Методические рекомендации по выполнению домашней контрольной работы
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Electronic principlesOf all the component parts used in modern systems radio communication, the electron tube is the most important one. Vacuum tubes are made in all sizes, from the tiny or to the giant 100-kW water-cooled tubes used in large radio transmitters. They function as oscillators, amplifiers, detectors, rectifiers, modulators, as voltmeters, oscillographs, in any special ways. The importance of having a good working knowledge of their properties and application cannot be overestimated. Metallic conductors are composed of atoms and molecules, with a great number of free electrons, in continual random motion, which are not bound closely to particular atoms. If the temperature of a conductor is raised sufficiently, some of these free electrons will acquire enough kinetic energy to permit their escape by penetrating the surface of the conductor. This process is known as thermionic emission and it is found that various metals differ widely with respect to this property. In present-day tubes, the most commonly used materials for the purpose are as follows tungsten, thoriated tungsten, oxide-coated emitters. Emitters made of tungsten are used principally in large transmitting tubes, where heavy emission current are required. Tungsten emitters must be operated at 2,500 К, and they require relatively large amounts of power for heating. The operating temperature is close to the melting point of tungsten, and consequently the heating voltage must be regulated. Within this limitation, however, tungsten emitters are rugged and long-lived, and capable of withstanding considerable overloads. Thoriated tungsten is tungsten containing a small percentage of thorium oxide. After suitable heat treatment it is found that migration of thorium atoms produces an activated layer on the filament surface, with the result that electrons are emitted at a much lower temperature (1,900°) than for pure tungsten. This type of cathode has, therefore a greater emission efficiency, but it is much more sensitive to overload than pure tungsten, as the thorium layer is stripped off or evaporated when excessive emission currents are demanded. Filaments and indirectly heated cathodes of oxide coated type consist of an inert base, usually a nickel alloy covered with a layer of barium and strontium oxides. Cathodes of this type operate at a still lower temperate (1150°K), and the emission efficiency is very high. Almost all tubes of the small receiving type, as well as many of medium size, utilize cathodes of this type. 2. Составьте письменно лексический словарь по тексту с транскрипцией и переводом (20 слов и выражений). Например, Device [di`vais] – устройство, приспособление 3. Выберите правильный вариант конструкции в пассивном залоге и перепишите предложения 1. This theatre … (build) over 100 years ago. a. had been built b. has been built c. was built 2. Is your car still for sale? – No. It … already (sell). a. has been sold b. had been sold c. was sold 3. Sometimes mistakes … (make). a. are made b. are being made. c. have been made 4. For the past few days I (work) in Jack’s office, as my own … (decorate). a. have been working/is being decorated b. worked/decorated c. am worked/is being decorated. 5. While my friend … (talk) to me, his wallet .. (steal). a. was being talked/ was being stolen b. was talking/ was stolen c. talked/stole 6. Where is your friend Bob? – - I don’t know. He … (not/ seen) resently. a. hasn’t seen b. didn’t see c. hasn’t been seen 7. If someone … (report) you to the police, you … (make) to pay a big fine. a. reports/ will be made b. will report/ will make c. is reported/ will be made 8. Professor … ( give) another lecture at the same time next week. a. will have been given b. will be given c. will give 9. Look at the dust in here! It … (look) as if this room (not/clean) … for a month. a. is looked/ hasn’t cleaned b. looks/ hasn’t been cleaned c. has looked/ isn’t cleaned 10. The door … (open) and a young lady … (come in). It should be admitted that the door … (open) by herself. a. opened/ came in/ was opened b. was opened/ came in/ was opened c.opened/ came in/ opened ВАРИАНТ 8 1. Прочтите, перепишите и письменно переведите текст The invention of a transistor You can forget inventions like air conditioning, television, the computer and the Internet. The single most important invention of the 20th century was the transistor, according to some researchers and analysts. Yes, that's right. The transistor. The little-talked-about transistor is the building block for the processor. Without the transistor, some say our servers would be three stories high, and laptops would be a prop on Star Trek. Our televisions would still use vacuum tubes, and our cars couldn't guide us to the nearest Indian restaurant. Sixty years ago -- on Dec. 16, 1947, to be exact -- the transistor was invented at Bell Labs, igniting a series of changes and advances that would change the way people listen to their favorite music, do their jobs, pay their bills, educate themselves and buy everything from books to used toaster ovens. Transistors inside pacemakers keep our hearts going. Computer chips run inside our cars, cell phones and even tiny, implantable LoJack-like devices that help find lost pets. The PC and the Internet have been phenomena, but how usable and ubiquitous would they be without millions of tiny transistors running inside laptops, desktops and servers?
