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This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Refrigeration knowledge and support exam preparation. Choose a topic below to get started.
1. |
A refrigerator works on a reversed Carnot cycle. The Coefficient of performance is 7. If the capacity of the refrigerator is 12 TR. What is the value of heat rejected from the system? |
A. | 46 kW |
B. | 50 kW |
C. | 42 kJ/min |
D. | 48 kJ/min |
Answer» E. | |
2. |
A refrigerator works on a reversed Carnot cycle. The Coefficient of performance is 3.5. If the capacity of the refrigerator is 6 TR. Find out the power required to run the refrigerator. |
A. | 5 kW |
B. | 3.5 kW |
C. | 360 kJ/min |
D. | 520 kJ/min |
Answer» D. 520 kJ/min | |
3. |
Two refrigerators M and N operate in series. The refrigerator M absorbs energy at the rate of 1 kW from a body at temperature 400 K and rejects energy as heat to a body at a temperature T. The refrigerator N absorbs the same quantity of energy which is rejected by the refrigerator N from the body at temperature T, and rejects energy as heat to a body at temperature 800 K. If both the refrigerators have the same C.O.P., what is the value temperature T? |
A. | 600 K |
B. | 200 K |
C. | 565.68 K |
D. | 459.21 K |
Answer» D. 459.21 K | |
4. |
C.O.P. of the refrigerator is always _____ the C.O.P. of the heat pump when both are working between the same temperature limits. |
A. | less than |
B. | greater than |
C. | equal to |
D. | inverse of |
Answer» B. greater than | |
5. |
If the Coefficient of performance of a heat pump is 5, then what is the value of the Coefficient of performance of the refrigerator operating under the same conditions? |
A. | 4 |
B. | 6 |
C. | 0.2 |
D. | 3 |
Answer» B. 6 | |
6. |
A reversed Carnot cycle is operating between temperature limits of 272 K and (+) 49 C. If it acts as a heat engine gives an efficiency of 15.52%. What is the value of C.O.P. of a refrigerator operating under the same conditions? |
A. | 6.44 |
B. | 0.1838 |
C. | 5.44 |
D. | 2 |
Answer» D. 2 | |
7. |
If the reversed Carnot cycle operating as a refrigerator between temperature limits of 405 K and 255 K, then what is the value of C.O.P.? |
A. | 2.7 |
B. | 0.588 |
C. | 1.7 |
D. | 0.370 |
Answer» D. 0.370 | |
8. |
For the systems working on reversed Carnot cycle, what is the relation between C.O.P. of Refrigerator i.e. (C.O.P.)R and Heat Pump i.e. (C.O.P.)P? |
A. | (C.O.P.)<sub>R</sub> + (C.O.P.)<sub>P</sub> = 1 |
B. | (C.O.P.)<sub>R</sub> = (C.O.P.)<sub>P</sub> |
C. | (C.O.P.)<sub>R</sub> = (C.O.P.)<sub>P</sub> 1 |
D. | (C.O.P.)<sub>R</sub> + (C.O.P.)<sub>P</sub> + 1 = 0 |
Answer» D. (C.O.P.)<sub>R</sub> + (C.O.P.)<sub>P</sub> + 1 = 0 | |
9. |
The C.O.P. of a reversed Carnot refrigerator is 5. What is the ratio of highest temperature to lower temperature? |
A. | 1.2 |
B. | 0.8 |
C. | 1.2 |
D. | 0.8 |
Answer» D. 0.8 | |
10. |
The efficiency of Carnot heat engine is 40%. What is the value of C.O.P. of a refrigerator operating on reversed Carnot cycle? |
A. | 2.5 |
B. | 1.5 |
C. | 4 |
D. | 10 |
Answer» C. 4 | |
11. |
If the condenser and evaporator temperatures are 320 K and 240 K respectively, then what is the value of the C.O.P.? |
A. | 0.25 |
B. | 4 |
C. | 0.33 |
D. | 3 |
Answer» E. | |
12. |
In a refrigerating machine working on the reversed Carnot cycle, if the lower temperature is fixed, then what can be done to increase the C.O.P.? |
A. | Increasing higher temperature |
B. | Operating machine at higher speed |
C. | Decreasing higher temperature |
D. | Operating machine at a lower speed |
Answer» D. Operating machine at a lower speed | |
13. |
If a refrigeration system having T1 and T2 as lower and higher temperatures respectively then, what is the value of C.O.P of the refrigeration system working on the reversed Carnot cycle? |
A. | T<sub>2</sub> / (T<sub>2</sub> T<sub>1</sub>) |
B. | (T<sub>2</sub> T<sub>1</sub>) / T<sub>1</sub> |
C. | (T<sub>2</sub> T<sub>1</sub>) / T<sub>2</sub> |
D. | T<sub>1</sub> / (T<sub>2</sub> T<sub>1</sub>) |
Answer» E. | |