Вопросы и задания.

I. Дайте ответы на следующие вопросы:

1. What is the photoelectric cell?

2. What does the principle of television require?

3. Why do we have to amplify the current of the photoelectric cell?

4. How are pictures to be sent by television?

5. Why should the process of analyzing and reassembling the picture be carried out very rapidly?

6. What fact was taken advantage of in colour television?

7. What were the drawbacks of earlier TV sets?

8. What is the key to the fully portable TV set?

II. Верны ли следующие утверждения?

1. Although television is widely used in everyday life it is hardly used in industry or scientific work.

2. In the photoelectric cell the current decreases as the light is made brighter.

3. The speed of reassembling the television picture is not important.

4. At present colour television is in а somewhat limited usage.

5. In the early days both television and their screens were very small.

III. Разбейте текст на смысловые части и озаглавьте их.

IV. Составьте аннотацию к тексту, используя подходящие клише из перечисленных ниже:

characteristics of ... are discussed, the use of ... is discussed, the requirements of ... are examined, the effects of ... are explained, the method of … is introduced, data on ... are presented, the effect of ... is evaluated, applications of … are examined.

Грамматика.

5. Страдательный залог. Модальные глаголы. Инфинитив.

Упражнения.

I. Переведите на русский язык следующие предложения, содержащие страдательный залог:

1. Our country's successes in the construction of hydropower stations have been universally recognized.

2. The weight of the atom is almost entirely concentrated at its centre in the nucleus.

3. If a piece of material is struck by rays of light, electrons will leave the material.

4. The future of astronautics will be a logical continuation of what has already been achieved.

5. Two methods of reproducing sound have already been achieved.

6. Nearly all properties of matter are affected in some degree by temperature changes.

7. Automation is being introduced in building work.

8. The new block of flats was being built at the time of our holidays.

9. We were informed that many scientists were working at the problem of radioactivity.

10. Elimination of the housing shortage which is being realized at present is a problem of great importance.

11. More and more is being learned about outer space and conditions for life there.

12. Numerous new instruments are being used in many branches of science and technology.

II. Переведите на русский язык предложения, содержащие модальные глаголы:

1. A model of the proposed chamber may be made of the transparent plastics so that flow through the chamber can be observed or photographed.

2. Surging must be avoided when the aircraft is put into a dive.

3. An axial compressor cannot be run at too high speed.

4. We may say that a gas turbine engine comprises three main sections.

5. Changes in the shape of the chamber can really be made.

6. Blade vibration may become dangerous.

7. The thrust can be varied by the pilot.

8. Conditions must be studied to find the best fuel.

9. The method described above also enables us to obtain a better value for a frition constant.

10. The rocket is able to travel in a vacuum even better than it can through the air.

11. The speed has to be reduced.

12. The spaceship has to overcome the gravity.

III. Переведите следующие предложения, обращая внимание на функцию инфинитива:

1. То economize on transmitted power and to provide accurate target reporting, Rg energy is concentrated in a very narrow beam by the antenna system.

2. Experiments on the improvement of radar equipment began to be made during World War II.

3. It is possible to control flights of aircraft by means of ground-based radar.

4. Radio waves may be made to perform many services more or less closely related to communication.

5. To design, construct and operate а radar system is a great technical achievement.

6. Astronomers use radar to explore the universe.

7. The Greek philosopher Phales was the first to record the fact that objects which were electrically charged would attract each other at that time the only known way to generate electricity was by friction on amber.

8. The first thing to be noted when considering the chemical properties of metals is that they vary widely in degree of chemical activity.

9. At sea level our atmosphere presses with sufficient force to support a column of mercury 78 centimeters high.

10. To supply the most important and universal demands for oxygen does not cost a cent, it is as free as the air because it comes from the air.

11. It is often possible to build (synthesize) a compound directly from its elements or to separate (analyze) a compound into its elements.

12. To launch the satellite we had to make use of the step principle.

LIGHT

Light consists of waves of the same sort as radio waves, infrared rays, ultra-violet waves, Х-rays and gamma rays. All these are electromagnetic waves of different wave lengths. Radio waves and heat rays are not visible because they are too long. Light waves are of just the right 1ength to affect our eyes, and so we can see light. X-rays and gamma rays are too short to be visible.

As we move down the scale of wave length from the very long ones, like radio waves, to the very short ones, like X-rays and gamma rays, we find that they become more and more powerful. For example, ultra-violet waves are invisible, and are shorter than those of ordinary light waves. They are present in sunlight, but fortunately most of them are stopped by the outer atmosphere of the earth because in large doses they can damage human skin. X-rays and gamma rays are more dangerous still because of their extremely short wave length. X-rays are so powerful that they can travel through many substances that are opaque to light. They can, for example, pass through flesh and show up the bones inside.

Although light shows many of the properties of waves it also behaves sometimes as if it consisted of little particles, only they are not made of any substance but energy. These little packets of energy are called "photons", and the amount of energy in each is called a "quantum". There is much more energy in a quantum of X-rays than there is in a quantum of light or radio waves, and this explains why X-rays can damage the body, whereas radio waves have no effect on us.

Strangely enough, we can no more see light waves than radio waves. We only see light when the waves enter our eyes and stimulate our optic nerves. We can see the objects around us because they reflect the light which falls on them so that some of the rays are directed into our eyes. You can see light in the air because it is scattered by the dust particles, but a beam of light in a vacuum is quite invisible.

We get nearly all our heat and light from the sun. The moon sometimes is very bright, but it does not give out its own light like the sun. It merely reflects the sunlight which falls on it, just as a ping-pong ball will reflect the light of a lamp.

Bodies such as the sun, fires, lighted lamps, which give out their own light, are given the special name of “luminous” bodies. The moon and all ordinary objects are not luminous because they do not give out their own light.

Лексико-грамматический комментарий

of the same sort – того самого вида

light waves are of just the – световые волны имеют как раз ту волну, right length to affect our eyes которая позволяет воздействовать на органы зрения

X-rays and gamma rays are too – рентгеновские и гамма лучи

short to be visible слишком короткие, чтобы их можно было зрительно воспринимать

from the very long ones … to – от очень длинных … до очень the very short ones коротких

because of their extremely из-за их чрезвычайно коротких длин волн short wave length …--

… only they are not made of – только они состоят не из вещества, а из any substance but energy энергии

they are present – присутствуют

strangely enough – довольно странно

we can no more see … light – мы не можем видеть … световые волны, waves than radio waves так же как и радиоволны

as if it consisted – как будто он состоит