Explore topic-wise MCQs in Bioprocess Engineering.

This section includes 23 Mcqs, each offering curated multiple-choice questions to sharpen your Bioprocess Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

A 10,000 liter (of liquid) bioreactor contains 5 g / L of growing cells qO2 = 20 mmoles O2 / (g cells hr) DT = 2 m, DI = 1 m, (6 – blade turbine agitator) x 3 blades and CL = 1 mg O2/L. Calculate OUR.

A. 200 mmoles O2 / (g cells hr)
B. 250 mmoles O2 / (g cells hr)
C. 100 mmoles O2 / (g cells hr)
D. bioreactor contains 5 g / L of growing cells qO2 = 20 mmoles O2 / (g cells hr) DT = 2 m, DI = 1 m, (6 – blade turbine agitator) x 3 blades and CL = 1 mg O2/L. Calculate OUR.a) 200 mmoles O2 / (g cells hr)b) 250 mmoles O2 / (g cells hr)c) 100 mmoles O2 / (g cells hr)d) 150 mmoles O2 / (g cells hr)
Answer» D. bioreactor contains 5 g / L of growing cells qO2 = 20 mmoles O2 / (g cells hr) DT = 2 m, DI = 1 m, (6 – blade turbine agitator) x 3 blades and CL = 1 mg O2/L. Calculate OUR.a) 200 mmoles O2 / (g cells hr)b) 250 mmoles O2 / (g cells hr)c) 100 mmoles O2 / (g cells hr)d) 150 mmoles O2 / (g cells hr)
Discussion
2.

Which of the following does not affect KLa value?

A. Air flow rate
B. Presence of enzymes
C. Presence of antifoam agents
D. Degree of agitation
Answer» C. Presence of antifoam agents
Discussion
3.

Which of the following is not a chemical method to measure kLa?

A. Dynamic gassing out method
B. Sodium sulfite oxidation method
C. Carbon dioxide absorption method
D. Glucose oxidase method
Answer» B. Sodium sulfite oxidation method
Discussion
4.

Speed is the factor affecting the value of kLa.

A. True
B. False
Answer» B. False
Discussion
5.

Refer to Q5 and, calculate: An error is made determining the steady-state oxygen level which, instead of 78%, is taken as 70%. What is the percentage error in kLa resulting from this 10% error in \(\bar{C_{AL}}\)?

A. 50%
B. 25%
C. 75%
D. 100%
Answer» E.
Discussion
6.

A 20-1 stirred fermenter containing a Bacillus thuringiensis culture at 30°C is used for production of microbial insecticide, kLa is determined using the dynamic method. Air flow is shut off for a few minutes and the dissolved-oxygen level drops; the air supply is then re-connected. When steady state is established, the dissolved-oxygen tension is 78% air saturation. The following results are obtained. Estimate kLa.

A. 0.080 s-1
B. 0.083 s-1
C. 0.085 s-1
D. 0.081 s-1View Answer
Answer» D. 0.081 s-1View Answer
Discussion
7.

What is the proper concentration unit of kLa?

A. h-1
B. ml/h
C. mmol/h
D. ml/sec
Answer» B. ml/h
Discussion
8.

What do you mean by “kLa”?

A. Volumetric mass transfer coefficient
B. Henry’s law coefficient
C. Volumetric oxygen transfer coefficient
D. Volumetric Solute transfer coefficient
Answer» D. Volumetric Solute transfer coefficient
Discussion
9.

WHICH_OF_THE_FOLLOWING_IS_NOT_A_CHEMICAL_METHOD_TO_MEASURE_KLA??$

A. Dynamic gassing out method
B. Sodium sulfite oxidation method
C. Carbon dioxide absorption method
D. Glucose oxidase method
Answer» B. Sodium sulfite oxidation method
Discussion
10.

A 10,000 liter (of liquid) bioreactor contains 5 g / L of growing cells qO2 = 20 mmoles O2 / (g cells hr) DT = 2 m, Di = 1 m, (6 – blade turbine agitator) x 3 blades and CL = 1 mg O2/L. Calculate OUR.$#

A. 200 mmoles O<sub>2</sub> / (g cells hr)
B. 250 mmoles O<sub>2</sub> / (g cells hr)
C. 100 mmoles O<sub>2</sub> / (g cells hr)
D. 150 mmoles O<sub>2</sub> / (g cells hr)
Answer» D. 150 mmoles O<sub>2</sub> / (g cells hr)
Discussion
11.

Which of the following does not affect KLa value?$

A. Air flow rate
B. Presence of enzymes
C. Presence of antifoam agents
D. Degree of agitation
Answer» C. Presence of antifoam agents
Discussion
12.

KLa is measured in the absence of microorganisms?

A. True
B. False
Answer» B. False
Discussion
13.

From Q12 and Q13, which of the following condition is relevant?

A. OTR>OUR
B. OTR<OUR
C. OTR=OUR
D. OTR≠OUR
Answer» C. OTR=OUR
Discussion
14.

Refer to Q12 and, calculate OTR. (Given: kLa = 169 mmol O2/ 1 hr atm, P* = 0.0263 atm and PO2 = 0.21 atm).

A. 30.05 mmoles O<sub>2</sub>/ liter hr
B. 31.05 mmoles O<sub>2</sub>/ liter hr
C. 20.05 mmoles O<sub>2</sub>/ liter hr
D. 21.05 mmoles O<sub>2</sub>/ liter hr
Answer» C. 20.05 mmoles O<sub>2</sub>/ liter hr
Discussion
15.

Speed is the factor affecting the value of kLa?

A. True
B. False
Answer» B. False
Discussion
16.

Which of the following technique does not require the measurement of dissolved oxygen concentrations?

A. Dynamic gassing out method
B. Static gassing out method
C. Oxygen-Balance method
D. Sulphite oxidation method
Answer» E.
Discussion
17.

“The kLa value will depend upon the design and operating conditions of the fermenter”, is this statement true or false?$

A. True
B. False
Answer» B. False
Discussion
18.

Refer to Q5 and, calculate: An error is made determining the steady-state oxygen level which, instead of 78%, is taken as 70%. What is the percentage error in kLa resulting from this 10% error in C ÃÖAL?$

A. 50%
B. 25%
C. 75%
D. 100%
Answer» E.
Discussion
19.

A 20-1 stirred fermenter containing a Bacillus thuringiensis culture at 30°C is used for production of microbial insecticide, kLa is determined using the dynamic method. Air flow is shut off for a few minutes and the dissolved-oxygen level drops; the air supply is then re-connected. When steady state is established, the dissolved-oxygen tension is 78% air saturation. The following results are obtained.$

A.
B. 0.080 s-1
C. 0.083 s-1
Answer» D.
Discussion
20.

Which of the following is the efficient value for oxygen concentration?

A. Equal to Ccrit
B. Below Ccrit
C. Above Ccrit
D. Ccrit
Answer» D. Ccrit
Discussion
21.

What is the proper concentration unit of kLa?

A. h<sup>-1</sup>
B. ml/h
C. mmol/h
D. ml/sec
Answer» B. ml/h
Discussion
22.

For which type of mass transfer does Oxygen-Balance method is used?

A. Gas- Gas
B. Gas-Solid
C. Gas-liquid
D. Liquid-Liquid
Answer» D. Liquid-Liquid
Discussion
23.

What do you mean by “kLa”?

A. Volumetric mass transfer coefficient
B. Henry’s law coefficient
C. Volumetric oxygen transfer coefficient
D. Volumetric Solute transfer coefficient
Answer» D. Volumetric Solute transfer coefficient
Discussion