Unit 1                                                                                          SHAPES

 

 

The nouns and adjectives below can be used to describe the shapes of components and assemblies. 

 

Notes: The noun cylinder is often used to describe a hollow cylinder that is enclosed - for example, piston cylinders (in engines) or gas cylinders (gas containers). A hollow cylinder that is open at both ends is generally called a tube.

The difference between a dome and a hemisphere is that a dome is hollow (not solid), and is not necessarily perfectly hemispherical. In everyday English, spiral is often

used to describe a helix- for example, a spiral staircase. The helical groove on a screw, bolt or nut is called a thread.

 

Unit 2                                                      UNITS OF MEASUREMENT

 

 

Sl base units 

The International System of Units - abbreviated as SI from the French name, Systeme International d'Unites - is the most widely used system of measurements. Some SI units, such as metres and kilograms, are often described as metric units.

The seven base units of the SI system are shown in the table below.

 

Note: 0 kelvin (K) = -273 degrees Celsius (OC). 0 K is the lowest possible temperature- often called absolute zero.

 

Sl derived units 

SI derived units are related to the SI base units. They include a wide range of specific units. The table below lists SI derived units commonly used in engineering.

 

 

 

 

 

Unit prefixes 

The prefixes below can be written in front of units to multiply them or divide them by a specific number. For example, 1 milliamp (mA) = 0.001 amps, and 1 kilonewton (kN) = 1,000 newtons. 

 

Unit 3                                               MATHEMATICAL OPERATIONS    

 

ADDITION AND SUBTRACTION

addition  додавання subtraction  віднімання plus  плюс minus  мінус to add  додавати to subtract  віднімати

to equal  дорівнювати

 

5 + 7= 12- five plus seven equals twelve

66 + 13 =79 - sixty-six plus thirteen is equal to seventy-nine a + b = с - a plus b is equals с

15-6 = 9 - fifteen minus six equals nine

81-33=48 - eighty-one minus thirty-three is equal to fortyeight

с - b = a - с minus b equals a

 

1.     Solve and read:

 

99 + 77 =	8-3 =	315 + 145 =
61 - 50 =	47 -18 =	859 - 600 =
114 + 316	1,203+419 =	4,444 + 7,777 =
b + d =	d-c =	a-b =

 

2.     Pair work. Think of six examples of your own. Put them down. Ask your groupmate to solve them.

 

 

                                                   MULTIPLICATION AND DIVISION multiplication  множення, добуток multiply  множити multiplied by  помножене на  once  один раз twice  двічі three times  тричі four times  чотири рази division  ділення to divide ділити

divided by  поділене на

 

1x1 = 1- once one is one 

2x2 = 4- twice two is four 

3x3=9- three times three equals nine 

4x4=16- four times four is equal to sixteen 

12 x 10 = 120 - twelve multiplied by ten is equal to one hundred and twenty 

35:7 = 5- thirty-five divided by seven equals five 

1000 : 25 = 40 – one thousand divided by twenty-five is equal to forty 

 

1.     Solve and read

10 x 7 =	49:7 =	13x3 =	749:7 =
100 x 100 =	175:25 =	618:6 =	3,550x5
234 x 6 =	12x12=	33:33 =	10,660:10=
b • с =	n : m =	1 • к =	1x1 =

 

2.     Pair work. Think of five examples of your own. Put them down. Ask your groupmate to solve them.

 

 

                                           COMMON AND DECIMAL FRACTIONS fractions  дроби

decimal fractions  десятинні дроби common fractions  прості дроби numerator  чисельник denominator  знаменник nought  нуль zero  нуль

point  крапка

 

  one half/a half                  

1/3  one third

2/7 two sevenths

3 ½   three and a half 5 ¾ five and three quarters

0.2   zero point two

1.1   one point one

5.36   five point three six

65.57   sixty-five point five

 

1. Read these common and decimal fractions:

 

9 5/8               15 8/9           7 1/2             5/8                2/5                1/3

79.31              0.0003          205.35           10.01            0.009            0.23

 

 

 

Unit 4                                                                                         ENERGY

 

1. Read and translate the text.

 

In the language of science, energy is the ability to do work. There are various forms of energy, such as: heat, mechanical, electrical, chemical, atomic and so on. One might also mention the two kinds of mechanical energy — potential and kinetic, potential energy being the energy of position, while kinetic energy is the energy of motion. It is well known that one form of energy can be changed into another.

A waterfall may serve as an example. Water falling from its raised position, energy changes from potential to kinetic energy. The energy of falling water is generally used to turn the turbines of hydroelectric stations. The turbines in their turn drive the electric generators, the latter producing electric energy. Thus, the mechanical energy of falling water is turned into electric energy. The electric energy, in its turn, may be transformed into any other necessary form.

When an object loses its potential energy, that energy is turned into kinetic energy. Thus, in the above-mentioned example when water is falling from its raised position, it certainly loses its potential energy, that energy changing into kinetic energy (Fig. 1).

 

  

Fig. 1. Examples of kinetic energy.

We have already seen that energy of some kind must be employed to generate the electric current. Generally speaking, the sources of energy usually employed to produce current are either chemical, as in the battery, or mechanical, as in the electromagnetic generator. Chemical sources of current having a limited application the great quantities of electric energy generated today come from various forms of mechanical energy.

Rising standards of modern civilization and growing industrial application of the electric current result in an increasing need of energy. Every year we need more and more energy. We need it to do many useful things that are done by electricity. However, the energy sources of the world are decreasing at the same time as the energy needs of the world are increasing. These needs will continue to grow as more motors and melted metals are used in industry and more electric current is employed in everyday life. As a result, it is necessary to find new sources of energy.

The sun is an unlimited source of energy. However, at present, only a little part of solar energy is being used directly. How can we employ solar energy directly to produce useful energy? This is a question which has interested scientists and inventors for a long time. Lavoisier and other great scientists of the past melted metals with the help of solar furnaces. Today, solar furnaces illustrate just one of the numerous ways to harness the sun. Using semiconductors, scientists, for example, have transformed solar energy into electric energy.

 

2.     Active Words and Expressions

 

battery, to change, chemical, to drive, to employ, energy, generator, in its turn, kinetic, kind, potential, to produce, source, semiconductor, station, to turn

 

3.     Give short answers to the following questions:

 

1. Can one form of energy be changed into another form? 2. Does a generator produce mechanical energy? 3. Is the sun an unlimited source of energy? 4. Can we employ solar energy directly? 5. Have scientists transformed solar energy into electric energy? 6. Is potential energy the energy of motion? 7. Do we need more and more electric energy every year? 8. Are there various forms of energy? 9. Do you use electric energy every day? 10. Can the energy of falling water be used to drive turbines? 11. Is kinetic energy the energy of position?

 

4. State the energy change that takes place in each of the following devices:

 

Model: The motor changes electrical energy into mechanical energy.

1. generator 2. lamp 3. battery 4. washing machine 5.electric furnace 6. vacuum cleaner 7. Semiconductor

 

5.     Describe Fig. 1.

6.     Retell the text.

 

 

 

Unit 5                                                                                  LIGHTNING

 

 

1. Read and translate the text.

 

The lightning flash is certainly the earliest manifestation of electricity known to man, although for a long time nobody knew that lightning and atmospheric electricity are one and the same thing. Indeed, for thousands of years people knew nothing about thunderstorms. However, they saw long sparks falling from the dark sky and heard thunder. They knew that these sparks could kill people or strike their houses and destroy them. Trying to understand that dangerous phenomenon, they imagined things and invented numerous stories.

Take the early Scandinavians as an example. They thought that thunderstorms were produced by Thor, the god of thunder. Besides his throwing both thunder and lightning at some people he was a hammer-thrower. According to the story, his powerful hammer had the property of always coming back to his hands after it had been thrown. The fifth day of the week, that is Thursday, was named after him. A story like that invented by those early Scandinavians could be also heard from other peoples.

However, time flies. Thunderstorms have long stopped being a problem that scientists tried to solve. Now everybody knows that lightning is a very great flash of light resulting from a discharge of atmospheric electricity either between a charged cloud and the earth or between charged clouds.

Even now some people do not like being out during a thunderstorm. Dark clouds cover the sky, turning day into night. There are lightning flashes followed by thunder which can be heard for kilometers around. Needless to say, there is always some danger in a thunderstorm for a very high building or a man standing in the open field.

Many years ago, people learned to protect their houses from thunderstorms. Coming down from a charged cloud to the earth, lightning usually strikes the nearest conductor. Therefore, it is necessary to provide an easy path along which electrons are conducted to the earth. That Benjamin Franklin invented the lightning conductor is a well-known fact. The lightning conductor, familiar to everybody at present, is a metal device protecting buildings from strokes of lightning by conducting the electrical charges to the earth.

Franklin’s achievements in the field of electricity were known to Lomonosov who, in his turn, made experiments of his own. Along with other scientific problems that Lomonosov studied was that of atmospheric electricity. Both Lomonosov and his friend Professor Rihman took great interest in it. Both of them tried to solve the problem in question. They made numerous experiments and observations without thinking of the possible danger. The first electrical measuring that kind was dangerous and Professor Rihman was killed by a stroke of lightning while he was making one of his experiments.

As for Franklin’s well-known kite experiment, you will read about it in the following lesson.

 

2.     Active Words and Expressions

 

charge, to conduct, to destroy, discharge, electron, experiment, to invent, lightning, like, to name after, observation, path, phenomenon, property, to provide, scientific, to solve a problem  

 

3.     Put questions to the words in bold type:

 

1. For thousands of years people knew nothing about thunderstorms. 2. The fifth day of the week was named after Thor. 3. Lightning is a discharge of atmospheric electricity. 4. The lightning conductor provides an easy path for conducting electric charges to the earth. 5. Rihman constructed the first electrical measuring device. 6. Experiments on atmospheric electricity were made by Lomonosov. 7. Many years ago people learned to protect their houses from thunderstorms. 8. We use atomic energy for peaceful purposes.

 

4.     Put 5 questions to the text beginning with the word what.

5.     Speak on the story told by the early Scandinavians.

 

 

 

Unit 6                                                                                MAGNETISM

 

 

1. Read and translate the text.

 

In studying the electric current, we observe the following relation between magnetism and the electric current: on the one hand magnetism is produced by the current and on the other hand the current is produced from magnetism.

Magnetism is mentioned in the oldest writings of man. Romans, for example, knew that an object looking like a small dark stone had the property of attracting iron. However, nobody knew who discovered magnetism or where and when the discovery was made. Of course, people could not help repeating the stories that they had heard from their fathers who, in their turn, heard them from their own fathers and so on.

One story tells us of a man called Magnus whose iron staff was pulled to a stone and held there. He had great difficulty in pulling his staff away. Magnus carried the stone away with him in order to demonstrate its attracting ability among his friends. This unfamiliar substance was called Magnus after its discoverer, this name having come down to us as “Magnet”

According to another story, a great mountain by the sea possessed so much magnetism that all passing ships were destroyed because all their iron parts fell out. They were pulled out because of the magnetic force of that mountain.

The earliest practical application of magnetism was connected with the use of a simple compass consisting of one small magnet pointing north and south.

A great step forward in the scientific study of magnetism was made by Gilbert, the well-known English physicist (1540- 1603). He carried out various important experiments on electricity and magnetism and wrote a book where he put together all that was known about magnetism. He proved that the earth itself 'was a great magnet.

Reference must be made here to Galileo, the famous Italian astronomer, physicist and mathematician. He took great interest in Gilbert’s achievements and also studied the properties of magnetic materials. He experimented with them trying to increase their attracting power. One of his magnets, for example, could lift objects weighing 25 times its own weight.

At present, even a schoolboy is quite familiar with the fact that in magnetic materials, such as iron and steel, the molecules themselves are minute magnets, each of them having a north pole and a south pole. When iron and steel are magnetized, the molecules arrange themselves in a new orderly way instead of the disarrangement in which they neutralize each other.

Dividing a bar magnet into two parts, one finds that each of the two parts is a magnet having both a north pole and a south pole. Thus, we obtain two magnets of a smaller size instead of having a single one of a larger size. Dividing one of these two smaller magnets into two will give us the same result. Thus, we could continue this process, always getting similar results. 

On placing an unmagnetized iron bar near a strong magnet, we magnetize it. Rubbing the magnet is not required for that process. In other words, our iron bar has been magnetized by the strong magnet without rubbing it.

 

2.     Active Words and Expressions

 

ability, to attract, to carry out, to consist of, force, iron, magnetism, to make reference to, to obtain on the one hand ... on the other (hand), to possess, to prove, physicist, relation, single, steel, weight

 

3.     Translate the following sentences:

 

1. Protecting buildings from strokes of lightning was a great achievement in the field of electricity. 2. Speaking of the magnet, the inventor made reference to its property of attracting iron and steel. 3. Experiments showing the changes in substances are very important for industry. 4. The teacher objects to our translating such- an easy text with a dictionary. 5. People constructed many hydroelectric stations. 6. In studying magnetism, we cannot help observing the relation between magnetism and the electric current. 7 Having invented the lightning conductor, Franklin continued working at the problem of atmospheric electricity. 8. The experiments having been made, we could discuss the results. 9. The atoms of different substances have different weights, their properties being also different. 10. Having experimented with electricity and magnetism, Gilbert wrote a book on magnetism. 11. Gilbert greatly contributed to the study of magnetism, Galileo taking great interest in Gilbert’s achievements.

 

4. Translate the following questions and answer them:

 

1. Чи існує зв'язок між електрикою і магнетизмом? 2. Чи знаєте ви, хто відкрив магнетизм? 3. Що ви знаєте про атмосферну електрику? 4. Хто довів, що наша земля є великим магнітом? 5. Що ви знаєте прo магнетизм? 6. Які властивості магніту? 7. Хто цікавився досягненнями Гільберта? 8. Які досліди проводив Франклін?

 

5. Translate the following sentences paying attention to the words in bold type:

 

1. These electrical devices are very large. Who can help me to carry them to another laboratory? 2. After the experiment had been carried out the students carried the devices away. 3. What were the students doing when the teacher came into the classroom? They were doing the exercises. 4. Why can’t you do without the thermometer? The temperature of this metal is known. 5. He could not go to the cinema yesterday. 6. Do not turn the light off, I shall go on working. 7. I see nothing, turn the light on, please. 8. On heating, ice turns into water. 9. Water, in its turn, turns into ice on freezing.

 

6. Make up a story of Franklin’s kite experiment using the following sentences as well as sentences of your own (our sentences are given in a disorderly way):

 

1. The key was connected to the lower end of the string. 2. The story about Franklin’s famous kite is known all over the world. 3. They took some necessary things such as: a kite with a long string, a key, and so on. 4. It was proved that lightning is a discharge of electricity. 5. It was a stormy day. 6. The electricity was conducted from the clouds down the string to the key. 7. The kite was flying high among the clouds.

8. The rain wetted the string. 9. Atmospheric electricity greatly interested Franklin.

10. The rain fell.

 

7.     Form two sentences with each of the following words:

similar, simple, single

 

8.     Use the following expressions in sentences of your own:

all over the world; as well as; in this connection; in the form of; needless to say; to pay attention to; on the other hand

 

9.     Put two questions to each paragraph of the text and answer them.

 

10. Compare:

1.                   A generator and a motor.

2.                   Potential energy and kinetic energy.

3.                   Chemical energy and mechanical energy.

4.                   A nuclear power station and a steam power station.

Unit 7                 THE ELECTRICAL PROPERTIES OF MATERIALS

 

 

The electrical conductivity of material was first demonstrated in 1792 by the English experimenter Gray. His demonstrating this phenomenon made his name well-known at that time. 

It was he who touched a charged glass rod to the end of a moistened cord and discovered that the cord transmitted the electricity to a distance of about 1,000 feet. 

Today the exploration of the electrical properties of solids is disclosing much more interesting phenomena. We know of many new experiments having been carried out in this field. All these have turned out to be of fundamental significance in the understanding of matter, as well as of great technological importance.

