2021 Thermodynamics： Fundamentals and Application(Beijing Jiaotong University) 最新满分章节测试答案

本答案对应课程为:点我自动跳转查看
本课程起止时间为:2021-04-12到2021-08-06

Project 1 Basic concepts Quiz for Project 1

1、 问题:Consider a submarine cruising 30 m below the free surface of seawater whose density is 1025 kg/m^3. The increase in the pressure exerted on the submarine when it dives to a depth of 110 m below the free surface is
选项：
A:480 kPa
B:804 kPa
C:1400 kPa
D:144 kPa
答案: 【804 kPa】

2、 问题:The pressure drop in a duct is to be measured by a differential oil manometer. If the differential height between the two fluid columns is 3.2 cm and the density of oil is 860 kg/m^3, the pressure drop in the duct is
选项：
A:28 Pa
B:135 Pa
C:482 Pa
D:270 Pa
答案: 【270 Pa】

3、 问题:The atmospheric pressures at the top and the bottom of a mountain are read by a barometer to be 93.8 and 100.5 kPa. If the average density of air is 1.25 kg/m^3, the height of the mountain is
选项：
A:5360 m
B:683 m
C:547 m
D:8200 m
答案: 【547 m】

Project 2 The first law of thermodynamics Quiz for Project 2

1、 问题:A piston-cylinder device contains 3 kg of air at 300 kPa and 25 °C. During a quasi-equilibrium isothermal expansion process, 20 kJ of boundary work is done by the system, and 8 kJ of paddle-wheel work is done on the system. The heat transfer during this process is
选项：
A:28 kJ
B:20 kJ
C:36 kJ
D:12 kJ
答案: 【12 kJ】

2、 问题:A bucket of water with a mass of 20 kg at 18 °C is to be cooled to 0 °C by dropping ice cubes at 0 °C into it. The latent heat of fusion of ice is 334 kJ/kg, and the specific heat of water is 4.18 kJ/kg.°C. The amount of ice that needs to be added is
选项：
A:4.5 kg
B:0.25 kg
C:10 kg
D:20 kg
答案: 【4.5 kg】

3、 问题:An 8 L cylinder contains air at 300 kPa and 300 K. Now air is compressed isothermally to a volume of 2 L. The work done on air during this compression process is
选项：
A:119 kJ
B:1.8 kJ
C:3.3 kJ
D:4.5 kJ
答案: 【3.3 kJ】

4、 问题:A 1.2 m^3 rigid tank contains nitrogen gas at 200 kPa and 350 K. Now heat is transferred to the nitrogen in the tank and the pressure of nitrogen rises to 900 kPa. The work done during this process is
选项：
A:840 kJ
B:0 kJ
C:156 kJ
D:240 kJ
答案: 【0 kJ】

Project 3 The second law of thermodynamics Quiz for Project 3

1、 问题:A heat engine operates between the temperature limits of 1200 °C and 300 °C. If heat is supplied to the heat engine at a rate of 200 kJ/s, the maximum power output of this heat engine is
选项：
A:200 kW
B:327 kW
C:78  kW
D:122 kW
答案: 【122 kW】

2、 问题:A heat engine receives heat from a source at 800 °C and rejects the waste heat to a sink at 40 °C. If heat is rejected from this engine at a rate of 80 kJ/s, the maximum power this heat engine can produce is
选项：
A:194 kW
B:1520 kW
C:80 kW
D:241 kW
答案: 【194 kW】

3、 问题:A heat engine cycle is executed with steam in the saturation dome. The pressure of steam is 2 MPa during heat addition, and 0.1 MPa during heat rejection. The highest possible efficiency of this heat engine is
选项：
A:47% 
B:53%
C:100%
D:23%
答案: 【23%】

Project 4 Properties of gases Quiz for Project 4

1、 问题:A unit mass of an ideal gas at temperature T undergoes a reversible isothermal process from volume V1 to volume V2 while loosing heat to the surroundings at temperature T in the amount of q. If the gas constant of the gas is R, the entropy change of the gas Ds during this process is
选项：
A:Ds =R ln(V2/V1)-q/T
B:Ds = R ln(V2/V1)
C:Ds =R ln(V1/V2)
D:Ds =R ln(V1/V2)-q/T
答案: 【Ds = R ln(V2/V1)】

2、 问题:A frictionless piston-cylinder device and a rigid tank contain 5 kg of helium gas at the same temperature, pressure and volume. Now heat is transferred, and the temperature of both systems is dropped by 12 °C. The amount of extra heat that must be supplied to helium gas in the cylinder that is maintained at constant pressure is
选项：
A:125 kJ
B:0 kJ
C:312 kJ
D:187 kJ
答案: 【125 kJ】

3、 问题:The pressure in an air storage tank is measured to be 250 kPa (gage) in the morning, and 275 kPa (gage) in the afternoon as a result of solar heating. The local atmospheric pressure is 100 kPa. If the temperature of air in the tank is 15 °C in the morning, the air temperature in the afternoon is 
选项：
A:15.9 °C 
B:31.5 °C
C: 38.0 °C
D:16.2 °C
答案: 【31.5 °C】

4、 问题:A rigid tank contains 7 kg of an ideal gas at 5 atm and 30 °C. Now a valve is opened, and half of mass of the gas is allowed to escape. If the final pressure in the tank is 1.5 atm, the final temperature in the tank is
选项：
A:-91 °C 
B:-182 °C
C: 91 °C
D:15 °C
答案: 【-91 °C 】

Project 6 Properties of water vapor Quiz for Project 6

1、 问题:A rigid tank contains 0.8 kg of steam at 10 MPa and 300 °C. The volume of the tank is 
选项：
A:11 m^3
B:21 m^3
C:4.3 m^3
D:1.1 m^3
答案: 【1.1 m^3】

2、 问题:Water is boiled at 300 kPa pressure in a pressure cooker. The cooker initially contains 3 kg of water. Once boiling started, it is observed that half of the water in the cooker evaporated in 30 minutes. If the heat loss from the cooker is negligible, the average rate of energy transfer to the cooker is
选项：
A:2.3 kW
B:136 kW
C:3.6 kW
D:1.80 kW
答案: 【1.80 kW】

3、 问题:A 230 m^3 rigid tank is filled with saturated liquid-vapor mixture of water at 120 °C. If 25% of the mass is liquid and the 75% of the mass is vapor, the total mass in the tank is 
选项：
A:252 kg
B:824 kg
C:344 kg
D:230 kg
答案: 【344 kg】

Project 7 Ideal gas mixture and humid air Quiz for Project 7

1、 问题:The air in a house is at 25 °C and 72 percent relative humidity. Now the air is cooled at constant pressure. The temperature at which the moisture in the air will start condensing is
选项：
A:8.7 °C
B:15.3 °C
C:18.0 °C
D:19.6 °C
答案: 【19.6 °C】