Refrigeration and Air Conditioning

61. rick up the incorrect statement

  1. lithium bromide used in vapour absorption cycle is nonvolatile
  2. lithium bromide plant can't operate below 0°C
  3. a separator is used in lithium bromide plant to remove the unwanted water vapour by condensing
  4. concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator
  5. weak solution in liquid heat exchanger gives up heat to the strong solution.

Correct answer: (C)
a separator is used in lithium bromide plant to remove the unwanted water vapour by condensing

62. Short horizontal lines on pressure-enthalpy chart show

  1. constant pressure lines
  2. constant temperature lines
  3. constant total heat lines
  4. constant entropy lines
  5. constant volume lines.

Correct answer: (A)
constant pressure lines

63. Superheating in a refrigeration cycle

  1. increases COP
  2. decreases COP
  3. COP remains unaltered
  4. other factors decide COP
  5. unpredictable.

Correct answer: (B)
decreases COP

64. The advantage of dry compression is that

  1. it permits higher speeds to be used
  2. it permits complete evaporation in the evaporator
  3. it results in high volumetirc and mechanical efficiency
  4. all of the above
  5. none of the above.

Correct answer: (D)
all of the above

65. The bank of tubes at the back of domestic refrigerator are

  1. condenser tubes
  2. evaporator tubes
  3. refrigerant cooling tubes
  4. capillary tubes
  5. throttling device.

Correct answer: (A)
condenser tubes

66. The boiling point of ammonia is

  1. -100°C
  2. -50°C
  3. - 33.3°C
  4. 0°C
  5. 33.3°C.

Correct answer: (C)
- 33.3°C

67. The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will

  1. increase
  2. decrease
  3. remain unaffected
  4. may increase or decrease depending on the type of refrigerant used
  5. unpredictable.

Correct answer: (A)
increase

68. The C.O.P. of a domestic refrigerator in comparison to domestic air conditioner will be

  1. same
  2. more
  3. less
  4. dependent on weather conditions
  5. unpredictable.

Correct answer: (C)
less

69. The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperature constant, will

  1. increase
  2. decrease
  3. may increase or decrease depending on the type of refrigerant used
  4. remain unaffected
  5. unpredictable.

Correct answer: (A)
increase

70. The change in evaporator temperature in a refrigeration cycle, as compared to change in condenser temperature, influences the value of C.O.P.

  1. more
  2. less
  3. equally.
  4. unpredictable
  5. none of the above.

Correct answer: (A)
more

Previous
Page 7 of 10
Next
Copyright © EngineeringMCQ.com