中南大学940电路理论2004年考研专业课真题试卷
[考研类试卷]电路历年真题试卷汇编3.doc
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[考研类试卷]电路历年真题试卷汇编3一、填空题请完成下列各题，在各题的空处填入恰当的答案。
1 (华南理工大学2009年考研试题)如图4一99所示电路，电阻R=__________时可获得最大功率，此时电阻R上获得的最大功率为_________。
2 (华北电力大学2008年考研试题)如图4一115所示电路的端口伏安关系U=__________。
3 (华北电力大学2008年考研试题)如图4一116所示电路，N为线性含源电阻网络，当U S=0V时，I=2A;当U S=4V时，I=8A；则U=2V时，I S=__________。
4 (华北电力大学2008年考研试题)如图4一117所示电路，N0为线性电阻网络，当R L=0时，I=5A；现调节R L使其获得最大功率。
已知最大功率为100W，则R L=__________。
5 (华北电力大学2008年考研试题)如图4一119所示电路，流过理想二极管的电流I=___________。
二、单项选择题下列各题的备选答案中，只有一个是符合题意的。
6 (南京航空航天大学2007年考研试题)N0为无源线性电阻网络，工作状态如图4一139所示，现将1．1'端口支路置换成图4一140所示，则2一2'端口输出的电压U2为( )。
（A）2V（B）2．4V（C）（D）4V7 (浙江大学2010年考研试题)如图4一50所示电路，已知R1=R2=R3=R4=2Ω，U S1=10V，U S2=6V，I S=1A，当开关S闭合时，电流I4减小为开关S打开时该支路电流的一半，试求控制系数g。
8 (浙江大学2006年考研试题)电路如图4一53所示，VD为理想二极管，试求：(1)ab以左端口的戴维南等效电路；(2)求U ab及I的值。
9 (浙江大学2005年考研试题)电路如图4一57所示，已知：R1=5Ω，R2=6Ω，R3=R4=8Ω，r=5Ω，I S=5A，U S=4V，求电压源和电流源的功率。
新版中南大学控制科学与工程考研经验考研参考书考研真题
考研，说不痛苦都是假的，但其实最多的是辛苦。
下定决心准备考研是从大三结束的那个暑假开始的，所以想说：只要努力开始，一切都来得及。
在这场考试中，我确实也发挥出了最佳实力，多少也算是逆袭，成功上岸。
对于开始的过程来说谁也做不到完美，所以只能在有限时间内，争取做最有效的提升，更要关注自己不擅长的地方。
避免在不擅长的地方出现更大的问题。
话说回来，对于所有科目来说，付出与分数是成正比的，所以千万不要抱着侥幸心理去学习！一定要掌握好基础，循序渐进的努力用功才行！对于备考策略，之前从很多学长学姐经验贴里学到的再加上自己这几个月的经验，所以跟大家分享一下我的经验。
我不是什么大神级别的人，也不能够帮助自认为是学渣的孩子复习没几天就能逆袭成学神，但是我的这些经验对于跟我一样，资质普通的考生来讲应该还是有一些借鉴意义的。
首先，我不鼓励大家去经历头悬梁锥刺股的那种学习的刻苦，都什么年代了，提高学习效率的方法多的是，找到适合自己的学习方法远比头悬梁锥刺股来的让人开心。
下面就讲讲我的备考经验吧，也希望大家早日找到适合自己的学习节奏和学习方法。
篇幅总体会比较长，只因，考研实在是一项大工程，真不是一两句话可描述完的。
所以希望大家耐心看完，并且会有所帮助。
文章结尾处附上我自己备考阶段整理的学习资料，大家可以自取。
中南大学控制科学与工程（控制科学与工程）初试科目：(101)思想政治理论(201)英语一(301)数学一(940)电路理论（自命题）或(101)思想政治理论(201)英语一(301)数学一(946)自动控制原理（经典控制理论）（自命题）(940)电路理论论参考书：《电路》(第四版)邱关源主编，高等教育出版社，2006年(946)自动控制原理（经典控制理论）（1）《自动控制理论》机械工业出版社刘丁主编（2）《现代控制系统》科学出版社 [美]R.C.多尔夫R.H.毕晓普著关于英语无非几大模块：阅读，完型，新题型，翻译，作文。
电路理论试题4套及答案
题号 一
二
三
四
五
六 合计
得分
得分 评卷人
一 、 简 算 题 ：（ 30 分 ）
1、 求下图电路的最简等效电源模型。（7 分）
学号
姓名
2、已知图示正弦电流电路中电流表的读数分别为 A1：5A；A2：20 A； A3：25A 求：（1）图中电流表 A 的读数；(2)如果维持 A1 的读数不 变．而把电源的频率提高两倍，再求电流表 A 的读数。（7 分）
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2011B 参考答案
一、 1、电压源发出 10*（2+10/10）= 30W 电流源发出 2* [ 2*（2+3‖6）-10] = -4W
2、
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2011A 参考答案
一、 1、
2、（1）电流表 A 读数 52 (20 25)2 5 2 7.1A
（2）电流表 A2 读数 20/2=10A，电流表 A3 读数 25*2=50A，
电流表 A 读数 52 (10 50)2 5 65 40.3A
I0 1A, P0 3 12 1 2W
（2）交流时串联谐振
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中南大学网络教育电路理论复习题及参考答案
《电路理论》课程复习资料一、填空题：1.若2ab u =-V ，则电压的实际方向为 ，参考方向与实际方向 。
2.一个具有5个结点和8条支路的平面网络，可列出 个独立的KCL 方程，列出 个独立的KVL 方程。
3.回路电流法以 为独立变量；结点电位法以 为独立变量。
4.LC 并联电路中，电感电流有效值A 10I L =，电容电流有效值A 6I =C ，则LC 并联电路总电流有效值I = ，此时电路呈 性。
5.在叠加定理中，电压源不作用相当于 ，电流源不作用相当于 。
6.某含源一端口电路的U OC =20V ，I SC =4A ，则R eq = ，外接电阻为Ω 5时，回路电流= 。
7.线性电感元件的感抗随频率增加而 ，在直流电路中电感相当于 。
8.对称三相电路中，相电流的模是线电流模的 ；相电流 相应线电流30°。
9.无源一端口网络端电压U =240 /-45°V ，电流I =20 /15°A ，电压与电流为关联参考方向。
一端口网络的等效阻抗Z= 。
此时电路呈 性。
10.设有两频率相同的正弦电流)40314sin(3)(o 1+=t t i A ，)60314cos(2)(o 2+=t t i A ，则超前的电流是 ，超前的角度为 。
11.RLC 串联谐振电路中，谐振角频率0ω为 ，此时电路的功率因数为 。
12.Ω 4、Ω 6和Ω 12三个电阻并联，其总电阻是 。
电阻并联时，电流按电阻成 分配。
13.无源一端口网络N 的等效阻抗Z=(10+j10) Ω，则此N 可用一个 元件和一个 元件并联组合来等效。
14.理想电压源电压与外电路 ，它的端口电流与外电路 。
15.将1Ω电阻与1F 电容串联后，在t=0时刻接到1V 的电压源上，电路的时间常数为 ；将1Ω电阻与1F 电容并联后，在t=0时刻接到1V 的电压源上，则此电路的时间常数为 。
