Question

Match the following psychrometric processes (Column I) with the respective changes in thermodynamic properties (Column II) of air-water vapor mixture:

 

• A. 1-R, 2-S, 3-Q, 4-P
• B. 1-P, 2-R, 3-S, 4-Q
• C. 1-R, 2-S, 3-P, 4-Q
• D. 1-P, 2-Q, 3-S, 4-R

Hint:

When solving psychrometric process problems, focus on the changes in both dry bulb and dew point temperatures to correctly match the processes with their respective thermodynamic properties.

Answer 1

The Correct Option is C

Step 1: Understand each psychrometric process and its effect on thermodynamic properties.

1. Sensible cooling:
   In this process, the dry bulb temperature of the air decreases while the dew point temperature remains constant. The air loses heat, but no condensation occurs.
   → Matching: 1 → R (Dry bulb temperature decreases and dew point temperature remains constant).
2. Cooling and dehumidification:
   During this process, both the dry bulb temperature and the dew point temperature decrease, but the air also loses moisture.
   → Matching: 2 → S (Dry bulb temperature decreases and dew point temperature decreases).
3. Chemical dehumidification:
   Chemical dehumidification removes moisture from the air using a chemical desiccant. This usually results in an increase in dry bulb temperature and a decrease in dew point temperature.
   → Matching: 3 → P (Dry bulb temperature increases and dew point temperature decreases).
4. Heating and humidification:
   In this process, air is both heated and moisture is added. Thus, both dry bulb and dew point temperatures increase.
   → Matching: 4 → Q (Dry bulb temperature increases and dew point temperature increases).

Step 2: Conclusion
Based on the analysis above, the correct matching is:

\({1 \rightarrow R, \quad 2 \rightarrow S, \quad 3 \rightarrow P, \quad 4 \rightarrow Q}\)

Thus, the correct answer is (C) 1-R, 2-S, 3-P, 4-Q.