Материал: Сибирский государственный университет телекоммуникаций и информатики

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the change in direction of a light beam as it crosses a boundary between two media with different refractive indexes;

  • a heated cathode with an associated system of electrodes and coils for producing and focusing a beam of electrons, used especially in cathode-ray tubes.



    XVIII. Complete each sentence with a word from the box.


    Flyback, vidicon tube, deflection soils, television, scanning, electron gun, bandwidth, aerial, electron beam, microphone


    1. The purpose of the …………….. is to convert the sound pressures into electrical impulses of varying amplitude.

    2. The electron beam that scans the picture in the ……………… must be in exactly the same position at all times as the electron beam that scans the screen in the picture tube.

    3. The vision signal contains only half the picture information thereby reducing the ………………. by half to 5.5 MHz.

    4. Both line and frame synchronizing pulses are added back to the video signal during the …………….. when the line is blanked out.

    5. …………….are conventionally divided into transmitting and receiving, though in most cases there is no principle difference between them.

    6. A kinescope is a large vacuum tube used for ……………… and viewing the transmitted pictures.

    7. When colour ………………. was introduced in the UK in 1967, consideration had to be given to owners of monochrome receivers so that they could continue to receive a normal monochrome picture.

    8. In the television system devised by Vladimir K. Zmorykin a narrow …………….. is used to scan the image in a photoelectric tube of special design called an iconoscope.

    9. The electron beam is produced by an ………………. , which consists of a heated cathode, a grid and the anodes.

    10. All three electron guns scan the screen under the control of the same ……………… .


    XIX. Translate the sentences, paying attention to the meanings of highlighted words


    1. Setting targets is very important when you want to achieve something. 2. He has become the target for a lot of criticism recently. 3. The campaign is clearly targeted on the young. 4. She scanned the advertisement pages of the newspaper over breakfast. 5. I scanned the book for every detail of the transistor operation. 6. Text and pictures can be scanned into the computer. 7. The camera tubes are scanned in synchronism using internal electron beams that produce three separate voltages, representing the 8 MHz colour information. 8. Suppose the picture being scanned has n elements. 9. Luckily I managed to get home half an hour before the first spots of rain started to fall. 10. His jacket was covered with spots of mud. 11. The process of scanning consists of moving an exploring element or spot over the image to be transmitted in a periodically repeated path covering the entire image area.


    XX. Change the sentences, using the words in brackets according to the model.


    Model: The attendants don’t permit the taking of photographs. (visitors)

    The attendants don’t permit visitors to take photographs.


    1. The engineer advised using a variable capacitor to tune different stations in. (their colleges)

    2. The teacher recommends recalling the material about audio amplifier. (the student)

    3. The necessity to save “radio space” doesn’t permit increasing of bandwidth. (radio station)

    4. The professor intends using amplitude modulation to transmit the bandwidth. (the engineer)

    5. A new communication satellite allowed using regular Hi-Vision service. (tiny aerials)


    • XXI. Discussion. In pairs discuss the following questions.


    1. Speak about different types of television, their advantages and disadvantages. (cable television, colour television, digital television, high-definition television).

    2. Paraphrase the following quotation. Express your opinion about it.

    “It is only when they go wrong that machines remind you how powerful they are.” Clive James (Australian critic)


    Unit 9


    1. Условные предложения

    2. Значения слова provide

    3. Значения союзов unless, suppose, in case, on condition that, but for

    4. Префиксы over-, super-, under-, mono-, semi-, mal-, non-, sub-, out-, mis-.

    5. Текст «The charge-coupled device»


    I. Translate conditional sentences and define their types.


    1. If a scientific research is closely linked with practice the results are always good. 2. If you looked at the equipment of 1946 you would notice the difference with that available at present. 3. If the satellite speed were less than necessary it would go down from the orbit and enter the atmosphere. 4. If you watch a laser operate, you might be surprised at the simplicity of a device having such a power. 5. If we wanted to make a journey in a plane to the nearest star we should have to travel for several thousand centuries. 6. If we had tested this material we should have used it in our work. 7. If ordinary gases are greatly compressed they become liquids. 8. If supercomputers had not been used for thermodynamic calculations designers would have spent all their lives on computations. 9. If you think that a computer never makes mistakes you are wrong. 10. If the number of negative charges is unlike the number of positive charges, the matter will produce electrical effects.


