Q.1.
Why is multi-stage or compound VCR with water intercooler, liquid sub-cooler, and flash intercooler used?
- a) To improve C.O.P.
- b) To decrease refrigeration effect
- c) To increase work
- d) To increase leakage loss
Q.2.
What is the purpose of using intercooler?
- a) To increase the cost of the compressor
- b) To cool the superheated refrigerant
- c) To re-heat superheated refrigerant
- d) To reduce the volumetric efficiency
Q.3.
What is the purpose of using liquid sub-cooler?
- a) To increase the cost of the compressor
- b) To reduce the volumetric efficiency
- c) To re-heat superheated refrigerant
- d) To increase the refrigeration effect
Q.4.
What is the purpose of using a flash intercooler?
- a) To increase pressure
- b) To decrease pressure
- c) To separate vapor and liquid refrigerant and de-superheat
- d) To evaporate refrigerant partially
Q.5.
What does process 1-2 and 4-5 represent?
- a) Evaporation
- b) Compression
- c) Condensation
- d) Expansion
Q.6.
What does process 2-3 represent?
- a) Evaporation
- b) Compression
- c) Intercooling
- d) Condensation
Q.7.
What do PC, PE, and PF represent?
- a) Evaporator, expansion and flash chamber pressure
- b) Compression, expansion and flash chamber pressure
- c) Condenser, evaporator and flash chamber pressure
- d) Intercooling pressure
Q.8.
What does process 3-4 represent?
- a) Separation of refrigerant and de-superheating
- b) Compression
- c) Mixing of refrigerants
- d) Condensation
Q.9.
What does process 6-7 represent?
- a) Evaporation
- b) Compression
- c) Mixing of refrigerant coming from the flash chamber
- d) Sub-cooling
Q.10.
What do process 7-8 and 9-represent?
- a) Expansion
- b) Compression
- c) Mixing of refrigerant coming from the flash chamber
- d) Sub-cooling
Q.11.
What does process 8-9 and 8-4 represent?
- a) Expansion
- b) Separating the vapor and liquid form of refrigerant
- c) Compression
- d) Sub-cooling
Q.12.
What is the ratio of m2 / m1 for the following arrangement?
- a) (h1 – hf6) / (h2 – h1) – (h4 – h3)
- b) (h1 – hf6) / (h2 – h1) + (h4 – h3)
- c) (h8 – hf10) / (h9 – hf10)
- d) (h3 – hf9) / (h4 – h8)
Q.13.
What is the value of work done for the following arrangement?
- a) m1 (h2 – h1) + m2 (h4 – h3)
- b) (h1 – hf10) / (h4 – h9)
- c) (h8 – hf10) / (h9 – hf10)
- d) m1 (h2 – h1) + m2 (h5 – h4)
Q.14.
What is the value of work done for the following arrangement?
- a) m1 (h1 – hf9) / m1 (h2 – h1) + m2 (h5 – h4)
- b) m3 (h1 – hf10) / m2 (h4 – h9)
- c) m2 (h8 – hf10) / m1 (h9 – hf10)
- d) m1 (h1 – h11) / m1 (h2 – h1) + m2 (h5 – h4)
Q.15.
What is the value of Refrigeration effect if m1 = 4 kg/min, and enthalpies for the point9 areandkJ/kg. If the refrigeration effect iskJ/min and work done iskW, then what is the value of C.O.P.?
- a) 4.85
- b) 5.50
- c) 4.75
- d) 6.00