Discussion
Home ‣ Mechanical Engineering ‣ Heat Transfer, Refrigeration and Air Conditioning Comments
- Question
In actual air-conditioning applications for R-12 and R-22, and operating at a condenser temperature of 40° C and an evaporator temperature of 5° C, the heat rejection factor is about
Options- A. 1
- B. 1.25
- C. 2.15
- D. 5.12
- Correct Answer
- 1.25
- 1. The expression Q = ? AT4 is called
Options- A. Fourier equation
- B. Stefan-Boltzmann equation
- C. Newton-Rikhmann equation
- D. Joseph-Stefan equation Discuss
- 2. The undesireable property of a refrigerant is
Options- A. non-toxic
- B. non-flammable
- C. non-explosive
- D. high boiling point Discuss
- 3. The most commonly used method for the design of duct size is the
Options- A. velocity reduction method
- B. equal friction method
- C. static regain method
- D. dual or double method Discuss
- 4. Which of the following refrigerant is highly toxic and flammable?
Options- A. Ammonia
- B. Carbon dioxide
- C. Sulphur dioxide
- D. R-12 Discuss
- 5. In order to cool and dehumidify a stream of moist air, it must be passed over the coil at a temperature
Options- A. which lies between the dry bulb and wet bulb temperatures of the incoming stream
- B. which lies between the wet bulb and dew point temperatures of the incoming stream
- C. which is lower than the dew point temperature of the incoming stream
- D. of adiabatic saturation of incoming stream Discuss
- 6. The heating of air, without any change in its specific humidity, is known as sensible heating.
Options- A. True
- B. False Discuss
- 7. In counter-current flow heat exchangers
Options- A. both the fluids at inlet are in their hottest state
- B. both the fluids at inlet are in their coldest state
- C. both the fluids at exit are in their hottest state
- D. one fluid is coldest and the other is hottest at inlet Discuss
- 8. In a refrigeration system, the expansion device is connected between the
Options- A. compressor and condenser
- B. condenser and receiver
- C. receiver and evaporator
- D. evaporator and compressor Discuss
- 9. During sensible cooling of air, specific humidity
Options- A. remains constant
- B. increases
- C. decreases Discuss
- 10. Thermal conductivity of solid metals __________ with rise in temperature.
Options- A. remains same
- B. decreases
- C. increases Discuss
Heat Transfer, Refrigeration and Air Conditioning problems
Search Results
Correct Answer: Stefan-Boltzmann equation
Correct Answer: high boiling point
Correct Answer: static regain method
Correct Answer: Ammonia
Correct Answer: which is lower than the dew point temperature of the incoming stream
Correct Answer: True
Correct Answer: both the fluids at inlet are in their hottest state
Correct Answer: receiver and evaporator
Correct Answer: remains constant
Correct Answer: decreases
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