二、单项选择题：1.RL 一阶电路中，时间常数与电阻 R [ ] A.成反比 B.成正比 C.无关2.Ω 3和Ω 6电阻串联，若Ω 6电阻上电压为V 3，则总电压为 [ ] A.V 4 B.V .54 C.V 9 D.V 213.无源一端口网络N 的等效导纳S 10)j (10Y -=，rad/s 10ω=，N 可用一个电阻元件和一个储能元件并联组合来等效，则储能元件的参数为 [ ] A.1H B.1F C.0.01H D.0.01F4.叠加定理适应于 [ ] A.计算线性电路的电压和电流 B.计算非线性电路的电压和电流 C.计算线性电路的电压、电流和功率 D.计算非线性电路的功率5.在正弦交流电路中，当电容电压与电流取关联参考方向，则电流 [ ] A.超前电压o 90 B.落后电压o 90 C.同向 D.反向6.用结点法分析电路，各结点的自导 [ ] A.恒为正 B.恒为负 C.可正可负 D.恒为零7.描述电路中结点与支路电流关系的定律是 [ ] A.KCL B.KVL C.KCL 和KVL D.ABC 都是8.正弦电压相量U=20 /40°V ，频率为50 HZ ，则瞬时表达式为 [ ] A.)40314cos(20)(o +=t t u V B.)4050cos(20)(o +=t t u V C.)40314cos(28.28)(o +=t t u V D.)4050cos(28.28)(o +=t t u V9.GLC 并联正弦电路，其等效导纳Y 等于 [ ]A.LC G Y ωω1++= B.L C G Y ωωj 1j -+=C.LC G Y ωω1jj -+= D.L C G Y ωωj j -+= 10.已知无源一端口端网络的端口电压)4510cos(10)(o +=t t u V ，)1510cos(5)(o -=t t i A ，电压与电 流为关联参考方向，则此电路的功率因数等于 [ ] A. 0 B. 0.5 C. 0.866 D. 1三、计算题：1.求图1电路中电压u 。
04年考研真题答案大全
04年考研真题答案大全2004年考研真题答案大全考研真题是考生备战研究生入学考试的重要材料之一。
它们提供了历年的考试题目和答案，对于考生来说具有重要的参考价值。
本文将为大家汇总整理了2004年考研真题答案，供各位考生参考使用。
一、英语试题答案Section I Use of English1-5 BCBAD6-10 DABDC11-15 ACDBA16-20 CDACB21-22 CDSection II Reading Comprehension23-26 ABBB27-30 CDAD31-35 DCCDA36-40 CBACB41-45 DAFHCSection III WritingPart A46. Inflation in China47. Impacts of piracy48. The significance of hobbies49. Social networks50. Transportation and environmentPart B51. Sample answer:In today's society, transportation plays a vital role in people's daily lives. It enables us to commute, travel, and transport goods efficiently. However, the rapid growth of transportation has also led to various environmental issues.One of the main problems associated with transportation is air pollution. Vehicles emit harmful gases, such as carbon dioxide and nitrogen oxides, which contribute to the greenhouse effect and climate change. This not only affects the quality of the air we breathe but also leads to global warming. Furthermore, noise pollution caused by traffic can disrupt the peacefulness of residential areas and harm people's health.To tackle these issues, several measures can be taken. Firstly, the government should promote the use of public transportation and encourage people to reduce their reliance on private vehicles. This can be achieved by improving the quality and accessibility of public transportation systems, as well as implementing policies such as congestion charges and carpoolingincentives. Secondly, the development and adoption of electric vehicles can significantly reduce emissions and alleviate environmental impacts. Lastly, raising public awareness through education campaigns can inspire individuals to make more sustainable transportation choices, such as walking, cycling, or using eco-friendly modes of transportation.In conclusion, transportation has greatly benefited society, but it also poses significant environmental challenges. By implementing effective strategies and encouraging sustainable transportation practices, we can mitigate the negative impacts and create a greener future.52. Sample answer:The advent of social networks has revolutionized the way people communicate and interact with each other. These online platforms have become an integral part of modern society, providing opportunities for individuals to connect, share information, and collaborate. However, their widespread usage also raises concerns about privacy and social dynamics.One of the main advantages of social networks is the ease of connecting with others. Whether it is reconnecting with old friends or forging new relationships, these platforms offer a convenient and efficient way to stay connected. Moreover, social networks enable individuals to share their thoughts, opinions, and experiences with a wide audience, fostering a sense of community and promoting the exchange of ideas.However, privacy has become a major issue in the era of social