Industrial application of D.C. generators.

  D.C. generators are used for electrolytic processes such as electroplating. We know that large d.c. generators are employed in certain manufacturing processes, such as steel making.

The d.c. generator of small capacities is used for various special purposes such as arc welding, automobile generators, train lighting systems, etc. It also finds rather extensive use in connection with communication systems.

For supplying direct-current power networks, the supply comes first from an alternating-current source and is converted to direct current by synchronous convenors or motor-generator sets.

 II. а) Find in the text English equivalents:

-производство стали

-малых мощностей - дуговая сварка

-силовые сети постоянного тока - энергия поступает

b) Translate the text.

Атомы любого вещества располагаются на некотором расстоянии друг от друга. В металлах расстояния между атомами настолько малы, что электронные оболочки практически соприкасаются. Это дает возможность электронам свободно блуждать от ядра к ядру, создавая при этом электрический ток, поэтому металлы, а также некоторые другие вещества являются проводниками электричества.

IV.Fill in the blanks with the articles a, an, the and prepositions, where necessary:

We live in... nice flat...new house near … park.... flat is on... second floor. There are... two rooms in it. We have also... kitchen and... bathroom, kitchen is... big enough. As... rule, my mother cooks for us. We spend... lot of...time together in … kitchen. There is...TV set in... corner of... kitchen, and we often watch... TV there.

V. Put the verbs in brackets into the correct voice and tense-forms:

I not (write) this letter now. I (write) it in some days.

Peter and Ann (go) away five minutes ago.

She already (answer) the letter.

I (not see) him for three years.

You (switch off) the light before you left the house?

I (not meet) him last week.

I read these books when I was at school. I (like) them very much.

He (not smoke) for a month. He is trying to give it up.

VI. Fill in the blanks with prepositions and adverbial particles where necessary:

1. Instead... buying something... everyday wear, as she had first intended, Mary bought a... sleeveless dress... better wear. 2. I don't advise you to buy this pair...shoes. I am afraid they'll soon wear... 3. I wonder why the water has set the table... two persons instead... three.

4. Speaking at the production meeting, the director … the factory pointed... that each... the workers and engineers was responsible... carrying... the plan.

Контрольная работа № 15

I.  Translate the text:

The compound motor

The features of the shunt and series type of motors may be combined in one machine by providing both series and shunt windings for the field. This arrangement gives the compound motor. There are two windings on each field pole; a heavy or series winding for carrying the armature current, and a shunt winding connected to the supply. Each winding is formed by the series connection of the corresponding coils, and the fields due to the respective windings aid each other.

Speed control of a compound motor may be obtained by means of resistance in the field or armature circuit, as in the case of the shunt motor.

The compound motor may be regarded as having a higher starting torque than a shunt motor and a more constant speed under changing load conditions than the series motor. Either feature may be emphasized by varying the proportion of the total field strength due to each winding.

 II. а) Find in the text English equivalents:

- используя обмотки как последовательного, так и параллельного возбуждения для создания поля

-соединенный с источником питания - регулировка числа оборотов

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 the blanks with the articles a, an, the and prepositions, where necessary:

1. What... fine day it is today! 2.  ... History and Computer Science were... my favorite subjects at... school. 3.1 don't know  ... way to... station. 4. He is... engineer by... profession. 5. Usually I get up at...7 o'clock in...morning. 6....Rostov is on... right bank of... Don. 7. Will you have...cup... of tea?  8....Warsaw is... capital of Poland. 9. We shall go to... cinema together with... our friends. 10. This is... book... book is very interesting. 11. Do you see... sun in... sky today?

V. Put the verbs in brackets into the correct tense-forms: