22. The collection efficiency by impaction increases with
A.increasing particle diameter
B.increasing air flow velocity
C.both (a) and (b)
D.increasing particle size

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23. The efficiency of fibrous filter by combined mechanism is given by(where ηimp,ηint,ηdif are the efficiencies by impaction, interception and diffusion respectively)
A.1 - ηimpηintηdif
B.1 - (1 - ηimp)(1 - ηint)( 1 - ηdif)
C.1 - ( ηimpηint/ηdif)
D.None of the above

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24. The heat conduction in dry air is
A.less rapid than in steam
B.more rapid than in steam
C.similar to steam
D.none of these

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25. For laminar flow of Newtonian fluid through a smooth round pipe, the ratio of average fluid velocity to the maximum velocity is
A.0.5
B.0.75
C.0.87
D.0.37

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26. The reduction of number of cells from 1010 to one will result into the del factor (Δ) of
A.1
B.10
C.23
D.103

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27. Sterilization can be carried out by
A.heat
B.radiation
C.chemical agents
D.all of these

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28. The collection efficiency by the inertial impaction mechanism is the function of
A.Stokes and Reynolds number
B.Stokes and Schmidt number
C.Grashoff and Reynolds number
D.Stokes and Grashof number

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