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Question: Reynolds (Rei) number for the impeller is given by (where Di, stirrer diameter; N, stirrer speed, ρ, density of fluid and μ, viscosity of fluid)
[A].

DiVρ/μ

[B].

Di2Nρ/μ

[C].

Di2Vρ/μ

[D].

DiNρ /μ

Answer: Option B

Explanation:

No answer description available for this question.

Question: Power consumption by agitation is
[A].

a function of physical properties

[B].

a function of operating conditions

[C].

a function of vessel and impeller geometry

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: The power consumption in a stirring vessel can be assessed by using a
[A].

dynamometer

[B].

strain gauge attached to agitator shaft

[C].

watt meter attached to agitator motor

[D].

all of these

Answer: Option D

Explanation:

No answer description available for this question.

Question: The power required by an agitator operating in a gas-sparged system is
[A].

lesser than the power required by an impeller in operating at same speed in a gas free system

[B].

more than the power required by an impeller in operating at same speed in a gas free system

[C].

same as the power required by an impeller in operating at same speed in a gas free system

[D].

none of the above

Answer: Option A

Explanation:

No answer description available for this question.

Question: Which of the following(s) is/are non-mechanically agitated reactors?
[A].

Stirrer tank reactor

[B].

Bubble column

[C].

Air lift reactor

[D].

Both (b) and (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: Industrial paddle agitators turn at the speed of
[A].

20 and 150 rpm

[B].

150 and 300 rpm

[C].

400 and 800 rpm

[D].

1150 rpm

Answer: Option A

Explanation:

No answer description available for this question.

Question: Larger propellers turn at the speed of
[A].

20 to 150 rpm

[B].

150 to 300 rpm

[C].

400 to 800 rpm

[D].

1150 rpm

Answer: Option C

Explanation:

No answer description available for this question.

Question: Small propellers turn at the speed of either
[A].

20 or 150 rpm

[B].

150 or 300 rpm

[C].

400 or 800 rpm

[D].

1150 rpm or 1750 rpm

Answer: Option D

Explanation:

No answer description available for this question.

Question: Flooding is a condition/phenomenon which occur in a bioreactor when
[A].

The air escapes without being distributed by the agitator

[B].

The fermenter medium spills out the reactor due to foaming

[C].

The volume of foam is more than the volume of broth

[D].

None of the above

Answer: Option A

Explanation:

No answer description available for this question.

Question: Which device is commonly used for measuring the rate of rotation (rpm) of the stirrer shaft?
[A].

Anemometer

[B].

Manometer

[C].

Tachometer

[D].

Barometer

Answer: Option C

Explanation:

No answer description available for this question.