Biochemical Engineering

Question: 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

Answer: Option C

Explanation:

No answer description available for this question.

Question: 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

Answer: Option C

Explanation:

No answer description available for this question.

Question: 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

Answer: Option D

Explanation:

No answer description available for this question.

Question: 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

Answer: Option B

Explanation:

No answer description available for this question.

Question: 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

Answer: Option C

Explanation:

No answer description available for this question.

Question: 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

Answer: Option B

Explanation:

No answer description available for this question.

Question: 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

Answer: Option B

Explanation:

No answer description available for this question.

Question: 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

Answer: Option A

Explanation:

No answer description available for this question.

Question: 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

Answer: Option A

Explanation:

No answer description available for this question.

Question: 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

Answer: Option A

Explanation:

No answer description available for this question.