Refrigeration and Air-conditioning: Assignment 5:

1. A mixture of dry air and water vapour, when the air has diffused the maximum amount of water vapour into it, is called

Dry air

Moist air

Saturated air

Specific humidity

Ans: c

2. The ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure, is called

Humidity ratio

Specific humidity

Absolute humidity

Relative humidity

Ans: d

3.The mass of water vapour present in 1kg of dry air is called 

Humidity ratio

Relative humidity

Absolute humidity

Degree of saturation

Ans: c

4. The temperature of air recorded by a thermometer, when it is not affected by the moisture present in the air, is called

Wet bulb temperature

Dry bulb temperature

Dew point temperature

None of these

Ans: b

5. In a saturated air-water vapour mixture, the

Dry bulb temperature is higher than wet bulb temperature

Dew point temperature is lower than wet bulb temperature

Dry bulb, wet bulb and dew point temperature are same

Dry bulb temperature is higher than dew point temperature

Ans: c

6. The difference between dry bulb temperature and dew point temperature, is called

Dry bulb depression

Wet bulb depression

Dew point depression

Degree of saturation

Ans: c 

7. During adiabatic saturation process on unsaturated air, the 

DBT remains unchanged

WBT remains unchanged

DPT remains unchanged

Saturation temperature remains unchanged

Ans: b

8. DPT line on psychrometric chart are

Horizontal

Vertical

Curved

Straight inclined sloping downward to the right

Ans: a

9. The comfort conditions in the air-conditioning are at

25°DBT & 100% RH

20°DBT & 80% RH

24°DBT & 60% RH

25°DBT & 40% RH

Ans: c 

10. The wet bulb depression is zero when relative humidity is

Zero

0.5

0.75

1.0

Ans: d