Answer questions about the text.

1.Who discovered the existence of radio waves?

2.What is a nature of a radio wave?

3.How does data transportation take place?

4.What definition of a radio wave can you give?

5.What specific features do radio waves have?

6. How are the wave bands usually classified?

7.What is a wave band?

8.Where are radio waves used?

EXERCISE 3

In the picture you can see the way that original sound passes before it becomes reproduced sound. Describe this way in your own words.

Answer questions about the text. - student2.ru


Fig.1 Electromagnetic spectrum and diagram of radio transmission of an audio signal.

EXERCISE 4

Work in pairs. Ask and answer questions about the inventions of the scientists.

A: What happened in 1894?

B: Alexander Popov invented the first radio.

A: What happened in… ?

The identity of the original inventor of radio, at the time called wireless telegraphy, is contentious. The controversy over who invented the radio, with the benefit of hindsight, can be broken down as follows:

1894 - Alexander Popov built his first radio receiver, which contained a coherer (detecting device consisting of tubes filled with iron filings).

1895, May 7 - Further refined as a lightning detector, it was presented on the Russian Physical and Chemical Society.

1893 - Nikola Tesla developed means to reliably produce radio frequencies, publicly demonstrated the principles of radio, and transmitted long-distance signals. He holds the US patent for the invention of the radio defined as "wireless transmission of data."

18967 - Guglielmo Marconi was an early radio experimenter. He founded the first commercial organization devoted to the development and use of radio. In 1909 – awarded the Noble prize.

1906 - Reginald Fessenden and Lee de Forest invented amplitude-modulated (AM) radio, so that more than one station can send signals (as opposed to spark-gap radio, where one transmitter covers the entire bandwidth of the spectrum).

1913 - Edwin H. Armstrong invented frequency-modulated (FM) radio, so that an audio signal can avoid "static," that is, interference from electrical equipment and atmospherics.

1893 – 1894 - Roberto Landell de Moura, a Brazilian priest and scientist, conducted experiments. He did not publicize his achievement until 1900 but later obtained Brazilian and American patents.

EXERCISE 5

Ask and answer more questions about inventions.

A: When did Alexander Popov invent the first radio?

B: In 1894.

A: When did … ?

EXERCISE 6

Choose the correct verbs from the brackets to complete the passage. Use the Past Simple Tense.

Brief history of the radio

Early radios run the entire power of the transmitter through a carbon microphone. While some early radios ______ 1some type of amplification through electric current or battery, until the mid 1920s the most common type of receiver ______2 the crystal set. In the 1920s, amplifying vacuum tuberadio receivers and transmitters ______3 into use.

(use, be, ran, come)

One of the first developments in the early 20th century (1900-1959) ______4 that aircraft _______5 commercial AM radio stations for navigation. This ______6 until the early 1960s when VOR systems finally ______7 widespread (though AM stations are still marked on U.S. aviation charts).

(use, be, become, continue)

In 1960, Sony ______8 its first transistorized radio, small enough to fit in a vest pocket, and able to be powered by a small battery. It ______9 durable, because there ______ 10 no tubes to burn out. Over the next 20 years, transistors ________11 tubes almost completely except for very high-power uses.

(be, introduce, replace, be)

In 1963 color television commercially ______12, and the first (radio) communication satellite, TELSTAR,_______13. In the late 1960s, the U.S. long-distance telephone network _________14 to a digital network, employing digital radios for many of its links. In the 1970s, LORAN _______15 the premier radio navigation system. Soon, the U.S. Navy _______16.withsatellite navigation, culminating in the invention and launch of the GPS constellation in 1987. Digital transmissions ________17 to be applied to broadcasting in the late 1990s.

(Begin, be converted, become, be transmitted, experiment, be launched)

EXERCISE 7

T 7

Translate the following text into English.

Электромагнитное излучение распространяется благодаря колебаниям электромагнитного поля, которое образуется как в воздушном пространстве, так и в вакууме. Для этого излучению не нужна особая проводящая среда (как, например, эфир). Когда радио волны проходят через проводник, колебания электрического или магнитного поля индуцируют в нем переменный ток. Он преобразуется в аудио- или другие сигналы, несущие информацию. Слово «радио» поясняет этот процесс. Телевизионные и радиопередачи, передача информации с помощью сотовой связи являются радиочастотными излучениями.

EXERCISE8

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