Questions and answers for exam Preparation

MCQs

Total Questions : 99 | Page 2 of 10 pages

Question 11. A Newtonian fluid is one in which the viscosity

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

Discuss Question

Answer: Option A. -> is constant regardless of the stirrer speed or mixing time
Answer: (a).is constant regardless of the stirrer speed or mixing time

Question 12. The viscosity of the culture fluid is classified as both pseudoplastic and thixotropic which indicates that the viscosity

increases with stirring speed but decreases with mixing time
increases with stirring speed and increases with mixing time
decreases with stirring speed but increases with mixing time
decreases with stirring speed and decreases with mixing time

Discuss Question

Answer: Option D. -> decreases with stirring speed and decreases with mixing time
Answer: (d).decreases with stirring speed and decreases with mixing time

Question 13. Animal cell cultures do not have much effect on shear forces because

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

Discuss Question

Answer: Option A. -> the cell size is generally smaller than the critical eddy size at which shear will have an effect
Answer: (a).the cell size is generally smaller than the critical eddy size at which shear will have an effect

Question 14. Pluronic F68 is added to cell culture media as

a nutrient
a shear protectorant
to increase oxygen transfer rates
all of these

Discuss Question

Answer: Option B. -> a shear protectorant
Answer: (b).a shear protectorant

Question 15. Which pattern of mixing is preferred in stirred tank reactors during the culture of aerobic microorganisms?

Laminar flow
Transient flow
turbulent flow
all of these

Discuss Question

Answer: Option C. -> turbulent flow
Answer: (c).turbulent flow

Question 16. A pseudoplastic fluid is one in which the viscosity

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

Discuss Question

Answer: Option D. -> decreases with increasing stirrer speed
Answer: (d).decreases with increasing stirrer speed

Question 17. A viscoelastic fluid is one in which the viscosity

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

Discuss Question

Answer: Option B. -> changes during mixing but returns to its original state after mixing
Answer: (b).changes during mixing but returns to its original state after mixing

Question 18. Reynolds number for laminar flow over a plate should be less than