MCQOPTIONS
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MCQOPTIONS
This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Water at 250 C, 1000 kPa is brought to saturated vapour in a piston/cylinder with an isothermal process. Find the specific work. |
| A. | -38 kJ/kg |
| B. | -138 kJ/kg |
| C. | -238 kJ/kg |
| D. | -338 kJ/kg |
| Answer» E. | |
| 2. |
A piston/cylinder has 2kg water at 250 C, 1000 kPa which is now cooled with a constant load on the piston. This isobaric process ends when the water has reached a state of saturated liquid. Find the work. |
| A. | -363.1 kJ |
| B. | -463.1 kJ |
| C. | -563.1 kJ |
| D. | -663.1 kJ |
| Answer» C. -563.1 kJ | |
| 3. |
A cylinder containing R-134a at 150 kPa, 10 C has an initial volume of 20 L. A piston compresses the R-134a in a isothermal, reversible process until it reaches the saturated vapour state. Calculate the required work in the process. |
| A. | -1.197 kJ |
| B. | -2.197 kJ |
| C. | -3.197 kJ |
| D. | -4.197 kJ |
| Answer» D. -4.197 kJ | |
| 4. |
A piston cylinder has R-134a at 100 kPa, 20 C which is compressed to 500 kPa in a reversible adiabatic process. Find the specific work. |
| A. | -41.63 kJ/kg |
| B. | -11.63 kJ/kg |
| C. | -21.63 kJ/kg |
| D. | -31.63 kJ/kg |
| Answer» E. | |
| 5. |
A piston/cylinder has 2kg ammonia at 100 kPa, 50 C which is compressed to 1000 kPa. The temperature is assumed to be constant. Find the work for the process assuming it to be reversible. |
| A. | -727.6 kJ |
| B. | -794.2 kJ |
| C. | -723.6 kJ |
| D. | -743.2 kJ |
| Answer» B. -794.2 kJ | |
| 6. |
1kg of water at 300 C expands against a piston in a cylinder until it reaches 100 kPa, at which point the water has a quality of 90.2%. The expansion is reversible and adiabatic. How much work is done by the water? |
| A. | 371.2 kJ |
| B. | 471.2 kJ |
| C. | 571.2 kJ |
| D. | 671.2 kJ |
| Answer» C. 571.2 kJ | |
| 7. |
Compression and heat transfer brings R-134a from 50 C, 500 kPa to saturated vapour in an isothermal process. Find the specific work. |
| A. | -24.25 kJ/kg |
| B. | -25.25 kJ/kg |
| C. | -26.25 kJ/kg |
| D. | -27.25 kJ/kg |
| Answer» D. -27.25 kJ/kg | |
| 8. |
An insulated cylinder fitted with a piston contains 0.1 kg of water at 100 C and 90% quality. The piston is moved, compressing the water till it reaches a pressure of 1.2 MPa. How much work is required in the process? |
| A. | -27.5 kJ |
| B. | -47.5 kJ |
| C. | -17.5 kJ |
| D. | -37.5 kJ |
| Answer» E. | |
| 9. |
A cylinder-piston contains ammonia at 50 C, 20% quality, volume being 1 L. The ammonia expands slowly, and heat is transferred to maintain a constant temperature. The process continues until all liquid is gone. Determine the work for this process. |
| A. | 7.11 kJ |
| B. | 9.11 kJ |
| C. | 5.11 kJ |
| D. | 8.11 kJ |
| Answer» B. 9.11 kJ | |
| 10. |
1kg of ammonia in a piston/cylinder at 50 C, 1000 kPa is expanded in a reversible adiabatic process to 100 kPa. Find the work for this process. |
| A. | 222.4 kJ |
| B. | 232.4 kJ |
| C. | 242.4 kJ |
| D. | 252.4 kJ |
| Answer» C. 242.4 kJ | |
| 11. |
1kg of ammonia in a piston/cylinder at 50 C, 1000 kPa is expanded in a reversible isobaric process to 140 C. Find the work in the process. |
| A. | 50.5 kJ |
| B. | 60.5 kJ |
| C. | 70.5 kJ |
| D. | 80.5 kJ |
| Answer» B. 60.5 kJ | |
| 12. |
1kg of ammonia in a piston/cylinder at 50 C, 1000 kPa is expanded in a reversible isothermal process to 100 kPa. Find the work for this process. |
| A. | 333.75 kJ |
| B. | 343.75 kJ |
| C. | 353.75 kJ |
| D. | 363.75 kJ |
| Answer» E. | |
| 13. |
In a Carnot-cycle heat pump, heat is rejected from R-22 at 40 C, during which the R-22 changes from saturated vapor to saturated liquid. The heat is transferred to the R-22 at 0 C. Determine the COP for the cycle. |
| A. | 6.83 |
| B. | 7.83 |
| C. | 8.83 |
| D. | 9.83 |
| Answer» C. 8.83 | |