MCQOPTIONS
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MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
One kg of steam at 200 kPa with 20% quality is heated at constant pressure to 400°C. Calculate the work done by the system . |
| A. | 274.261 kJ |
| B. | 374.261 kJ |
| C. | 474.261 kJ |
| D. | 574.261 kJ |
| Answer» B. 374.261 kJ | |
| 2. |
A gas confined in a piston-cylinder is compressed in a quasi-static process from 80 kPa and 0.1 m3 to 400 kPa and 0.03m3. If the pressure and volume are related by PV^n= constant, calculate the work involved in the process. |
| A. | – 12.87 kJ |
| B. | 12.87 kJ |
| C. | – 11.87 kJ |
| D. | 11.87 kJ |
| Answer» D. 11.87 kJ | |
| 3. |
A piston/cylinder contains air at 100 kPa, 300 K. It is now compressed in a reversible adiabatic process to a volume 7 times as small. Use constant heat capacity and find the specific work. |
| A. | -233.6 kJ/kg |
| B. | -243.6 kJ/kg |
| C. | -253.6 kJ/kg |
| D. | -263.6 kJ/kg |
| Answer» D. -263.6 kJ/kg | |
| 4. |
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 adiabatic. |
| A. | -112.0 kJ |
| B. | -212.0 kJ |
| C. | -312.0 kJ |
| D. | -412.0 kJ |
| Answer» D. -412.0 kJ | |
| 5. |
Helium contained in a cylinder at ambient conditions, 100 kPa, 20°C, is compressed in a reversible isothermal process to 600 kPa, after which the gas is expanded back to 100 kPa in a reversible adiabatic process. Calculate the net work per kilogram of helium. |
| A. | -623.6 kJ/kg |
| B. | +467.4 kJ/kg |
| C. | -1091.0 kJ/kg |
| D. | none of the mentioned |
| Answer» B. +467.4 kJ/kg | |
| 6. |
A spring loaded piston cylinder contains 1.5 kg air at 160 kPa and 27°C. It is heated in a process where pressure is linear in volume, P = A + BV, to twice the initial volume where it reaches 900 K. Find the work assuming a source at 900 K. |
| A. | 61.4 kJ |
| B. | 161.4 kJ |
| C. | 261.4 kJ |
| D. | 361.4 kJ |
| Answer» C. 261.4 kJ | |
| 7. |
Consider a small air pistol with a cylinder volume of 1 cm3 at 27°C, 250 kPa. The bullet acts as a piston and is released so the air expands in an adiabatic process. If the pressure should be 100 kPa as the bullet leaves the cylinder find the work done by the air. |
| A. | 0.115 J |
| B. | 0.125 J |
| C. | 0.135 J |
| D. | 0.145 J |
| Answer» E. | |
| 8. |
A piston/cylinder contains air at 400 K, 100 kPa which is compressed to a final pressure of 1000 kPa. Consider the process to be a reversible isothermal process. Find the specific work. |
| A. | −264 kJ/kg |
| B. | −364 kJ/kg |
| C. | −464 kJ/kg |
| D. | −564 kJ/kg |
| Answer» B. −364 kJ/kg | |
| 9. |
A piston/cylinder contains air at 400 K, 100 kPa which is compressed to a final pressure of 1000 kPa. Consider the process to be a reversible adiabatic process. Find the specific work. |
| A. | -166.7 kJ/kg |
| B. | -266.7 kJ/kg |
| C. | -366.7 kJ/kg |
| D. | -466.7 kJ/kg |
| Answer» C. -366.7 kJ/kg | |
| 10. |
A mass of 1 kg of air contained in a cylinder at 1000 K, 1.5 MPa, expands in a reversible isothermal process to a volume 10 times larger. Calculate the heat transfer during the process. |
| A. | 460.84 kJ |
| B. | 560.84 kJ |
| C. | 660.84 kJ |
| D. | 760.84 kJ |
| Answer» D. 760.84 kJ | |
| 11. |
A piston/cylinder of total 1kg steel contains 0.5 kg ammonia at 1600 kPa both masses at 120°C with minimum volume being 0.02 m3. The whole system is cooled down to 30°C by heat transfer to the ambient at 20°C, and during the process the steel keeps same temperature as the ammonia. Find the work. |
| A. | – 28.14 kJ |
| B. | – 38.14 kJ |
| C. | – 48.14 kJ |
| D. | – 58.14 kJ |
| Answer» E. | |
| 12. |
A piston/cylinder contains 2kg water at 200°C, 10 MPa. The water expands in an isothermal process to a pressure of 200 kPa. Any heat transfer takes place with an ambient at 200°C and whole process is be assumed reversible. Calculate the total work. |
| A. | 1290.3 kJ |
| B. | 1390.3 kJ |
| C. | 1490.3 kJ |
| D. | 1590.3 kJ |
| Answer» B. 1390.3 kJ | |
| 13. |
Water at 250°C, 1000 kPa is brought to saturated vapor in a piston/cylinder with an adiabatic process. Find the specific work. |
| A. | 139.35 kJ/kg |
| B. | 149.35 kJ/kg |
| C. | 159.35 kJ/kg |
| D. | 169.35 kJ/kg |
| Answer» D. 169.35 kJ/kg | |
| 14. |
A heavily insulated cylinder/piston contains ammonia at 60°C, 1200 kPa. The piston is moved, expanding the ammonia in a reversible process until the temperature is −20°C during which 600 kJ of work is given out by ammonia. What was the initial volume of the cylinder? |
| A. | 0.285 m3 |
| B. | 0.385 m3 |
| C. | 0.485 m3 |
| D. | 0.585 m3 |
| Answer» C. 0.485 m3 | |
| 15. |
Water at 250°C, 1000 kPa is brought to saturated vapour in a piston/cylinder with an isobaric process. Find the specific work. |
| A. | -18.28 kJ/kg |
| B. | -48.28 kJ/kg |
| C. | -28.28 kJ/kg |
| D. | -38.28 kJ/kg |
| Answer» E. | |