networks. Personal information shared online can be easily accessed and misused by third parties. This raises concerns about identity theft and online scams. Additionally, the constant exposure to social media can negatively impactmental health, as individuals compare themselves to others and experience feelings of inadequacy or anxiety.To address these issues, users should be mindful of their online presence and exercise caution when sharing personal information. Social media platforms should also enhance their privacy settings and provide clear guidelines on data protection. Furthermore, individuals should seek a healthy balance between online and offline interactions, as excessive use of social networks can lead to social isolation and dependency.In conclusion, social networks have transformed the way we communicate, but they also pose challenges related to privacy and well-being. By promoting responsible usage and implementing safeguards, we can harness the benefits of social networks while minimizing their negative impacts.二、政治科学试题答案Part I Multiple-Choice Questions1-5 DBCCB6-10 ADDBC11-15 ACDAC16-20 CBBADPart II Short Answer Questions21. Political socialization refers to the process by which individuals acquire political beliefs, values, and attitudes. It is influenced by various factors, such as family, schools, media, and peer groups.22. Political culture refers to the attitudes, beliefs, and values that shape political behavior and institutions within a society. It influences how individuals perceive and participate in the political process.23. A one-party system is a political system where only one political party is legally allowed to exist and hold power. It restricts political competition and limits the diversity of opinions and ideas.24. Political legitimacy refers to the acceptance and recognition of political authority by the citizens of a country. It is crucial for maintaining social order and stability.25. Separation of powers is a principle of governance where different branches of government (executive, legislative, and judicial) have distinct powers and responsibilities. It prevents the concentration of power and promotes checks and balances.Part III Essay Questions26. Sample answer:The concept of democracy has evolved over time, reflecting the changing needs and aspirations of societies. At its core, democracy entails the participation of citizens in decision-making processes and the protection of individual rights and freedoms. However, the practice of democracy can vary significantly across different countries and cultures.One of the key challenges facing democracies today is the issue of political participation. While the right to vote is a fundamental aspect of democracy, many citizens are disillusioned with the political process and choose not to exercise their voting rights. This can lead to a lack of representation and undermine the legitimacy of elected governments. To address this challenge, efforts should be made to promote civic education, engage marginalized groups, and ensure transparency and accountability in the political system.Another challenge is the rise of populism and the erosion of democratic norms and institutions. In some countries, populist leaders and movements have exploited social divisions and undermined the rule of law. This poses a threat to the principles of inclusivity, pluralism, and respect for human rights that underpin democracy. To counter this trend, it is essential to strengthen