Post-text exercises. I. Find the English equivalents for the following Ukrainian words and word combinations:

I. Find the English equivalents for the following Ukrainian words and word combinations:

1. загальний опір; 2. потужність; 3.співвідношення; 4 багатокаскадний; 5. затухання; 6. частотна область; 7. форма сигналу; 8. послідовно; 9. підсилювачі постій­ного струму; 10. коефіцієнт підсилення; 11. затримка; 12. підсилювати

a. frequency domain; b. waveform; c. delay; d. impedance; e. in tandem; f. power; g. multistage; h. ratio; i. emphasize; j. attenuation; k. gain; l. d.с. amplifiers

II. Arrange synonyms in pairs and translate them:

a) change, constant, amount, similar to, rarely, in tan­dem, amplify, supply, happen, for instance, join;

b) in series, seldom, provide, alike, quantity, stable, vary, enlarge, take place, for example, couple.

III. Name the verbs from which the following nouns derived and translate them:

amplifiers, distortion, attenuation, connection, introduction, equipment, statement, correction, generator, transference, expression

IV. Put the words in order:

1. To, to, amplify, or, means, bigger, make, enlarge. 2. Some, amplifiers, are, designed, be, to, non-1inear. 3. The, opposite, of, attenuation, is, gain, opposite. 4. are, amplifiers, by, named, the, frequency, range, operate, over, they, which.

V. Fill in the blanks with the following words:

element, characteristics, an amplifier, decibel, ideal, operating, attenuation, nonlinear

1.... can be shown as a " black box". 2. One of the... of an amplifier is the gain. 3. Point P is the... point for the amplifier. 4. Amplifiers can't have the... gain and phase characteristics, 5. It is necessary to have one active... in an amplifier to change the power. 6. The word... is often used in different fields of telecommunication. 7. There are linear and... amplifiers. 8.... can be shown graphically as negative gain.

VI. Answer the following questions:

1. What is an amplifier used for? 2. What is a linear amplifier? 3. When is the time delay constant for all parts of the signal in the time domain? 4. What does a multistage amplifier consist of? 5. What can you tell about the gain of a power amplifier?

VII. Translate the following definitions and memorize the terms:

Amplifier. An electronic instrument for strengthening an controlling electrical signals, consists of a preamplifier-equalized section plus a power amplifier section.

Decibel(db). A numerical expression of acoustical or electrical rations, such as the relative intensity of a sound оr relative strength of a signal. Two decibels is the smallest change in sound perceptible to the ear.

Frequency. The number of periods per unit time.

Gain. The increase in signal power in transmission from one point to another under stated conditions.

Generator. A machine that converts mechanical power into electric power.

VIII. Translate the following sentences paying attention to the Subject clauses:

1. It is necessary that a current amplifier should have a very small input impedance and a large output impedance. 2. That more amplification is obtained when amplifiers are connected in tandem is well known to every specialist. 3. That a v.f. amplifier is used for voice frequencies, 300 to 3, 300 cycles per second, is a matter of common knowledge. 4. It is no doubt that the word " figure" has several equivalents in Russian. 5. It is desirable that students should memorize the new words from the text " Amplifiers". 6. By what characteristics amplifiers can be described is known to those who work in the field of radioengineering. 7. What the lecturer told you about the use of feedback in different types of amplifiers is very important. 8. How feedback influences the parameters of elements and characteristics of amplifiers was the problem of study of our laboratory. 9. Why they didn't reach an agreement last year is not clear to anyone.

IX. Translate the following sentences paying attention to the Predicative clauses:

1. The main property of a linear amplifier is that the gain of it is constant. 2. The problem is whether phase delay is proportional to frequency domain. 3. The main effect of amplification is that current, voltage and capacity of an electric signal are increased. 4. The task our laboratory is working at is how we can obtain linear distortion less amplification. 5. The difficulty was whether we could decrease the presence of distortions introduced by feedback in amplifiers. 6. The aim of our test is whether we can use only part of a load line to provide small non-linear distortions. 7. The problem was whether we could carry out all necessary tests in time. 8. The question which it is necessary to clarify is that all components of the output signal are delayed by the same amount. 9. The disadvantage of the given circuit was that output resistance was higher than input resistance in the ammeter. 10. The possibility of reduction of the number of stages of a pre-amplifier is that gain of amplification of each stage must be small.

X. Translate the following sentences paying attention to the Object clauses. Name the tenses:

1. We know that there exist different types of amplifiers. 2. One should remember that operating point will move because of changes in temperature or power supply levels. 3. The article reads that amplifiers can be described in the time domain. 4. The students knew that a great many amplifiers were three terminal devices. 5. The laboratory assistant said that he would demonstrate a linear amplifier. 6. The examiner asked the student if he had been present at the lecture on multistage amplifiers. 7. The lecturer stressed that an amplifier might have at least one active element in it. 8. Students asked the teacher what amplifiers were called linear. 9. The head of the laboratory reported that they were working at three terminal devices. 10. Students were told that their hometask was to learn the new words from the second part of the text " Amplifiers".

XI. Change the following sentences into Indirect speech. Mind the Sequence of Tenses:

M о d e l: He said: " I shall do this work."

He said that he would do this work.

1. The lecturer pointed out: " Amplification is the ratio of the output voltage to the input signal voltage." 2. The author of the article stated: " High frequency links will be an important port of the world communication system in future. 3. The head of the research laboratory reported: " Our laboratory is developing testing equipment for new communication systems." 4. The examiner asked the student: " What amplifier has only one active element in it? " 5. One of the students asked: " Is it possible to have the ideal gain and phase characteristics over the whole frequency range? " 6. The speaker concluded: " There exist many problems concerning space communication and one of them will be discussed at the next meeting." 7. The teacher asked: " Who knows the difference between a linear and non-linear amplifier? " 8. The laboratory assistant said: " The output signal was distorted." 9. Students were told: " This current amplifier will have a very small input impedance." 10. Students asked the teacher: " What text shall we read after we finish reading Amplifiers'? " 11. He said: " I have finished the work."