At 750°K and 1 atm, the approximate value of Schmidt number for air is_________________?

Related Mcqs:

1. For the case of flow of air past a wet bulb thermometer (air water vapour system), the approximate value of h2/ky.Cz is around____________________?

   A. 0.60
   B. 0.24
   C. 1
   D. 0.72

2. Schmidt number and Lewis number for pure air at atmospheric conditions are respectively__________________?

   A. < 1 and ≈ 1
   B. 1 and 0
   C. > 1 and ≈ 1
   D. 0 and ≈ 1

3. At equilibrium the concentration of water in vapour phase (C*) in kg/m3 of air space and the amount of water (m) adsorbed per kg of dry silica gel are related by, C* = 0.0667m. To maintain dry conditions in a room of air space 100m3 containing 2.2 kg of water vapour initially, 10 kg of dry silica gel is kept in the room. The fraction of initial water remaining in the air space after a long time (during which the temperature is maintained constant) is_________________?

   A. 0.0
   B. 0.2
   C. 0.4
   D. 1.0

4. A mixture of 10% C6H6 vapour in air at 25°C and 750 mm Hg has a dew point of 20°C. Its dew point at 30°C and 700 mm Hg will be around _______________ °C?

   A. 21.7
   B. 20
   C. 27.3
   D. 18.7

5. The Schmidt number which is defined as, μ/ρ D, is the ratio of the_____________________?

   A. Momentum diffusivity to the mass diffusivity
   B. Thermal diffusivity to the mass diffusivity
   C. Momentum diffusivity to the thermal diffusivity
   D. None of these

6. In physical terms, Schmidt number means _________________?

   A. Thermal diffusivity/mass diffusivity
   B. Thermal diffusivity/momentum diffusivity
   C. Momentum diffusivity/mass diffusivity
   D. Mass diffusivity/thermal diffusivity

7. Schmidt number is given by ___________________?

   A. μ/ρDAB
   B. Re × Pe
   C. Sh × Pe
   D. Re/Pe

8. Weight of 1 m3 of humid air as compared to 1 m3 of dry air, under the same conditions, is_________________?

   A. Less
   B. More
   C. Same
   D. Unpredictable

9. An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively. The humidity of air sample expressed as kg of water vapour/kg of dry air is__________________?

   A. 0.048
   B. 0.079
   C. 0.122
   D. 0.152

10. Pick out the system with minimum boiling azeotrope at 1 atm ?

    A. Benzene-toluene
    B. Ethyl alcohol-water
    C. Hydrochloric acid-water
    D. All A., B. and C.