MCQ on Refrigeration and Airconditioning RAC for JE Exam part 7
| 61. Air refrigeration work on which cycle? (a) Rankine (b) Bell-Coleman cycle (c) Reversed Carnot cycle (d) Both B and C/B |
| Ans : (b) |
| 62. The centrifugal compressors are generally used for refrigerants that require (a) smalller displacements and low condensing pressures (b) large displacements and high condensing pressures (c) small displacements and high condensing pressure (d) large displacements and low condensing pressures |
| Ans : (d) |
| 63. The colour of halide torch flame, in case of leakage of freon refrigerant will change to (a) Bright green (b) Yellow/heeruee (c) Red/ (d) Orange |
| Ans : (a |
| 64. Which has minimum freezing point (a) Freon-22 (b) Freon-12 (c) Carbon dioxide (d) Ammonia |
| Ans : (a) |
| 65. Determine COP of a refrigeration system if its condenser rejects heat at the rate of 100kW and compressor consumes a power of 50kW |
(a) 2 (b) 3
(c) 4 (d) 0.5
| Ans : (a) |
| 66. At lower temperatures and pressures, the latent heat of vaporisation of a refrigerant. (a) decreases drastically (b) increases (c) unchanged (d) depends on other factors |
| Ans : (b) |
67. The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is:-
(a) bigger
(b) smaller
(c) equal
(d) None of the above
| Ans : (a) |
| 68. The refrigeration effect in a dry evaporator compared to flooded evaporator in a similar plant is : (a) Same (b) more (c) less (d) None of the above |
| Ans : (c) |
| 69. Condensing temperature in a refrigerator is the temperature : (a) of freezing zone (b) of compressor (c) At which refrigerant has becomes liquid (d) of cooling medium
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