Q.1
Which type of forces stretch and distort the bubbles?
  • a) Shear forces
  • b) Strain forces
  • c) Surface tension
  • d) Frictional forces
Q.2
Viscosity is inversely proportional to the size of eddies?
  • a) True
  • b) False
Q.3
Larger foam is produced in bioreactors with increased headspace and small workspace?
  • a) True
  • b) False
Q.4
“Instrument air compressor” should be used generally as a compressor?
  • a) True
  • b) False
Q.5
What is the function of Pluronic f-68?
  • a) To increase the foaming
  • b) To decrease the foaming
  • c) Increase cell attachment
  • d) To change the composition of the cells
Q.6
Microcarrier beadsμm in diameter are used to culture recombinant CHO cells for production of growth hormone. It is proposed to use a 6-cm turbine impeller to mix the culture in a 3.5-1itre stirred tank. Air and carbon dioxide are supplied by flow through the reactor headspace. The microcarrier suspension has a density of approximatelykg m-3 and a viscosity of 1.3 x 10-3 Pa s. Estimate the kinematic viscosity.
  • a) 1.30 × 10-6 m2s-1
  • b) 1.29 × 10-6 m2s-1
  • c) 1.50 × 10-6 m2s-1
  • d) 1.49 × 10-6 m2s-1
Q.7
Refer to Qand calculate the power dissipated per unit mass of fluid.
  • a) 0.050 m2 s-3
  • b) 0.042 m2 s-3
  • c) 0.040 m2 s-3
  • d) 0.052 m2 s-3
Q.8
Referring to Q6 and Q7 and, calculate the stirrer power.
  • a) 1.13×10-2 W
  • b) 1.10×10-2 W
  • c) 1.20×10-2 W
  • d) 1.23×10-2 W
Q.9
Referring to Q7 and Qand calculate the stirrer speed.(Given: Np’ = 5)
  • a) 80.5 rpm
  • b) 85.0 rpm
  • c) 85.5 rpm
  • d) 80.0 rpm
Q.10
What is the function of microcarrier beads?
  • a) To give the cells the shape of beads
  • b) It provides non-buoyancy condition
  • c) It helps in the lysis of cells
  • d) It provides protection and surface area
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