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McqMate
Chapters
1. |
Reversed carnot cycle comprises |
A. | two isentropic processes and two adiabatic processes |
B. | two isentropic processes and two isothermal processes |
C. | two isentropic processes and two isobaric processes |
D. | two isentropic processes and two isochoric processes |
Answer» B. two isentropic processes and two isothermal processes |
2. |
Two Carnot Refrigerators are employed, one for ice making and other for comfort cooling |
A. | The COP of the refrigerator for ice making is higher than that for other |
B. | The COP of the refrigerator for ice making is same as that for the other |
C. | The COP of the refrigerator for ice making is lower than that for other |
D. | The COP of Carnot refrigerator will depend on refrigerant used |
Answer» C. The COP of the refrigerator for ice making is lower than that for other |
3. |
A reversed Carnot cycle has a COP of 4. The ratio of higher temperature to lower temperature will be |
A. | 1.25 |
B. | 1.5 |
C. | 2 |
D. | 2.5 |
Answer» A. 1.25 |
4. |
Carnot refrigerator absorbs heat at -13° C and requires 1 kW for each 6.5 kW of heat absorbed, the COP and temperature of heat rejections respectively |
A. | COP = 6.5, t = 27° C |
B. | COP = 7.5, t = 27° C |
C. | COP = 6.5, t = 30° C |
D. | COP = 7.5, t = 37° C |
Answer» A. COP = 6.5, t = 27° C |
5. |
The dense air refrigeration system as compared to open air refrigeration system for same range of temperatures using Bell- Colemann cycle requires. |
A. | Same power/Ton of Refrigeration |
B. | Lower power/Ton of Refrigeration |
C. | Higher power/Ton of Refrigeration |
D. | Unpredictable Results. |
Answer» B. Lower power/Ton of Refrigeration |
6. |
For very high speed planes cruising at Mach number 2.5 and above, the air craft refrigeration system recommended is |
A. | Simple evaporative type |
B. | Boot-strap type |
C. | Regenerative type |
D. | Boot strap evaporative type |
Answer» D. Boot strap evaporative type |
7. |
The air craft system giving Lowest Dry Air Rated Turbine discharge temperature at supersonic cruising speeds of the plane, is |
A. | Reduced ambient system of Refrigeration |
B. | Boot-strap system of Refrigeration |
C. | Regenerative system of Refrigeration |
D. | Boot strap evaporative system of Refrigeration |
Answer» D. Boot strap evaporative system of Refrigeration |
8. |
There are two cooling turbines in |
A. | Reduced ambient system of Refrigeration |
B. | Boot-strap system of Refrigeration |
C. | Regenerative system of Refrigeration |
D. | Boot strap evaporative system of Refrigeration |
Answer» A. Reduced ambient system of Refrigeration |
9. |
There are two stages of compression of air in |
A. | Reduced ambient system of Refrigeration |
B. | Boot-strap system of Refrigeration |
C. | Regenerative system of Refrigeration |
D. | Simple evaporative system of Refrigeration |
Answer» B. Boot-strap system of Refrigeration |
10. |
The amount of heat absorbed by the system at low temperature is |
A. | COP |
B. | Refrigerating effect |
C. | work done on the system |
D. | refrigeration efficiency |
Answer» B. Refrigerating effect |
11. |
No refrigerator using reversed Carnot cycle has been constructed because |
A. | it is less efficient |
B. | it is uneconomical |
C. | isentropic portions of cycle require low speeds where as isothermal portions require high speeds |
D. | isentropic portions of cycle require high speeds where as isothermal portions require low speeds |
Answer» D. isentropic portions of cycle require high speeds where as isothermal portions require low speeds |
12. |
A refrigeration cycle is usually a |
A. | open cycle |
B. | closed cycle |
C. | mixed cycle |
D. | Hybrid cycle |
Answer» B. closed cycle |
13. |
Co-efficient of performance of a Reversed Carnot cycle refrigerator working between higher temperature T2 and lower temperature T1 |
A. | will increase with increase in T1 keeping T2 fixed |
B. | will decrease with increase in T1 keeping T2 fixed |
C. | will first increase with increase in T1 and then decrease with increase T1 keeping T2 fixed |
D. | None of the above |
Answer» A. will increase with increase in T1 keeping T2 fixed |
14. |
Bell-Colemann cycle comprises |
A. | two isentropic processes and two adiabatic processes |
B. | two isentropic processes and two isothermal processes |
C. | two isentropic processes and two isobaric processes |
D. | two isentropic processes and two isochoric processes |
Answer» C. two isentropic processes and two isobaric processes |
15. |
The COP of Carnot Refrigerator is 3 and it produces 1 TR. The work that will be done is equal to |
A. | 70 kJ/min |
B. | 100 kJ/min |
C. | 200 kJ/min |
D. | 210 kJ/min |
Answer» A. 70 kJ/min |
16. |
In Bell – Colemann refrigerator for the same temperature range |
A. | COP of dense air system is equal to COP of open air system |
B. | COP of dense air system is lower than COP of open air system |
C. | COP of dense air system is higher than COP of open air system |
D. | COP of dense air system may be higher or lower than COP of open air system depending upon pressure ratio. |
Answer» C. COP of dense air system is higher than COP of open air system |
17. |
The air craft system giving Lowest Dry Air Rated Turbine discharge temperature at supersonic cruising speeds of the plane, is |
A. | Reduced ambient system of Refrigeration |
B. | Boot-strap system of Refrigeration |
C. | Regenerative system of Refrigeration |
D. | Boot strap evaporative system of Refrigeration |
Answer» D. Boot strap evaporative system of Refrigeration |
18. |
A Bell-Colemann cycle is |
A. | reversed Carnot Cycle |
B. | reversed Joule Cycle |
C. | reversed Rankine cycle |
D. | None of the above |
Answer» B. reversed Joule Cycle |
19. |
In a refrigeration cycle the heat is rejected by refrigerant at |
A. | expansion valve |
B. | compressor |
C. | condenser |
D. | all the above |
Answer» C. condenser |
20. |
A reversible refrigerator working between two fixed temperatures |
A. | has the same COP whatever the working substance |
B. | has its COP increased for working substance with high enthalpy of evaporation |
C. | has its COP increased for working substance with higher specific heats |
D. | none of the above |
Answer» A. has the same COP whatever the working substance |
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