1. Закончите предложение:

The transmitter is a device that ... .

1. receives waves sent out by a transmitter

2. produces radio-frequency energy

3. transmits and receives signals and programs by electromagnetic waves

4. transfers high-frequency energy from the transmitter to the receiver

9.2 Найдите соответствующий перевод подчеркнутого слова:

a) так как c) с тех пор

b) с d) с тех пор как

Задание № 10 Прочитайте текст.

Telephony is the transmitting of speech over a considerable distance by means of electric current, using wires. Telephony communication includes 1) telephone sets to change sound energy into electrical waves and back again, 2) transmitting

system to carry electric waves over any distance, and 3) switching system to con-

nect any two telephone sets. Telephone is a device for reproducing sounds over considerable distances. Telephone set includes a transmitter and an electric net-

work in addition to the receiver. The transmitter transmits sounds and the receiver receives them. The receiver includes a telephone and a microphone. Both the mi-

crophone and the telephone are linked to a common circuit with an apparatus at the

other end of the line.

10.1 Ответьте на вопрос:

What is telephone?

1. It is the transmitting of speech over a considerable distance.

2. It is the switching system.

3. It is the device.

4. It is the transmitter.

10.2 Определите, какой из заголовков соответствует тексту:

a) Telephony c) The Receiver

b) Telephone Sets d) The Transmitter

Задание № 11 Прочитайте текст и заполните пропуски 1-4 предложе-

ниями, обозначенными буквами a-d.

1________ . The world’s first receiver was built in 1895 by the great Russian scientist Alexander Popov. There were no transmitters then, therefore his receiver could only pick up signals produced by lightning discharges during a thunder-storm. Popov demonstrated a device called a storm indicator at a meeting of scient-

ists in St. Petersburg on May 7, 1895. 2_________ .

Soon A. Popov found a way of transmitting Morse code signals. In 1896 he sent the world’s first wireless telegram over a distance of 250m. 3_________ . Since then, the methods of transmission and reception have been constantly improved.

4________ .

1. Four years later the range of transmission was increased to 50 km.

2. Nowadays radio communication has no limits.

3. Radio was invented in Russia.

4. This day is marked now as a Radio Day.

Задание № 12 Прочитайте текст и выберите утверждение, соответствую-щее содержанию текста.

The telephone was invented in 1876. Speech transmission in those days was limited to a distance of a few miles and and the construction of the first telephone

was simple. The main parts were a transmitter and a receiver. At first there was a simple telephone circuit in which only one device served as both transmitter and

receiver.

Later development of the telephone changed its construction, it became more

complex. Transmitters and receivers were separated.The need to connect any two of a large number of telephone sets led to the development of a switchboard in 1878. The advantage of a central switching office with a switchboard was great. In

1889 telephone sets were interconnected automatically.

The number of telephones to be interconnected increased, and large cities needed more switchboard offices. Central offices grew in number.

1. The construction of the first telephone was complex.

2. Only one device served as both transmitter and receiver.

3. A switchboard appeared in 1889.

4. The number of telephones to be interconnected decreased.

Задание № 13 Прочитайте текст. Выполните задания.

Telephony is widely used in everyday life. By means of a telephone people can communicate with each other at a distance of thousands of kilometers.

When speaking over the telephone, we press the receiver to our ear. We speak in-

to the microphone or transmitter. The transmission of sounds over a distance is the transmission of oscillations. The frequency of the transmitted oscillations must be constant.

The microphone or transmitter consists of microphone housing, carbon chamber, carbon diaphragm, carbon granules, insulating spacer and conductor.

The current passes through the diaphragm, carbon chamber and carbon granules.