VII. Answer the following questions:

1. What does electrical energy that has escaped into free space exists? 2. What is the velocity of these waves? 3. What are the essential properties of a radio wave? 4. Does the wave always travel in a direction at left angles to the wave front? 5. What is the direction of polarization of the wave? 6. What is the velocity of the radio waves? 7. What is the length of a low-frequency wave?

VIII. Speak on different kinds of radio waves and their use in communi­cation.

IX. Translate the following sentences into Ukrainian:

1. We know electric current to be surrounded by a magnetic field. 2. We have seen the existence of life on the earth depend upon the continuous receipt of enormous quantities of energy from the sun. 3. To transmit the human voice around the earth became possible by means of the radio. 4. Air under normal conditions has been found to contain few ions. 5. The radio set may have been plugged in the wrong way, therefore there is nothing happening.6. The engineer wants the new devices to be tested in the laboratory. 7. Radio beacons permit the pilot to find the way in fog or storm.

X. Translate the following sentences paying attention to the Infini­tive and its function:

1. To understand the text you must read it attentively. 2. To make a long story short they repeated the experiment and compared the results. 3. A new machine was invented both to receive and to transmit messages with greater speed. 4. The circuit can be broken to interrupt the flow of electri­city. 5. He stopped there so as to rest a little. 6. You must work hard and systematically in order to master a foreign language in a short time. 7. I don't know him well enough to ask him for help.

XI. Translate the following sentences into the English:

1. Відомо, що кольоровому телебаченню належить майбутнє.2. Кажуть, що наш завод отримав нові електронні прилади. 3. Вважають, що напівпровідники застосовуються все більше в усіх галузях науки. 4. Відомо, що електричний струм оточений магнітним полем. 5. Передача людського голосу стала можлива завдяки радіо. 6. Необхідно, щоб цей прилад був перевірений.

XII. Try to remember the origin of the word RADIO.

Radio communication was called “wireless telegraphy and telephone”. This name was too long for convenience and was later changed to “radio” which comes from the Latin word “radius”-a straight line drawn from the centre of a circle to a point on its circumference.

XIII. Imagine that you are at the scientific conference. Tell about the basic task and applications of radio.

XIV. Read the following supplementary text and translate it without a dictionary: entitle it.

Modem radio engineering is a powerful tool in spending up the scientific and technical progress. Radio engineering has penetrated into the national economy, science, industry, our culture and everyday life... One of the most important applications of radio engineering involves long-distance communication by means of electromagnetic waves. The development in various specialized branches of radio engineering is closely allied to the general use of radio for broadcasting and communication, while television covers steadily expanding regions in many parts of the globe. Radio engineering equipment provides for stable round-the-clock communication with marine vessels, aircraft, and spaceships. Radio engineering systems enable us to effect interplanetary communications and to control sophisticated apparatus of space probes. Such branches of radio engineering as radio location (or radar), radio navigation, radio telemetry, radio control, etc., which just a few years ago were regarded as new techniques are now in general use. However, the above applications by no way exhaust all the possibilities of modem radio engineering. Radio methods have penetrated into well-known sciences and led to their qualitative change and development. New sciences have been born such as radio physics, radio astronomy, etc.

LESSON 12

Text: Television

Pre-text exercises: