2026知到答案 热工基础（留）（北京科技大学） 最新智慧树满分章节测试答案

第一章 单元测试

1、多选题：
Which of the following statements correctly describe the characteristics of a closed thermodynamic system?
选项：
A:In a closed system, the boundary can be either fixed or mobile.
B:The system has a constant mass and does not exchange matter with its surroundings.
C:The system can exchange both heat and work with its surroundings.
D:A sealed thermos flask is a practical example of a closed system.
E:The system is always isolated from its surroundings in terms of energy transfer.
答案: 【In a closed system, the boundary can be either fixed or mobile.;
The system has a constant mass and does not exchange matter with its surroundings.;
The system can exchange both heat and work with its surroundings.;
A sealed thermos flask is a practical example of a closed system.】

2、单选题：
Which of the following best describes a closed system in thermodynamics?
选项：
A:A system that only allows heat transfer but no mass or work transfer.
B:A system where mass can enter and leave freely.
C:A system with no mass transfer but possible heat and work transfer.
D:A system completely isolated from its surroundings with no mass, heat, or work transfer.
答案: 【A system with no mass transfer but possible heat and work transfer.】

3、单选题：
In the context of heat engines, which of the following working mediums is most suitable for an environmentally friendly refrigeration system due to its low global warming potential?
选项：
A:Water-Lithium Bromide solution
B:Ammonia
C:High-pressure steam
D:Carbon dioxide in supercritical state
答案: 【Carbon dioxide in supercritical state】

4、判断题：
In a sealed thermos flask, there is no mass transfer with the surrounding, making it an example of a closed system.
选项：
A:对
B:错
答案: 【对】

5、单选题：
In a sewage treatment process, the water temperature increases from 15 °C to 22 °C. Which thermodynamic principle explains why the temperature change depends only on the initial and final states?
选项：
A:The law of conservation of energy.
B:The ideal gas law.
C:The zeroth law of thermodynamics.
D:The path independence of state parameters.
答案: 【The path independence of state parameters.】

6、判断题：
An equilibrium state in thermodynamics is a state where the state parameters of a working medium do not change with time without external influence.
选项：
A:错
B:对
答案: 【对】

7、多选题：
Which of the following conditions must be met for a real-world process to be approximated as quasi-static?
选项：
A:The process is irreversible with significant energy dissipation.
B:The driving forces such as pressure or temperature differences are very small.
C:The relaxation time of the system is much shorter than the process time.
D:The system is isolated from its surroundings.
E:The process involves rapid changes in system properties.
答案: 【The driving forces such as pressure or temperature differences are very small.;
The relaxation time of the system is much shorter than the process time.】

8、单选题：
What is the key characteristic of a quasi-static process in thermodynamics?
选项：
A:The process occurs infinitely fast with sudden changes.
B:The system experiences large pressure and temperature gradients.
C:Every intermediate state is infinitely close to an equilibrium state.
D:The process involves significant dissipative effects like friction.
答案: 【Every intermediate state is infinitely close to an equilibrium state.】

9、判断题：
In thermodynamics, work is a state variable that depends only on the initial and final states of the system.
选项：
A:错
B:对
答案: 【错】

第二章 单元测试

1、单选题：
According to the first law of thermodynamics for closed systems, which equation correctly represents the relationship between heat added, internal energy change, and work done by the system?
选项：
A:

B:

C:

D:

答案: 【

】

2、单选题：
Which of the following statements best describes the concept of stable flow in thermodynamics?
选项：
A:The system boundaries expand and contract periodically.
B:The state parameters at any point in the system remain constant over time.
C:The flow rate of the working medium changes significantly over time.
D:The working medium does not cross the system boundaries.
答案: 【The state parameters at any point in the system remain constant over time.】

3、单选题：
What is the main principle described by the First Law of Thermodynamics?
选项：
A:Heat always flows from a hotter body to a colder one.
B:Energy cannot be created or destroyed, only transformed.
C:The entropy of an isolated system never decreases.
D:The total energy of a closed system remains constant.
答案: 【Energy cannot be created or destroyed, only transformed.】

4、单选题：
Which of the following correctly describes the relationship between technical work and expansion work in an open system?
选项：
A:

B:

C:

D:

答案: 【

】

5、单选题：
Which equation correctly represents the energy balance for any working medium in a reversible process?
选项：
A:

B:

C:

D:

答案: 【

】