MCQOPTIONS
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MCQOPTIONS
This section includes 12 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
With the use of reheat, |
| A. | the net work output of the plant increases |
| B. | there is only a marginal increase in cycle efficiency |
| C. | the quality of steam at turbine exhaust is kept within a limit |
| D. | all of the mentioned |
| Answer» E. | |
| 2. |
The optimum reheat pressure is ____ times that of the initial steam pressure. |
| A. | 0.2 |
| B. | 0.23 |
| C. | 0.25 |
| D. | all of the mentioned |
| Answer» E. | |
| 3. |
Why should the reheat pressure be optimized? |
| A. | a low reheat pressure brings down the mean temperature of heat addition and hence the cycle efficiency |
| B. | a high reheat pressure increases the moisture content at turbine exhaust |
| C. | both of the mentioned |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 4. |
Why is steam not allowed to to expand deep into two-phase region before being taken for reheating. |
| A. | to protect the reheater tubes |
| B. | to prevent solid deposits being left behind while evaporating |
| C. | both of the mentioned |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 5. |
The correct sequence of expansion in a reheat cycle is |
| A. | HP turbine LP turbine constant pressure in boiler |
| B. | HP turbine constant pressure in boiler LP turbine |
| C. | LP turbine constant pressure in boiler HP turbine |
| D. | LP turbine HP turbine constant pressure in boiler |
| Answer» C. LP turbine constant pressure in boiler HP turbine | |
| 6. |
Which of the following is true about a reheat cycle? |
| A. | used to limit the quality at turbine exhaust at 0.85 when steam pressure is higher than (p1)max |
| B. | after partial expansion in turbine, steam is brought back to boiler |
| C. | the steam is reheated by combustion gases |
| D. | all of the mentioned |
| Answer» E. | |
| 7. |
To fix the maximum steam pressure at the inlet of turbine we need to first fix |
| A. | the maximum steam temperature at turbine inlet |
| B. | minimum temperature of heat rejection |
| C. | the minimum quality of steam at turbine exhaust |
| D. | all of the mentioned |
| Answer» E. | |
| 8. |
To prevent erosion of blades, quality should not fall below |
| A. | 85% |
| B. | 90% |
| C. | 95% |
| D. | 100% |
| Answer» B. 90% | |
| 9. |
The maximum temperature of steam that can be used is not fixed. |
| A. | true |
| B. | false |
| Answer» C. | |
| 10. |
If we ____ the superheat at constant pressure then the cycle efficiency ____ |
| A. | decrease, increases |
| B. | increase, decreases |
| C. | increase, increases |
| D. | decrease, decreases |
| Answer» D. decrease, decreases | |
| 11. |
The efficiency of Rankine cycle is given by |
| A. | 1 (Q1/Q2) |
| B. | 1 (Tmean/T2) |
| C. | 1 (T2/Tmean) |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 12. |
In the Rankine cycle, heat is added reversibly at |
| A. | constant pressure and constant temperature |
| B. | constant pressure and infinite temperature |
| C. | infinite pressure and constant temperature |
| D. | infinite pressure and infinite temperature |
| Answer» C. infinite pressure and constant temperature | |