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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