From the History of Electricity

There are two types of electricity, namely, electricity at rest or in a static condition and electricity in motion, that is, the electric current. Both of them are made up of electric charges, static charges being at rest, while electric current flows and does work. Thus, they differ in their ability to serve mankind as well as in their behaviour.

Let us first turn our attention to static electricity. For a long time it was the only electrical phenomenon to be observed by man. As previously mentioned at least 2,500 years ago, or so, the Greeks knew how to get electricity by rubbing substances. However, the electricity to be obtained by rubbing objects cannot be used to light lamps, to boil water, to run electric trains, and so on. It is usually very high in voltage and difficult to control, besides it discharges in no time.

As early as 1753, Franklin made an important contribution to the science of electricity. He was the first to prove that unlike charges are produced due to rubbing dissimilar objects. To show that the charges are unlike and opposite, he decided to call the charge on the rubber – negative and that on the glass – positive.

In this connection one might remember the Russian academician V.V. Petrov. He was the first to carry on experiments and observations on the electrification of metals by rubbing them one against another. As a result he was the first scientists in the world who solved that problem.

Who does not know that the first man to get the electric current was Volta after whom the unit of electric pressure, the volt, was named? His discovery developed out of Galvani’s experiments with the frog. Galvani observed that the legs of a dead frog jumped as a result of an electric charge. He tried his experiment several times and every time he obtained the same result. He thought that electricity was generated within the leg itself.

Volta began to carry on similar experiments and soon found that the electric source was not within the frog’s leg but was the result of the contact of both dissimilar metals used during his observations. However, to carry on such experiments was not an easy thing to do. He spent the next few years trying to invent a source of continuous current. To increase the effect obtained with one pair of metals, Volta increased the number of these pairs. Thus the voltaic pile consisted of a copper layer and a layer of zinc placed one above another with a layer of flannel moistened in salt water between them. A wire was connected to the first disc of copper and to the last disc of zinc.

The year 1800 is a date to be remembered: for the first time in the world’s history a continuous current was generated.

Volta’s Short Biography. Volta was born in Como, Italy, on February 18, 1745. For some years he was a teacher of physics in his home town. Later on he become professor of natural sciences at the University of Pavia. After his famous discovery he traveled in many countries, among them France, Germany and England. He was invited to Paris to deliver lectures on the newly discovery chemical source of continuous current. In 1819 he returned to Como where he spent the rest of his life. Volta died at the age of 82.

 

IV. Language.

Exercise 9. Find the correspondence.

1. instrument 2. liquid 3. means 4. purpose 5. difference 6. law 7. matter 8. heat 9. light 10. opposite 11. condition 12. flow 13. behaviour 14. charge

1. різниця 2. речовина 3. стан, умова 4. заряд 5. потік 6. рідина 7. протилежний 8. закон 9. засіб 10. тепло 11. ціль 12. поведінка 13. прилад 14. світло

 

V. Comprehension.

Exercise 10. Find the wrong statements and correct them.

1. To show that the charges are unlike and opposite Franklin decided to call the charge on the rubber position and that on the glass negative. 2. Galvani thought that electricity was generated because of the contact of the two dissimilar metals used. 3. Volta took great interest in atmospheric electricity and began to carry on experiments. 4. To increase the effect obtained with one pair of metals, Volta was the first to carry on experiments and observations on the electrification of metals by heating them.

6. Electricity is also used to transmit and process information.

 

Exercise 11. Answer the following questions:

1. What types of electricity do you know?

2. what is the difference between electricity at rest and electricity at motion?

3. What kind of experiment did Galvani carry on?

4. What did Franklin prove?

5. What are two kinds of electricity charge?

6. Who was the first to produce a continuous current?

7. What was Volta?

8. What can you say about behaviour of static charge?

9. What did Volta take interest in?

10. What is Volta’s discovery result in?

11. What did Volta’s device consists of?

12. Where did he spent the rest of his life?

 

VI. Oral Practice.

Exercise 12. Ask questions to which the following sentences will be answers.

1. The Greeks knew how to get electricity.

2. Franklin called the charges negative and positive.

3. Volta was the first man to get the electric current.

4. It was not easy to invent a source of continuous current.

5. A continuous current was generated in 1800.

6. Electricity made possible the engineering progress today.

7. Scientists are looking for new and more economical sources of energy.

 

Exercise 13. Speak on the main points of the text A.

1. Two types of electricity.

2. Static electricity.

3. Franklin’s contribution to the science of electricity.

4. Petrov’s invention.

5. Volta’s discovery.

 

Exercise 14. Retell Volta’s biography.

VII. Reading.

Exercise 15. Read the text B.

Text B.

Electricity Serves Man

All around us – in the factory shop, the laboratory and at home – we find an obedient force ready to serve us in some way. It is electricity.

Electricity (electric power) has become so much a part of our daily life we seldom think of its importance. All you have to do is turn a switch and electric devices will be doing their job for you. Electric motors operate washing machines, refrigerators, vacuum cleaner, electric razors and many other electric appliances.

Electricity made possible the engineering process of today. Electricity serves as the basis of modernizing industry, increasing equipment efficiency, mechanizing and automating processes and concentrating production.

Electricity not only tremendously increases man’s power but it becomes an increasable part of technology. Not long ago, electricity affected the objects of labour mainly indirectly. It was a motive force, provided favourable conditions for processing or machining. Now it is becoming a processing or machining element itself as well as the basis of automatic production control.

And think of the role of electricity for communication or automation! It is used to trnsmit and process information. It is the basis of the comprehensive automation of all production process – technology, management, regulation, control and evaluation. Electricity does not merely make work easier it changes it completely. Electricity is the basis of electronics which is doing much of the routine brain work.

Little could be done in modern research laboratory without the aid of electricity. Nearly all the measuring devices used in developing nuclear power are electrically operated. Geiger counters which detect the presence of uranium ores in the earth are run with batteries. X-ray machines, which depend upon electricity, are used in industry to detect flaws in metal.

Much of today’s scientific researches depends on the solution of difficult mathematical problems, some of which would require days and months to solve by the usual methods. Electrically operated computers now make the answer to these problems available in seconds.

 

Notes:

obedient – слухняний;

to serve – служити;

to turn a switch – повернути вимикач;

job – робота;

to operate – приводити в рух;

appliance – прилад;

inseparable – невіддільний;

to affect – впливати;

labour – праця;

indirectly – частково, посередньо;

to transmit – передавати;

to process – обробляти;

to measure – вимірювати;

available – наявний.

 

VIII. Language.

Exercise 16.

a) Find in the text sentences about the role of electricity for the engineering process and technology.

b) Find in the text sentences telling about the use of electricity in the solution of mathematical problems.

IX. Oral Practice.