To begin with, the wide range of electrical conductivities exhibited by materials is itself a striking fact. The difference in electrical conductivity between the most conductive substances (for example, copper and silver) and the most resistive (polystyrene) amounts, to 23 orders of magnitude.

If we want to understand the extent of this spread, we should compare it with extremes in the scales of distance. One might note, for instance, that the ruler needed to measure the size of the universe is only some 23 orders of magnitude larger than the mile ruler that measures distance on the earth.

Evidently then, the electrical conductivity (or rather its inverse resistivity, the quantity used in statements of Ohm’s Law) is one of the most widely varying of all physical quantities.

The individual materials begin showing great variability in resistivity according to the conditions of temperature, pressure and the mixture of component substances. 

If a minute trace of gallium or arsenic (one part per billion) were added to pure germanium, its conductivity would be increased by two orders of magnitude (nearly l, 000 fold) and would rather make it suitable for using in transistors. 

A tiny further addition of the impurity could increase the conductivity 100,000 fold, converting germanium to a conductor.

Similarly, silicon and metal oxides such as nickel and titanium dioxide are lowered in resistivity by introducing of appropriate impurities. Indeed, nickel oxide, which is an insulator in the pure state, is reduced in resistivity by 13 orders of magnitude by adding only one per cent of helium.

We know of great changes being produced by changes in temperature. 

Thus, a semiconductor can be made a conductor by heating it to a high temperature or it can be made an insulator by cooling it to a low temperature.

In contrast, the resistivity of a pure metal is much less increased by heating and reduced by cooling.

In some cases, the change is very abrupt. For example, above 150 Kelvin vanadium is a semiconductor, when it is cooled its resistivity suddenly jumps and it becomes a good insulator. Some semiconductors and insulators are extremely sensitive to light. Thus, upon illuminating, their conductivity may be several orders of magnitude higher than it is in the dark. This phenomenon is called photoconductivity.

 

Active Words and Expressions

 

to disclose – виявляти                                            appropriate – відповідний dark – темний                                                         convert – перетворювати inverse – зворотній                                                evidently – очевидно to touch – торкатися                                              to reduce – скорочувати to transmit – передавати                                        rather – досить tiny – малюсінький                                                resistivity – опірність trace – риса, простежувати                                   to spread – поширювати magnitude – величина                                           suddenly – раптом striking – вражаючий                                            sensitive – чутливий insulator – ізолятор                                                exploration – дослідження

 

1. Answer the following questions

 

1.   When was the electrical conductivity of material first demonstrated?

2.   What experiment did Gray carry out?

3.   What is the most resistive substance?

4.   What do the individual materials show?

5.   What happens if a minute trace of gallium or arsenic is added to pure germanium?

6.   When are nickel oxide and titanium dioxide lowered in resistivity?

7.   What changes are produced by changes in temperature?

8.   When does vanadium become good insulator?

9.   What phenomenon is called photoconductivity?

 

2.     Read and translate the following word combinations:

 

electrical conductivity, fundamental significance, technological importance, on the earth, the individual materials, inverse resistivity, minute traces, suitable for using, extremely sensitive.

 

3.     Make the sentences using the words:

 

conduct, improve, resist, increase, exist, reduce, effect, semiconductor, illumination, resistivity, individual, variability, fundamental, experimental, technological.

 

4.     Translate the words in the brackets into English:

 

1. The electrical (провідність) of different materials was investigated by many scientists. 2. Today (дослідження) of the electrical properties of solids has revealed many interesting phenomena. 3. To understand (значення) of this investigation we must compare it with the previous one. 4. If а (найдрібніший) trace of arsenic were added to pure germanium, the conductivity of the latter would increase. 5. Great (зміни) can be produced by increasing temperature. 6. In some (випадках) the change is very abrupt. 7. Some (напівпровідники та ізолятори) are extremely sensitive to light. 8. Can you say what principles (пояснюють) the great differences in conductivity between metals and insulators? 9. The resistivity of a pure metal is known to be increased by heating and (знижена) by cooling.

 

5.     Fill in the blanks with prepositions:

 

1.When you leave the laboratory don’t forget to turn . . . the light and gas. 2. Mercury is a good conductor . . . heat and electricity. 3. This can be accounted . . . the increase of temperature and pressure. 4. The resistances in ohms of these and other frequently used conductors turned out to have been carefully measured. 5. When we turn . . . the light and our electric lamp is burning, the tungsten of the lamp has about 30 times the resistance that it had. 6. The impact of light has an effect . . . electrical resistivity. 7. The resistance . . . some conductors was much greater when they carried a large current.

 

6.     Translate the text using a dictionary.

 

Conductivity

 

It will be interesting to note that an iron wire of the same length as a copper one has a greater resistance. Under the same conditions the copper wire allows more current flowing than the iron wire. Copper has a greater conductivity. Conductivity means the ability of carrying the current. The unit of conductivity is the Siemens or the mho. The unit of resistance is the Ohm.

In 1826 Ohm found a simple correlation between resistance, current and voltage. He also observed that if the voltage remains the same, the greater the resistance, the smaller the current is. So, it can be stated: the current that flows in a circuit is directly proportioned to the voltage and inversely proportioned to the resistance.

 

 

Unit 8                                                         WHAT IS ELECTRICITY?

 

 

1. Read the text.

All substances, solids, liquids or gases, are composed of one or more of the chemical elements. Each element is composed of identical atoms.  

Each atom is composed of a small central nucleus consisting of protons and neutrons around which orbit shells of electrons. These electrons are very much smaller than protons and neutrons.

The electrons in the outermost shell are called valence electrons and the electrical properties of the substance depend on the number of these electrons.

Neutrons have no electric charge, but protons have a positive charge while electrons have a negative charge. In some substances, usually metals, the valence electrons are free to move from one atom to another and this is what constitutes an electric current.

 

2. Read the text again and complete the sentences with the missing information.

 

•      1 Elements make up ____________________________________________.

•      2 Identical atoms ______________________________________________.

•      3 Atoms consist of _______________, ________________ and _________. • 4 Inside there are ____________ and ____________, while outside ______.

•      5 Shells _____________________________________________________.

•      6 Valence electrons ____________________________________________.

•      7 Neutrons do not have _________________________________________.

•      8 Electricity is generated when ___________________________________.

 

3.  Complete the text with the missing information.

 

Electricity consists of a (1) ___________________ of free electrons along a conductor. To produce this current flow, a generator is placed at the end of the conductor in order to move the (2) _______________________________

Conductors

Electricity needs a material which allows a current to pass through easily, which offers little (3) __________________________ to the flow and is full of free electrons. This material is called a conductor and can be in the form of a bar, tube or sheet. The most commonly used (4) _________________________ are wires, available in many sizes and thicknesses.

They are coated with insulating materials

such as plastic.

Semiconductors

Semiconductors such as silicon and germanium are used in transistors and their conductivity is halfway in between a conductor and an (5) ____________________________. Small quantities of other substances, called impurities, are introduced in the material to (6) ___________________ the conductivity. Insulators

A material which contains very (7) __________________________ electrons is called      an insulator.     Glass,          rubber,         dry     wood and    (8) ___________________________ resist the flow of electric charge, and as such they are good insulating materials. 

 

4.  Read the text again and decide if the following statements are true (T) or false (F), then correct the false ones.

 

1   A flow of electrons moving inside a conductor creates an electric current.              

2   A generator is used to move the charges.

3   Electrons can easily pass through any material.

4   Any material is a good conductor.

5   Conductors are coated with insulators.

6   The presence of free electrons affects the conductivity of materials.

7   Impurities are introduced to increase conductivity.

8   Insulating materials resist the flow of electrons.

 

5.  Read the text and complete the table with the missing information.

 

There are two types of current: Direct current (DC) and Alternating current (AC).

Direct current is a continuous flow of electrons in one direction and it never changes its direction until the power is stopped or switched off.  

Alternating current constantly changes its direction because of the way it is generated. The term 'frequency' is used to indicate how many times the current changes its direction in one second.

Alternating current has a great advantage over direct current because it can be transmitted over very long distances through small wires, by making energy high voltage and low current.

There are several quantities that are important when we

are talking about electric current. Volts (V) - so named after the Italian physicist Alessandro Volta - measure the difference of electric potential between two points on a conducting wire. Amperes (A) measure the amount of current flowing through a conductor, that is to say the number of electrons passing a point in a conductor in one second.

Coulomb (C) measure the quantity of charge transferred in one second by a steady current of one ampere. Power is the rate at which work is performed and it is measured in watts (W). A

Kilowatt (kW), which is equal to one thousand watts, is used to measure the amount of used or available energy. The amount of electrical energy consumed in one hour at the constant rate of one kilowatt is called kilowatt-hour.

 

Unit of measurement	What does it measure?
1 ____________________________	the number of electrons passing a given point in a conductor in one second
2 ____________________________	the quantity of electricity transferred by a steady current of one ampere
3 ____________________________	the amount of electric energy used
4 ____________________________	the difference of potential between two points on a conductor
5 ____________________________	rate at which work is done

 

MY GLOSSARY

charge _____________________________ to pass through ____________________________ coated _____________________________ property __________________________________ conductor __________________________ semiconductor _____________________________ current flow ________________________ shell______________________________________ halfway ____________________________ steady ____________________________________ impurity ___________________________ to switch off _______________________________ insulator ___________________________ thickness __________________________________ to name after _______________________ valence ____________________________________ to orbit ____________________________

 

 

 

Unit 9                             FROM THE HISTORY OF ELECTRICITY

 

1. Read and translate the text.

 

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. 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 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 scientist 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 a steady, 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 steady, continuous current was generated.

 

VOLTA’S SHORT BIOGRAPHY

 

Volta was born in Como, Italy, February 18, 1745. For some years he was a teacher of physics in his home town. Later on, he became professor of natural sciences at the University of Pavia. After his famous discovery he travelled in many countries, among them France, Germany and England. He was invited to Paris to lecture on the newly discovered 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.

 

2.     Active Words and Expressions

 

as well as, at rest, to control, behaviour, condition, copper, flow, in motion, negative, opposite, positive, previously, to remember, the rest of, to travel, to try, unlike, charge

 

3.     Answer the following questions:

 

1. What types of electricity do you know? 2. What is the difference between electricity at rest and electricity in motion? 3. What kind of experiments did Galvani carry on? 4. What did Franklin prove? 5. What are the two kinds of electrical charges? 6. Who was the first to produce a steady, continuous current? 7. What was Volta? 8. What can you say about the behaviour of static charges? 9. What did Volta take interest in? 10. What did Volta’s discovery result in? 11. What did Volta’s device consist of? 12. Where did he spend the rest of his life?

 

4. Translate the following sentences:

 

1. The students carried out an experiment looking at the thermometer from time to time. 2. The cinema was invented before my time. 3. It is high time to begin work. 4. Four times three is twelve. 5. “Am I late?” “No, you are just in time”. 6. “What is the time?” “It’s dinner time”. 7. The students went to the club and had a good time there. 8. It took a long time before people learned to split the atom. 9. I shall be back in no time. 10. For a long time people did not know that lightning and atmospheric electricity are one and the same thing. 11. Lomonosov lectured at the university and at the same time worked in different fields of science. 12. I work in the laboratory two times a week.

 

5. Fill in the blanks with the words one or for:

 

1. Kyiv is ... of the largest cities in the world. 2. ... must remember that it is necessary to study English at least an hour a day. 3. As ... rubber it was brought to Europe as early as the 15th century. 4. ... understands the importance of electricity when ... sees trams, trolley-buses and trains driven by it. 5. The energy of the atom is used ... peaceful purposes in our country. 6. ... must know the chemical properties of the atom. 7. We produce rubber ... it is quite necessary ... the development of our industry. 8. In 1819 Volta returned to Como ... he wanted to spend the rest of his life there. 9. This is a more important problem than that .... 10. I haven’t got a dictionary, I must have ....

 

6.      Give antonyms for the following words: north pole, dark, on the one hand, small, arrangement, larger, magnetized, unfamiliar, like, positive, similar, to rest, in motion

 

7.      Explain the meaning of the following compound words:

newspaper, schoolboy, thunderstorm, icebreaker, waterfall, fisherman

 

 

 

 

 

 

Unit 10                                                                      ELECTRIC LAMP

 

An incandescent electric lamp does not seem to have much resemblance to a heater but the two devices are similar in many respects. A lamp is a white-hot wire inside a glass bulb and a heater is a wire that is only red-hot. The lamp’s filament is heated by the passage of electric current. It glows because it is so hot.

Lamps using glowing wires were made as early as 1845 but they did not work well because all known wires burned or melted before they got white-hot.

Edison wanted to find a wire that

would not burn or melt at high temperatures. It was easy enough to avoid burning. He simply surrounded the wire by a glass bulb from which the air had been pumped out. Now the wire could not burn because there was no oxygen in the bulb.

But the problem of melting was harder to solve. The carbon-filament lamp which he produced as a result of thousands of experiments with different kinds of filaments could operate at a temperature of about 1900°C. Today instead of carbon filaments we use tungsten wires which usually operate at 2800°C. Tungsten is a metal with one of the highest melting points known. Because of their higher operating temperature tungsten- filament bulbs give almost 6 times as much light as carbon-filament bulbs for the same amount of electrical energy.

Lodygin, the well-known scientist and inventor, was the first to discover the advantages of the metal wire filaments in comparison with other filaments. It is he who introduced tungsten filaments in a vacuum. He produced the first incandescent lamp and demonstrated his invention in 1873, lighting several Petersburg streets with his lamps. It was the world’s first practical application of the incandescent lamp for lighting purposes.

Another inventor, Yablochkov, invented the arc lamp in 1876. He was working in Paris at that time. His electric candle, as he called it, consisted of two carbon rods placed in parallel and separated by an insulating material. The first alternating current generator was designed and used with the Yablochkov candle. The electric candle appeared in Paris streets in 1878. Compared with the existing gas lamps they were so brilliant that the system was used by many European cities.

Yablochkov’s invention together with the alternating current generator was a new and simple means of arc lighting.

 

Active Words and Expressions

 

incandescent lamp – лампочка розжарювання carbon rod – вуглецевий стрижень

advantage – перевага  filament – нитка розжарювання

candle – свічка melt – плавитися

lighting – освітлення

 

1. Answer the following questions

 

1.   What is incandescent electric lamp?

2.   Why they did not work well?

3.   What do you know about the carbon-filament lamp?

4.   Where tungsten was used?

5.   What discovery was made by Lodygin?

6.   What do you know about Russian inventor Yablochkov and his invention?

 

2. Finish the sentences according to the text:

 

1.   A lamp is a white-hot wire inside a...

2.   ...were made as early as 1845 but they did not work well...

3.   The carbon-filament lamp which he... 4. ...which usually operate at 2800°C.

5.   Lodygin, the well-known Russian scientist and inventor...

6.   Yablochkov invented...

7.   The first alternating current generator was designed and used...

8.   ...Paris streets in 1878.

 

3.     Translate the following sentences into Ukrainian:

 

1. Such conditions can and do occur due to a shortage of generating plants in this area. 2. It was in our laboratory that the device in question was first tested. 3. If this system is to serve as a voltmeter, a resistor has to be added in series. 4. In 1870 Mendeleyev arranged the elements in the form of a table and of the periodic law. 5. Provided the magnetic field is produced by a coil of several turns, its intensity is much greater than if only one turn were used. 6. Naturally, this circuit can be modified, if necessary. 7. Evidently, the frequency could be varied to meet different conditions. 8. It is impossible to say whether future improvements may not depend on the results of researches. 9. The decision had to be made as to whether the uranium should be in the form of long rods.10. It was the diameter of the wire that we did change to obtain the above results.

          

4.     Put much, many, little or few. 

 

1. My brother is a young teacher. Every day he spends... time preparing for his lessons. 2. I know very ...about this writer. It is the first book I am reading. 3.

The students of our group ask ...questions at the lecture. They want to know everything. 4. You do not make ... mistakes in your spelling. 5. Does your sister read

...? - Yes, she does. And your brother? - Oh, he doesn’t. He has so ... books, but he reads very... 6. Walk quicker, please. We have very ... time. 7. I am sorry to say, I have read very ... books by Jack London.

