-filtering centrifuge not used?
a) Solids are main product
b) Low cake moisture content
c) High solid recovery desired
d) High liquid recovery desired
View Answer
Answer: d
Explanation: When high liquid recovery is desired, basket filtering centrifuge is not used.
5 - Question
Why are gravity separators not used in bioseparations?
a) Because density differences are very large
b) Because density differences are very small
c) Because gravity separators are too small
d) Because the cultures get damaged
View Answer
Answer: b
Explanation: Gravity separators are not used in bioseparations because density differences are very small.
6 - Question
Calculate the sigma factor for the following operating conditions
Bowl length L=0.1m
Rotation rate n=2000/s
R0=0.02m, R1=0.01m
a) 50
b) 55
c) 111
d) 165
View Answer
Answer: b
Explanation: Sigma factor= Lω2(R02-R12)/gln(R0/R1), hence sigma factor= 55m.
7 - Question
Calculate the sigma factor for the following operating conditions
Bowl length L=0.2m
Rotation rate n=2000/s
R0=0.02m, R1=0.01m
a) 50
b) 55
c) 111
d) 165
View Answer
Answer: c
Explanation: Sigma factor= Lω2(R02-R12)/gln(R0/R1), hence sigma factor= 111m.
8 - Question
Calculate the sigma factor for the following operating conditions
Bowl length L=0.3m
Rotation rate n=2000/s
R0=0.02m, R1=0.01m
a) 50
b) 55
c) 111
d) 165
View Answer
Answer: d
Explanation: Sigma factor= Lω2(R02-R12)/gln(R0/R1), hence sigma factor= 111m.
9 - Question
Calculate the sigma factor for the following operating conditions
Bowl length L=0.05m
Rotation rate n=2000/s
R0=0.02m, R1=0.01m
a) 27
b) 55
c) 111
d) 165
View Answer
Answer: a
Explanation: Sigma factor= Lω2(R02-R12)/gln(R0/R1), hence sigma factor= 27m.
10 - Question
Calculate the sigma factor for the following operating conditions
Bowl length L=0.1m
Rotation rate n=4000/s
R0=0.02m, R1=0.01m
a) 323
b) 212
c) 234
d) 222
View Answer
Answer: d
Explanation: Sigma factor= Lω2(R02-R12)/gln(R0/R1), hence sigma factor= 222m.