MCQOPTIONS
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MCQOPTIONS
This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A cylinder/piston contains saturated vapour R-22 at 10°C; the volume is 10 L. The R-22 is compressed to 60°C, 2 MPa in a reversible polytropic process. If all the heat transfer during the process is with the ambient at 10°C, calculate the work done. |
| A. | −6.26 kJ |
| B. | −7.26 kJ |
| C. | −8.26 kJ |
| D. | −9.26 kJ |
| Answer» C. −8.26 kJ | |
| 2. |
A piston/cylinder contains air at 100 kPa, 300 K. A reversible polytropic process with n = 1.3 brings the air to 500 K. Any heat transfer if it comes in is from a 325°C reservoir and if it goes out it is to the ambient at 300 K. Find the specific work. |
| A. | -171.3 kJ/kg |
| B. | -181.3 kJ/kg |
| C. | -191.3 kJ/kg |
| D. | -201.3 kJ/kg |
| Answer» D. -201.3 kJ/kg | |
| 3. |
A mass of 2 kg ethane gas at 100°C, 500 kPa, undergoes a reversible polytropic expansion with n = 1.3, to a final temperature of 20°C. Find the work done. |
| A. | 43.7 kJ/kg |
| B. | 53.7 kJ/kg |
| C. | 63.7 kJ/kg |
| D. | 73.7 kJ/kg |
| Answer» E. | |
| 4. |
A cylinder/piston contains 100L of air at 25°C, 110 kPa. The air is compressed in a reversible polytropic process to a final state of 200°C, 800 kPa. Assume the heat transfer is with the ambient at 25°C. Find the work done by the air. |
| A. | -11.28 kJ |
| B. | -21.28 kJ |
| C. | -31.28 kJ |
| D. | -41.28 kJ |
| Answer» C. -31.28 kJ | |
| 5. |
A cylinder/piston contains carbon dioxide at 300°C, 1 MPa with a volume of 200L. The total external force acting on the piston is proportional to V3. This system is allowed to cool to room temperature, 20°C. Find the work. |
| A. | -24.4 kJ |
| B. | -34.4 kJ |
| C. | -44.4 kJ |
| D. | -54.4 kJ |
| Answer» B. -34.4 kJ | |
| 6. |
Helium in a piston/cylinder at 20°C, 100 kPa is brought to 400 K in a reversible polytropic process with exponent n = 1.25. Helium can be assumed to be an ideal gas with constant specific heat. Find the specific work. |
| A. | -587.7 kJ/kg |
| B. | -687.7 kJ/kg |
| C. | -787.7 kJ/kg |
| D. | -887.7 kJ/kg |
| Answer» E. | |
| 7. |
A cylinder/piston contains 1kg methane gas at 100 kPa, 20°C. The gas is compressed reversibly to a pressure of 800 kPa. Calculate the work required if the process is polytropic, with exponent n = 1.15. |
| A. | -314.5 kJ |
| B. | -414.5 kJ |
| C. | -514.5 kJ |
| D. | -614.5 kJ |
| Answer» B. -414.5 kJ | |
| 8. |
A cylinder/piston contains 1kg methane gas at 100 kPa, 20°C. The gas is compressed reversibly to a pressure of 800 kPa. Calculate the work required if the process is isothermal. |
| A. | -216.0 kJ |
| B. | -316.0 kJ |
| C. | -416.0 kJ |
| D. | -516.0 kJ |
| Answer» C. -416.0 kJ | |
| 9. |
Neon at 400 kPa, 20°C is brought to 100°C in a polytropic process with n = 1.4. Find the work done. |
| A. | -52.39 kJ/kg |
| B. | -62.39 kJ/kg |
| C. | -72.39 kJ/kg |
| D. | -82.39 kJ/kg |
| Answer» E. | |
| 10. |
The piston/cylinder contains carbon dioxide at 300 kPa, with volume of 0.2 m3 and at 100°C. Mass is added at such that the gas compresses with PV^(1.2) = constant to a final temperature of 200°C. Determine the work done during the process. |
| A. | -80.4 kJ |
| B. | -40.4 kJ |
| C. | -60.4 kJ |
| D. | -50.4 kJ |
| Answer» B. -40.4 kJ | |
| 11. |
A polytropic process(n = − 1) starts with P = 0, V = 0 and ends with P= 600 kPa, V = 0.01 m3. Find the boundary work done. |
| A. | 1 kJ |
| B. | 2 kJ |
| C. | 3 kJ |
| D. | 4 kJ |
| Answer» D. 4 kJ | |