 

 

Unit 11                  HEATING EFFECT OF AN ELECTRIC CURRENT

 

 

The production of heat is perhaps the most familiar among the principal effects of an electric current, either because of its development in the filaments of the electric lamps or, may be, because of the possible danger from overloaded wires.

As you know, of course, a metal wire carrying a current will almost always be at a higher temperature than the temperature of that very wire unless it carries any current. It means that an electric current passing along a wire will heat that wire and may even cause it to become red-hot. Thus, the current can be detected by the heat generated provided it flows along the wire.

The heat produced per second depends both upon the resistance of the conductor and upon the amount of current carried through it. As a matter of fact, if some current flowed along a thin wire and then the same amount of current were sent through a thicker one, a different amount of heat would be developed in both wires. When the current is sent through the wire which is too thin to carry it freely, then more electric energy will be converted into heat than in the case of a thick wire conducting a small current. 

Let us suppose now that a small current is flowing along a thick metal conductor. Under such conditions the only way to discover whether heat has been developed is to make use of a sensitive thermometer because the heating is too negligible to be detected by other means. If, however, our conductor were very thin while the current were large, the amount of generated heat would be much greater than that produced in the thick wire. In fact, one could easily feel it. Thus, we see that the thinner the wire, the greater the developed heat. On the contrary, the larger the wire, the more negligible is the heat produced.

Needless to say, such heat is greatly desirable at times but at other times we must remove or, at least, decrease it as it represents a waste of useful energy. In case heat is developed in a transmission line, a generator or a motor, it is but a waste of electric energy and overheating is most undesirable and even dangerous. It is this Waste that is generally called “heat loss” for it serves no useful purposes and does decrease efficiency.

Nevertheless, one should not forget that the heat developed in the electric circuit is of great practical importance for heating, lighting and other purposes. Owing to it we are provided with a large number of appliances, such as: electric lamps that light our homes, streets and factories, electrical heaters that are widely used to meet industrial requirements, and a hundred and one other necessary and irreplaceable things which have been serving mankind for so many years. In short, many of the invaluable electrical appliances without which life would seem strange and impossible at present can be utilized only because they transform electric energy into heat. The production of heat by an electric current is called heating effect. One might also name it light effect provided the heat in the conductor is great enough to make it white-hot, so that it gives off light as well as heat.

Take the filament of an electric lamp as an example. We know it to glow because of heat. By the way, were we able to look inside a hot electric iron, we should see that its wires were glowing too? A similar statement could be applied as well to almost any electric heating device. All of them give off a little light and a lot of heat.

Active Words and Expressions

 

a number of – кількість чогось                   loss – втрата appliance – пристрій, прилад                      negligible – незначний to convert – перетворювати                        principal – головний to detect – виявляти, знаходити                 to remove – усувати desirable – бажаний                                    to send – відправляти

waste – відходи                                           white-hot – розпечений до біла

 

1.     Answer the following questions

 

1.How can electricity be detected?

2.     What are the principal effects of an electric current?

3.     Why does the current-carrying wire become red-hot?

4.     What does the heat produced per second depend upon?

5.     Why is heat developed in a transmission line undesirable?

6.     What device turns heat into work?

7.     What do we call the heating effect of an electric current?

8.     When does the conductor become white-hot?

9.     What takes place inside any electric heating device?

 

2.     Translate the following word combinations

 

at least; thanks to; because of; as to; in case; at times; in short; by means of;

in spite of; instead of; all over the world;

 

через променисту енергію; за допомогою теплового двигуна; завдяки хімічній реакції; у випадку зменшення кпд; стосовно теплової втрати; по крайній мірі всередині лампочки; іноді це бажано; в усьому світі; замість механічної енергії.

 

3.     Read and translate the following text.

 

IF THERE WERE NO ELECTRICITY

 

At present it is difficult even to imagine the time when there was no electricity, when people had to do without it.

What would our everyday life be like if there were no electricity?

Can you imagine a situation when all devices producing electricity would stop operating?

If this happened in the evening while you were in the cinema, you would be sitting in the dark without light. Then you would walk along dark streets. You would try to take a trolley-bus or a tram, it would be impossible. As there would be no light at home, you should use either a smoking kerosene lamp or a candle.

You would like to use the telephone or to watch TV but they would not work because they both depend upon the electric current. This example shows the importance of electricity in everyday life.

 

 

Unit 12                                                             ELECTRICAL SUPPLY

 

 

Direct current and alternating current

The current from a cell is direct current (DC) -a constant flow of electricity which travels around a circuit in one direction. The electricity supplied to homes and other buildings - called mains electricity- is alternating current (AC). Unlike a DC supply, an AC supply flows backwards and forwards - its direction continually alternates. The rate at which the current alternates- called the frequency- is measured in hertz (Hz). For example, in the UK, AC supply is 50 Hz - it alternates 50 times per second. On a graph, the AC supply of mains electricity forms a sine wave.

The current supplied to most homes is single-phase - it forms one sine wave. In factories and large buildings, which have powerful electrical equipment, the supply is often three-phase -effectively three currents, each with a different phase (timing). This provides a smoother supply as it reduces the gaps between the voltage peaks.

Note: The term mains electricity is not used in American English -terms like supply are used.

 

AC generation and supply

Mains electricity is generated (produced) at sites called power stations, which use large generators. A generator converts mechanical energy to electrical energy. A generator rotates a magnet within an iron surround. The iron- called an armature- has coils of wire around it, called field coils (or field windings). As the magnet rotates, it causes current to flow through the field coils, due to electromagnetic induction.

Current from the generators leaves the power station and enters the power grid (or grid) - the network of power lines (cables) which transmit it around the country. At the point where it enters the grid, the electricity flows through transformers -specifically step-up transformers, which increase voltage and decrease amperage. This reduces the energy lost from the power lines over long distances, as high-voltage (HV) supplies flow more efficiently than low-voltage (LV) supplies. Before the supply is used by homes and other buildings, it passes through several step-down transformers, which reduce its voltage and increase its amperage.

The supply may be stepped up to over 400,000 volts at the point where it enters the large transmission lines (long-distance power lines) leaving the power station. It is normally then stepped down in stages, first passing through a wider network of lower-voltage transmission lines, and finally through the small distribution lines which supply streets and houses –in many countries at around 230 volts.

 

DC generation and use  

The extract below is from a consumer magazine.

 

Photovoltaic cells (PVs) - or solar cells - are an effective way of generating your own electricity from sunlight. The current they produce can be used immediately, may be stored in rechargeable batteries (like the ones in cars), or can be fed into the power grid and sold to the electric company. But PVs produce direct current. This is fine for charging batteries, but is not suitable for powering household appliances, which require alternating current. For this, the DC supply from PVs and batteries needs to go through an inverter - a device which converts DC to AC.

 

1.  Complete the text about inverters  

 

Inverters      convert      (1)      _______________________________      to         (2)

_______________________. If an inverter is used to supply electrical appliances in a home, it must copy the supply of (3) ___________________________electricity produced by the generators at power stations. Most inverters can produce a current which alternates precisely at the required (4) ______________________________for example, 50 (5) __________________________ (50 cycles per second). However, not all types are able to produce a current which follows the pattern of a

(6) ________________________,  like that of the (7) _______________________________ AC supply used in homes. So-called 'square wave inverters' only produce a very approximate copy of this wave, which can affect the functioning of many electrical appliances.

 

2.     Choose the correct words from the brackets to complete the descriptions of different stages of AC generation and supply (a-f). Then, put the stages in the correct order. 

 

a.        After the step-up transformer, the current enters a (distribution\transmission) line.

b.        Current is produced, by electromagnetic induction, in the (magnet\field coils) of a generator.

c.        The   current         goes   from the     last    step-down    transformer to       a

(distribution\transmission) line.

d.        The current leaves the power (grid\station) and enters the home.

e.        Amperage is reduced and voltage is increased by a (step-up\step-down) transformer.

f.         The current is stepped (up\down) from a higher voltage to a lower voltage, in stages.

 

3.     Decide whether the sentences below are true or false; correct the false sentences. 

 

1.     Photovoltaic cells produce direct current.

2.     The electricity supply from PVs can be used to charge rechargeable batteries.

3.     Rechargeable batteries supply electricity as alternating current.

4.     Inverters convert sunlight to alternating current.

 

OVER TO YOU

Think of some large and small electrical appliances you're familiar with. Explain their electrical supply requirements. What type of current is required, and how is it supplied and/or converted?

 

 

Unit 13                          CURRENT, VOLTAGE AND RESISTANCE

 

Electric current

The photo on the opposite page shows a simple electric circuit (or circuit). A cell provides an electric current (or current). This flows through wires, which conduct the electricity (provide a way for it to travel). The current is used to light a lamp. So, like all circuits, the example includes:

•                     an electrical supply - in this case, the cell

•                     an electrical conductor (or conductor)- an electrical path- in this case, wires

•                     one or more electrical components (or components)- electrical devices (in this case, the lamp) which have a function.

Current- measured in amperes, or amps (A) -is the rate of flow of electric charge. Electric charge is carried by electrons- particles with a negative charge (), which are normally attached to atoms. When an electric current flows through a conductor; the electrons move from one atom to another- in the case of a copper wire, from one copper atom to the next. If the number of electrons flowing through a conductor increases, then the amperage, or ampage (current) increases. When electrons flow, carrying a current, they can be called charge carriers. 

Notes: In everyday English, cells are called batteries. In technical English, a battery is a number of cells placed together. Lamps are often called bulbs in everyday English.

 

Voltage and resistance

The amount of current (in amps) flowing through a circuit will partly depend on the electromotive force (EMF) of the electrical supply. Electromotive force is measured in volts (V), and is generally called voltage. The voltage depends on the 'strength' of the electrical supply. In the diagram above, adding a second cell would supply a higher voltage.

The amount of current will also depend on electrical resistance (or resistance). This value - in ohms (Ω) - is a measure of how easily current can flow through the conductors and components in a circuit. For example, a lamp creates resistance because the filament - the metal wire inside it - is very thin. This limits the amount of current that can flow. Resistance also depends on the materials used as conductors. For example, copper has a low resistance and so is a good conductor.

Materials with very high resistance, such as plastics, are called electrical insulators (or insulators). Only very high voltages cause current to flow through them. Materials that are good insulators are used to insulate conductors. An example is plastic insulation around electric wires. This stops people from touching the conductor and- if it is live (carrying current)- from getting a dangerous electric shock.

 

Electrical power

The text below, about electrical power, is from a home improvements magazine. 

The amount of current, in amps, required by an electrical appliance- such as a TV or an electric kettle -depends on the power of the appliance. This number- expressed in watts (W)- will be marked somewhere on the appliance. To calculate the required current, simply take the wattage and divide it by the voltage of the electrical supply in your home- around 230 volts in most of Europe. Therefore, for an electric kettle with a power rating of 2,000 watts (as specified by the manufacturer), the current required is:      2,000 watts   = 8.7 𝑎𝑚𝑝𝑠 230 𝑣𝑜𝑙𝑡𝑠

 

1.  Complete the word puzzle and find the word going down the page.

1   another term for amperage 

2   provided by a battery, for example 

3   measured as a wattage 

4   allows current to flow through it 

5   has very high electrical resistance 

6   carried by moving electrons  

7   another term for an electrical 'device' 

8   the consequence of a person touching a live conductor

 

2. Complete the extract about current and power calculations using the words in the box.

amps components conductor circuit current ohms

resistance supply voltage volts wattage watts

 

In electrical calculations, electromotive force is expressed by the letter E, resistance by the letter R, and current by the letter 1 (which comes from the word 'intensity').

According to Ohm's Law: I = E/R.

In other words, the (1) ................................ flowing through a (2) ............................, measured in (3) ................................, equals the (4) ................................ of the electrical (5) ................................, measured in (6) ................................, divided by the total (7) ................................, measured in (8) ................................. To work out the value of R, it is necessary to calculate the total resistance of all the (9)

................................ and connecting lengths of (10) ................................ that make up the circuit. Once both the voltage and amperage are known, it is possible to work out the power, measured in (11) ................................, that will be consumed. Power (P) can be calculated using the equation P = EI. Therefore (12) ................................ equals voltage multiplied by amperage.

3. Say how much power is required by an electrical appliance you know about, and what voltage and current are used to power it. Then use these values to calculate and state what the total resistance of the appliance is.

 

 

Unit 14                                                              ELECTRIC CIRCUITS

 

1.     Read the text and name the parts of electric circuit.

An electric circuit or network is a pathway through which the electric current can flow. A simple circuit consists of a power source, two conducting wires, each one attached to a terminal of the source and a device through which electricity can flow. This device is called a load and it's attached to the wires. If all the parts are properly connected, the current flows and the lamp lights up. This kind of circuit is called 'closed'.

On the contrary, if the wires are disconnected the circuit is called 'open' or 'broken'.

The circuit can be opened and closed by a device called a switch.

Loads can turn electrical energy into a more useful form. Some examples are: 

•         light bulbs, which change electrical energy into light energy;

•         electric motors, which change electrical energy into mechanical energy;

•         speakers, which change energy into sound.

The source provides the electrical energy used by the load. It can be a storage battery

or a generator. The switch interrupts the current delivered to the load by the source and allows us to control the flow.

When an abnormally high amount of current passes through a network, you get a short circuit. This may occur when there is a drop in the resistance or a broken insulation. In order to prevent short circuits, it is best to use fuses, which melt when too much current flows through them, interrupting in this way the circuit.

 

2.     Match the words with their definitions. 

 

1.     load 2.     switch 3.     source 4.     fuse 5.     closed circuit 6.     broken circuit

a.      a device which interrupts the circuit b.     a circuit in which wires are disconnected c.      a device which provides power

 

d.     a complete circuit with no breaks at all

e.      a device which consumes electric power

f.       a protective device.

 

 

3.     Read the text again and answer the following questions.

 

1.     What does a simple circuit consist of? 

2.     What happens to the lamp in a closed circuit?

3.     Can you name some examples of loads?

4.     What is a generator?

5.     What is the function of a switch?

6.     When does a short circuit occur?

7.     What can we use to prevent short circuits?

8.     How does a fuse work?

 

4. Complete the texts with the words from the box. 

 

 

The (1) components of a circuit can be wired in two different ways: series or parallel. If components are arranged one after another to form a single (2) ________________ between the terminals and the components, the circuit is known as a series circuit. In this type of circuit, the (3) _________________ flows from the negative terminal to the (4) ______________ terminal, passing through all the other components of the circuit. This means that the (5) _________________ of energy passing through all the components in the series is the same. The main disadvantage of a series circuit is that when a single component in the path (6) ________________, the entire circuit stops operating (e.g. Christmas tree lights).

A parallel circuit consists of several paths connecting the different components. Each separate path is called a (7)_________________ of the circuit.

Current from the source divides and flows through the different branches. Unlike series circuits, if one of the components in the parallel circuit burns out, the other paths (8)________________ to operate. Parallel circuits are    commonly   used   to       connect        (9)

____________________ at home, so that each socket can function independently. For example, you don't have to (10) ________________ the light

in your room for the TV socket to work.

 

5. Read the text and find synonyms for the words below.

 

A fuse can be added to an electric circuit to protect it from the effects of undue power. This safety device, which is made of a heat-sensitive alloy, is connected in series with the circuit it has to protect. If an excessive amount of current flows through the circuit, the alloy will liquefy and open the circuit. A circuit breaker is fundamental in a house to protect circuits against overloading, overheating and short circuits. The advantage of a circuit breaker is that it can be reset after the overloading by replacing the fuse. A professional electrician should always provide his customers with a map of the electric circuit in the house so that it will be easier to work on it in case of faults.

