In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the ______________ number ?

Related Mcqs:

1. _______________ number indicates the ratio of the rates of the heat and mass transfer incase of a cooling tower?

   A. Sherwood
   B. Stanton
   C. Lewis
   D. Peclet

2. The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives___________________?

   A. Low pressure drop and high hold up
   B. High pressure drop and low hold up
   C. Low pressure drop and low hold up
   D. High pressure drop and high hold up

3. Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the____________________?

   A. Packing may be crushed due to thermal expansion/contraction of the components of the
   equipments
   B. Pressure drop in the equipment will be very high
   C. Viscosity variation of the fluids may cause channelling/flooding
   D. None of these

4. According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity) ?

   A. D
   B. D2
   C. D0.5
   D. 1/D

5. For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is___________________?

   A. Calculated
   B. Unknown
   C. Known
   D. Not required

6. JD factor for mass transfer is a function of Reynolds number. Mass transfer by molecular diffusion from a single drop to surrounding still air is given by___________________?

   A. Nsh = 2
   B. Nst = 2
   C. Nsc = 2
   D. None of these

7. Water entrained by circulating air in cooling towers is termed as________________?

   A. Drift
   B. Blow down
   C. Vapor load
   D. None of these

8. Pick out the wrong statement pertaining to the cooling towers ?

   A. In case of induced draft cooling tower, the fan is placed at the top of the tower
   B. Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and
   hot discharged air
   C. A natural draft cooling tower is recommended to be used, when the air humidity is low and air
   temperature is also low
   D. Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb
   temperature

9. Water entrained by circulating air in cooling towers is termed as____________________?

   A. Drift
   B. Blow down
   C. Vapor load
   D. None of these

10. Pick out the wrong statement pertaining to the cooling towers ?

    A. In case of induced draft cooling tower, the fan is placed at the top of the tower
    B. Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and
    hot discharged air
    C. A natural draft cooling tower is recommended to be used, when the air humidity is low and air
    temperature is also low
    D. Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb
    temperature