Protection and control equipment

  In electrical systems for the generation, distribution and use of electrical energy, considerable control equipment is necessary. It can be divided into t\v. classes: A) equipment used at the generating and distributing end; b) equipment used at the receiving end of the system.

Safety switches are used at the point where the power enters the building. They are of the knife type and are usually enclosed in metallic boxes.

    A magnetic contactor is used to make and break the circuit at the points where considerable power used.

  An automatic starter is a device which is used to keep the current from being excessive while the motor is obtaining full speed. It is a kind of a resistance inserted in series with the direct current armature. As the motor obtains speed it gradually removes.

 II a) Find in the text English equivalents:                

-аварийный выключатель, предохранительный выключатель

-замыкать и размыкать цепь

-предохранять от сверхтоков, от перегрузки

-постепенно выводится

b) Translate the text:

Вещества, которые имеют далеко расставленные атомы, электроны, прочно связанные с ядром, которые не могут свободно перемещаться. Такие вещества не являются проводниками и их принято называть диэлектриками, самым известным из которых является резина. Это и есть ответ на вопрос, почему электрические провода делают из металла.

IV. Fill in blanks with the Past Progressive or the Past Simple Tense of the verbs in margin.

1. I... a letter to my friend yesterday.                                                                                write

2. We... to a lecture yesterday at ten o'clock.                                                        listen

3. She... the piano from 11 till 12 o'clock.                                                                        play

4. When he... in, I... my exercises.                                                                               come, do

5. What... you yesterday at 8 o'clock?                                                                                  do
6. Yesterday when I... the newspaper, my sister... to a concert over the radio.            read, listen

7. She... out of the window when I... her.                                                             look, see

8. I... along the street with my friend when the car … by.                                                 walk

9. It... the whole day yesterday.                                                                                           rain

V.   Choose the correct word form those given in brackets:

When I saw that actress on the stage for the first time, she (to look like, to take after) a small girl. From her biography I learnt that she (to look like, to take after) her mother, who had also been a great actress. 2. If you want some information on trade, go to the Ministry library. There are a lot of good (magazines, a journals) on the subject there.

VI. Fill in the blanks with the necessary forms of Modal Verbs:

(must, should, would, ought to, needn't, can, could, may, might)

1. They... not do this work themselves. 2. You...take my dictionary. 3. You don't look well, you... consult the doctor. 4. Why... I give you my money? 5. She... not speak any foreign language. 6. He... to help them, they need his help. 7.... you tell me the time?  8.... I go with you? No, you....  9. Your daughter... have told about it. 10. In winter we... often skate. 11. You... not miss your classes. 12.... you play the piano before?

Контрольная работа №19

I. Translate the text

Automatic Voltage regulators

In the generation and distribution of electrical energy it is important to keep the line voltage constant as the load or speed changes.

Where the load is changed gradually rheostats are used, in installations where the load may change rapidly automatic voltage regulators are used.

To protect electrical equipment and the wiring from damage due to short circuits and overloads, fuses or circuit breakers are usually used. The fuse is known to be a device for inserting in the circuit a strip of metal which melts at a relatively low temperature. The fuse will melt if the current gets above a certain limit.

A circuit breaker is similar to the magnetic contactor.

 II. a) Find in the text English equipment:

- при изменении нагрузки или оборотов поддерживать линейное напряжение постоянным - из-за коротких замыканий и перегрузок

-известно, что плавкий предохранитель представляет собою приспособление
- если ток переходит определенный предел         

     b) Translate the text.