 

1.      excessive_______________________ 2.      reacting to high temperatures____________________ 3.      to melt ________________________

4.      loading up______________________ 5.      adjusted _______________________ 6.      clients _________________________

           

 MY GLOSSARY

to arrange _____________________   power source _________________________ branch ________________________  to prevent ____________________________ to burn out _____________________ series circuit __________________________ device ________________________  short circuit ___________________________ fault __________________________ socket _______________________________ fuse __________________________  speaker ______________________________ light bulb ______________________ switch _______________________________ load __________________________ to turn into ____________________________ to melt ________________________ undue ________________________________ parallel circuit __________________

 

 

Unit 15                                             CIRCUITS AND COMPONENTS

 

1. Read the text. Make up ten questions to it.

Simple circuits

The circuit diagrams below show lamps connected in a parallel circuit and in a series circuit.

The supply has live and neutral conductors. On an alternating current (AC) supply, the difference between live and neutral is that conductors on the neutral side of appliances are earthed- that is, connected to earth (the ground).

 

 

 

  

Mains AC circuits and switchboards

Where an AC supply enters a building, it is connected to a switchboard. This has a number of switches to allow different circuits in the building to be switched on and off. Circuits include power circuits. These supply the power sockets (or sockets) for the plugs on appliances. Usually, a circuit-breaker is fitted to each circuit. This is a safety switch that switches off automatically if there is a problem. This may happen if a person touches a live conductor, or if there is a short circuit. A short circuit is when current flows directly from a live conductor to a neutral conductor -for example, due to damaged insulation. Circuit breakers also allow circuits to be switched off manually, to isolate them (switch them off safely) -for example, before maintenance work.

Note: The equipment in switchboards is often called switchgear.

Printed and integrated circuits

The circuits in electrical appliances are often printed circuits, on printed circuit boards (PCBs). These are populated with (fitted with) electrical components. Many appliances also contain small, complex integrated circuits- often called microchips (or chips) - made from silicon wafers (very thin pieces of silicon). They act as semiconductors, which can be positively charged at certain points on their surface and negatively charged at other points. This principle is used to make very small circuits.

 

Electrical and electronic components

 

There are many types of electrical and electronic components. These can be used individually or combined with other components to perform different tasks. For example:

•                     Sensors or detectors can sense or detect levels of- or changes in - values such as temperature, pressure and light.

•                     Control systems use feedback from sensors to control devices automatically. For example, mechanical devices such as water valves may be moved or adjusted by servomechanisms – electrically powered mechanisms that are controlled automatically by signals ('messages') from sensors.

•                     Logic gates are widely used in control systems. They send signals, in the form of low voltages, to other devices. An output signal from the logic gate is switched on or off, depending on the input signals it receives.

Notes: The term electronic, rather than, generally describes small but often very complex circuits and components that operate at a low voltage.

 

2.     Make word combinations with circuit using words from A and B opposite. Then match the combinations with the descriptions (1- 6) below.

a…………………….. a ……………………. a …………………….   a ……………………. a …………………….. an …………………….

1.     a circuit containing one or more sockets

2.     a simple circuit where all the components are placed one after the other along the same conductor

3.     a microchip - a very small, often complex circuit

4.     what happens if live and neutral conductors touch while a current is flowing, and there is no component or appliance between them

5.     a circuit which allows different components to be controlled independently by separate switches

6.     a circuit that can be populated with a large number of components

 

3.     Complete the task from an engineering textbook. Sometimes more than one word is possible.

In an experiment, the lights in a room are connected to two types of electronic

(1) ................................. The first is an occupancy sensor, which will (2) ................................ the movement of a person entering the room, and the second is some kind of photosensor, which can determine whether it's daylight or dark. These two devices are connected to an AND gate - a (3)

................................................................ that will produce an output current only if it receives two input currents - in this case, from both the occupancy sensor and the photosensor.

Therefore, a (4) ................................ will be sent to the light switch to (5) .............................................................. the lights only if a person enters the room and if it's dark.

However, for this system to work, we are assuming that the type of photosensor used will be one which is designed to produce a current in the dark, and which will then (6) ............................................................. as soon as daylight appears. But such a sensor may be designed to work in the opposite way - producing a current when it detects daylight and no current in the dark. This would cause an obvious problem. In this case, what type of logic gate could be placed between the photosensor and the AND gate in order to solve the problem?

                  

A printed circuit board                                                               An integrated circuit on a microchip  

Sensing, measuring and regulating devices

Device	Function
voltmeter	detects and measures voltage
ammeter	detects and measures electric current
ohmmeter	detects and measures electrical resistance
thermostat	regulates temperature- switches a heating or cooling system on or off at a set temperature
thermocouple	measures or controls temperature - produces a voltage which varies proportionally as the temperature difference between two points varies
thermistor	measures or controls temperature- produces a resistance which varies proportionally as temperature varies (thermistor is short for 'thermal resistor')
photosensor	a general term for devices that detect and measure light
proximity sensor	measures the distance between itself and nearby objects
piezoelectric sensor	measures movement and strain- produces an electric current when stressed mechanically
flowmeter	measures the rate of flow of a fluid
barometer	measures atmospheric pressure
hygrometer	measures the amount of moisture (water vapour) in the air
altimeter	measures altitude, usually as a height above sea level
smoke detector	detects smoke, usually to provide a fire warning
accelerometer	measures acceleration and deceleration forces
motion detector	detects movement- usually of people- that are a certain distance away
microphone	detects sound

 

 

 

Unit 16                                                                                 RESISTORS

  

 

A resistor is one of the most common elements of any circuit. Resistors are used:

1.                 to reduce the value of current in the circuit;

2.                 to produce IR voltage drop and, in this way, to change the value of the voltage.

When current is passing through a resistor its temperature rises high. The higher the value of current the higher is the temperature of a resistor. Each resistor has a

maximum temperature to which it may be heated without a trouble. If the temperature rises higher the resistor gets open and opens the circuit.

Resistors are rated in watts. The watt is the rate at which electric energy is supplied when a current of one ampere is passing at a potential difference of one volt. A resistor is rated as a 1-W resistor if its resistance equals 1,000,000 ohms and its current-carrying capacity equals 1/1,000,000 amp, since P = E x I= IR x I = I 2 R where P - power is given in watts, R - resistance is given in ohms and I - current is given in amperes.

If a resistor has a resistance of only 2 ohms but its current-carrying capacity equals 2,000 amp, it is rated as an 8,000,000-W resistor.

Some resistors have a constant value - these are fixed resistors; the value of other resistors may be varied - these are variable resistors.

 

1.Complete the sentences using the correct option:

 

1.       A resistor is used      a) to measure the resistance.

b)  to reduce the current.

c)   to change the resistance.

d)  to produce IR voltage drop.

 

2.       When current passes through a a) its temperature drops. resistor    b) its temperature rises.

         

3.       Resistors are rated    a) in ohms

b)   in volts.

c)    in watts.

 

 

4.       Power is given         a) in amperes.

b) in watts.

 

5.       Fixed resistors have a) a constant value.

b) a variable value.

 

6.       The value of a variable resistor     a) is fixed.

b) is varied.

 

7.       A two-ohm resistor rated as an a) has a current-carrying capacity equal

8,000,000-W resistor                                to 2,000 amp.

b) has a current-carrying capacity equal to 200 amp.

 

8.       The higher the value of current,    a) the lower is the temperature of a resistor,

b) the higher is the temperature of a resistor.

 

2.     Answer the questions.

 

1.       What is a resistor used for?

2.       When does the temperature of a resistor rise?

3.       What element is used to change the value of voltage?

4.       How are resistors rated?

5.       What types of resistors do you know?

6.       When does a resistor get open?

7.       What does an open resistor result in?

8.       What is the difference between a fixed resistor and a variable resistor?

9.       How much is the current-carrying capacity of a two-ohm resistor?

10.   What resistors have a variable value?

 

3.     Solve the problem:

 

What is the maximum current for a resistor having a 5-watt capacity and a resistance of 20,000 ohms?

 

 

 

Unit 17                                                                              CAPASITORS

 

 

 

A capacitor is one of the main elements of a circuit. It is used to store electric energy. A capacitor stores electric energy provided that a voltage source is applied to it.

The main parts of a capacitor are metal plates and insulators. The function of insulators is to isolate the metal plates and, in this way, to prevent a short.

In the diagram one can see two common types of capacitors in use nowadays: a fixed capacitor and a variable one. The plates of a fixed capacitor cannot be moved; for this reason, its capacity does not change. The plates of a variable capacitor move; its capacity changes. The greater the distance between the plates, the less is the capacity of a capacitor. Variable capacitors are commonly used by radiomen; their function is to vary the frequency in the circuit. Fixed capacitors are used in telephone and radio work.

Fixed capacitors have insulators produced of paper, ceramics and other materials; variable capacitors have air insulators. Paper capacitors are commonly used in radio and electronics; their advantage is their high capacity: it may be higher than 1,000 picofarad.

Besides, electrolyte capacitors are highly in use. They also have a very high capacity: it varies from 0.5 to 2,000 microfarad. Their disadvantage is that they change their capacity when the temperature changes. They can operate without a change only at temperatures not lower than -40° C.

Common troubles in capacitors are an open and a short. A capacitor stops operating and does not store energy in case it has a trouble. A capacitor with a trouble should be substituted by a new one.

 

1. Complete these sentences using the correct variant:

 

1. A capacitor is used	a)   to supply voltage. b)  to increase the voltage output. c)   to store energy.
2. The main parts of a capacitor are	a)                 insulators only. b)                metal plates only. c)                 metal plates and insulators between them.
3. The function of insulators is	a)   is constant. b)  is varied.
4. The capacity of a capacitor depends on	a)   can be moved. b)  cannot be moved.
5. The capacity of a fixed capacitor	a)   to the metal plates. b)  to the insulators.
6. The plates of a variable capacitor	a)                 the greater is the capacity of a capacitor. b)                the less is the capacity.
7. In order to charge a capacitor a voltage source is applied	a)                 to store energy. b)                to isolate the metal plates. c)                 to prevent a short between the metal plates.
8. The greater the distance between the plates	a)   the size of the plates. b)  the distance between the plates. c)   the material of the insulators.
9. Variable capacitors have	a) air insulators.

10. Electrolyte capacitors have

b)  paper insulators.

c)   ceramic insulators.

 

a)   a very low capacity.

b)  a very high capacity.

 

11. In case a capacitor has a trouble           a) it operates.

b) it stops operating.

 

2. Answer the questions

 

1.   What is a capacitor used for?

2.   What are the main parts of a capacitor?

3.   What is the function of insulators?

4.   What does the capacity of a capacitor depend on?

5.   What is the difference between a fixed capacitor and a variable one?

6.   What should be done in order to change a capacitor?

7.   What is the relation between the value of capacity and the distance of plates?

8.   What type of insulators have variable capacitors?

9.   What should be done in case a capacitor has a trouble?

 

 

Unit 18                                        CONDUCTORS AND INSULATORS

 

 

Conductors are materials having a low resistance so that current easily passes through them. The lower the resistance of the material, the more current can pass through it.

The most common conductors are metals. Silver and copper are the best of them. The advantage of copper is that it is much cheaper than silver. Thus, copper is widely used to produce wire conductors. One of the common functions of wire conductors is to connect a voltage source to a load resistance. Since copper wire conductors have a very low resistance a minimum voltage drop is produced in them. Thus, all of the applied voltage can produce current in the load resistance. It should be taken into consideration that most materials change the value of resistance when their temperature changes.

 

Metals increase their resistance when the temperature increases while carbon decreases its resistance when the temperature increases. Thus, metals have a positive temperature coefficient of resistance while carbon has a negative temperature coefficient. The smaller is the temperature coefficient or the less the change of resistance with the change of temperature, the more perfect is the resistance material.

Materials having a very high resistance are called insulators. Current passes through insulators with great difficulty.

The most common insulators are air, paper, rubber, plastics.

Any insulator can conduct current when a high enough voltage is applied to it. Currents of great value must be applied to insulators in order to make them conduct. The higher the resistance of an insulator, the greater the applied voltage must be.

When an insulator is connected to a voltage source, it stores electric charge and a potential is produced on the insulator. Thus, insulators have the two main functions:

1. to isolate conducting wires and thus to prevent a short between them and

3. to store electric charge when a voltage source is applied.

 

1. Find answers to these questions in the text above:

 

1.   What materials are called conductors?

2.   What is the advantage of copper compared with silver?

3.   What is the most common function of wire conductors?

4.   Why is a minimum voltage drop produced in copper conductors?

5.   What is the relation between the value of resistance and the temperature in carbon?

6.   What materials are called insulators?

7.   What are the most common insulators?

8.   What are the two main functions of insulators?

 

2. Complete the sentences using the correct variant:

 

1.   Insulators are materials having      a) low resistance.

b) high resistance.

 

2.   Current passes through conductors          a) easily.

b) with great difficulty.

 

3.   Copper and silver are a) common conductors.

b) common insulators.

 

4.   Air, paper and plastics are    a) common insulators.

b) common conductors.

 

5.   In case a high voltage is applied to an a) it does not conduct current. insulator    b) it conducts current.

 

6.   Insulators are used     a) to store electric charge.

b)  to reduce voltage.

c)   to prevent a short between conducting wires.

 

7. Metals increase their resistance	a)   when the temperature decreases. b)  when the temperature increases.
8. Carbon decreases its resistance	a)   when the temperature increases. b)  when the temperature decreases.
9. Metals have	a)                 a positive temperature coefficient of resistance. b)                a negative temperature coefficient of resistance.

 

 

3.     Answer the questions

 

1.   What is the difference between conductors and insulators?

2.   How does current pass through insulators?

3.   What materials are commonly used to produce insulators?

4.   What materials are commonly used to produce conductors?

5.   In what case do insulators conduct current?

6.   How does resistance change when the temperature decreases?

 

4.     Translate into Ukrainian

 

iron core                              primary winding closed core                          secondary winding input voltage                       step-up transformer output voltage                     step-down transformer

 

 

 

Unit 19                                                                      TRANSFORMERS

 

 

A transformer is used to transfer energy. Due to the transformer electric power may be transferred at a high voltage and reduced at the point where it must be used to any value. Besides, a transformer is used to change the voltage and current value in a circuit.

A two-winding transformer consists of a closed core and two coils (windings). The primary winding is connected to the voltage source. It receives energy. The secondary winding is connected to the load resistance and supplies energy to the load.

The value of voltage across the secondary terminal depends on the number of turns in it. In case it is equal to the number of turns in the primary winding the voltage in the secondary winding is the same as in the primary.

In case the secondary has more turns than the primary the output voltage is greater than the input voltage. The voltage in the secondary

is greater than the voltage in the primary by as many times as the number of turns in the secondary is greater than the number of turns in the primary. A transformer of this type increases or steps up the voltage and is called a step-up transformer. In case the secondary has fewer turns than the primary the output voltage is lower than the input. Such a transformer decreases or steps down the voltage, it is called a stepdown transformer.

Common troubles in transformers are an open in the winding, a short-between the primary and the secondary, and a short between turns. In case a transformer has a trouble, it stops operating or operates badly. A transformer with a trouble should be substituted.

 

1. Complete the sentences using the correct variant:

1.       A transformer is used         a) to store charge.

b)  to prevent the change of energy.

c)   to transfer energy.

d)  to change the voltage and current value in a circuit.

 

2.       Electric power is transferred at a high a) due to resistors.

voltage and reduced to any value               b) due to capacitors.

c) due to transformers.

 

3.       A transformer consists of   a) cores only.

b)the primary and the secondary windings.

c)  a core and the primary and the secondary windings.

 

4.       The function of the primary is      a) to prevent the change of voltage.

b)   to supply energy.

c)    to receive energy.

 

5.       The function of the secondary is a) to receive energy.

b)   to supply energy.

c)    to transfer energy.

d)   to decrease the value of charge.

 

6.       A step-up transformer is used       a) to step down or decrease the secondary voltage.

b) to step up or increase the primary voltage.

 

7.       A step-down transformer is used a) to step down the secondary voltage.

b) to step down the primary voltage.

 

8.       A transformer with an iron core    a) is used for high-frequency currents.

b) is used for low-frequency currents.

 

9.       A transformer with an air core is used a) for high-frequency currents and for low-frequency currents.

b) for high-frequency currents only.

