Discussion
Home ‣ Mechanical Engineering ‣ Heat Transfer, Refrigeration and Air Conditioning Comments
- Question
The temperature rise, between the condenser outlet and expansion valve in ammonia vapour compression system, should be as low as possible.
Options- A. Yes
- B. No
- Correct Answer
- Yes
- 1. The dry bulb temperature lines, on the psychrometric chart are
Options- A. vertical and uniformly spaced
- B. horizontal and uniformly spaced
- C. horizontal and non-uniformly spaced
- D. curved lines Discuss
- 2. The operating temperature of a cold storage is - 2° C. The heat leakage from the surrounding is 30 kW for the ambient temperature of 40° C. The actual C.O.P. of refrigeration plant used is one fourth that of ideal plant working between the same temperatures. The power required to drive the plant is
Options- A. 1.86 kW
- B. 3.72 kW
- C. 7.44 kW
- D. 18.6 kW Discuss
- 3. The C.O.P. of a heat pump working on a reversed Carnot cycle is
Options- A.
- B.
- C.
- D.
Discuss
- 4. The inclined and non-uniformly spaced straight lines on a psychrometric chart indicates wet bulb temperature.
Options- A. Agree
- B. Disagree Discuss
- 5. A thermostatic expansion valve in a refrigeration system
Options- A. ensures the evaporator completely filled with refrigerant of the load
- B. is suitable only for constant load systems
- C. maintains different temperatures in evaporator in proportion to load
- D. none of the above Discuss
- 6. The refrigerant carbon dioxide is not widely used because of its __________ power require ments per tonne of refrigeration and high operating pressures.
Options- A. low
- B. high Discuss
- 7. The total pressure exerted by the mixture of air and water vapour is equal to the sum of pressures which each constituent would exert, if it occupied the same space by itself. This statement is called
Options- A. Kinetic theory of gases
- B. Newton's law of gases
- C. Dalton's law of partial pressures
- D. Avogadro's hypothesis Discuss
- 8. The comfort conditions in air conditioning are at (where DBT = Dry bulb temperature, and RH = Relative humidity)
Options- A. 25°C DBT and 100% RH
- B. 20°C DBT and 80% RH
- C. 22°C DBT and 60% RH
- D. 25°C DBT and 40% RH Discuss
- 9. A low wet bulb temperature indicates very __________ humidity.
Options- A. low
- B. high Discuss
- 10. A refrigerating system operating on reversed Brayton refrigeration cycle is used for maintaining 250 K. If the temperature at the end of constant pressure cooling is 300 K and rise in the temperature of air in the refrigerator is 50 K, then the net work of compression will be (assume air as working substance with cp = 1 kJ/kg)
Options- A. 25 kJ/kg
- B. 50 kJ/kg
- C. l00 kJ/kg
- D. 125 kJ/kg Discuss
Heat Transfer, Refrigeration and Air Conditioning problems
Search Results
Correct Answer: vertical and uniformly spaced
Correct Answer: 18.6 kW
Correct Answer:
Correct Answer: Agree
Correct Answer: ensures the evaporator completely filled with refrigerant of the load
Correct Answer: high
Correct Answer: Dalton's law of partial pressures
Correct Answer: 22°C DBT and 60% RH
Correct Answer: low
Correct Answer: 50 kJ/kg
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