2015年电大汽车电工电子基础及电路分析作业1-3答案.doc

一、填空题1、有甲灯220V60W和乙灯110V40W白炽灯，把他们串联后接到220V电源上时灯较亮；若把他们并联后接到48V电源上时灯较亮。2、交流电的最大值反映其变化范围，角频率（或频率、周期）反映其，初相角反映其。3、市用照明电的电压为220V，这是指电压的值，它的最大值为。4、稳压二极管工作处于区，在该区内，稳压管的电流在很大的范围内变化，却基本不变，这就是稳压管的稳压作用。5、串联负反馈能使放大器的输入电阻。6、射极输出器是典型的放大器。7、编码器的作用是。二、选择题1、在全电路中、负载电阻增大，端电压将（ ）A、增高 B、减小 C、不变D、不确定2、当硅稳压二极管稳压电路输出电流不够时，应该采用下面（ ）种做法。A、将两制相同型号的稳压二极管串联。B、将两制相同型号的稳压二极管并联。C、更换一只稳压值相同，功率更大的二极管。3、晶体三极管在放大交流信号时，其集电极电压（ ）A、只含有放大了交流信号B、只含有直流静态电压C、既有直流静态电压又有交流信号电压4、影响放大器工作点点稳定的主要因素是（ ）A、偏置电阻的阻值B、负载的变化 C、交流旁路电容的容量 D、温度5、负反馈改善了放大器的性能，但使放大电路的放大信数（ ）A、降低 B、不变 C、增加 D、不确定6、下列电路中，具有记忆、计数功能的电路是（ ）A、单稳态电路 B、运行放大电路 C、多谐震荡器 D、双稳态电路7、十序逻辑电路的输出与（ ）有关。A、只在当前的输入 B、与当前的输入和原来的状态C、只与原来的状态 D、与电源电压8、逻辑功能为输入有“O”时，输出就为“I”的门电路是（ ）A、车门B、或门 C、与非门 D、或非门9、晶体三极管按共发射极接法组成放大器工作时，其输出电流、输出电压在输入电压的相位关系是（ ）A、输出电流、输出电压均与输入电压相反B、输出电流、输出电压均与输入电压相反C、输出电流与输入电压相同，输出电压与输入电压相反三、判断题1、220V60W灯泡，若安在110V电源上使用，它的实际功率只有30W。 （ ）2、当电路处于通路状态时，外电路电阻上的电压等于电源电动势。（ ）3、基尔霍夫第二定律只使用与闭合回路，在开口电路中还使用。 （ ）4、串联反馈都是电流反馈，并联反馈都是电压反馈。 （ ）5、计数器是一中组合逻辑电路。 （ ）6、主从JK触发器的输出状态是在CP脉冲的下降沿到来时改变的。 （ ）答案一、填空1、甲；乙；2、变化快慢；交变起点3、有效；311V；4、反向击穿；击穿电压Uz；5、增大；6、电压串联负反馈；7、二进制数码表示不同的信号二、选择题1、A； 2、C；3、C；4、D；5、A；6、D；7、B；8、C；9、C三、判断题1、； 2、 ；3、； 4、；5、；6、；汽车电工电子基础及电路分析作业讲评（三）此门课为中央电大命题，根据命题要点出一些题目，仅供参考。计算题1电路如图所示，已知：ES=8V、IS=1A、R1=1W、 R2=5W、R3 =3W，用叠加定理求R3中的电流I。 -R3ES+R1IR2IS2右图所示电路中，设三极管的值为100，UBE0.7V，rbb=200，C1和C2足够大，又知UCC10V，Rb490k，RC=RL=3k。试求：（1）静态时IBQ、ICQ、UCEQ；（2）计算rbe；（3）求电压放大倍数Au；（4）求输入电阻Ri和输出电阻Ro。答案120V电压源单独作用时：将5A电流源开路，如图所示。由此图可得I的一个分量为 5A电流源单独作用时：将20V电压源短路，如图所示。由此图可得I的另一个分量为R25AR1I“ -R220V+R1I 两电源共同作用时；总电流2答：（1），（2），（3），请您务必删除一下内容，O(_)O万分谢谢！2015年中央电大期末复习考试小抄大全，电大期末考试必备小抄，电大考试必过小抄Indonesia has emerged as a top vacation destination for Chinese this summer, along with Thailands Phuket island and the Maldives archipelago. Encouraged by growth in Chinese travelers to Indonesia, the government in Jakarta has recently relaxed its visa policy. Since June 10, Chinese tourists can enter Indonesia through nine appointed locations, including the Soekarno Hatta International Airport in Jakarta, the Ngurah Rai International Airport in Bali and the Kuala Namu International Airport in Medan, by just getting their passports stamped on arrival. Officially, it is called the free-visa scheme. The new policy also means Chinese tourists can save $35 on visa fees, which will likely make trips to Indonesia more alluring. While such an arrangement allows Chinese visitors to stay up to 30 days for the purpose of traveling, those seeking extensions will need to get paid visas from that countrys missions inBeijing,Shanghai,GuangzhouorHong Kong, according to an official at the Indonesia embassy in Beijing. Santo Darmosumarto, head of the embassys information, social and cultural section, says the new policy is aimed at strengthening people-to-people contacts between the two countries. Dai Yu, marketing director of Ctrip, a major Chinese online travel agency, says: Weve seen a nearly 50 percent growth over the previous month in the number of Chinese tourists to Bali since the policy was announced. During his trip to China in March, Indonesian President Joko Widodo proposed that his country and China aim to increase two-way visits to a maximum of 10 million people in the next few years. The Indonesian government has set their sights on greeting 2 million Chinese tourists by the end of this year, according to the official. The Indonesian government hopes that Indonesian nationals would also be given preferential treatment while visiting China, says Darmosumarto. In 2013, the number of Chinese tourists who visited Indonesia stood around 807,000. Last year, it increased to 959,000, he adds. Bali remains the most popular