 

10.   In a step-up transformer     a) the number of turns of the secondary

winding is greater than the number of turns of the primary,

b) the number of turns of the primary winding is greater than the number of turns of the secondary.

 

11.   A transformer should be substituted a) in case it has an open in the winding.

b)  in case it has a short between the primary and the secondary,

c)   in case it has a short between turns.

 

2.     Answer the questions

 

1.       What is a transformer used for?

2.       What does a transformer consist of?

3.       What is the function of the primary winding?

4.       What is the function of the secondary winding?

5.       What type of transformer is called a step-up transformer?

6.       What type of transformer is used for high-frequency currents?

7.       What type of transformer is called a step-down transformer?

8.       What type of transformer is used for low-frequency currents?

9.       What is the relation between the number of turns in the windings and the value of current?

10.   What are common troubles in a transformer?

11.   What should be done in case a transformer has a trouble?

 

3.     Read about current transformers. Answer the questions that follow.

 

Current Transformers

Current transformers are used for operating ammeters, wattmeters, and other measuring devices. They produce in the meters a current lower than the measured current but proportional to it.

Current transformers also insulate the instrument from the circuit which is being measured. This is necessary for high voltage circuits.

 

1.   What is a current transformer used for?

2.   What type of current does it produce?

 

 

 

Unit 20                                                                       ELECTRIC MOTOR

 

 

The electric motor is a device employed for transforming electrical energy into mechanical energy. We know it to turn machinery and various appliances.

We have already seen the generator convert mechanical energy into electric energy. Now, the process is reversed. It is electricity that is supplied to the machine and it is motion that we obtain. From all that has been said in the previous articles about our getting magnetism from electricity and about the generation of electric current by using magnetism, it is obvious that generators and motors are similar in certain respects. There is certainly some difference in detail but in both of them we find an armature with windings, a commutator and brushes combined with an electromagnet for producing the magnetic field.

However, in an electric motor one shunt binding is not sufficient and a second one called a series winding should be added. “Why is it necessary?” one might ask. The fact is that the motor should have a powerful effect at the very moment when the current is switched on, as for instance, in an electric tram or a train. A very strong magnetic field is needed to obtain a so- called powerful starting torque. This is achieved fey adding a series winding to the magnetic coils. It is connected not in shunt with the armature but in series with it. Thus, all the heavy starting current, passing through the armature winding, now passes through the series field coil and provides a strong field

necessary for starting, the shunt field winding providing the running

conditions.

No appliance ever created by man has probably such a wide range of size and such a variety of application as a motor. In fact, on the one hand, there are all kinds of mighty giants in the motor world. These giants are known to perform innumerable operations wherever required. On the other hand, there exist all kinds of small-sized and even minute motors which are able to power various complex machines and operate equally well under any conditions. Much of our farm equipment is also driven by means of electric motors. So far nothing was said of what a motor does in our homes. In a modern home there are many different electric motors in machines and devices utilized to meet our daily requirements: to tell the time, to wash clothes, to cool the refrigerator, to clean or brush various things, to shave, to emulate air in a warm room on a hot summer day, and so on. In effect, vacuum cleaners, washing machines, and modern refrigerators do work thanks to electric motors. It follows that in the electric motor we have a valuable and powerful appliance capable of fulfilling the required operations exactly and with just the desirable power and rate of motion. It is readily switched on, at will, and it continues running until we switch it off. There are often cases when it is simply impossible to replace it by any other means. In short, the motor finds application in industry and engineering, in agriculture and transport, in our homes.

 

Active Words and Expressions

 

brush – щітка  so-called – так званий commutator – перетворювач струму field winding – обмотка збудження

to exist – існувати s efficient – достатній it follows – відповідно  torque – обертати, скручувати to fulfill – виконувати  mighty – могутній, величезний to perform – виконувати  variety– різноманітність rate – ступінь, розряд  shunt– шунт, маневрувати

to replace– заміщувати

 

1. Answer the following questions

 

1.       What device is discussed in this text?

2.       What is a motor employed for?

3.       What kind of motors do you know?

4.       What does the generator do?

5.       What parts of a motor do you know?

6.       What is a very strong magnetic field needed for?

7.       What does the shunt field winding provide?

8.       What does a motor do in our homes?

9.       Do motors serve you every day?

10.   Where does a motor find its wide application?

 

2. Complete the following sentences:

 

1.   A transformer is a device which ...

2.   A dynamo is a machine which ...

3.   A battery is a device which ...

4.   A switch is a device which ...

5.   An engine is a machine which ...

6.   A thermometer is a device, which ...

7.   A motor is a device which ...

8.   A generator is a machine which ...

 

3. Translate the following sentences:

 

The flow of current being reduced, the speed of the motor is decreased. 2. It is on the above basis that all our power plants are constructed at present. 3. We know of this substance having been used owing to its high quality. 4. Copper being a good conductor, we were asked to use it when carrying on our research work. 5. By changing the value of the resistance, we can increase the current. 6. Having been used for a long time, the instrument lost its former quality. 7. Were that solid substance heated, it would greatly expand. 8. To observe is the primary rule of any experiment. 9. The professor wants us to turn our attention to the problem of semiconductors. 10. The new invention proved to be of great practical importance.

 

 

Unit 21                                                                TRANSMISSION LINES

 

А power system is an interconnection of electric power stations by high voltage power transmission lines. Nowadays the electricity is transmitted over long distances and the length of transmitting power lines varies from area to area.

А wire system is termed а power line in case it has nо parallel branches and а power network in case it has parallel branches.

According to their functions, power lines and networks are subdivided into transmission   and    distribution lines.

Transmission lines serve to deliver power from а station to distribution centers. Distribution lines   deliver         power          from distribution centers to the loads. 

Lines are also classed into: overhead; indoor;        cable

(underground). Overhead lines include          line    conductors,

insulators, and supports. The conductors are connected to the insulators, and these are connected to the supports. The greater the resistance, the higher are the heating losses in the conducting wires. In order to reduce the losses, а step-down transformer саn bе used. Indoor lines include conductors, cords, and buses. Тhe conductor mау include оnе wire or а combination of wires not insulated from оnе another. Тhey deliver electric current to the consumers.

As to underground lines, they are used in city areas. Accordingly, they are used in cities and towns, and in the areas of industrial enterprises.

 

Active Words and Expressions

 

area – площа, область  cord – провід

to distribute – розподіляти  as to – що до distance – відстань  bus – шина to support – підтримувати  accordingly – відповідно network – електрична мережа  long distance – значна відстань to term – називати  enterprise – підприємство

distribution centre –розподільчий центр power consumption –споживання електроенергії to divide – ділити  support – щогла,опора

 

1. Answer the following questions

 

1. Ву what means is еlеctriс power system transmitted? 2. Which system has nо рarallеl branches?

3.   Into what groups are all the transmitting lines classed?

4.   What соmponents does an overhead line have?

5.   What еlеments do conductors consist of?

6.   In what areas are overhead (underground) lines used?

 

2.        Translate the following word- combinations:

 

interdependent city areas, interacting underground lines, interconnected overhead lines, transmitting power lines, transmission and distribution lines, overhead lines, step-down transformer, indoor lines, underground lines.

 

3.        Finish the sentences according to the text:

 

1. ...voltage power transmission lines. 2. А wire system is termed а power line in case...

3.   ...subdivided into transmission and distribution lines.

4.   Lines are also classed into...

5.   The greater the resistance, the higher are...

6.   Indoor lines include...

7.   Тhe conductor mау include оnе wire...

8.   ...and in the areas of industrial enterprises.

 

4. Correct the following sentences.

 

1. I did went to the movies last night. 2. She didn’t ate at the Chinese restaurant. 3. When they visited San Francisco? 4. Who you did call? 5. Who call you last night? 6. Why she called her mother this morning? He had not any money. 8. Where fell you? 9. Did she drank a glass of milk? 10. Where was she find the ring? 11. You didn’t finished your dinner.

 

 

Unit 22                                                                                             FUSES

 

Fuses are widely used nowadays as protection devices. They are utilized in various circuits, electrical equipment and installations. Fuses serve to protect them against overcurrent and short-circuit.

There are different types of fuses in use nowadays. Of them, quartz sand fuses serve for voltages up to 500 volts; fuses of this kind are produced with current ratings of 15 to 60 аmр. and of 100 to 350 аmр.

Fuses are commonly used in low voltage industrial installations rated uр to 1,000 V. Fuse protection is based on а very simple principle: in case of а short-circuit or overcurrent, when the maximum value of

current has been exceeded, the fusible link of а fuse is heated to its melting point.

This opens the circuit and disconnects the circuit from the power source. In case of а fault, one should replace the faulty fusible element by а new one.

Fuses are used both in direct current (d.c.) and alternating current (а.с.) circuits.

 

Active Words and Expressions

 

fuse – запобіжник  to protect – захищати link –зв’язок 

to utilize– використовувати fault – дефект  to equip – обладнувати faulty – несправність  to serve – служити equipment – обладнання  to melt – плавитися installation – пристрій 

up to –аж до

 

1. Answer the following questions

 

1.   What does а fuse serve for?

2.   For what type of current are fuses used?

3.   What should bе done in case of а faulty fuse?

4.   What principle is fuse protection based оn?

 

2.                        Form the words according to the model and translate them. Model: charge – overcharge – перевантаження cоnnесt– disconnect – роз’єднати

 

pressure, beat, stress, current, load, organize, place, stress, use.

 

3.                        Finish the sentences according to the text:

 

1.   Fuses are widely used in...

2.   ...against overcurrent and short-circuit.

3.   Fuses are commonly used in low...

4.   ...in case of а short-circuit or overcurrent, when the maximum value of current has been exceeded... 5. In case of а fault, one should... 6. ...direct сurrent (d.c.) and altenating сurrent (а.с.) circuits.

 

4. Fill in the gaps with am, is, are, was, and were.

 

1. Last year she ... 22, so she ... 23 now. 2. Today the weather ... nice, but yesterday it ... cold. 3. I ... hungry. Can I have something to eat? 4. I ... hungry last night, so I had something to eat. 5. Where ... you at 11 o’clock last Friday morning? 6. Don’t buy those shoes. They ...too expensive. 7. Why ... you so angry yesterday? 8. We must go now. It ...very late. 9. This time last year I ... in Paris. 10. We ... tired when we arrived home, so we went to bed. 11. Charlie Chaplin died in 1978. He ...a famous American film star.

 

 

Unit 23                                                                              SUBSTATIONS

 

А substation is designed to receive energy from а power system, convert it and distribute it to the feeders. Thus, а substation serves as а distribution centre. Substations feed (supply) various consumers provided that their basic load characteristics are similar.

Therefore, the energy is distributed without transformation of the voltage - supplied.

Соmmon substations comprise isolators, switchgear buses, оil circuit breakers, fuses, power and instrument transformers and reactors. Substations are classed into step-uр and step-down ones.

Тhе step-uр substation includes transformers that increase the voltage. Connected to the bus bars of the substation are the power transmission lines of power plants of the system. As to step down substations, they reduce the voltage to 10 or 6 kV. At this voltage the power is supplied to the distribution centers and to the transformer substations of power consumers.

А transformer substation serves for transmitting and distributing electric power. It comprises а storage battery, control devices and auxiliary structures.

Transformer substations are classed into indoor and outdoor; both types are used for feeding industrial enterprises. Compared to other types of substations, transformer substations have certain advantages. They have flexible construction and easy and reliable operation.

In case of а fault in the left-hand section, the main circuit breaker opens while the normally ореn section circuit breaker closes and puts the voltage of the section to normal. Power from а substation is delivered to distribution centers.

 

Active Words and Expressions

 

auxiliary – допоміжний  flexible – гнучкий breaker – вимикач  to comprise – включати в себе busbar – збиральна шина  to distribute – розподіляти feeder – фідер 

as ... to – стосовно

 

1. Answer the following questions

 

1.   What does а substation serve for?

2.   What type of consumers does а substation feed?

3.   What parts are the power transmission lines connected to? 4. What components does а substation comprise?

5. What types are substations classed into? 6. What аrе advantages of а transformer substation?

 

2.        Translate the following word-combinations:

 

circuit breaker, auxiliary units, distribution centre, flexible construction, reliable operation, switch gear bus, hydraulic as well as solar sources of energy, as to phaseword motors.

 

3.        Finish the sentences according to the text:

 

1.   А substation is designed to receive energy...

2.   Соmmon substations comprise... 3. Тhе step up substation includes...

4. ...they reduce the voltage to 10 or 6 kV. 5. А transformer substation serves for...

6. ...are used for feeding industrial enterprises. 7. In case of а fault...

8. ...is delivered to distribution centers.

 

4. Insert соmmas where necessary and translate the sentences:

1.                 Wattmeter is an instrument for the direct measurement of the power in watts of а circuit.

2.                 If two conductors are placed in contact or joined by а conductor of much lower resistance than the rest of the circuit most of the current will flow direct between these conductors which are then said to be short-circuited or shorted.

3.                 Alternating current is а flow of electricity which after reaching а maximum in one direction decreases, finally reversing and reaching а maximum in the opposite direction.

4.                 А few pounds of uranium саn supply а medium-sized town with power it needs for а year.

5.                 Since the energy sources of the world are decreasing it is necessary to turn to atomic energy.

6.                 Тhe engine cannot bе restarted until its оil level is brought up to the correct level. 7. Pierre Curie examined properties of crystals which led him to the discovery of piezoelectric properties.

8. Тhe capacity of the generating units has been increased which made it possible to build super-high-capacity power stations.

 

5. Complete the sentences with suitable tense forms. 

 

Karen, Emily and Anne all (go) ... to college together 20 years ago. They(have) ... a wonderful time and (learn) ... a lot. Now, the three of them(work) ... at the same insurance company. They (eat) ... lunch together every day and sometimes (tell) ... stories about their school days. Yesterday, they (remember) ... a funny accident at a special banquet during their sophomore year. At this dinner, they (sit) ...at the same table as the president of the university. Everything (go) ... along fine, but then disaster(strike) ... To make a long story short, Karen (spill) ... a serving dish full of spaghetti onto the president. Karen (be)...terribly embarrassed. She (apologize) ...

profusely and (leave) ... the banquet room in tears.

 

 

 

Unit 24                                                    ELECTRIC POWER PLANTS

 

The two main types of power plants traditionally have been the fossil-fuel steam-electric plant and the hydroelectric plant.

Other types, including internal-combustion-engine plants and nuclear plants also have been built. The selection of a particular type of generating plant and its location involves consideration of a number of factors such as plant, fuel, and transmission line costs; availability of cooling water; and environmental considerations.

For several reasons, the relative importance of the various types of power plants has been shifting. Good sites for new hydroelectric plants have become scarce in many countries.

Distribution networks have been extended so that less expensive power from large steam-electric stations has been replacing power from smaller diesel-generator units. Nuclear-electric power plants have been built instead of fossil-fuel steamelectric plants because the cost of coal and oil has been increasing.

For example, in the United States in 1970, fossil-fuel steam-electric plants accounted for 76% of the power generated, hydroelectric plants for 16%, and nuclear plants for 2%. In 2000 45% of the electric power in the United States is generated from fossil-fuel steam-electric plants, 45% from nuclear plants, and 10% from hydroelectric plants.

 

1. Answer the following questions

 

1.   What kinds of power plants are in use nowadays?

2.   What does the selection of a type of generating plant depend on?

3.   For what reason are nuclear-electric power plants being built instead of fossil-fuel steam-electric plants?

4.   What can you say about situation in the USA?

 

2. Finish the sentences according to the text:

 

1.   ...steam-electric plant and the hydroelectric plant.

2.   For several reasons, the relative importance...

3.   Distribution networks have been extended so...

4.   ...the cost of coal and oil has been increasing.

5.   For example, in the United States in...

 

3. Complete the sentences using the required prepositions:

 

according to, because of, through, of, at, for, by, during, in, in case of, into.

 

1.   The power transmitted ... a wire is the product... the voltage times the amperage. ... resistive losses, it is desirable to transmit power ... low amperage and high voltage.

2.   ... doubling the voltage, the capability ... a given circuit can be quadrupled.

