IV. Look through the text and translate the following sentences:

1. Коли електричний заряд знаходиться у стані спокою про нього говорять як про статичну електрику.

2. Не всі речовини є гарними провідниками електрики.

3. Існує велика кількість речовин, котрі не являються ні гарними провідниками, ні гарними ізоляторами.

4. У 1756 році великий російський вчений М.В.Ломоносов перший провів теоретичний аналіз електричних явищ.

5. Відповідно сучасній теорії вся матерія складається з атомів або крихітних часток.

6. Електричний струм, котрий протікає по провіднику в одному напрямку, називається постійним струмом.

7. Змінний струм протікає спочатку в одному напрямку, а потім в іншому.

2. The Electric Circuit and its Elements

Word List

A source		джерело
Primary		початковий
A cell		елемент
A receiver		приймач
A terminal		клема
Radiant		променевий
A loop		петля, контур
Uninterrupted		безперервний
A stream		струмінь
A circuit		ланцюг
A resistance		опір
A magnitude		розмір

Read and translate the text:

The electric circuit and its elements

The simplest electric circuit consists of a source of energy, or power source (e.g.¹, an electric lamp, electric heating device, or electric motor), and two conductors connecting the receiver and power source terminals. The power source (or for short², the source) transforms mechanical, chemical, thermal, or other energy into electromagnetic energy, which for brevity, is often simply called electric energy, the energy receiver (or simply receiver), on the contrary, transforms the electric energy to other forms of energy: radiant, thermal, mechanical and so on. The power source together with the conductors and receiver (load) connected to it form a closed loop, along which an uninterrupted stream of electric charge (an electric current) flows. This is called an electric circuit. With respect to³ the source, the conductors and receiver (load) form the so-called⁴ external circuit.

The direct cause of flow of electric current in a circuit is the electromotive force (emf) of the power source. Conventionally, the direction of the current in the circuit is taken to coincide with the direction of the emf. The terminal of the source through which the current “leaves” for the external circuit is called positive (+) and the terminal through which the current enters the source from the external circuit, the (-). The direction of the current is thus from + to – in the external circuit and from - to + inside the source. Both the external circuit and⁵ the source possess resistance, the value of which depends upon the material, shape and dimensions of the conductors composing these parts of the electric circuit. The magnitude or the intensity of the current (or, simply, the current) in the circuit depends on the magnitude of the emf and the resistance of the whole circuit. The relationship between these three quantities is expressed by Ohm’s law, which plays a very important role in electrical engineering, being the basis of many practical calculations. According to this law, the current I in the circuit is directly proportional to the emf E and inversely proportional to the resistance R of the whole circuit:

Ohm’s law can be applied to the circuit as a whole⁶ and separately to any portion of the circuit outside the power source.

Commentary

1 e.g. = for example – наприклад

2 for short – скорочено

3 with respect to - по відношенню до

4 so-called – так звану

5 both … and – як ... так

6 as a whole – в цілому