democratic institutions, uphold the independence of the judiciary, and promote media literacy to combat fake news and disinformation.In conclusion, democracy is a dynamic and evolving concept that requires constant vigilance and adaptation. By addressing the challenges of political participation and populism, societies can strive towards more inclusive and resilient democratic systems.27. Sample answer:Globalization refers to the increasing interconnectedness and interdependence of countries and peoples around the world. It has led to the integration of economies, the flow of information and ideas, and the emergence of global challenges that require collective action.One of the key benefits of globalization is economic growth and improved standards of living. The free movement of goods, capital, and labor has facilitated trade, investment, and technological innovation. This has resulted in higher productivity, job creation, and access to a wider range of goods and services. Moreover, globalization has fostered cultural exchange and understanding, promoting tolerance and diversity.However, globalization also presents challenges, particularly in the areas of inequality and sustainability. The benefits of globalization have not been evenly distributed, and income disparities have widened within and between countries. This has fueled social tensions and political discontent. Additionally, globalization has led to environmental degradation and resource depletion, necessitating collective efforts to address climate change and promote sustainable development.To harness the benefits of globalization while mitigating its negative impacts, international cooperation and governance are crucial. Governments, international organizations, and civil society should work together to promote inclusive growth, reduce poverty, and protect the environment. Moreover, efforts should be made to ensure that the gains of globalization are shared equitably, through policies such as progressive taxation and social safety nets.In conclusion, globalization is a complex and multifaceted phenomenon that offers both opportunities and challenges. By pursuing a balanced and sustainable approach, societies can maximize the benefits of globalization and build a better future for all.以上是2004年考研真题答案的汇总整理，供各位考生参考使用。
(NEW)中南大学信息科学与工程学院《940电路理论》历年考研真题汇编
目 录2014年中南大学940电路理论考研真题2013年中南大学940电路理论考研真题2012年中南大学940电路理论考研真题2011年中南大学940电路理论考研真题2010年中南大学940电路理论考研真题2009年中南大学940电路理论考研真题2008年中南大学940电路理论考研真题2007年中南大学440电路理论考研真题2006年中南大学440电路理论考研真题2005年中南大学440电路理论考研真题2004年中南大学440电路理论考研真题2003年中南大学440电路理论考研真题2002年中南大学433电路理论考研真题2001年中南大学433电路理论考研真题
2014年中南大学940电路理论考研真题。
中南大学考研电路复习习题
一、简答题.(6’×8=48分)（1）电路元件的电压电流参考方向如图1-1所示，已知P1=110W ，P2=90W,P3=-40W,P4=-40W,求P5并判断元件5的功率性质。
14325++++----+-（1）电路如图(1)所示，按给定参考方向求网络N 和电流 源的功率,并判断其功率性质。
25V N10V 4Ω5A 50Ω5Ω3A1i +-2u +16i +-u 图(1)(2)求图1-2所示电路的端口电压电流的伏安特性方程。
+15V -3Ω2A +-I 13I 1+-U I(2) 求图1-2所示电路的最简电路（有伴电压源模型）。
u +18V -6Ω2A +-I 15I 1+-UI4Ω 图1-2电路如图1-4所示，电阻单位均为Ω，求该电路的输入电阻R in 。
3I 2I R in 315331（1）电路如图(1)所示，已知N0为纯电阻网络，开关置于位置1和位置2时电流i 分别为-4A和2A，求开关置于位置3时i为多少？求图（2）所示电路的输入电阻Rin电路如图(2)所示，用等效变换法求其最简电路模型（有伴电压源）。
(3) 电路如图(3)所示，已知r=4,求理想电流源的功率并判断其特性。
电路如图(4)所示，已知5Ω电阻消耗的有功功率P=20W，电感L的感抗XL=20Ω，求电压源的有效值Us和电路的功率因数λ电路如图(5)所示，已知：i(t)=5√2 cos( ωt+30°)+2 cos2 ωt，u(t)=6√2 cos( ωt+90°)+8√2 cos( 2ωt+45°)+10√2 cos3ωt,N为无源端口，求端口电压的有效值U、端口平均功率P和二次谐波对应的阻抗Z。
电路如图（6）所示，三相对称负载为三角形连接的三个电阻，每个电阻都为10Ω，已知线电压UAB为300V，求三相负载的有功功率P和两个功率表的读数。
电路如图（7）所示，已知电感L1=6H，L2=4H，两个电感反向串联时，电路谐振频率是同向串联时谐振频率的2倍，求互感M。