The invention of the transistor was probably the most important invention in the 20th century. 2. Составьте письменно лексический словарь по тексту с транскрипцией и переводом (20 слов и выражений). Например, Device [di`vais] – устройство, приспособление 3. Повторите тему «Степени сравнения прилагательных» и переведите письменно следующие предложения на русский язык. 1. What is your height? You are taller than me. 2. She felt as strong as her brother. 3. We started earlier than you. 4. He was more careful than I. 5. This student is the most attentive in our group. 6.I need a warmer coat. 7. He is as tired as you. 8. He was one of the most experienced workers at the factory. 9. Better late than never. 10. She was not so attractive as her mother. 11. His work is not so difficult as mine. 12. He was the eldest in the family. 13. It is easier to swim in the sea than in the river. 14. This is the smallest room in our flat. ВАРИАНТ 9 1. Прочтите, перепишите и письменно переведите текст Computers Computer is an electronic device that can receive a set of instructions called program and then carry out them. The modern world of high technology could not be possible without computers. Different types and sizes of computers find uses throughout our society. They are used for the storage and handling of data, secret governmental files, information about banking transactions and so on. Computers have opened up a new era in manufacturing and they have enhanced modern communication systems. They are essential tools in almost every field of research, from constructing models of the universe to producing tomorrow's weather reports. Using of different databases and computer networks make available a great variety of information sources. There are two main types of computers, analog and digital, although the term computer is often used to mean only the digital type, because this type of computer is widely used today. That is why I am going to tell you about digital computers. Everything that a digital computer does is based on one operation: the ability to determine: on or off, high voltage or low voltage or — in the case of numbers — 0 or 1 or do-called binary code. The speed at which the computer performs this simple act is called computer speed. Computer speeds are measured in Hertz or cycles per second. A computer with a «clock speed» of 2000 MHz is a fairly representative microcomputer today. It is capable of executing 2000 million discrete operations per second. Nowadays microcomputers can perform from 800 to over 3000 million operations per second and supercomputers used in research and defense applications attain speeds of many billions of cycles per second. Digital computer speed and calculating power are further enhanced by the amount of data handled during each cycle. Except two main types of computers, analog and digital there are eight generations of digital computers or processing units. The first generation was represented by processing unit Intel 8086. The second generation central processing unit was represented by processing unit Intel 80286, used in IBM PC AT 286. The third generation is Intel 80386, used in IBM PC AT 386. The microprocessors of the fourth generation were used in computers IBM PC AT 486. There are also central processing units of the fifth generation, used in Intel Pentium 60 and Intel Pentium 66, central processing units of the sixth generation, used in computers Intel Pentium 75, 90,100 and 133. Few years ago appeared central processing units of seventh and eighth generations. They are much more powerful and can perform from 2000 to over 3000 million operations per second. 2. Составьте письменно 5 вопросов различного типа к переведенному тексту: 1) общий вопрос 2) специальный вопрос 3) Разделительный вопрос 4) Вопрос к подлежащему 5) Альтернативный вопрос 3. Повторите грамматическую тему «Неопределенные местоимения». Вставьте somebody, anybody, nobody или everybody. Запишите предложения. 1. Has ... in this group got a dictionary? 2. ... left a magazine in our classroom yesterday. 3. The question was so difficult that ... could answer it. 4. I am afraid I shan't be able to find ... in the office now: it is too late. 5. ... knows that water is necessary for life. 6. Is there ... here who knows French? 7. You must find ... who can help you. 8. ... knew anything about America before Columbus discovered it. 9. I saw ... in the train yesterday who looked like you. 10. There is ... in the next room. I don't know him. 11. Please tell us the story. ... knows it. 12. Is there ... in my group who lives in the dormitory? 13. Has ... here got a red pencil? 14. ... can answer this question. It is very easy. ВАРИАНТ 10 1. Прочтите, перепишите и письменно переведите текст The Internet The Internet has already entered our ordinary life. Everybody knows that the Internet is a global computer network, which embraces hundred of millions of users all over the world and helps us to communicate with each other. The history of Internet began in the United States in 1969. It was a military experiment, designed to help to survive during a nuclear war, when everything around might be polluted by radiation and it would be dangerous to get out for any living being to get some information to anywhere. Information sent over the Internet takes the shortest and safest path available from one computer to another. Because of this, any two computers on the net will be able to stay in touch with each other as long as there is a single route between them. This technology was called packet switching. Invention of modems, special devices allowing your computer to send the information through the telephone line, has opened