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Fluid Flow MCQ Questions & Answers

Fluid Flow MCQs : This section focuses on the "Fluid Flow". These Multiple Choice Questions (MCQs) should be practiced to improve the Fluid Flow skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.




Question 1

Bubble free aeration systems requires

A. silicone tubing or gas permeable membranes to facilitate gas transfer
B. carbon dioxide instead of air to supply oxygen
C. silicone tubing or gas permeable membranes to remove carbon dioxide by oxygen in the form of hydrogen peroxide
D. filled headspace of the reactor with carbon dioxide

View Answer

Question 2

Which of the following describes the importance of the Kolmogorov eddy size in the biotechnology?

A. The Kolmogorov eddy size is a measure of the smallest eddy size in a liquid
B. When the Kolmogorov eddy size become equivalent or smaller than the cell or particle diameter, then the cell or particle will become susceptible to shear damage
C. At the Kolmogorov eddy size, much of the energy of the originating eddy will be released
D. All of the above

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Question 3

The flow of fluid which is highly chaotic is called as?

A. Laminar
B. Turbulence
C. Reynolds
D. Irrotational flow

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Question 4

The SI unit for viscosity is

A. kg.m-1.s-1
B. kg.m-2.s-2
C. kg.m-3.s-1
D. kg.m-1.s-2

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Question 5

Which of the following describes the detrimental effect of bubbles on animal cells?

A. Cells trapped on the surface of bubbles can be damaged when the bubbles explode, releasing their pressure and surface energies
B. Cells trapped in the moving foam can be dragged apart by the bubbles
C. Both (a) and (b)
D. Bubbles can explode in the liquid medium causing the release of ultraviolet radiation

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Question 6

The viscosity of a fluid increases with the length of time that it is being mixed. This fluid would be best described as being

A. newtonian
B. rheopectic
C. viscoelastic
D. thixotropic

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Question 7

Which of the following can act as a shear protectorant?

A. Serum
B. Silicone oil
C. Glucose
D. Glutamic acid

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Question 8

Which of the following affect the Kolmogorov eddy size?

A. Stirrer speed
B. Physical properties of the liquid
C. Size and type of impeller
D. All of these

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Question 9

Reynolds number for laminar flow over a plate should be less than

A. 500 mm
B. 5 x 10-5
C. 5 x 105
D. 5 m

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Question 10

Non-linear relationship between shear stress and shear rate exists in

A. newtonian fluids
B. non-newtonian fluids
C. both (a) and (b)
D. none of these

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Question 11

A liquid is flowing at 11,400 l.h-1 along a pipeline having a diameter of 4 cm. If the liquid has a density of 1 g.ml-1 and viscosity of 0.001kg.m-1.s-1, then the liquid would be in the

A. laminar phase
B. transient phase
C. turbulent phase
D. Any of these

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Question 12

The viscosity of the culture fluid is classified as both pseudoplastic and thixotropic which indicates that the viscosity

A. increases with stirring speed but decreases with mixing time
B. increases with stirring speed and increases with mixing time
C. decreases with stirring speed but increases with mixing time
D. decreases with stirring speed and decreases with mixing time

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Question 13

The viscosity of water at STP is approximately

A. 0.005 kg.m-1.s-1
B. 0.001 kg.m-1.s-1
C. 0.003 kg.m-2.s-1
D. 0.1 g.cm-1.s-1

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Question 14

The viscosity of a fluid changes with either stirrer speed or mixing time. But when mixing ceases, the viscosity returns to its original state. This fluid is best described as

A. newtonian
B. rheopectic
C. viscoelastic
D. thixotropic

View Answer

Question 15

Pluronic F68 is added to cell culture media as

A. a nutrient
B. a shear protectorant
C. to increase oxygen transfer rates
D. all of these

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Question 16

Which pattern of mixing is preferred in stirred tank reactors during the culture of aerobic microorganisms?

A. Laminar flow
B. Transient flow
C. turbulent flow
D. all of these

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Question 17

Which of the following factors will affect the sensitivity of animal cells to shear conditions?