    II. Choose the right variant in brackets paying attention to the type of conditional sentences.


    1. If they (discover/discovered) iron ore deposits in that district, an iron and steel works will be built there. 2. I would (have brought/bring) the book, but you did not tell me you needed it. 3. If I were you, I would (write/have written) a letter of complaint to the company. 4. If you had studied harder, you would not (fail/have failed) your exams. 5. If I (see/saw) you yesterday I would have given you my text-book. 6. If there were no difference of potential between two points of a conductor, electrons would not (continue/have continued) to flow. 7. If helium were obtained only from the air, it would (be/have been) a rare gas. 8. If we (tested/had tested) this material we should have used it in our work. 9. If every light fixtures in buildings (contain/contained) a small wireless node, people would not only be able to control the lighting more effectively but put them to many other uses too. 10. If you (look/looked) at the number of internet capable mobile phones, PDAs and so on, you will see that they are rapidly outnumbering the things we think of as computers.


    III. Put the verbs in the right form in the conditional sentences.


    1. If we bring the charged ebonite rod near the ball, the latter (attract) towards it. 2. If a great enough velocity is reached, each electron (have) sufficient energy to release one or more electrons from the plate.

    3. If a difference of potential between two points of a conductor (maintain) by some means or other, electrons will continue to flow, giving life to a continuous current.

    4. If there were no force of gravitation, both the Moon and the Earth (fly off) into space along a straight line.

    5. If we (have) to examine most solid substances, we should see that they are crystalline.

    6. Would you mind if I (come) to work an hour later on Monday?

    7. If the post were more reliable, we (not have to) depend on couriers.

    8. If cast iron had not been so brittle, it (find) much more applications in industry. 9. If a given amount of energy is put into a machine, precisely that very amount (be) developed.

    10. If white cast iron were slowly cooled in the moulds it (have) a structure of ferrite and free carbon in the form of graphite.

    11. What would you use if you (want) to measure air pressure?

    12. If you (look) at the engine for a moment, you would have seen what was missing.

    13. If there were no atmosphere, there (be) no clouds, no rain.

    14. If you (melt) the snow you would get water.


    IV. Put the verbs in brackets into the correct tenses.


    1. The launching of the rocket was delayed half an hour by bad weather. If the weather (be) good they (launch) it at 7.30 instead of at 8.00. 2. It is a pity he never patented his invention. If he (patent) it he (make) a lot of money. 3. I failed my exam. If I (try) again, I think that I (succeed). 4. Sally forgot her briefcase. If she (be) in such a hurry she (not forget) her briefcase. 5. He knows that this cable is alive. If he (touch) that electric cable he (be) electrocuted. 6. We did not go to the lecture yesterday. If we (be) at the lecture we (answer) your questions. 7. I (do) this work long ago if I (have) got the necessary tools. 8. Extra measures have to be taken to cool a hypersonic craft. If extreme temperatures generated by atmospheric friction (not be) so high a hypersonic craft (not require) complicated cooling measures. 9. If you (drive) more carefully you (not have) an accident. 10. If I (knew) that you needed help I (help) you.

    V. Rewrite the sentences according to the model.


    Model: I did not see the signal, so I did not stop.

    If I had seen the signal, I would have stopped.


    1. The exit doors were blocked, so people couldn′t escape from the burning hall.

    2. He had all the necessary books and made his report in time.

    3. I did not read the instruction that is why I did not manage to install the equipment.

    4. Drivers are not attentive while driving, so there are a lot of accidents on the road.

    5. They applied a new method and got good results.

    6. Gases are not greatly compressed, so they can′t become liquids.

    7. He was at the lecture yesterday and answered all the teacher′s questions.

    8. Current does not flow across from one wire to the other because two wires are separated by the air gap.

    9. A potential difference does not exist between two objects because they were charged equally.

    10. The heat causes mechanical troubles when the temperature is raised above a certain limit.


    VI. Finish the sentences.


    1. If I could travel anywhere in the world…

    2. If I owned a company…

    3. If I were the president of …

    4. If I had $1 million…

    5. If I practiced more …

    6. If I had more time…

    7. If I had a camera…

    8. If the weather is fine…

    9. If I get my university degree…

    10. If I find a well-paid job…


    VII. Change the following sentences of real condition into sentences of unreal condition.


    Model: If you put salt on ice it will melt.

    If you put salt on ice it would melt.

    Источник: https://tut-files.ru/previewfile/123948

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