8. Translate into your native language

1. I would come to see him next week if I had enough time. 2. We would have accepted these results if we hadn’t had any opportunity to improve them. 3. If you had been more attentive, you would have had the text correctly. 4. You would get more experience if you had your practical training on this plant. 5. We would convice her if she took our advice. 6. If we had known about this offer earlier, we would have agreed to it. 7. Last month the results would have been better if everybody had understood the advantages of our position. 8. You wouldn’t have made these mistakes in the dictation if you had revised this rule at home.

9. Speak about Euclidean geometry

UNIT26. WHAT IS AN ELECTRIC CURRENT?

1.Memorize the following words:

copper – мідь

stream – потік

electric current – електричний струм

existence – існування

conductor – провідник

solution – розчин

circuit – ланцюг

surplus – надлишок, надмір

electromotive force –електрична рухома сила

to furnish – постачати, забезпечувати

properties – властивості

wire – дріт

2. Translate the following international words without a dictionary

Electron, atom, ampere, system, germanium, silicon, selenium, oxide, progress, element, dynamite, equivalent, technical, theory, mechanic, process, generator, magnetic, electric, effect, chemical, battery, practical, volt

3. Read and translate the text:

The question is often asked: “What is an electric current?” If we could examine the inside of a copper wire while a current is flowing, we should see an electron, leaving one copper atom, moving over to the next copper atom and so on. This stream of electrons moving along from atom to atom is called an electric current. The practical unit of current is called the ampere.

No one has ever seen an electric current. We only know of the existence of a current owing to its effects. A current can heat a conductor, it can have a chemical action when passing through a solution, or it can produce a magnetic effect. We can measure currents by observing their heating, chemical or magnetic effects.

Two things are necessary to cause an electric current to flow: first – a complete circuit, and second – a driving force called the electromotive force (e.m.f.).

A battery has a surplus of electrons on one of its two plates: so we say that a battery furnishes an e.m.f. If the battery was disconnected and a generator substituted for it, we should have a typical lighting system. Both batteries and generators are the most common sources of electromotive force. The practical unit of e.m.f. is the volt.

Substances whose properties lie between those of conductors and insulators are called semiconductors. Let us name but a few most widely used at present, they are germanium, silicon, selenium and copper oxides. The importance of semiconductors in our life cannot be overestimated. But for these tiny “workhorses” electronic industry would not have achieved a great progress.

4. Answer the questions on the text:

1. What is an electric current?

2. What is the unit of current?

3. What can an electric current do?

4. What is necessary to cause an electric current to flow?

5. What are the most common sources of electromotive force?

6. How does current flow in various substances?

7. What semiconductors do you know?

8. Why the importance of semiconductors in our life is great?