MCQOPTIONS
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MCQOPTIONS
This section includes 5 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 compressor is used to bring saturated water vapour initially at 1 MPa up to 17.5 MPa, where the actual exit temperature is 650°C. Find the second-law efficiency. |
| A. | 0.651 |
| B. | 0.751 |
| C. | 0.851 |
| D. | 0.951 |
| Answer» E. | |
| 2. |
Steam enters a turbine at 550°C, 25 MPa and exits at 5 MPa, 325°C at a flow rate of 70 kg/s. Determine the second law efficiency. |
| A. | 0.68 |
| B. | 0.78 |
| C. | 0.88 |
| D. | 0.98 |
| Answer» D. 0.98 | |
| 3. |
The condenser in a refrigerator receives R-134a at 50°C, 700 kPa and it exits as saturated liquid at 25°C. The flow-rate is 0.1 kg/s and air flows in the condenser at ambient 15°C and leaving at 35°C. Find the heat exchanger second-law efficiency. |
| A. | 0.77 |
| B. | 0.87 |
| C. | 0.47 |
| D. | 0.67 |
| Answer» B. 0.87 | |
| 4. |
A heat pump has a COP of 2 using a power input of 2 kW. Its low temperature is To and high temperature is 80°C, with an ambient at To. Find the second law efficiency. |
| A. | 0.11 |
| B. | 0.41 |
| C. | 0.51 |
| D. | 0.31 |
| Answer» E. | |
| 5. |
A steam turbine inlet is at 1200 kPa and 500°C. The actual exit is at 300 kPa having an actual work of 407 kJ/kg. Find its second law efficiency? |
| A. | 0.88 |
| B. | 0.98 |
| C. | 0.78 |
| D. | 0.68 |
| Answer» C. 0.78 | |