Discussion
Home ‣ Mechanical Engineering ‣ Heat Transfer, Refrigeration and Air Conditioning Comments
- Question
The refrigerant used in small-tonnage commercial machines (hermetically sealed units) is
Options- A. ammonia
- B. carbon dioxide
- C. sulphur dioxide
- D. R-12
- Correct Answer
- sulphur dioxide
- 1. When the air is passed through an insulated chamber having sprays of water maintained at a temperature higher than the dew point temperature of entering air but lower than its dry bulb temperature, then the air is said to be
Options- A. cooled and humidified
- B. cooled and dehumidified
- C. heated and humidified
- D. heated and dehumidified Discuss
- 2. The lowest temperature during the cycle in a vapour compression system occurs after
Options- A. compression
- B. expansion
- C. condensation
- D. evaporation Discuss
- 3. The process of heat transfer from one particle of the body to another by the actual motion of the heated particles, is called
Options- A. conduction
- B. convection
- C. radiation Discuss
- 4. A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer,
Options- A. the better insulation must be put inside
- B. the better insulation must be put outside
- C. one could place either insulation on either side
- D. one should take into account the steam temperature before deciding as to which insulation is put where Discuss
- 5. The material of pipe lines for a system using freon as a refrigerant should be
Options- A. brass
- B. copper
- C. steel
- D. aluminium Discuss
- 6. In a vapour absorption refrigeration system, the compressor of the vapour compression system is replaced by
Options- A. liquid pump
- B. generator
- C. absorber and generator
- D. absorber, generator and liquid pump Discuss
- 7. A refrigerant compressor is used to
Options- A. raise the pressure of the refrigerant
- B. raise the temperature of the refrigerant
- C. circulate the refrigerant through the refrigerating system
- D. all of the above Discuss
- 8. In aircraft, air refrigeration Cycle is used because of
Options- A. low weight per tonne of refrigeration
- B. high heat transfer rate
- C. low temperature at high altitudes
- D. higher coefficient of performance Discuss
- 9. The pressure at the inlet of a refrigerant compressor is called
Options- A. suction pressure
- B. discharge pressure
- C. critical pressure
- D. back pressure Discuss
- 10. The power per tonne of refrigeration is
Options- A. 3.5/C.O.P.
- B. C.O.P/3.5
- C. 3.5 x C.O.P.
- D. none of these Discuss
Heat Transfer, Refrigeration and Air Conditioning problems
Search Results
Correct Answer: cooled and humidified
Correct Answer: evaporation
Correct Answer: convection
Correct Answer: the better insulation must be put inside
Correct Answer: copper
Correct Answer: absorber, generator and liquid pump
Correct Answer: all of the above
Correct Answer: low weight per tonne of refrigeration
Correct Answer: suction pressure
Correct Answer: 3.5/C.O.P.
Comments
There are no comments.More in Mechanical Engineering:
Programming
Copyright ©CuriousTab. All rights reserved.