MCQOPTIONS
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MCQOPTIONS
This section includes 21 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The volumetric efficiency is given by |
| A. | 1-C+C(p2/p1)^(1/n) |
| B. | 1+C-C(p2/p1)^(1/n) |
| C. | 1+C+C(p2/p1)^(1/n) |
| D. | 1-C-C(p2/p1)^(1/n) |
| Answer» C. 1+C+C(p2/p1)^(1/n) | |
| 2. |
Clearance(C) is defined as |
| A. | (piston displacement per cycle / clearance volume )^n |
| B. | piston displacement per cycle / clearance volume |
| C. | clearance volume / piston displacement per cycle |
| D. | (clearance volume / piston displacement per cycl |
| E. | ^n |
| Answer» D. (clearance volume / piston displacement per cycl | |
| 3. |
The ratio of the actual volume of gas taken into cylinder during suction stroke to the piston displacement volume is called the volumetric efficiency. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 4. |
The isothermal efficiency of a compressor is given by |
| A. | p1*v1/ total work of compression |
| B. | p1*v1*ln(p2/p1) / total work of compression |
| C. | total work of compression / p1*v1*ln(p2/p1) |
| D. | total work of compression / p1*v1 |
| Answer» C. total work of compression / p1*v1*ln(p2/p1) | |
| 5. |
If there are N stages of compression, then the pressure ratio in each stage is |
| A. | p2/p1 = (discharge pressure/suction pressure)^(1/N) |
| B. | p2/p1 = (suction pressure/discharge pressure)^(1/N) |
| C. | p2/p1 = (discharge pressure/suction pressure)^N |
| D. | p2/p1 = (suction pressure/discharge pressur |
| E. | ^(1/N)b) p2/p1 = (suction pressure/discharge pressure)^(1/N)c) p2/p1 = (discharge pressure/suction pressure)^Nd) p2/p1 = (suction pressure/discharge pressure)^N |
| Answer» B. p2/p1 = (suction pressure/discharge pressure)^(1/N) | |
| 6. |
For ɣ>n>1 and for the same pressure ratio p2/p1, the maximum work is needed for |
| A. | isothermal compression |
| B. | adiabatic compression |
| C. | polytropic compression |
| D. | all need same work |
| Answer» C. polytropic compression | |
| 7. |
THE_ISOTHERMAL_EFFICIENCY_OF_A_COMPRESSOR_IS_GIVEN_BY?$ |
| A. | p1*v1/ total work of compression |
| B. | p1*v1*ln(p2/p1) / total work of compression |
| C. | total work of compression / p1*v1*ln(p2/p1) |
| D. | total work of compression / p1*v1 |
| Answer» C. total work of compression / p1*v1*ln(p2/p1) | |
| 8. |
Clearance(C) is defined as$ |
| A. | (piston displacement per cycle / clearance volume )^n |
| B. | piston displacement per cycle / clearance volume |
| C. | clearance volume / piston displacement per cycle |
| D. | (clearance volume / piston displacement per cycle)^n |
| Answer» D. (clearance volume / piston displacement per cycle)^n | |
| 9. |
The_ratio_of_the_actual_volume_of_gas_taken_into_cylinder_during_suction_stroke_to_the_piston_displacement_volume_is_called_the_volumetric_efficiency.$ |
| A. | true |
| B. | false |
| Answer» B. false | |
| 10. |
For a fixed clearance, as the pressure ratio is increased, the volumetric efficiency of a compressor |
| A. | decreases |
| B. | increases |
| C. | remains constant |
| D. | none of the mentioned |
| Answer» B. increases | |
| 11. |
Compressors are built with the maximum clearance. |
| A. | true |
| B. | false |
| Answer» C. | |
| 12. |
Volumetric efficiency decreases as the clearance _____ and as the pressure _____ |
| A. | decreases, increases |
| B. | increases, decreases |
| C. | decreases, decreases |
| D. | increases, increases |
| Answer» E. | |
| 13. |
The_volumetric_efficiency_is_given_by |
| A. | 1-C+C(p2/p1)^(1/n) |
| B. | 1+C-C(p2/p1)^(1/n) |
| C. | 1+C+C(p2/p1)^(1/n) |
| D. | 1-C-C(p2/p1)^(1/n) |
| Answer» C. 1+C+C(p2/p1)^(1/n) | |
| 14. |
If there are N stages of compression, then the pressure ratio in each stage i? |
| A. | p2/p1 = (discharge pressure/suction pressure)^(1/N) |
| B. | p2/p1 = (suction pressure/discharge pressure)^(1/N) |
| C. | p2/p1 = (discharge pressure/suction pressure)^N |
| D. | p2/p1 = (suction pressure/discharge pressure)^N |
| Answer» B. p2/p1 = (suction pressure/discharge pressure)^(1/N) | |
| 15. |
Heat rejected in the intercooler is given by (here cp is the specific heat at constant pressure) |
| A. | cp*(T3-T2) |
| B. | cp*(T3+T2) |
| C. | cp*(T2-T3) |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 16. |
The intermediate pressure that produces minimum work will also result in |
| A. | equal pressure ratios in the two stages of compression |
| B. | equal work for the two stages |
| C. | equal discharge temperatures |
| D. | all of the mentioned |
| Answer» E. | |
| 17. |
For minimum work the intermediate pressure is the _____ of the suction and discharge pressures. |
| A. | arithmetic mean |
| B. | geometric mean |
| C. | sum |
| D. | difference |
| Answer» C. sum | |
| 18. |
A two-stage compression process includes, |
| A. | the gas is first compressed isentropically in the low pressure cylinder |
| B. | it is cooled in the intercooler to its original temperature |
| C. | it is compressed isentropically in the high pressure cylinder |
| D. | all of the mentioned |
| Answer» E. | |
| 19. |
Staging of compression process is done with intermediate cooling. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 20. |
For …£>n>1 and for the same pressure ratio p2/p1, the maximum work is needed for$ |
| A. | isothermal compression |
| B. | adiabatic compression |
| C. | polytropic compression |
| D. | all need same work |
| Answer» C. polytropic compression | |
| 21. |
In a gas compressor, |
| A. | work is done on the gas to raise its pressure |
| B. | there is an appreciable increase in its density |
| C. | both of the mentioned |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |