McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
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 | |
Done Studing? Take A Test.
Great job completing your study session! Now it's time to put your knowledge to the test. Challenge yourself, see how much you've learned, and identify areas for improvement. Don’t worry, this is all part of the journey to mastery. Ready for the next step? Take a quiz to solidify what you've just studied.