MCQOPTIONS
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MCQOPTIONS
This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A piston-cylinder contains water at 3 MPa, 500 C. It is cooled in a polytropic process to 1 MPa, 200 C. Find the specific work in the process. |
| A. | 155.2 kJ |
| B. | 165.2 kJ |
| C. | 175.2 kJ |
| D. | 185.2 kJ |
| Answer» B. 165.2 kJ | |
| 2. |
R-12 in a piston-cylinder arrangement is initially at 50 C, x = 1. It is then expanded in a process so that P = Cv^( 1) to a pressure of 100 kPa. Find the work. |
| A. | 23.2 kJ/kg |
| B. | 33.2 kJ/kg |
| C. | 43.2 kJ/kg |
| D. | 53.2 kJ/kg |
| Answer» D. 53.2 kJ/kg | |
| 3. |
Consider a piston-cylinder with 0.5 kg of R-134a as saturated vapour at -10 C. It is compressed to a pressure of 500 kPa in a polytropic process with n = 1.5. Determine the work done during the process. |
| A. | -6.07 kJ |
| B. | -7.07 kJ |
| C. | -8.07 kJ |
| D. | -9.07 kJ |
| Answer» C. -8.07 kJ | |
| 4. |
A balloon behaves such that pressure inside it is proportional to the diameter squared. It contains 2kg of ammonia at 0 C, 60% quality. They are now heated so that the final pressure is 600 kPa. Find the work done in the process. |
| A. | 117.5 kJ |
| B. | 127.5 kJ |
| C. | 137.5 kJ |
| D. | 147.5 kJ |
| Answer» B. 127.5 kJ | |
| 5. |
A balloon behaves according to the equation P = (C2)V^(1/3), C2 = 100 kPa/m. The balloon is blown up with air from a volume of 1 m^3 to a volume of 3 m^3. Find the work done by the air assuming it is at 25 C. |
| A. | 219.5 kJ |
| B. | 229.5 kJ |
| C. | 239.5 kJ |
| D. | 249.5 kJ |
| Answer» E. | |
| 6. |
A gas initially at 500 C, 1 MPa is contained in a piston-cylinder arrangement with an initial volume of 0.1 m^3. It is then slowly expanded according to the relation PV = constant until a final pressure of 100 kPa is attained. Determine the work for this process. |
| A. | 200.3 kJ |
| B. | 210.3 kJ |
| C. | 220.3 kJ |
| D. | 230.3 kJ |
| Answer» E. | |
| 7. |
A piston-cylinder contains carbon dioxide at 2MPa with V=50 L. The device has a mass of 4 kg. Everything is initially at 200 C. By heat transfer the whole system cools to 25 C, at which point the gas pressure is 1.5 MPa. Find the work done. |
| A. | -10.0 kJ |
| B. | -12.0 kJ |
| C. | -14.0 kJ |
| D. | -16.0 kJ |
| Answer» D. -16.0 kJ | |
| 8. |
A cylinder/piston contains air at 100 kPa and 20 C with a V=0.3 m^3. The air is compressed to 800 kPa in a reversible polytropic process with n = 1.2, after which it is expanded back to 100 kPa in a reversible adiabatic process. Find the net work. |
| A. | -174.6 kJ/kg |
| B. | -154.6 kJ/kg |
| C. | -124.6 kJ/kg |
| D. | -194.6 kJ/kg |
| Answer» B. -154.6 kJ/kg | |