4. Контрольная работа № 3

3.1. Общие указания к выполнению контрольной работы № 3

Для выполнения контрольной работы №3 студенту необходимо изучить следующие грамматические разделы курса английского языка:

1. Пассивный залог видовременных форм Indefinite, Continuous, Perfect.

2. Грамматические функции и значения слов one, that, it.

3. Простые неличные формы глагола. Инфинитив в функции:

а) подлежащего;

б) обстоятельства цели;

в) составной части сказуемого;

г) определения.

4. Бессоюзное подчинение в определительных и дополнительных придаточных предложения.

Требования к выполнению и оформлению контрольной работы№3 остаются такие же, как и к контрольной работе №2.

3.2. Контрольные задания

Вариант № 1

Задание 1

Перепишите следующие предложения, определите в каждом из них видовременную форму и залог глагола сказуемого. Переведите предложения на русский язык.

1) At present the nature of electrification is being explained by the electron theory.

2) These synchronous motors have been made to operate from a single-phase power source.

3) In some newer machines this reversal will be accomplished using power electronic devices, for example, diode rectifiers.

4) The first source of continuous current was produced by Volta.

Задание 2

Перепишите следующие предложения и переведите их на русский язык, обращая внимание на разные значения слов that, one, it.

1) One should take into consideration that the energy sources of the world are decreased.

2) It is possible to carry out the repairs within the time.

3) This pull-push amplifier was introduced last year, and that one will be employed next four months.

4) One method of detecting the presence of a current in a wire is to measure the temperature rise in the wire.

Задание 3

Перепишите следующие предложения и переведите их на русский язык, обращая внимание на разные значения глаголов to be, to have, to do.

1) There is some force of attraction acting between the mole­cules of matter.

2) A two-winding transformer has two coils which have to be arranged so that the magnetic lines of force of one coil pass through the other one.

3) Both terminals of a generator are to be connected to the same pole of the current.

4) This material does not possess desired properties.

Задание 4

Перепишите следующие предложения и переведите их на русский язык, обращая внимание на бессоюзное подчинение.

1. Everybody knows this generator must operate continuously throughout the twenty four hours.

2. Solar power the scientists and engineers suggest to use is inexhaustible.

Задание 5

Перепишите следующие предложения и переведите их на русский язык, обращая внимание на функцию инфинитива.

1) To transmit a given amount of energy, less current is re­quired at a high voltage than at a low voltage.

2) The circuit to be described will operate at high frequen­cies.

3) The magnetic flux is considered to be the result or ef­fect due to the action of a magnetic force on a magneti­zable body.

4) To simplify and make power generation cheaper the engineers will develop new type of energy generated installations.

Задание 6

Перепишите и письменно переведите первые 2 абзаца текста.

The Main Types of Transformers

Transformers may be classed according to the use they are designed for. Sometimes the transformer is used for operating a.c. ammeters, wattmeters and other measuring devices. Trans­formers may be used to make two electrical circuits electrically independent. But nearly all transformers come under one of the follow­ing classes: step-up and step-down transformers varying the ratio of turns between the primary and the secondary we can step up or step down the voltage. Some transformers are designed to raise the primary voltage to a higher value, such being known as step-up transformers. Others are constructed to reduce the primary voltage to a lower value, they are called step-down transformers.

A step-up transformer has more turns in the secondary than in its primary. In this type of transformer the current on the secondary side is lowered in the same ratio as the voltage is raised. In a step-down transformer there are fewer turns in the secondary than in its primary, the output voltage being smal­ler. In step-down transformers the current on the secondary side is raised in the same ratio as the voltage is lowered.

Transformers have many applications in a.c. circuits that require both the raising and lowering of the primary voltage аз well as the lowering and raising of the primary current.

There are transformers in which the number of turns in the secondary is the same as the number of turns in the primary. The secondary voltage is the same as the primary and this type of transformer is said to be a "one-to-one" transformer.

Transformers are widely applied in long-distance power transmission as well as in telephone, radio transmitters and receivers, television, electronic equipment. Transformers have a wide application on ships with different purposes. So as we have seen transformers are widely used in electrical en­gineering and they are of great importance.

Задание 7

Ответьте письменно на следующие вопросы:

1. What are transformers used for?

2. What are the main types of transformers?

3. According to what are transformers classed into step- up and step-down ones?

4. What is the main property of a step-down transformer?

5. What is а "one-to-one" transformer?