Refrigeration Questions and Answers – Air Refrigerator Working on Reverse Carnot Cycle – 1

This set of Refrigeration Multiple Choice Questions & Answers (MCQs) focuses on “Air Refrigerator Working on Reverse Carnot Cycle – 1”.

1. For a refrigerating system that works on reversed Carnot cycle having vapor as refrigerant, which one of the following is not a process of the cycle in p-v diagram?

a) Isentropic compression process
b) Isothermal compression process
c) Adiabatic expansion process
d) Isothermal expansion process
View Answer

2. What is the coefficient of performance of the refrigerant system working on reversed Carnot cycle, having Q_a as heat absorbed by the air during isothermal expansion per kg of air and Q_r as heat rejected during isothermal compression per kg of air?
a) COP=\(\frac{Q_a}{(Q_r – Q_a)}\)
b) COP=\(\frac{Q_r}{(Q_r – Q_a)}\)
c) COP=\(\frac{Q_a}{(Q_r + Q_a)}\)
d) COP=\(\frac{Q_a}{(Q_a – Q_r)}\)
View Answer

3. The COP of refrigerator may be improved by _________
a) decreasing the higher (T₂) as well as the lower (T₁) temperature
b) decreasing the higher (T₂) temperature and increasing the lower (T₁) temperature
c) increasing the higher (T₂) as well as the lower (T₁) temperature
d) keeping the higher (T₂) temperature the same while decreasing the lower (T₁) temperature
View Answer

4. What happens to the COP of a Carnot refrigerator in summer and in winter?
a) The COP is more in winter
b) The COP is more in summer
c) The COP remains unaffected
d) The COP fluctuates continuously during winter and summer
View Answer

5. A refrigerating machine working on Carnot cycle operates between 300K and 250K. Determine the COP.
a) 5
b) 6
c) 4
d) 10
View Answer

6. The COP_r of a Carnot refrigerating machine is 7.89. What will be the COP_p of heat pump?
a) 10.3
b) 7.89
c) 8.89
d) 6.89
View Answer

7. Which one is not a limitation of the Carnot cycle with air or gas as refrigerant?
a) It has low efficiency when working between two fixed temperature limits
b) Machine has to run at high and low speeds during adiabatic and isothermal process. Such variation of speed is not possible
c) Extreme pressure and large volume are developed
d) It is not possible to carry out isothermal heat transfer process in practice
View Answer

8. For a refrigerating system that works on Carnot cycle having air or gas as refrigerant s, which one of the following is not a process of the cycle in p-v diagram?

a) Adiabatic compression process
b) Isothermal compression process
c) Adiabatic expansion process
d) Isentropic expansion process
View Answer

9. What is the COP of a refrigerator when it’s refrigerating effect R is 6.2755 KW and work consumed is 0.82 KW?
a) 8.8
b) 6.77
c) 7.65
d) 8.56
View Answer

10. Out of the following reasons which one is responsible for Carnot cycle not being used in practice?
a) It gives low COP
b) It gives high refrigeration effect
c) It gives low refrigeration effect
d) It has low theoretical efficiency
View Answer

Sanfoundry Global Education & Learning Series – Refrigeration & Air Conditioning.

To practice all areas of Refrigeration & Air Conditioning, here is complete set of 1000+ Multiple Choice Questions and Answers.