MCQOPTIONS
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MCQOPTIONS
This section includes 13 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 chip dissipates 2 kJ of electric work and rejects it as heat transfer from its surface which is at 50°C to 25°C air. How much entropy is generated outside the chip? |
| A. | 0.419 J/K |
| B. | 0.519 J/K |
| C. | 0.619 J/K |
| D. | 0.719 J/K |
| Answer» C. 0.619 J/K | |
| 2. |
A chip dissipates 2 kJ of electric work and rejects it as heat transfer from its surface which is at 50°C to 25°C air. How much entropy is generated in the chip? |
| A. | 4.19 J/K |
| B. | 5.19 J/K |
| C. | 6.19 J/K |
| D. | 7.19 J/K |
| Answer» D. 7.19 J/K | |
| 3. |
The rate at which entropy is transferred out must ____ the rate at which entropy enters the control volume. |
| A. | be less than |
| B. | equal to |
| C. | exceed |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 4. |
Mass and energy are conserved quantities, but entropy is generally not conserved. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 5. |
The rate of entropy increase of the control volume ____ or ____ the net rate of entropy transfer to it. |
| A. | exceeds or is less than |
| B. | exceeds, is equal to |
| C. | is less than, or equal to |
| D. | none of the mentioned |
| Answer» C. is less than, or equal to | |
| 6. |
In an open system, there is a transfer of which of the following quantity? |
| A. | mass |
| B. | energy |
| C. | entropy |
| D. | all of the mentioned |
| Answer» E. | |
| 7. |
If the path A causes more entropy generation than path B, then |
| A. | path A is more irreversible than path B |
| B. | path A involves more lost work |
| C. | both of the mentioned |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 8. |
Any thermodynamic process is accompanied by entropy generation. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 9. |
The amount of entropy generation is given by |
| A. | S2+S1+∫(dQ/T) |
| B. | S2-S1+∫(dQ/T) |
| C. | S2-S1-∫(dQ/T) |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 10. |
Lost work is given by |
| A. | pdV-dW |
| B. | pdV+dW |
| C. | -pdV-dW |
| D. | pdV*dW |
| Answer» B. pdV+dW | |
| 11. |
The entropy increase due to internal irreversibility is also called entropy production or entropy generation. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 12. |
Entropy increase dS of the system can be expressed as |
| A. | dS=dS(due to external heat interaction)-dS(due to internal irreversibility) |
| B. | dS=dS(due to external heat interaction)+dS(due to internal irreversibility) |
| C. | dS=-dS(due to external heat interaction)-dS(due to internal irreversibility) |
| D. | dS=-dS(due to external heat interaction)+dS(due to internal irreversibility) |
| Answer» C. dS=-dS(due to external heat interaction)-dS(due to internal irreversibility) | |
| 13. |
The entropy of any closed system can increase in which if the following way? |
| A. | by heat interaction in which there is entropy transfer |
| B. | dissipative effects or internal irreversibilities |
| C. | both of the mentioned |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |