Transport Phenomena in Bioprocesses Mid - I, September - 2014

1.A fermenter broth with viscosity 10-2 and density 1000kg/m3 is agitated in a 2.7m3 baffled tank using a Rushton turbine with diameter 0.5M and stirrer speed 1s -1 . Estimate the mixing time.
  • 15 sec
  • 33 sec
  • 23 sec
  • Insufficient data
Answer: B
2.Toothpaste is a
  • Bingham plastic
  • Pseludoplastic,
  • Newtonian liquid
  • Dilatant.
Answer: D
3.Units of thermal conductivity?
  • W/m2
  • Btu h-1ft-2
  • Wm-1k-1
  • W m-2
Answer: C
4.Rate of heat flow through a body is given by Q = KA(t1 - t2)/x then answer the following the term x/KA is known as
  • thermal resistance
  • thermal conductivity
  • temperature gradient
  • thermal loading
Answer: A
5.Heat is transferred from electric bulb by
  • conduction
  • convection
  • radiation
  • all of the above
Answer: C
6.fluid in equilibrium means
  • its viscosity is zero
  • shear stresses are acting on the fluid but no flow behavior is manifested
  • it is free from shear stresses
  • a hypothetical situation because fluids are never in equilibrium.
Answer: B
7.Which are the three physical processes included in the mechanism of mixing?
  • Distribution, dispersion, diffusion
  • Circulation, diffusion, agitation
  • Distribution, diffusion, propagation
  • All the above
Answer: A
8.Units of thermal conductivity?
  • W/m2
  • Btu h-1ft-2
  • Wm-1k-1
  • W m-2
Answer: C
9.Transfer of heat by molecular collision is smallest in
  • liquids
  • solids
  • gases
  • all of the above
Answer: C
10.Many animal cells used in bioprocessing are
  • Anchorage dependent
  • Anchorage independent
  • Naked cell
  • None of the above
Answer: A
11.Fourier’s law of heat transfer in x direction is given by ___________________.
Answer: Q/A = k.dT/dX
12.Newton’s law of viscosity may be defined as _____________
Answer: velocity gradient is directly proportional to shear stress
13.LMTD means____________________.
Answer: Logarithmic Mean Temperature Difference
14.The ratio of average velocity to maximum velocity is (in laminar flow) ___________________
Answer: 0.5
15.Euler’s equation is given by __________________________.
Answer: Ρ(DV/Dt)= - grad(ρ)+ρg
16.Give equation to represent temperature gradient ______________.
Answer: t1– t2/x
17.The process of heat transfer from one particle of the body to another without actual motion of the particle is know as ____________
Answer: conduction
18._____________analogy between heat and momentum transfer.
Answer: q = -kdT/dy τ = -μ dV/dy
19.Units of kinematic viscosity _______________.
Answer: m2/sec
20.The part of the fluid where flow is affected by the solid is called the ______________
Answer: Boundary layer