3.   Devices are classed ... the operation they are intended....

4.   This type ... aerial is useful and popular ... its small size.

5.   ... a faulty device its readings are not to be relied ...

6.   Coal and oil contain sulfur ... concentrations ... a few percent.

7.   As these fuels are burned, the sulfur is converted ... sulfur- dioxide gas.

8.   ... the operation ... a plant, the sulfur-dioxide and other products are discharged ...

the air stacks, some ... which are about 305 meters high.

 

4. Translate the following sentences:

 

The ammeter is the very instrument to measure the electric current. 2. To heat a body we place it in contact with another body at a higher temperature. 3. We expect most bodies to expand when heated. 4. Under such conditions laboratory testing is assumed to expand rapidly. 5. Having been used for a long time, the instrument partly lost its former efficiency. 6. The pressure range being beyond the limits of the existing diagram, data have been calculated by other means. 7. Drawing curves gives us a means of showing the relation existing between the two constants. 8. Wishing to find out the cause of the fault, they examined the device in all its details. 9. The charge due to the presence of these electrons is called space charge.10. We know of copper having been used as a conductor owing to its suitable characteristics.

 

 

Unit 25                                                        WIND – POWER SYSTEMS

 

The Earth is unevenly heated by the sun resulting in the poles receiving less energy from the sun than the equator does. Also, the dry land heats up (and cools down) more quickly than the seas do. The differential heating drives a global atmospheric convection system reaching from the Earth’s surface to the stratosphere which acts as a virtual ceiling. Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160km/h (100 mph) occur. Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth’s surface and the atmosphere. The total amount of economically extractable power available from the wind is considerably more than present human power use from all sources.

 

Distribution of wind speed

 

The strength of wind varies, and an average value for a given location does not alone indicate the amount of energy a wind turbine could produce there. To assess the frequency of wind speeds at a particular location, a probability distribution function is often fit to the

observed data. Different locations will have different wind speed distributions.

Much of the energy comes in short bursts, because so much power is generated by higher wind speed. The consequence is that wind energy from a particular turbine or wind farm does not have as consistent an output as fuel-fired power plants; utilities that use wind power provide power from starting existing generation for times

when the wind is weak thus wind power is primarily a fuel saver rather than a capacity saver. Making wind power more consistent requires that various existing technologies and methods be extended in particular the use of stronger inter regional transmission to link widely distributed wind farms since the average variability is much less; the use of hydro storage and demand-side energy management.

 

Electricity Generation

 

Electricity generated by a wind farm is normally fed into the national electric power transmission network. Individual turbines are interconnected with a medium voltage (usually 34.5 kV) power collection system and communications network. At a substation, this medium-voltage electrical current is increased in voltage with a transformer for connection to the high voltage transmission system. The surplus power produced by domestic micro generators can, in some jurisdictions, be fed back into the network and sold back to the utility company, producing a retail credit for the consumer to offset their energy costs.

Induction generators, often used for wind power projects, require reactive power for excitation so substations used in wind-power collection systems include substantial capacitor banks for power factor correction. Different types of wind turbine generators behave differently during transmission grid disturbances, so extensive modeling of the dynamic electromechanical characteristics of a new wind farm is required by transmission system operators to ensure predictable stable behavior during system faults.

In particular, induction generators cannot support the system voltage during faults, unlike steam or hydro turbine-driven synchronous generators (however properly matched power factor correction capacitors along with electronic control of resonance can support induction generation without grid). Doubly-fed machines, or wind turbines with solid-state converters between the turbine generator and the collector system, have generally more desirable properties for grid interconnection. Transmission systems operators will supply a wind farm developer with a grid code to specify the requirements for interconnection to the transmission grid. This will include power factor, constancy of frequency and dynamic behavior of the wind farm turbines during a system fault.

 

Capacity

 

Electricity generated from wind power can be highly variable at several different timescales: from hour to hour, daily, and seasonally. Annual variation also exists, but is not as significant.

Because instantaneous electrical generation and consumption must remain in balance to maintain grid stability, this variability can present substantial challenges to incorporating large amounts of wind power into a grid system. Intermittency and the non-dispatchable nature of wind energy production can raise costs for regulation, incremental operating reserve, and (at high penetration levels) could require an increase in the already existing energy demand management, load shedding, or storage solutions or system interconnection with HVDC (high-voltage direct current – line) cables. At low levels of wind penetration, a fluctuation in load and allowance for failure of large generating units requires reserve capacity that can also regulate for variability of wind generation.

In particular geographic regions, peak wind speeds may not coincide with peak demand for electrical power. In California and Texas, for example, hot days in summer may have low wind speed and high electrical demand due to air conditioning. Some utilities subsidize the purchase of geothermal heat pumps by their customers, to reduce electricity demand during the summer months by making air conditioning up to 70 % more efficient; widespread adoption of this technology would better match electricity demand to wind availability in areas with hot summers and low summer winds. Geothermal heat pumps also allow renewable electricity from wind to displace natural gas and heating oil for central heating during winter, when winds tend to be stronger in many areas.

 

Active Words and Expressions

 

wind power – енергія вітру  turbine hub – корпус турбіни electricity consumption –споживання електрики power density – щільність розсіюваної потужності wind resources – ресурси вітру grid – енергетична система turbine wake – наслідки аварії турбіни wind turbine – вітряк install – встановлювати blade soiling– пошкодження лопаті turbine weight – вага турбіни

wind farm – вітряна електростанція

 

1. Answer the following questions

 

1.   In what countries are wind turbines a relatively common sight?

2.   What generators are often used for wind power projects? What do they require?

3.   What is grid management system?

4.   What are the essential timescales?

5.   What points and aspects should be taken into consideration before installation of the project?

6.   What ecological impact is noticeable?

 

2.     Translate the following word-combinations:

 

wind areas; current electricity consumption; wind energy recourses; wind energy applications; mean wind power density; advanced wind turbine technology; future generation technology; wind energy development; wind electric potential; turbine hug height; energy losses; wind resource assessment.

3.     Finish the sentences according to the text:

 

1.       Most of the energy stored in these wind movements can be...

2.       The strength of wind varies, and an average value...

3.       Making wind power more consistent requires that various existing...

4.       Individual turbines are interconnected with...

5.       ...capacitor banks for power factor correction.

6.       Electricity generated from wind power can be...

7.       ...of wind power into a grid system.

8.       In particular geographic regions...

9.       ...by making air conditioning up to 70 % more efficient.

10.   Geothermal heat pumps also allow renewable electricity from wind to...

 

 

Unit 26                                      HYDROELECTRIC POWER PLANTS

 

HYDROELECTRICITY

 

Hydroelectric power plants are built on rivers. Large-capacity hydroelectric power plants are commonly located at considerable distances from the consumers of electric power.

The production process at these plants is rather simple: the water flows into the hydro turbine runner, acts upon the runner blades and rotates the runner and the turbine shaft.

The generator shaft is connected to the turbine runner shaft. The difference in the water level influences the power capacity of a plant, i.e. the magnitude of the water head and the daily inflow of water fluctuate considerably according to the season.

The production process is different at power plants of different constructions and of different kinds. In atomic power plants, for example, it is not so simple as in

hydroelectric plants.

Hydroelectric power now supplies about 19% of world electricity. Large dams are still being designed. Apart from a few countries with an abundance of hydro power, this energy source is normally applied to peak load demand, because it is readily stopped and started. It also provides a high-capacity, low-cost means of energy storage, known as «pumped storage».

Hydropower produces essentially no carbon dioxide or other harmful emissions, in contrast to burning fossil fuels, and is not a significant contributor to global warming through CO2.

Hydroelectric power can be far less expensive than electricity generated from fossil fuels or nuclear energy. Areas with abundant         hydroelectric         power          attract industry.           The    chief advantage    of hydroelectric dams is their ability to handle seasonal (as well as daily) high peak loads. When the electricity demands drop, the dam simply stores more water (which provides more flow when it releases). Some electricity generators use water dams to store excess energy (often during the night), by using the

electricity to pump water up into a basin.

Electricity can be generated when demand increases. In practice the utilization of stored water in river dams is sometimes complicated by demands for irrigation which may occur out of phase with peak electrical demands.

Not all hydroelectric power requires a dam; a run-of-river project only uses part of the stream flow and is a characteristic of small hydropower projects.

There are some considerations in a micro-hydro system installation. The amount of water flow available on a consistent basis, since lack of rain can affect plant operation. The more head, the more power that can be generated. There can be legal and regulatory issues, since most countries, cities, and states have regulations about water rights and easements.

Over the last few years, the U.S. Government has increased support for alternative power generation. Many resources such as grants, loans, and tax benefits are available for small scale hydro systems.

In poor areas, many remote communities have no electricity.

Micro hydro power, with a capacity of 100 kW or less, allows communities to generate electricity. This form of power is supported by various organizations such as the UK’s Practical Action.

Micro-hydro power can be used directly as «shaft power» for many industrial applications. Alternatively, the preferred option for domestic energy supply is to generate electricity with a generator or a reversed electric motor which, while less efficient, is likely to be available locally and cheaply.

 

Active Words and Expressions

 

blade – лопать  to influence – впливати level – рівень magnitude – величина fluctuate – коливатися hydropower – гідроенергетика head – верхівка  evaporate – випаровуватися

plant – станція  runoff – об’єм runner – ротор  deposit – осаджувати shaft – привод, вал  to account for – нараховувати rotate – обертатися 

a great deal of – велика кількість residential customer – побутовий споживач abundant – у величезній кількості

 

1. Answer the following questions

 

1.   On what sites are hydroelectric power plants built?

2.   Are large-capacity plants located far from consumers of power?

3.   Is the production process at the plants simple or is it complex?

4.   What influences the power capacity of a plant?

5.   According to what factors does the daily inflow of water fluctuate?

6.   Does the production process at the plant depend on its construction?

 

2. Say whether the following statements are true or false:

 

1.   Hydropower provides a high-capacity, low-cost means of energy storage, known as «pumped storage».

2.   Hydropower produces essentially carbon dioxide or other harmful emissions.

3.   All hydroelectric power requires a dam.

4.   There are some considerations in a micro-hydro system installation.

5.   Governments of different countries have increased support for alternative power generation.

6.   Micro-hydro power can be used for many industrial applications.

7.   Hydroelectric power can be far more expensive than electricity generated from fossil fuels.

8.   The chief advantage of hydroelectric dams is their ability to handle seasonal high peak loads.

 

3. Translate the following sentences with the Gerund:

 

1.Hydropower was a clean and environmentally safe method of producing electricity.

2.   In this respect, hydropower is better than burning coal, oil or natural gas.

3.   Decaying vegetation, submerged by flooding, may give off quantities of greenhouse gases equivalent to those from other sources of electricity.

4.   Reservoirs can be used for ensuring adequate water supplies, providing irrigation and recreation.

5.   Damming a river can alter the amount and quality of water in the river downstream of the dam, as well as preventing fish from migrating upstream to spawn.

6.   These impacts can be reduced by requiring minimum flows downstream of a dam, and by creating fish ladders.

7.   Harnessing this resource would require billions of dollars.

 

4. Choose the correct word.

 

Whenever we met, Jack avoided (to look, looking) at me. 2. Most people enjoy (to travel, travelling) to different parts of the world. 3. Maggie needs (to find, finding) another job. Her present company is going out of business. 4. May I change the TV channel, or do you want (to watch, watching) more of this program? 5. Lily is considering (to change, changing) her major from pre-med studies to psychology. 6.

Although Joe slammed on his brakes, he couldn’t avoid (to hit, hitting) the small dog that suddenly darted out in front of his car. 7. I hope (to write, writing) my autobiography before I die. Do you think anyone would read it? 8. Joyce thanked us for (to invite, inviting) them to dinner and said that they wanted to have us over for dinner next week. 9. If you delay (to pay, paying) your bills, you will only incur more and more interest charges. 10. My lawyer advised me not (to say, saying) anything further about the accident.

 

 

Unit 27                                                                      NUCLEAR POWER

 

The EU is producing not only more electricity than ever, but also more favorable consideration as a viable part of the nation’s energy mix. Consider that, for the first time, political leaders are proposing nuclear power as an important, longterm energy solution. Even the mainstream media – known for its harsh treatment of the industry – has begun talking in terms of a nuclear industry «renaissance».

The near-term impetus for this turn-around stems from recent events – regional power shortages, increased natural gas costs, and premium market prices for electricity. However, the fact that nuclear power is in the position to be favorable considered is a result of the substantial performance improvements achieved at US plants during the past decade.

Most important, these performance gains came with equally impressive improvements in safety indicators. The challenge for individual nuclear stations is to continue this idea by solidifying competitive gains already achieved and squeezing further improvements from each unit.

US nuclear plants have done an excellent job of maintaining and improving plant design margins and operating reliability. Extensive monitoring and surveillance testing of plant systems, structures and components such as containment building, reactor vessel, reactor cooling system pressure boundary, steam generators, pressurizer, piping, pump casings and valve bodies are performed yearly to verify the plant is maintained in excellent condition. Few if any nuclear plant components will require replacement specifically to achieve extended operations for an additional 20 years.

Nuclear power is a very clean source of energy and none of our other energy sources are at present time as clean and efficient. But there is always the risk of leaks, explosions and so forth.

It seems that the horror story of Chernobyl still haunts our minds whenever this topic is brought up. And it was a terribly tragic accident that destroyed the life of not only the people near it but the lives of the whole world’s population generations ahead. This must not happen again. But if we take precautions, build the power plants in a place without risk of earthquakes and most importantly make sure it is properly funded we can narrow the risk down to almost nothing.

No source of energy is without problems and we have to ask ourselves – do we want to choose nuclear power or do we want oil and coal, that isn’t instantly as harmful as nuclear power, but which can’t be solved at all.

 

Active Words and Expressions

 

favorable consideration – сприятливе судження in the wake of – під впливом чого-небудь harsh treatment – жорстке ставлення renaissance – відродження

performance improvements – покращення робочих характеристик impetus – поштовх  steam generator – парогенератор unusual events – надзвичайні події reactor vessel – бак ядерного реактора pressurizer – компенсатор тиску  pump casing – корпус насосу piping – трубопровід  valve bodies – корпус вентиля energy mix – структура енергетики

containment building – захисна оболонка ядерного реактора

 

1. Answer the following questions

 

1.   How is nuclear power considered in the US in last decade?

2.   What does the near-term impetus for this turn-around stem from?

3.   What are extensive monitoring and surveillance testing of plant systems performed for?

4.   Will nuclear power prosper in our Ukraine?

5.   What can you say about an accident in Chernobyl?

 

2. Finish the sentences according to the text:

 

1.   Political leaders are proposing nuclear power...

2.   However, the fact that nuclear power is...

3.   US nuclear plants have done...

4.   ...as clean and efficient.

5.   ...horror story of Chernobyl...

6.   But if we take precautions...

7.   No source of energy is without...

8.   Chernobyl accident had happened...

 

3. Translate the sentences:

 

1. The filament heated, the electrons leave its surface and travel to the plate. 2. Multiplying the mass of a moving body by its velocity, we shall get its momentum. 3. In many instances an apparatus designed for quite a different purpose was adopted, certain changes being made when required. 4. The problem having excited a great deal of discussion, a series of tests had to be carried out. 5. The oil having been exhausted, the engine stopped. 6. There are two diagrams in this figure, one of them showing the relation between volume and temperature. 7. Working at his new device, the inventor made numerous improvements, the latter resulting from his own experiments. 8. They went on studying the nature of the new phenomenon. 9. There are different means of producing an electric current. 10. We heard of that experiment having been started last week.

