Saturday, 18 March 2017

Common Questions - Answer about Refrigerants

refrigerator opened



  1. Commonly used refrigerant in domestic vapour compression system
    • Freon - 12
    • Ammonia
    • CCl4
    • All of these

  2. Commonly used refrigerant in vapor absorption system is
    • Aqua-ammonia
    • Freon-12
    • Water
    • Ammonia

  3. Identify the refrigerant and absorbent in Lithium bromide absorption system
    • Refrigerant - water, absorbent - Lithium bromide
    • Refrigerant - Lithium bromide, absorbent – water
    • Refrigerant – Ammonia, absorbent – Lithium bromide
    • Refrigerant - Lithium bromide, absorbent – Ammonia

  4. In following refrigerant, which has the lowest freezing point?
    • R-22
    • Ammonia
    • R-11
    • R-118

  5. Which of the following is an example azeotrope refrigerant?
    • R-502
    • R-100
    • R-40
    • R-14

  6. The boiling point of R-12 is
    • -29° C
    • 20.5° C
    • -73.6° C
    • 9° C

  7. Which of the following refrigerant is flammable and highly toxic?
    • Ammonia
    • Sulphur dioxide
    • Carbon dioxide
    • R-118
    R-118 is water

  8. Which of the following refrigerant has the lowest boiling point?
    • Carbon dioxide
    • Sulphur dioxide
    • Ammonia
    • Air

  9. Environmental protection agencies advice against the use of chloro-fluoro-carbon refrigerants because
    • It react with ozone layer
    • It cause green-house effect
    • It react with water vapour and cause acid rain
    • It react with oxygen and cause its depletion

  10. Freon refrigerants are an example of
    • Halo-carbon refrigerants
    • Hydro-carbon refrigerants
    • Azeotrope refrigerants
    • Inorganic refrigerants

  11. In case of leakage of freon refrigerant change colour of the flame of halide torch to
    • Bright green
    • Orange
    • Yellow
    • Blue

  12. Which of the following refrigerant widely used in domestic refrigerators?
    • Ammonia
    • Sulphur dioxide
    • Carbon dioxide
    • R-12

  13. Which of the following refrigerant has the highest critical pressure?
    • Ammonia
    • R-12
    • Sulphur dioxide
    • R-22

  14. From following examples identify the refrigerant has the highest freezing point?
    • R-12
    • Carbon dioxide
    • Sulphur dioxide
    • Ammonia

  15. Why R-12 is preferred over R-22 in deep freezers?
    • R-12 is miscible with oil over large range of temperatures
    • R-12 has lower freezing point
    • R-12 gives higher coefficient of performance
    • R-12 has lower boiling point

  16. Which of the following cycle uses air as the refrigerant?
    • BeIl-Coleman
    • Carnot
    • Stirling
    • Ericsson

  17. The specific volume of a refrigerant should be
    • Low
    • High
    • Normal
    • None of these

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