A. Cell size
B. Availability of nutrients in the medium
C. The presence of shear protectorants in the medium
D. All of the above

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Question 18

A Brookfield viscometer cannot determine the shear stress because

A. the shear stress is not defined
B. a computer is required
C. the impeller type is given only by numbers
D. all of the above

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Question 19

The viscosity of a fluid increases with increasing stirrer speed. This fluid would be best described as being

A. newtonian
B. pseudoplastic
C. dilatant
D. thixotropic

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Question 20

A fluid in which the viscosity increases with increasing stirrer speed and mixing time can be called as

A. newtonian fluid
B. pseudoplastic, thixotropic fluid
C. dilatant, rheopectic fluid
D. dilatant pseudoplastic fluid

View Answer

Question 21

If the viscosity of a fluid decreases with the length of time that it is being mixed, then this fluid is

A. newtonian
B. rheopectic
C. viscoelastic
D. thixotropic

View Answer

Question 22

The liquid metal reduces its fluidity mainly due to?

A. high viscosity
B. high friction factor
C. high surface tension
D. high turbulence

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Question 23

A stirred tank reactor containing a fluid with a density of 2.5 g.ml-1 and viscosity of 0.002 kg m-1s-1 is mixed at 120 rpm. If the fluid is mixed with an impeller having diameter 50 cm, then the Reynolds number of the liquid in the reactor is

A. 2500
B. 100
C. 12,50,000
D. 1000000

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Question 24

A viscoelastic fluid is one in which the viscosity

A. is constant regardless of the stirrer speed or mixing time
B. changes during mixing but returns to its original state after mixing
C. increases with increasing stirrer speed
D. decreases with increasing stirrer speed

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Question 25

Reynolds number for turbulent flow over a plate should be more than

A. 5 x 10-5
B. 106
C. 5 x 105
D. 500

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Question 26

Filamentous fungal cells are more shear sensitive than bacterial cells because of

A. the presence of citin in cell walls of filamentous fungi
B. larger in size than bacterial cells and therefore are more susceptible to shear forces
C. fungal cells are much larger than bacterial cells
D. All of the above

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Question 27

A rheopectic fluid is one in which the viscosity

A. is constant regardless of the stirrer speed or mixing time
B. changes during mixing but returns to its original state after mixing
C. increases with mixing time
D. decreases with mixing time

View Answer

Question 28

The approach which is commonly used to determine the level of damage to animal cells in a culture medium is to monitor

A. the concentration of lactate in the medium
B. the level of lactate oxidase activity in the medium
C. the level of lactate dehydrogenase activity
D. the level of lactase activity in the medium

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Question 29

Non-linear relationship between shear stress and shear rate exists in

A. newtonian fluids
B. non-newtonian fluids
C. Both A and B
D. None of the above

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Question 30

A Brookfield viscometer measures viscosity by determining

A. the shear stress
B. the shear rate
C. the shear stress and shear rate
D. the torque required to move an impeller at a set speed

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Question 31

In animal cell bioreactor, bubble damage can be minimized by

A. the addition of a shear protectorant
B. using a bubble free oxygen delivery system
C. headspace aeration
D. All of the above

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Question 32

With an increase in the thickness of insulation around a circular pipe, heat loss to surrounding due to ____________

A. convection increase, while that the due to conduction decreases
B. convection decrease, while that due to conduction increases
C. convection and conduction decreases
D. convection and conduction increases

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Question 33

A thixotropic fluid is one in which the viscosity

A. is constant regardless of the stirrer speed or mixing time
B. changes during mixing but returns to its original state after mixing
C. increases with mixing time
D. decreases with mixing time

View Answer

Question 34

Which of the following describes the detrimental effect of bubbles on animal cells?

A. Cells trapped on the surfCells trapped on the surface of bubbles can be damaged when the bubbles explode, releasing their pressure and surface energiesace of bubbles can be damaged when the bubbles explode, releasing their pressure and surface energies
B. Cells trapped in the moving foam can be dragged apart by the bubbles
C. Both A and B
D. Bubbles can explode in the liquid medium causing the release of ultraviolet radiation

View Answer

Question 35

Which of the following affect the Kolmogorov eddy size?

A. newtonian fluidStirrer speed
B. Physical properties of the liquid
C. Size and type of impeller
D. All of the above

View Answer

Question 36

Animal cell cultures do not have much effect on shear forces because

A. the cell size is generally smaller than the critical eddy size at which shear will have an effect
B. cells are larger than the critical eddy size at which shear will have an effect
C. animal cells have cell walls
D. animal cells have cell membranes

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Question 37

The capability of molten metal to fill mold cavities is called ____________

A. viscosity
B. fluidity
C. turbulence
D. velocity

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Question 38

A pseudoplastic fluid is one in which the viscosity

A. is constant regardless of the stirrer speed or mixing time
B. changes during mixing but returns to its original state after mixing
C. increases with increasing stirrer speed
D. decreases with increasing stirrer speed

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Question 39

Which of the following compound, if added to a solution will lead to the greatest increase in viscosity?

