Вариант 4

1Переведите текст на русский язык письменно. Ответьте на вопросы после текста.

AMPLIFIERS

1. Amplification refers to the increase in voltage, current, or power that occurs between the input and output circuits of an electronic tube or of any other device or apparatus in which their may be such an increase. The amplification ratio or factor is equal to the output value divided by the input value as measured in the same unit.

2. A device, which increases the voltage or power of a signal by furnishing additional power from itself through the use of electronic tubes, is called an amplifier. The signal which controls local-power may come from an antenna, a microphone, a phonograph pickup, a photocell, a detector tube or a transmission line of amplifier, or it may operate a loudspeaker or some other reproducer for the signal.

Engineers recognize three distinct types of amplifiers, known as, and referred to universally as, Class A, Class B, and Class С

3. The differentiation lies principally in die relationship between input voltages and plate current flow, and the resulting waveform. The selection of the type of amplifier to be used depends on the results, which engineer wishes to get

4. A Class A amplifier is one in which the grid bias and excitation grid voltages are so chosen that plate current flows at all times. A theoretically perfect Class A amplifier produces an alternating component in the plate load which is an exact reproduction of the exciting grid voltage in form, but not necessarily in amplitude. The characteristics of such an amplifier are low efficiency and output.

Vocabulary:

To amplify – усиливать

Circuit – цепь, контур

Additional – дополнительный

Relationship – отношение

Flow – поток, течь

Perfect – совершенный

Output – мощность на выходе

Transmission - передача

2Ответьте на вопросы к тексту письменно.

1. What is the amplification ratio equal to?

2. What are three types of amplifiers?

3Определите функцию глаголовtobeиtohave. Переведите предложения.

1. My friends are engineers at this company.

2. The machine is cleaning the equipment.

3. He had to come at 7 o’clock.

4. Students have four exams.

4Раскройте скобки, употребляя глаголы в указанном времени. Переведите предложения на русский язык.

1. Russian engineers (create) new methods. – Future Simple

2. The bell (to ring) – Present Perfect

3. Sound waves (to produce) oscillations – Future Perfect

4. The workers (to test) equipment by the end of month – Past Perfect

5. At 10o’clock I (to establish) this equipment – Future Continuous

5Подчеркните модальные глаголы и их эквиваленты в предложениях, переведите предложения на русский язык.

1. My younger brother could read when he was 4.

2. It is a great film. You must see it.

3. May I use your telephone?

4. All our students have to study hard.

5. I wasn’t able to come to you yesterday.

6Переведите предложения, обращая внимание на употребление глаголов вPassiveVoice.

1. Computers are widely used in our life.

2. Many new computer programs have been created by this company.

3. Two wires will be connected together.

4. The new telephone station will have been built by our company.

5. The sounds were transmitted over long distances.

7Переведите предложения на английский язык, обращая внимание на повелительное наклонение

1. Позвоните мне в пятницу.

2. Закрой тетрадь.

3. Принесите ему зонтик.

4. Поставь компьютер около окна.

5. Купите оборудование в Японии.