Tiêu đề MCQ BASIC MECHANICAL ENGINEERING.pdf ✅

Way to Polytechnic ● Way to Polytechnic d) Third law 7. The Kelvin-Planck statement of the second law of thermodynamics deals with: a) Heat engines b) Refrigerators c) Both a and b d) None of the above 8. The Clausius statement of the second law of thermodynamics is concerned with: a) Heat engines b) Refrigerators c) Heat pumps d) Both a and b 9. The Carnot cycle is an idealized cycle for a: a) Refrigerator b) Heat engine c) Heat pump d) None of the above 10. The efficiency of a Carnot engine depends on: a) The working substance b) The temperatures of the source and sink c) The pressure of the system d) The volume of the system 11. What does COP stand for in the context of a heat pump or refrigerator? a) Coefficient of Performance b) Carnot Optimization Parameter c) Cycle Output Power d) Cold Operating Pressure 12. Entropy is a measure of: a) Temperature b) Disorder or randomness c) Pressure d) Internal energy 2
Way to Polytechnic ● Way to Polytechnic 13. In the context of thermodynamics, a heat pump is designed to: a) Extract heat from a cold reservoir b) Reject heat to a hot reservoir c) Both a and b d) Neither a nor b 14. Which diagram is commonly used to represent the Carnot cycle? a) P-V diagram b) T-S diagram c) H-R diagram d) Q-W diagram 15. According to the Kelvin-Planck statement, it is impossible to construct a device that: a) Operates on a Carnot cycle b) Converts heat completely into work c) Transfers heat from a colder body to a hotter body d) Achieves 100% efficiency 16. The First Law of Thermodynamics is a statement of: a) Conservation of energy b) Conservation of mass c) Conservation of momentum d) Conservation of entropy 17. Which of the following is a heat engine? a) Refrigerator b) Heat pump c) Both a and b d) None of the above 18. The concept of a heat engine is closely related to: a) Increasing entropy b) Decreasing entropy c) Conduction d) Adiabatic processes 19. The efficiency of a heat engine is defined as: a) The ratio of work output to heat input b) The ratio of heat input to work output 3
Way to Polytechnic ● Way to Polytechnic c) The difference between heat input and heat output d) None of the above 20. What is the key factor that limits the efficiency of real-world heat engines compared to the Carnot cycle? a) Friction b) Irreversibilities c) Heat leaks d) All of the above Answers: 1. d) All of the above 2. b) A defined quantity of matter 3. c) All properties are constant throughout the system 4. a) Characteristics that define the state of a system 5. a) A series of events that occur over time 6. b) First law 7. a) Heat engines 8. b) Refrigerators 9. b) Heat engine 10. b) The temperatures of the source and sink 11. a) Coefficient of Performance 12. b) Disorder or randomness 13. c) Both a and b 14. b) T-S diagram 15. c) Transfers heat from a colder body to a hotter body 16. a) Conservation of energy 17. d) None of the above 18. a) Increasing entropy 19. a) The ratio of work output to heat input 20. b) Irreversibilities 4