doors to the Internet for millions of people.Most of the Internet host computers are in the United States of America. It is clear that the accurate number of users can be counted fairly approximately, nobody knows exactly how many people use the Internet today, because there are hundred of millions of users and their number is growing. Nowadays the most popular Internet service is e-mail. Most of the people use the network only for sending and receiving e-mail messages. They can do it either they are at home or in the internet clubs or at work. Other popular services are available on the Internet too. It is reading news, available on some dedicated news servers, telnet, FTP servers, etc. In many countries, the Internet could provide businessmen with a reliable, alternative to the expensive and unreliable telecommunications systems its own system of communications. Commercial users can communicate cheaply over the Internet with the rest of the world. When they send e-mail messages, they only have to pay for phone calls to their local service providers, not for international calls around the world, when you pay a good deal of money. But saving money is only the first step and not the last one. There is a commercial use of this network and it is drastically increasing. Now you can work through the internet, gambling and playing through the net. However, there are some problems. The most important problem is security. When you send an e-mail, your message can travel through many different networks and computers. The data is constantly being directed towards its destination by special computers called routers. Because of this, it is possible to get into any of the computers along the route, intercept and even change the data being sent over the Internet. But there are many encoding programs available. Not with-standing, these programs are not perfect and can easily be cracked. Another big and serious problem of the net is control. Yes, there is no effective control in the Internet, because a huge amount of information circulating through the net. It is like a tremendous library and market together. In the future, the situation might change, but now we have what we have. It could be expressed in two words— an anarchist’s dream. 2. Составьте письменно лексический словарь по тексту с транскрипцией и переводом (20 слов и выражений). Например, Device [di`vais] – устройство, приспособление 3. Задайте письменно вопросы к следующим предложениям (общие и специальные):
ВАРИАНТ 11 1. Прочтите, перепишите и письменно переведите текст Electrical engineering Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics, and electromagnetism. This field first became an identifiable occupation in the later half of the 19th century after commercialization of the electric telegraph, the telephone, and electric power distribution and use. Subsequently, broadcasting and recording media made electronics part of daily life. The invention of the transistor, and later the integrated circuit, brought down the cost of electronics to the point they can be used in almost any household object. Electrical engineering has now subdivided into a wide range of subfields including electronics, digital computers, power engineering, telecommunications, control systems, radio-frequency engineering, signal processing, instrumentation, and microelectronics. The subject of electronic engineering is often treated as its own subfield but it intersects with all the other subfields, including the power electronics of power engineering. Electrical engineers typically hold a degree in electrical engineering or electronic engineering. Practicing engineers may have professional certification and be members of a professional body. Such bodies include the Institute of Electrical and Electronics Engineers (IEEE) and the Institution of Engineering and Technology (professional society) (IET). Electrical engineers work in a very wide range of industries and the skills required are likewise variable. These range from basic circuit theory to the management skills required of a project manager. The tools and equipment that an individual engineer may need are similarly variable, ranging from a simple voltmeter to a top end analyzer to sophisticated design and manufacturing software. 2. Письменно переведите следующие слова и выражения на английский язык: Цифровые компьютеры, системы контроля, сфера, применение электричества, электромагнетизм, электрический телеграф, электрическая сила, изобретение транзистора, телекоммуникации, микроэлектроника, инженерное дело, инженер, электроинженер, оборудование, вольтметр, программное обеспечение. 3. Поставьте глагол в скобках в одно из следующих грамматических времен Present Continuous, Present Perfect, Present Perfect Continuous, Past Simple. 1. Aren’t you about to finish with the dishes? 2. You ___ (wash) the dishes for thirty minutes or more. How long can it take you to wash the dishes? 3. It _______ (ring) for more than twenty minutes. 4. Can you translate this note from Stockholm? I understood Swedish when I _____ (be) a child, but I _____ (forget) it all. 5. What’s that dent in the side of the car? You _______ (have) an accident? 6. I’m sorry, John’s not here; he ____ (go) to the dentist. He ____ (have) trouble with a tooth for some time. 7. This cassette recorder is broken. You _______ (play) about with it? 8. Your Italian is very good. You _______ (study) it long? 9. Do you mind if I clear the table? You _______ (have) enough to eat? 10. Ann never _______ (go) camping. She _______ (not sleep) in a tent. ВАРИАНТ 12 1. Прочтите, перепишите и письменно переведите текст |
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