Related Mcqs:

1. 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

2. Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of _______________ humidity?

   A. Molal
   B. Relative
   C. Percentage
   D. None of these

3. Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of _______________ humidity?

   A. Molal
   B. Relative
   C. Percentage
   D. None of these

4. The percentage humidity is less than the relative humidity only at __________________ percent humidity?

   A. Zero
   B. Hundred
   C. Both zero and hundred
   D. None of these

5. The relative humidity of air decreases in-spite of an increase in the absolute humidity, when the____________________?

   A. Temperature rises
   B. Pressure rises
   C. Temperature falls
   D. Pressure falls

6. When the ____________________ the relative humidity of air decreases, despite an increase in the absolute humidity?

   A. Temperature rises
   B. Pressure rises
   C. Temperature falls
   D. Pressure falls

7. At a fixed pressure, the humidity depends upon the partial pressure of vapor in the mixture. Humidity of a vapour free gas is ________________ percent.?

   A. 100
   B. 0
   C. 50
   D. Between 0 and 100

8. 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

9. Which of the following processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C ?

   A. Humidification only
   B. Heating only
   C. Both heating and humidification
   D. Evaporative cooling

10. Which of the following can be calculated theoretically using steam table and Dalton’s law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known ?

    A. Dew point
    B. Humidity ratio
    C. Wet bulb temperature
    D. None of these