A. A globular protein
B. Glucose
C. A long chain protein such as albumin
D. Water

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Question 40

For a given heat flow and for the same thickness, the temperature drop across the material will be maximum for ____________

A. copper
B. steel
C. glass-wool
D. refractory brick

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Question 41

Mixing in stirred tank reactors can

A. be described as either laminar, transient or turbulent
B. achieve turbulent conditions by increasing the stirrer speed
C. induce laminar flow conditions by the addition of baffles
D. All of the above

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Question 42

The medium will have the highest viscosity (considering that the cells do not secrete gums) with the presence of

A. single celled bacteria
B. filamentous fungi that form pellets
C. filamentous fungi that grow as long poorly branched chains
D. yeast

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Question 43

In sparged mammalian cell bioreactors, the cell damage is caused because of

A. shear stress arising during mixing of the cell culture fluid
B. shear stresses arising from the breakup of bubbles at the liquid surface
C. shear stresses between bubbles in foam at the liquid surface
D. All of the above

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Question 44

The viscosity of liquid was classified as both dilatant and rheopectic, which means that the viscosity

A. increased with stirring speed but decreased with mixing time
B. increased with stirring speed and increased with mixing time
C. decreased with stirring speed but increased with mixing time
D. decreased with stirring speed and decreased with mixing time

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Question 45

The Komologorov eddy size

A. is constant at all stirrer speeds
B. increases with stirrer speed
C. decreases with stirrer speed
D. becomes zero when the stirrer speed is very low

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Question 46

Pluronic F68 protects mammalian cells from damage stems as it is a/an

A. surface active agent which stabilizes foams
B. surface active agent which destabilizes foams
C. excellent source of vitamins
D. coagulant

View Answer

Question 47

A fluid in which the viscosity decreases with increasing stirrer speed and mixing time, can be represented as

A. newtonian fluid
B. pseudoplastic, thixotropic fluid
C. dilatant, rheopectic fluid
D. dilatant, pseudoplastic fluid

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Question 48

Newtonian fluid is one in which the viscosity

A. remains constant with time and power input
B. increases with the level of power input
C. decreases with the level of power input
D. drastically increases with the level of power input

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Question 49

A Newtonian fluid is one in which the viscosity

A. is constant regardless of the stirrer speed or mixing time
B. changes during mixing but returns to its original state after mixing
C. increases with increasing stirrer speed
D. decreases with increasing stirrer speed

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Question 50

Which of the following is correct?

A. The viscosity of liquids and gases decrease with increasing temperature
B. The viscosity of liquids and gases increase with increasing temperature
C. the viscosity of gases increases with increasing temperature, but decreases in liquids
D. the viscosity of gases decreases with increasing temperature, but decreases in liquids.

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Question 51

Water is a

A. newtonian fluid
B. pseudoplastic
C. dilatant
D. rheopectic

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Question 52

A dilatant fluid is one in which the viscosity

A. is constant regardless of the stirrer speed or mixing time
B. changes during mixing but returns to its original state after mixing
C. increases with increasing stirrer speed
D. decreases with increasing stirrer speed

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Question 53

A liquid is flowing at 11,400 l.h-1 along a pipeline having a diameter of 4 cm. If the liquid has a density of 1 g.ml-1 and viscosity of 0.001kg.m-1.s-1, then the liquid would be in the

A. laminar phase
B. transient phase
C. turbulent phase
D. any of the phase

View Answer

Question 54

The best described action of Pluronic F68 (non-ionic detergent) in a cell culture medium is that, it

A. acts on the surface properties of the cells and the culture medium
B. provides nutrients for the cells
C. acts as a flocculant
D. acts as a coagulant

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Question 55

The viscous nature of a non-Newtonian fluid

A. remains constant with time and power input
B. changes with the level of power input and/or the length of time during which the fluid is mixed
C. is similar to that of a perfect gas
D. is similar to that of water

View Answer

Question 56

If the viscosity of a fluid decreases with increasing stirrer speed, then the nature of the fluid is

A. newtonian
B. pseudoplastic
C. dilatant
D. thixotropic

View Answer