Important questions about Sterilization. Sterilization MCQ questions with answers. Sterilization exam questions and answers for students and interviews.

1. The heat conduction in dry air is

Options

A : less rapid than in steam

B : more rapid than in steam

C : similar to steam

D : none of these

2. The destruction of microorganisms by steam may be described as

Options

A : first order chemical reaction

B : zero order chemical reaction

C : second order chemical reaction

D : none of these

3. For laminar flow of Newtonian fluid through a smooth round pipe, the ratio of average fluid velocity to the maximum velocity is

Options

A : 0.5

B : 0.75

C : 0.87

D : 0.37

4. Sterilization can be carried out by

Options

A : heat

B : radiation

C : chemical agents

D : all of these

5. The highest temperature which appears to be feasible for batch sterilization is

Options

A : 121°C

B : 100°C

C : 105°C

D : 130°C

6. The X 90 value for a filtration system is

Options

A : the time required to reduce microbial population by 90%

B : the time required to traverse survivor curve by one log cycle.

C : the depth required to reduce population by 90%

D : the depth of the filter required to reduce population by 99%

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

Options

A : Bacillus subtilis

B : Clostridium botulinum

C : Bacillus stearothermophilus

D : Aspergillus niger

8. The collection efficiency by diffusion increases with

Options

A : decreasing particle size

B : decreasing air velocity

C : both (a) and (b)

D : increasing particle size

9. Model proposed by the Friedlander, correlating the air filtration efficiency by impaction can be expressed as (where N St is the Stokes number)

Options

A : ? imp = 0.075 N St 1.2

B : ? imp = 0.75 N St 1.2

C : ? imp = 0.25 N St 1.2

D : ? imp = 0.025 N St 1.2

10. The K used in the equation for X 10 =2.303/K depends upon

Options

A : nature of the filter material

B : linear velocity of the air passing through filter

C : both (a) and (b)

D : thickness of the filter

1. The reduction of number of cells from 10 10 to one will result into the del factor (?) of

Options

A : 1

B : 10

C : 23

D : 10 3

2. If the packing density (?) is defined as the volume of the fiber unit volume of filter bed, the velocity within the filter void space is equal to (where V is velocity in fluid void space and V 0 is undisturbed fluid velocity)

Options

A : V = V 0 /(1-?)

B : V-V 0 = 1 - ?

C : V = V 0 (1 - ?)

D : V = V 0 /(1 + ?)

3. For the turbulent flow, the dispersion coefficient is correlated as a function of

Options

A : Reynolds number

B : Sherwood number

C : Schmidt number

D : Grashof number

4. The deviation from ideal plug flow due to axial mixing can be described by the

Options

A : dispersion model

B : Langmuir model

C : Friedlander model

D : Pasceri model

5. The del factor (?) increases as the final number of cells

Options

A : decreases

B : increases

C : zero

D : constant

6. For indirect heating, the plate and frame heat exchanger is generally more effective than the shell and tube heat transfer due to its

Options

A : larger heat transfer area

B : smaller heat transfer area

C : lesser cost

D : more number of plates

7. The overall del factor (?) may be represented as

Options

A : ? overall = ? heating + ? holding - ? cooling

B : ? overall = ? heating + ? holding + ? cooling

C : ? overall = ? heating - ? holding + ? cooling

D : ? overall = ? heating - ? holding - ? cooling

8. Typical aeration rates for aerobic fermentation are

Options

A : 0 - 0.5 vvm

B : 0.5 - 1.0 vvm

C : 1.0 - 1.5 vvm

D : 1.5 - 2.0 vvm

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

Options

A : <0.25?m

B : <0.5?m

C : <0.75?m

D : <1?m

10. Analogus 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 concentration of' n ')