 

4. Use Present Simple or Present Continuous tense.

 

1. I can’t afford that ring. It (cost) ... too much. 2. Look. It (begin) ... to rain. Unfortunately, I (have, not) ... my umbrella with me. Tom is lucky. He(wear) ... a raincoat. 3. I (own, not) ... an umbrella. I (wear) ... a waterproof hat on rainy days. 4. Right now I (look) ... around the classroom. Ann (write) ... in her book. Carlos (bite) ... his pencil. Peter (scratch)...his head. Ahmed (stare)...out of the window. He (seem) ... to be daydreaming, but perhaps he (think) ... hard about verb tenses. What you (think) ... Ahmed (do)? 5. There’s a book on my desk, but it (belong, not) ... to me. 6. Dennis (fix) ... the roof of his house today, and he (need) ... some help. Can you help him? 7. Barbara often (tutor) ... other students in her math class. This afternoon she(help) ... Steve with his math assignment because he (understand, not) ... the material they (work) ... on in the class this week. 8. Right now I (look) ... at Janet. She (look) ... angry. I wonder what’s the matter. She (have) ... a frown on her face. She certainly (have, not) ... any fun right now.

 

 

Unit 28                                                          NUCLEAR POWER PLANT

 

 

Atomic power plants are modem installations. They consist of several main units and a great number of auxiliary ones.

In a nuclear reactor uranium is utilized as a fuel. During operation process powerful heat and radioactive radiation are produced. The nuclear reactor is cooled by water circulation.

Cooling water circulates through a system of tubes, in which the water is heated to a temperature of 250-300°C. In order to prevent boiling of water, it passes into the reactor at a pressure up to 150 atmospheres.

                                                                                                                                                   A      steam      generator

includes a series of heat exchangers comprising tubes. The water heated in the reactor is delivered into the heat exchanger tubes. The water to be converted into steam flows outside these tubes. The steam produced is fed into the turbogenerator.

Besides, an atomic power plant comprises a common turbogenerator, a steam condenser with circulating water and a switchboard.

Atomic power plants have their advantages as well as disadvantages. The reactors and steam generators operate in them noiselessly; the atmosphere is not polluted by dust and smoke. As to the fuel consumption, it is of no special importance and there is no problem of fuel transportation. The disadvantage of power plants utilizing nuclear fuel is their radiation. Radioactive radiation produced in the reactors is dangerous for attending personnel. Therefore, the reactors and steam generators are installed underground. They are also shielded by thick (up to 1.5 m) concrete walls.

All their controls are operated by means of automatic devices. These measures serve to protect people from radioactive radiation.

Any operating nuclear power plant releases fission products into the environment, which causes environmental pollution. To prevent the harmful effects of nuclear power release, the nuclear power plants are supplied with protective installations that serve as barriers to the pollution. First, the nuclear fuel and the fission products are confined within sealed tubes made of stainless steel or zirconium. Then the assembly of tubes is placed in a steel reactor vessel. And finally, the steel reactor vessel is placed in a large steel and concrete housing.

As to the hot radioactive waste products they are disposed in heavily shielded cylinders. The cylinders are buried 305 to 610 meters underground.

 

Active Words and Expressions

 

exchanger – теплообмінник  to shield – захищати steam – пара  concrete – бетон tube – труба, лампа  fission – розщеплення

dust – пил 

stainless steel – нержавіюча сталь to deliver – постачати  steel vessel – посудина to pollute – забруднювати  wastе – відходи

attending personnel – обслуговуючий персонал to confine – уміщувати to release – вивільняти dispose– усувати 

withstand – протистояти

 

1. Answer the following questions

 

1.What are the main units of an atomic power plant?

2.By what means is the nuclear reactor cooled?

3.At what pressure does the water pass into the reactor?

4.What types of power plants pollute the air with dust and smoke?

5.       Why is it necessary to protect attending personnel?

6.       What kind of products does the operating nuclear power plant release?

7.       What installations are used to prevent the harmful effects of a nuclear power plant operation?

8.       What material are the tubes made of?

9.       Where are the fission products confined?

10.   In what part of the installation is the reactor vessel placed?

11.In what way are the hot radioactive waste products disposed?

 

2.     Translate the following words and word-combinations:

 

auxiliary units; heat exchanger; the polluted atmosphere; utilized nuclear fuel; shielded concrete walls; fuel consumption; steam generator; nuclear fuel; nuclear fission; steel vessel; reactor vessel; fission release; sealed tubes; concrete housing; waste products; nuclear waste; shielded cylinders.

3.     Finish the sentences:

 

1. A nuclear reactor is used in...

2.A nuclear reactor is cooled by...

3.Water is passed into the reactor...

4.High pressure...

5.Atomic power plants...

6.Attending personnel is shielded by...

7.   A nuclear power plant releases...

8.   The protective power plant installations...

9.   The fission products are confined...

10.The waste products are disposed...

 

4.     Give the English equivalents of the prepositions:

 

1.The energy (для) a nuclear power plant comes (з) the heat released (підчас) fissioning of uranium (в) a nuclear reactor. 2.There are two main differences (між) a nuclear power plant and a steam-electric power plant. 3.The nuclear power plant uses a nuclear fuel (замість) a fossil fuel, and it uses a reactor (замість) a boiler.4. (Через) their high fuel consumption gas turbines are more expensive to operate than steam turbines.5. The radioactive pollution produced (в) a reactor has all three forms: gaseous, liquid and solid.6.The beta particles are dangerous for man (тому, що) they penetrate deep (в) the matter.

 

5.     Translate the following sentences:

 

1. Radium is said to be one and a half million times more radioactive than uranium. 2. Tests have shown the thermometer to be very sensitive. 3. The oscillator referred to above seems to deliver only a small amount of power. 4. The instrument to be described here was designed several years ago. 5. To analyze this effect is to take into consideration all the elements of the circuit. 6. To analyze this effect we shall consider all the circuit elements. 7. We expected the discovery to produce great changes. 8. To explain that the formula given here are correct, it is necessary to study them first. 9. To explain why the formulas given here are correct would require considerable time.10. The apparatus to be designed is to be used at the power station.11. This type of engine is said to have some advantages.12. To find out the state of a mass of a gas is quite possible.

 

Unit 29                                                    THERMAL POWER STATION

 

 

A modern thermal power station is known to consist of four principal components, namely, coal handling and storage, boiler house, turbine house, switchgear. Besides the principal components mentioned above there are many additional parts of the plant. The most important of them is the turbo-generator in which the       current         is       actually generated. A steam turbine requires boilers to provide steam. Boilers need a coalhandling plant on the one hand and an ash-disposal plant on the other. Large fans are quite necessary to provide air for the furnaces. Water for the boilers requires feed pumps.

                                                                                                                                                 Steam         must         be

condensed after it has passed through the turbines, and this requires large quantities of cooling water. The flue gases carry dust which must be removed by cleaning the gases before they go into the open air.

A modern thermal power-station is equipped with one or more turbine generator units which convert heat energy into electric energy. The steam to drive the turbine which, in its turn, turns the rotor or revolving part of the generator is generated in boilers heated by furnaces in which one of three fuels may be used – coal, oil, or natural gas. Coal continues to be the most important and most economical of these fuels.

 

Active Words and Expressions

 

coal handling – подача вугілля,топка switchgear– розподільче обладнання

boiler house – бойлерна  storage – база, склад furnace – піч 

turbine house – турбінний зал fuels – паливо 

pump – насос

 

1. Answer the following questions

 

1.   What are the main components of the thermal power station?

2.   What is the most important fuel for these stations?

3.   What can you say about environmental impact of these stations?

4.   Name thermal power stations in your region and explain the great use of them.

 

2. Complete the sentences according to the text:

 

1.   A modern thermal power station consists of ...

2.   The most important part is ...

3.   A steam turbine requires ...

4.   Boilers need two kinds of plants, they are ...

5.   The flue gases carry dust which ...

6.   The modern thermal power station is equipped with ...

7.   ...one of three fuels may be...

8.   ...most economical of these fuels.

 

3.        Form nouns by adding the suffixes -er, -or.

 

to work, to invent, to compose, to calculate, to operate, to act, to react, to emit, to transmit, to use, to combine.

 

4.        Form adverbs from adjectives by adding the suffix -ly:

 

easy, reasonable, usual, special, physical, functional, real, regular, magnetical, different, logical, mathematical, subsequent, consequent.

 

 

Unit 30                     THERMAL STEAM-TURBINE POWER PLANTS

 

 

Large steam-turbine plants have two forms: condensing plants or electric power plants. 

The great masses of hot steam, having accomplished the mechanical work in the turbines of condensing steam-turbine plants, are condensed, i.e. are cooled down and turned back into distilled water, and returned to the boiler for production of steam to activate the turbine.

Condensation of steam takes place in condensers where the hot steam is cooled when it comes in contact with tubes through which cold water, supplied from a water reservoir (river or lake), is circulated. This cooling water, after it takes the heat from the spent steam, is returned to the water source carrying along with it the unutilized heat energy. This water is called the circulating water. The importance of the distilled water for feeding steam boilers is extremely great since chemically clean water decreases the formation of scale in the boiler tubes, and, thus, makes their service life longer.

Condensing plants of large generating capacity are built close to sources of fuel, in order not to transport large quantities of fuel over considerable distances. The electric power generated in such plants is transmitted over long distances for the supply of large industrial regions. So, these plants are called regional thermal power plants. Heat and electric power plants, in addition to electric power generation, also supply heat to closely located consumers (within a radius of 50 km), i.e. serve as district heat plants. To such heat consumers belong to all kinds of industrial enterprises that require heat for production purposes, and also municipal consumers such as baths, laundries and the heating systems of dwelling houses and other buildings.

The electric power developed by the generators is fed to the switchboard of the plant, whence it is delivered by overhead transmission and cable lines to the consumers.

 

1. Answer the following questions

 

1.   In what part of the power plant does condensation of steam take place?

2.   Why is distilled water used for feeding steam boilers?

3.   How closely does an electric power station located to consumers?

4.   What kinds of industrial enterprises that require heat for production purposes do you know?

 

2. Complete the sentences according to the text:

 

1.   ...condensing plants or electric power plants.

2.   ...in the turbines of condensing steam-turbine plants.

3.   Condensation of steam takes place in...

4.   The importance of the distilled water for...

5.   ...are built close to sources of fuel...

6.   The electric power generated in...

7.   ...closely located consumers (within a radius of 50 km).

8.   The electric power developed by the generators is fed to...

 

3. Translate the negative sentences into Ukrainian:

 

1. No charges can move in an open circuit. 2. Nothing less than a map of the Universe is planned by the research. 3. No special equipment is necessary to carry out the experiment.4. A current which does not change its polarity is called a direct current. 5. A dry battery is a type of a small battery containing no free liquid. 6. The efficiency of a machine can never be greater than unity; it is often given as a percentage.7. Electrically safe locations are those where conditions causing extremely high danger of electric shock do not exist.8. No electric device has only advantages. All of them have also disadvantages. 

 

4. Choose the correct form:

 

1. The aluminium plant is a (consumer, consumption) of the (local, locally) generated electric power. 2. The (new, newly) built shops are (importance, important) for the future of the power plant. 3. Nuclear energy is energy released during a nuclear (reactor, reaction) as a result of (convertible, conversion) of mass into energy. 4.Uranium is a (comparison, comparable, comparatively) rare element. 5. The most (importance, important) problems in (atom, atomic) power (generator, generation) are connected with the reactor. Reactor (technologist, technology) is still in (progressive, progress). 6. The light-water reactor types seem most (usefulness, usefully, useful).

 

 

Unit 31

THE ROLE OF ELECTRICITY AND ITS FUTURE APPLICATION

 

 

At a time when communication technologies are becoming ever more essential for uniting knowledge and making fast decisions, one third of the earth’s inhabitants – nearly 2 billion people – still have no access to a modern energy source. The implications of energy over the coming twenty years are wide and varied and will include issues as crucial as economic development and political stability in numerous countries, safeguarding our local and global environment, controlling global warming, social equity, achieving a balance between rural and urban development policies and so on. Briefly, sustainable human development.

Whether we are in charge of policy or the economy, it is our joint responsibility to place the issue of access to clean and cost-effective electricity for all at the centre of the much-needed debate to determine nor only what type of progress, democracy and humanism, but also what type of development, our generation will bequeath to the generations yet to come. We should consider the conditions for access to electricity, not in terms of sustainable economic, social and political development for all the inhabitants of this planet.

Wide disparities in access to affordable commercial energy threat to social stability and counter to the concept of human development. Air pollution and emissions of gases threaten our health, degrade our environment and alter the global climate system. The current consumption of primary energy increases at a rate of 2 % every year, but this growth is very unequal around the world:

–   Europe 0, 2 % year;

–   USA – Canada 1,4 % year; – Developing countries 4,5 % year.

If the global growth rate continues, it will mean a doubling of energy consumption by 2035 relative to 1998, and a tripling by 2055. Energy consumption is bound to increase.

Physical resources and technical opportunities are available to meet the challenge of sustainable development, but it requires policy changes, such as:

–   more effective use of energy (buildings, electric appliances, vehicles, production processes);

–   increased reliance on renewable energy sources;

–   accelerate development and deployment of new energy technologies; –as well as taking into account the costs of the various solutions.

 

Active Words and Expressions

 

to make fast decisions – приймати швидкі рішення unite knowledge – об’єднувати знання access – доступ issue – проблема essential– важливий, суттєвий  social equity – соціальна рівність implication – залучення varied – різноманітний sustainable – стійкий to be in charge of – опікуватися safeguard – гарантувати  determine – визначати treat – загрожувати  responsibility – відповідальність

to take into  account –брати до уваги to meet the challenge – прийняти виклик renewable – той, що поновлюється bequeath – заповідати

 

1. Answer the following questions

 

1.   What issues will the implications of energy include?

2.   What is our joint responsibility?

3.   What can alter the global climate system?

4.   What policy changes are required for physical resources and technical opportunities?

 

2. Complete the sentences according to the text:

 

1.   At a time when communication technologies are becoming ever more essential...

2.   ...to clean and cost-effective electricity for all...

3.   We should consider the...

4.   ...to the concept of human development.

5.   The current consumption of primary energy increases...

6.   Physical resources and technical opportunities are available to...

 

3.     Distribute the words into four columns.

 

Model: what?(use) what to do?(to use) what kind of ? (useful) how?(usefully) insulator, failure, fail, addition, additional, overestimate, equal, equalize, equality, equally, different, differ, difference, resist, resistance, resistivity, resistant, commonly, consumer, faulty, impossibility, carelessly, number, numerous, possible, clockwise

 

4.     Change the sentences into questions:

 

1.   There are various types of nuclear reactors.

2.   The use of underground transmission lines must be increased.

3.   The fuel can be enriched uranium.

4.   The fission heat is used to generate steam, which drives a turbine generator.

 

 

Unit 32

ENVIRONMENT SHOULD BE OUR COMMON CONCERN

 

 

Society which turns its back on nature is doomed. Many people today believe that the dominant forces of global society are, in fact, ignoring Nature’s needs. Everywhere the natural environment is being overexploited, weakened and soiled. Man uses atmosphere as both a resource and a place for depositing wastes. He takes from atmosphere oxygen as a necessary ingredient for his industrial activities and for his own biological processes. He returns to it a mixture of gases and solids, the by-products of combustion, respiration.

The historical development of urbanization and industrialization has produced geographical regions where the natural balance is disturbed. Evidence   abound        that    the dangers of uncontrolled industrialization are leading to the pollution of lakes and rivers and human tragedies like those which occurred in Bhopal (India), where thousands of people died as a result of a deadly gas leak from a chemical plant in 1984, or at Chernobyl atomic power plant in 1986. Just as obvious are the large - scale loss of tree cover, soils and biological diversity as a result of uncontrolled economic development, and the horrors of chemical warfare and nuclear power testing. We have all experienced the result: air pollution, a shortage of drinking water, the ruin of forests, soil degradation and etc. As a result people are affected directly or indirectly.

Some effects are direct and evoke physiological response (eye irradiation, respiratory diseases), other effects are indirect, but nonetheless disturbing. Women, for instance, have learned that their breast milk is contaminated with dioxin, that pesticides and herbicides are present in ground water. They are told that the lifegiving sun is becoming dangerous due to a weakened ozone layer, that children everywhere are vulnerable to genetic disorders caused by contaminated environments.

As the planet’s natural resources diminish, and a growing world population increases demands on those resources, competition for access to them will escalate. This struggle for limited resources will result in new resource wars.

