make up the circuit – створювати ланцюг
in tandem – послідовно
positive terminal – позитивний заряд
is opened anywhere – розімкнути де-небудь
another way of saying – інакше кажучи
to a common point – у загальній точці
free – вільний
drift – зміщення
maintain - підтримувати, утримувати
current – струм
circuit – ланцюг
connection – зв'язок, з’єднання
path – шлях
slight - крихткий, легкий
fuse – предохранитель
passage – прохід
offer – пропонувати
opposition – опір, протидія
concept – поняття
allow – дозволяти
exist – існувати
oppose – чинити опір
II. Read and translate the text.
The concepts of electric charge and potential are very important in the study of electric current. When an extended conductor has different potential at is ends, the free electrons of the conductor itself are caused to drift from one end to the other. The potential difference must be maintained by some electric source such as electrostatic generator or a battery of a direct current generator.
The wire and the electric source together from an electric circuit, the electrons are drifting around it as long as the conducting path is maintained. There are various kinds of electric of electric circuits such as: open circuits, closed circuits, series circuits, parallel circuits and short circuits.
To understand the difference between the following circuits connection is not difficult at all. If the circuit is broken or “opened” anywhere, the current is known to stop everywhere. The circuit is broken when an electric device is switched off. The path along which the electrons travel must be complete otherwise no electric power can be supplied from the source to the load. Thus the circuit is “closed” when an electric device is switched on.
When electrical devise are connected so that the current flows from one devise to another, they said “to be connected in series”. Under such conditions the current flow is the same in all parts of circuit as there is only a single path along which it may flow. The electrical bell circuit is considered to be a typical example of a series circuit. The “parallel” circuit provides two or more paths for the passage of current. The circuit is divided in such a way that part of the current flows through one path and part through another. The lamps in the houses are generally connected in parallel.
The “short” circuit is produced when the current can return to the source of supply without control. The short circuits often result from cable fault or wire fault. Under certain conditions the short circuit may cause fire because the current flows where it was not supposed to flow. If the current flow is too great a fuse is used as a safety device to the current flow.
Series circuits are those having only one closed path for the flow of electricity. All the elements, or devices which make up the circuit are connected in tandem, one after the other, so that the end of one is connected to the beginning of the other; or, in other words, the positive terminal of one is connected to the negative terminal of the other. If the series circuit is opened anywhere , the current will not flow through the circuit.
A parallel circuit is one divided into two or more branches, each branch carrying part of the current. Another way of saying the same thing is that all the elements or devices are connected so that one half of the terminals is fastened to a common conductor, and the other half are fastened to another common point, or another conductor.
III. Guess the meaning of the international words
Concept, potential, electrostatic generator, aluminum, Parallel, typical, controlIV. Give the English equivalents for the following words and word combinations:
1) Електричні ланцюги, 2) Електричний заряд, 3) Провідник, 4) опір, 5) рух електронів, 6) Ізолятор, 7) Коротке замикання, 8) Енергія.V. Say whether these sentences are true of false:
1. When an extended conductor has the same potential at its ends, free electrons are drifting from one end to another.2. The wire and the electric source together form an electric circuit.
3. A path of any material will allow current to exist.
4. Silver, copper and gold oppose very strongly.
5. The slighter the opposition is, the better the insulator is.
6. There is only one type of electric circuit.
7. We close the circuit when we switch on our electric device.
VI. Complete the sentences using the text:
1. The potential difference must be maintained by.........................................................2. Materials that offer slight opposition are called ……………………………………………
3. The best insulators are ………………………………………………………………………
4. There are various kinds of electric circuits such as …………………………………………
5. We “ open “ the circuit when ………………………………………………………………….
6. We “ close “ the circuit when ………………………………………………………………….
7.The “ short “ circuit is produced when ....................................................................
8. A fuse is ……………………………………………………………………………………........
VII. Answer the questions:
1. What concepts are very important in study of electric current?2. What forms an electric circuit?
3. What materials are the best conductors and insulators?
4. What kinds of electric circuits do you know?
5. How can we open and close the circuit?
6. When are electrical devices connected is series?
7. What is an example of a series circuit?
8. What can you say about “parallel“ circuits?
9. What does the short circuit often result from?
10. What classes of circuit can you name?
11. What are series circuits?
12. How all devices are connected?
13. When the current will not flow through the circuit?
14. To how many branches a parallel circuit is divided?
15. What does each branch carry?
VIII. Translate the following word combinations from English into Ukrainian.
A parallel circuit, combination of series-parallel, another conductor, a common conductor, part of the current, one half of the terminals, flow through the circuit, series circuits, elements or devices, one closed path, the flow of electricity, connected in tandem, positive terminal, the negative terminal, is opened anywhere, to a common point.
IX. Translate into English.
Перевантаження електричної мережі є однією з найпоширеніших причин короткого замикання. Коротке замикання може статися через вплив вологи. Електроустановлювальні пристрої – розетки та вимикачі також мають бути вологозахищеними. Внутрішнє проведення, а якщо це неможливо, то зовнішнє проведення має бути добре ізольована.