site among Chinese tourists. In February, more than 92,200 Chinese tourists made trips to Bali, ranking first among overseas visitors, the Bali Times reported. Last year, the island witnessed more than 586,000 arrivals from China, an increase of 51 percent over 2013. Bali isnt just for sightseeing, but also for weddings, honeymoons, golf and many outdoor activities, says Fan Wenqing, a marketing executive at Garuda, Indonesias national airliner. Garuda offers three nonstop flights between Beijing and Bali, and four each week between Beijing and Jakarta. There are daily flights from Guangzhou, inGuangdongprovince, and Shanghai to Jakarta as well. It takes from six to eight hours on a nonstop flight to reach Indonesia from China. Indonesia is home to more than 17,000 islands. Tourists can tour Yogyakarta to see Prambanam and Borobudur, two historical and religious sites, and explore the local handicraft markets. The base of a volcano, Bandung, which is also known as the Paris of Java, is ideal for adventure-seekers. Many ecotourism destinations, such as Toba Lake in Sumatra, Tanjung Puting National Park in Kalimantan and Bunaken in Manado, are places the embassy official recommends for tourists. Indonesia boasts world-class surfing facilities along the shores of Sumatra down to Nusa Tenggara Islands. Recently, Lombok, a sister island east of Bali has gotten so much attention from Chinese travelers that some travel agencies are offering twin packages for Bali and Lombok. The best time to visit Bali is from May to October, when it doesntrainmuch and the weather is cool. At press time, a weeklong package from Shanghai or Guangzhou to Bali was a little more than 3,000 yuan ($480) on Ctrips website. Chinese tourists have taken a shine to rafting in Ubud, sightseeing in Tanah Lot, and surfing and diving in Nusa Lembongan, says Dai. Civet coffee, essential oil and woodcarvings are among the most popular products for Chinese tourists in Indonesia, she says. Indonesian food is also something that visitors shouldnt miss. Local cuisines feature many spices, including peppers and cloves, and coconut pulp. Fried rice, dirty duck and roast suckling pig are recommended. Childrens illustration books first appeared in the 1600s in Europe. Their passage to China, however, took much longer, roughly 300 years. In China, childrens illustration books have a history of just 100 years and their development can be divided into four stages. From early 1900s to mid 1900s, a large number of books and magazines with illustrations appeared with the fast development of the modern publishing industry. The illustrationarts at that time were a mixed genre of Chinese traditionalpaintings and the westernstyle, and most of the stories originate from the fundamental changes that China experienced after the collapse of Qing Dynasty (1644-1911), the warlord struggles and the war against the Japanese invasion. The second stage was from mid 1900s to late 1970s, when the cultural revolution (1966-76) ended. The fast development of some special publishing houses for children gave birth to a large number of illustration-story books, which made a good use of folk art techniques, such as wood board carving, frescoes, and ink and wash painting, etc. Many of the popular stories are from Chinese history and wars after 1900s. The third stage is from early 1980s to late 1990s, a golden period for the development of childrens illustration books. The reform and opening-up brought in new concepts and ideas from the West to China, a country that had been closed to the West for nearly three decades. Fast development of economy, society and culture provided the writers and painters with a lot of inspiration to create new literature works and draw illustrations. China also imported large amounts of childrens illustration books from the West and Japan. Many young parents in China have a strong nostalgia about childrens illustration books they read in the 1980s and 1990s. This is also the last era in Chinas artistic innovation before the advent of the Internet period. The fourth stage is featured with the spread of the Internet and the other computerized means of art innovation. The hand-drawn childrens illustration books are gradually replaced by cartoons drawn and copied by software and machines, and shown on tablets, computers, television and smart phones, instead of books. Hainan Tropical Wildlife Park and Botanical Garden is natures haven, with no less than 4,000 rare birds and animals representing 200 species. With tropical forest covering over 90 percent of its area, the garden offers beautiful views of a wide range of tropical plants, flowers and fruit trees. The scenic spot about 25 kilometers from the center of Haikou offers a drive-thru safari tour where you can get up close with elephants, lions and bears. The Safari on Foot area features walking trails where visitors can see the rest of the animals, including hippos and monkeys, and feed them for a small fee. Visitors also can see what happens when you breed a lion and a tiger. Two unique attractions are rare hybrids: a liger, the offspring of a mallion and a female tiger and a tigon, which is created by a female lion and a male tiger. As ateaching center of the National Popular Science Education program, the park also serves as a second classroom for students to learn about wildlife and plants. Since it was established in 1995, it has received more than one million student visitors. At a crucial moment when pessimism has brought the Greek crisis to such a head that the country is closer to a default on its debt repayments than ever, Li offered a spark of enthusiasm to restart the stalled talks by calling on Greece and its creditors to reach a last-minute deal that will allow Greece to remain in the eurozone. Given the escalation of the countrys crisis over the weekend sent a shock wave through the global stock markets on Monday, there are ample reasons to worry about the uncertainties surrounding the events in Greece and the effect a default would have on Europe, relations between China and the EU, global financial stability and the nascent global economic recovery. Greece has announced that it will hold a referendum on a bailout plan proposed last week by the countrys creditors. In response, Greeces eurozone partners have refused to extend the countrys bailout program and the European Central Bank capped its emergency support for the countrys banks. A real danger now looms of Greece exiting the euro, which might derail the global economic recovery and damage the long-term viability of the euro as a currency. However, such a tragedy is neither certain nor unavoidable. The EU should shoulder its responsibility to prevent the Greek crisis from overshadowing the fragile global recovery. As a major customer and supplier of the 28-nation EU, and a responsible long-term holder of Eurobonds, Chinas confidence in and commitment to a strong eurozone offers EU leaders the necessary support to look at the Greek crisis from a broader and longer perspective. When Li said that China will not only consider a China-EU investment platform to back European Commission President Jean-Claude Junckers plan to revive the European economy, but also buy more bonds issued by the European Investment Bank, EU leaders should be clear that China