16. In the sterilization process, spore of which of the following organism is considered as control?

A. Bacillus subtilis
B. Clostridium botulinum
C. Bacillus stearothermophilus
D. Aspergillus niger

17. Analogous to the molecular diffusion, the x-directional flux of microorganisms suspended in a medium due to the axial mixing can be represented as (where J_n is flux component ‘n‘, c_n is the concentration of ‘n‘)

A. J_n= –dc_n/dx
B. J_n= dc_n/dx
C. J_n= –D dc_n/dx
D. J_n= D dc_n/dx

18. The typical size of particles collected by diffusion mechanism is

A. <0.25μm
B. <0.5μm
C. <0.75μm
D. <1μm

19. The X₉₀ value for a filtration system is

A. the time required to reduce the microbial population by 90%
B. the time required to traverse the survivor curve by one log cycle.
C. the depth required to reduce the population by 90%
D. the depth of the filter required to reduce the population by 99%

20. The value of K

A. increases with increase in air velocity
B. decreases with increase in air velocity
C. increases to an optimum with increase in air velocity and decreases on further increase of air velocity
D. none of these