The major environmental threat to life on Earth is the weakening of ozone layer. The Earth’s ozone shield – the vital layer of the atmosphere - protects all living creatures from the damaging effects of the Sun’s rays. Recent scientific research proved data that the protective layer of ozone around our planet is under severe attack. The major cause of weakening of the ozone layer is believed to be increasing amount of harmful chemicals that are being released into the atmosphere by mankind. Many scientists warn that the chemicals in spray cans also add to the destroying of the Earth’s ozone shield. Scientists stress that a further one per cent drop in the overall ozone layer can cause an increase of skin cancer.

The air contamination due to man’s economic activity is bringing mankind to the greenhouse effect. It appears when CO and certain other gases in the atmosphere allow the sun’s ultra-violet rays to penetrate and warm the earth but then absorb the infrared energy the earth radiates back into space forming a kind of thermal

blanket around the Earth.

Acid rains and forest fires play their role in the destruction of forests. As a consequence, the ruin of forests brings about ecological disaster. Machine tillage of the soil affects its natural fertility, while the ever-growing application of fertilizers and pesticides damages nature by changing the ecological conditions of human habitation.

Environmental protection is a task requiring the joint efforts of the entire world population, of government agencies, and public organizations of the world over.

 

Vocabulary notes

 

1.   to turn one’s back on – повернутися спиною до...

2.   evidence abounds that – є багато доказів того, що...

3.   deadly gas leak – витік смертельного газу

4.   the large-scale loss of tree cover – широкомасштабна втрата лісового покриття 5. chemical warfare and nuclear power testing – хімічна війна і ядерні випробування

6.   is under severe attack – перебуває під суворою руйнівною дією

7.   one per cent drop in the overall ozone layer – падіння на 1% усього озонового шару

 

Active Words and Expressions

 

oxygen – кисень 

to be doomed – бути приреченим combustion – згоряння by-product – побічний продукт global society – світове суспільство respiration – дихання response – реакція

necessary ingredient – необхідна складова diversity – різноманітність spray cans – аерозолі

natural balance – природна рівновага disease – хвороба  skin cancer – рак шкіри vulnerable – уразливий acid rain – кислотний дощ human habitation – житло людини severe – суворий

ultra-violet – ультрафіолетовий thermal blanket – теплова ковдра aggravate – погіршувати 

tillage – обробіток землі

 

1. Answer the following questions

 

1.       Does ignoring nature cause positive consequences?

2.       What does man use atmosphere?

3.       How do urbanization and industrialization affect nature?

4.       Can you name facts of negative consequences of economic activity?

5.       What can air pollution cause?

6.       What are the major environmental threats to life on earth at present?

7.       What is the major cause of the ozone layer weakening?

8.       When does the greenhouse effect appear?

9.       How do acid rains affect our environment?

10.   What can make environmental protection more effective?

 

2.        Translate the following word-combinations:

 

natural environment, industrial activity, biological process, natural balance, uncontrolled industrialization, atomic power plant, chemical warfare, nuclear power testing, air pollution, life-giving sun, ozone shield, protective layer, harmful chemicals, air contamination, greenhouse effect, acid rains, environmental protection.

 

3.        Finish the sentences according to the text:

 

1.   Man uses atmosphere as both a...

2.   The historical development of urbanization...

3.   ...in Bhopal (India), where thousands of people died as a result of...

4.   ...air pollution, a shortage of drinking water, the ruin of forests, soil degradation and etc.

5.   As the planet’s natural resources diminish, and a growing...

6.   The major environmental threat to life on Earth...

7.   ...is believed to be increasing amount of harmful... 8. The air contamination due to man’s economic activity is...

9.       Acid rains and forest fires play...

10.   ...by changing the ecological conditions of human habitation.

 

4. Put 4 types of the questions to the sentences:

 

1.   The major environmental threat to life on Earth is the weakening of ozone layer.

2.   Many people were affected by Chernobyl catastrophe.

3.   Plants and animals fail to live without oxygen.

4.   Industrial enterprises must use filters for exhaust gases to be purified.

 

 

Unit 33                                                            CHERNOBYL ACCIDENT

 

 

The accident, which was of global concern, was the accident in Ukraine in the Chernobyl power plant located in Polissya on the River Prypiat. It is considered the worst nuclear power plant accident in history and is the only level 7 event on the International Nuclear Event Scale.

On 26 April, 1986, Unit 4 of the Chernobyl nuclear plant suffered a major accident. The Chernobyl 4 reactor was a graphite-moderated, light-water-cooled       system.        The installed electrical generating capacity was 1 GW. The accident followed some engineering tests of a generator.

During the tests, basic operating

safety rules were being violated. Most control rods were withdrawn from the core and the safety systems were switched off. Two explosions and a fire that followed them damaged the reactor and the containment

building. The graphite started to bum. Explosive energy was released, which

resulted in the 1000-ton cover plate of the reactor being lifted up.

The fire inside Reactor 4 continued to burn until 10th of May; it is possible that well over half of the graphite burned out. The fire was extinguished by a combined effort of helicopters dropping over 5,000 metric tons of materials like sand, lead, clay, and boron onto the burning reactor and injection of liquid nitrogen. Ukrainian filmmaker Vladimir Shevchenko captured film footage of a Mi-8 helicopter as it collided with a nearby construction crane, causing the helicopter to fall near the damaged reactor building and kill its four-man crew.

A prolonged release of large quantities of radioactive products transported by the cloud from Chernobyl was detected not only in northern and southern Europe but also in Canada, Japan, and the USA.

The major part of the release took place over the period of about ten days. There were two peaks in release rate (26th April and 5th May). Later on, the release continued for many weeks at a lower rate before the destroyed reactor was finally sealed, which took place some five months later.

Initially the cloud of radioactive material was carried over the Baltic Sea into Scandinavia. After a few days the wind direction rotated clockwise and the cloud travelled eastwards across the USSR and southwards to Turkey.

The total mass of the radioactive particles released in the accident was about 6000-8000 Kg. More than half of it was deposited near the plant but the rest travelled thousands of kilometers. Great damage was done to their economy, nature and people’s health. The problem of Chernobyl has not been solved yet because of the economic difficulties that Ukraine is having now. The power plant was closed on December 15, 2000. There is no doubt that the nuclear plant

accidents offer a number of lessons to be learnt.

At present, over 200 nuclear power reactors for commercial electricity production operate in Europe. The accident at the Chernobyl nuclear plant has shown that large-scale accidents in nuclear power plants can lead to contamination of the entire continent.

 

1. Answer the following questions

 

1.   What was the cause of the Chernobyl accident?

2.   What was the path of the radioactive material released in the accident?

3.   What can accidents at the nuclear plants lead to?

4.   What Vladimir Shevchenko was doing near the atomic power station?

 

2. Finish the sentences according to the text:

 

1.       The Chernobyl 4 reactor was a...

2.       During the tests, basic operating...the graphite started to bum.

3.       ...until 10th of May; it is possible that well over half of the graphite burned out.

4.       ...over 5,000 metric tons of materials like sand, lead, clay, and boron onto the...

5.       Ukrainian filmmaker Vladimir Shevchenko captured film footage of a Mi-8 helicopter as...

6.       ...but also in Canada, Japan, and the USA.

7.       Initially the cloud of radioactive material...

8.       ...was about 6000-8000 Kg.

9.       ...on December 15, 2000.

10.   ...can lead to contamination of the entire continent.

 

3. Translate the following sentences into Ukrainian:

 

1. For many centuries the problem of air pollution was not paid attention to. 2. We ought to protect the environment for it is in danger of human activity. 3. Industrial enterprises must use filters for exhaust gases to be purified. 4. The ecosystem has a definite role to play for an overall balance has to be maintained. 5. Plants and animals fail to live without oxygen. 6. Many countries on the globe fail to fight man-made pollution. 7. The experiment was very tedious but they failed to get the desirable results. Transportation devices all over the world fail to prevent air from exhaust gases pollution. 8. Their attempt to make this experiment failed.9. The problem of environmental protection is very important, a special committee having been set up under the UNO. 10. The development of modern industry is likely to be accompanied by the development of wasteless production. 11. Concentration of CO happens to be rather high in air. 12. Primitive man appeared to disturb the balance of nature by farming and cattle breeding.

 

4. Match the English words with their definition:

 

1. Environment	a) an area set aside for preserving nature
2. Fauna	b)      organism’s      physical      and biological surroundings
3. Flora	c) warming of temperatures around the world
4. Garbage can	d) layer of gases that surrounds the earth
5. Global warming	e) animals or animal life
6. Climate	f) plants or plant life
7. Atmosphere	g) aspects of the weather (rainfall, light, air movement)
8. Biosphere	h) you can even kill with this dangerous thing
9. Litter	i)to continue to be alive after coming close to death
10.Pollution	j) to make dirty air, water, everything around us

                   11.Smog                                            k) rain polluted by chemicals

12.   Species          l) it may be nuclear, industrial, dangerous

13.   Acid rain        m) a result of people’s bad actions in

nature

14.   To pollute       n) mixture of smoke and fog

15.   Waste   o) a group of similar types of animals

or plants

16.   To poison       p) garbage like food, paper and cans

17.   To survive      q) waste bin

 

 

Unit 34                         CHERNOBYL NUCLEAR POWER STATION

 

 

On April 26, 1986 one of the history’s worst nuclear accident occurred at the Chernobyl Nuclear Power station in Ukraine. At 1:23 AM, technicians at the plant allowed the power in the 4th reactor to fall to low levels as part of a controlled experiment, which went terribly wrong. The reactor overheated and caused a meltdown of the core. This resulted in an explosive force of steam, which blew off the lid of the reactor. Large amounts of the radioactive materials were released into the atmosphere. The reactor-4 explosions released more radioactivities that the atomic bombs dropped on Hiroshima and Nagasaki during World War II.

Most of the discharged material was deposited close by as dust and debris, but wind carries the lighter radioactive material over Ukraine, Belarus, Russia and parts of Europe.

The operator’s over-confident decision-making, a flaw in the design of the reactor and inadequate safety systems are believed to be the major factors that caused the Chernobyl disaster. Many people were affected by this catastrophe. The accident caused 31 immediate deaths that were mainly the result of exposure the radiation. The main casualties were among those who fought the fires caused by the explosion. Once the fires were extinguished, a liquidating crew of around 200,000 people was initially employed to clean up the site. Later the number swelled to 600,000. This crew was exposed to high doses of radiation, which might affect their health in the long run.

Many children in the surrounding areas are developed thyroid cancer due to the radiation emitted. Many Ukrainians, Russians and Belarusians were evacuated and later given new homes in a different area.

Today reactor-4 is buried in cement tomb which was quickly built in order to allow the other reactors at the power station to continue working. However, this shelter is not strong and will not last and there are plants to replace it. Many people have suffered in some way as a result of the Chernobyl disaster and millions of dollars are still being spent today to contain reactor-4 and assure that no further radiation leakage occurs.

 

Active Words and Expressions

 

core – ядро, серцевина casualty– жертва lid – покриття crew – команда to release, deposit – випускати to clean up – прибирати to leak – витікати dust and debris – пил, уламки to enclose – огороджувати lack – недолік flaw – тріщина

explosion – вибух

 

1. Choose the correct option.

 

1. The Chernobyl disaster is thought to be ...

a)   as serious as Hiroshima and Nagasaki bombings;

b)  a minor accident with no future consequences;

c)   one of many similar accidents;

d)  Europe’s greatest catastrophe.

 

2. When the Chernobyl-4 reactor overheated ...

a)   technicians turned it down;

b)  it melted the core;

c)   the power plant was filled with steam;

d)  it sealed the lid of the reactor shut.

 

3. One of the causes of the accident was ...

a)   the raising of the power in 4th reactor to high levels;

b)  a design fault;

c)   the installation of proper safety back-up systems;

d)  the technicians lack of confidence.

 

4. The 4th reactor explosion resulted in the ...

a)   spread of the heavier radioactive material by the wind;

b)  immediate death of 200,000 people;

c)   release of dust and debris into the atmosphere;

d)  release of the 4th reactor’s cover.

 

5. Most of the people who died as a result of the explosion were...

a)   firefighters;

b)  members of clean- up crew;

c)   operators of the reactor;

d)  children.

 

6. The members of clean-up crew...

a)   developed thyroid cancer;

b)  put out the fires;

c)   were subject to high levels of radiation;

d)  were unharmed by the radiation.

 

7. Reactor-4...

a)   is steel leaking radiation;

b)  is enclosed in cement;

c)   will be replaced in future;

d)  cost millions of dollars.

 

2. Finish the sentences according to the text:

 

1.   ...Chernobyl Nuclear Power station in Ukraine.

2.   The reactor overheated and...

3.   The reactor-4 explosions released more radioactivity than...

4....radioactive material over the Ukraine, Belarus, Russia and parts of Europe.

5.   The accident caused 31 immediate deaths...

6.   Many children in the surrounding areas...

7.Today reactor-4 is buried in cement tomb which...

8. ...that no further radiation leakage occurs.

 

3.     Translate the following sentences:

 

1.Сьогодні проблеми навколишнього середовища найбільш важливі для сучасного суспільства.

2.Забруднення води, грунту та радіоактивне забруднення шкодять природі.

3.Учені вважають, що людська діяльність змінює клімат нашої планети та руйнує його.

4.Тільки зараз ми зрозуміли, що наша планета знаходиться під загрозою і це - наша провина.

 

4.     Put 4 types of the questions to the sentences:

 

1.   After the Chernobyl tragedy thousands of people greatly suffered from radiation.

2.   Lake Baikal is the deepest freshwater lake on the Earth.

3.   Modern plants and factories send a lot of smoke into air.

 

 

CONTENTS

 

Unit 1 SHAPES………………………………………………………………2

Unit 2 UNITS OF MEASUREMENT……………………………………….3

Unit 3 MATHEMATICAL OPERATIONS…………………………………6

Unit 4 ENERGY……………………………………………………………..8

Unit 5 LIGHTNING………………………………………………………..10

Unit 6 MAGNETISM………………………………………………………12

Unit 7 THE ELECTRICAL PROPERTIES OF MATERIALS…………….14

Unit 8 WHAT IS ELECTRICITY…………………………………………..16 Unit 9 FROM THE HISTORY OF ELECTRICITY……………………….19

Unit 10 ELECTRIC LAMP………………………………………………...22

Unit 11 HEATING EFFECT OF AN ELECTRIC CURRENT……………24

Unit 12 ELECTRICAL SUPPLY…………………………………………..26 Unit 13 CURRENT, VOLTAGE AND RESISTANCE……………………28

Unit 14 ELECTRIC CIRCUITS……………………………………………31 Unit 15 CIRCUITS AND COMPONENTS………………………………...33

Unit 16 RESISTORS……………………………………………………….37

Unit 17 CAPASITORS……………………………………………………..39 Unit 18 CONDUCTORS AND INSULATORS……………………………41

Unit 19 TRANSFORMERS………………………………………………..43

Unit 20 ELECTRIC MOTOR………………………………………………46

Unit 21 TRANSMISSION LINES…………………………………………48

Unit 22 FUSES……………………………………………………………..50

Unit 23 SUBSTATIONS…………………………………………………...52

Unit 24 ELECTRIC POWER PLANTS……………………………………54

Unit 25 WIND-POWER PLANTS…………………………………………56

Unit 26 HYDROELECTRIC POWER PLANTS…………………………..59

Unit 27 NUCLEAR POWER……………………………………………….62

Unit 28 NUCLEAR POWER PLANTS…………………………………….65

Unit 29 THERMAL POWER STATIONS…………………………………67

Unit 30 THERMAL STEAM-TURBINE POWER PLANTS……………...69 Unit 31 THE ROLE OF ELECTRICITY…………………………………...71

Unit 32 ENVIRONMENT SHOUL BE OUR COMMON CONCERN……73

Unit 33 CHERNOBYL ACCIDENT……………………………………….76

Unit 34 CHERNOBYL NUCLEAR POWER STATION………………….79

 

CONTENTS………………………………………………………………..82