Практический курс обучения профессионально ориентированному иностранному языку. Электроэнергетика и электротехника. В 2 частях. Ч.1. Учебное пособие

indicators on the meter’s face. This type of meter is designed for use with alternating current. It contains two electromagnets and a metal disk that is free to rotate between them. One electromagnet is powered directly by current from the incomingpower lines; the other, by current drawn through the building’s electrical circuits. The interaction of the magnetic fields produced by the coils causes the disk to rotate. Two permanent magnets near the disk’s edge brake the disk in such a way that the speed of rotation is proportional to the amount of current drawn. As the disk rotates, it turns the series of geared wheels connected to the indicators on the meter’s face.

Electronic watt-hour meters use solidstate circuits that produce electrical signals whose frequency or strength is proportional to the voltage and current being used. These signals are converted into energy measurements recorded by mechanical or electronic indicators. Electronic watt-hour meters are generally more expensive than electromechanical models, but are more accurate. They can provide such features as the ability to record separately the energy consumed during different times of day and the ability to report meter readings by means of signals sent through the power lines to the power company.

26. Render the text into English using language you have studied in this unit.

Во время проверки электрооборудования владелец автомобиля постоянно имеет дело с такими понятиями, как «напряжение», «сила тока», «сопротивление». Единицей измерения напряжения является вольт (V), сила тока измеряется в амперах (А), а сопротивление – ​в омах (Ом). Для проверки электрооборудования можно использовать универсальный измерительный прибор – ​ мультиметр. В данном приборе объединены вольтметр для измерения напряжения, амперметр для измерения силы тока, омметр для измерения сопротивления. Существуют два типа мультиметров: аналоговый и цифровой. Цифровые приборы обладают более высокой точностью, чем аналоговые, и отличаются простотой использования.

41

Unit 3

ELECTRICITY AND ELECTROMAGNETISM

LEAD-IN: vocabulary and speaking

1. Discuss the quotation below. Explain its meaning and say whether you agree or not, and why.

Thedaywhenweshallknowexactlywhatelectricityiswillchronicleanevent probably greater, more important than any other recorded in the history of the human race. The time will come when the comfort, the very existence, perhaps, of man will depend upon that wonderful agent.

Nikola Tesla, 1856–1943, Serbian-American inventor, electrical engineer

2. Study the list of words and their definitions. Give the Russian equivalents of the words. Consult the dictionary if necessary.

42

3. Complete the sentences with the words from the box.

3The next step is to __________ the cost of manufacturing each component of the product.

4 Did you __________ the camcorder’s batteries?

5 Darwin’s observations led him to __________ that plants and animals could adapt to their surroundings.

6The system is so sensitive that it can __________ differences in temperature as small as 0.003 degrees.

7 Major earthquakes like this _________ very rarely.

8The first astronomer to study the __________ of Mars was Galileo Galilei, who noted the phases of the planet in 1610.

9 U.S. __________ of carbon dioxide are still increasing.

10 Special noise __________ materials are even mixed with road asphalt and coat electric power lines here.

43

Reading 1

4. Discuss the questions using your knowledge of physics.

1 What is electricity?

2 What determines the conduction of electricity?

3 Why are metals good conductors? Which metals are the best conductors?

4 Do gases conduct electricity?

5 What are the different types of electricity?

6 What is a major advantage of AC electricity?

5. You are going to read the text about electricity. Seven sentences have been removed from it. Choose from sentences A–G the one which fits each gap (1–7). There is an example at the beginning. Then check your answers to the questions of exercise 4.

BASICS OF ELECTRICITY

AGases are not good conductors of electricity because of the distances between atoms.

BThis is the type of electricity that comes from the outlets in most homes.

CThis flow of electrons through the conductor is electricity.

DOften the electrons are pulled from the atoms on one surface and allowed to collect on the surface of another material.

EIthastheadvantageofbeingabletohaveitsvoltageeasilychangedto a higher or lower level.

F Theconductionofthoseelectronsisdeterminedbythetypeofmaterial. G This allows free electrons to roam about the material.

Electricity is the movement of free electrons in a material toward an area of positive (+) charges. 1__F__. (The conduction of those electrons is determined by the type of material.) Some conduct well, while other materials prevent the movement of electrons. Electricity can take the form of static electricity, direct current (DC) electricity, or alternating current (AC) electricity.

44

Conduction of electricity

Solid metals are good conductors of electricity, because electrons are allowed to move freely throughout the material. In the solid state, the atoms of metals are held in place and only vibrate. 2____. Copper and gold are some of the best conductors of electricity. Although iron is a good conductor, iron oxide (rust) is not.

In semi-conductors – ​such as materials used in computer chips – ​the electronshavelimitationstotheirmovement,suchasonlybeingallowed to move in one direction or in one plane.

Nonconductors inhibit the movement of electrons within the material. But they often do allow electrons and ions to collect on their surfaces. Examples of nonconductors or electrical insulators are: plastic, rubber, glass, most metal oxides (like rust), air, oil, pure de-ionized water. 3____. Electrons have difficulty moving through gases, unless the gas is ionized or heated to higher temperatures.

Types of electricity

Common types of electricity are static electricity, direct current (DC) electricity and alternating current (AC) electricity.

Static electricity is the collection of free electrons on the surface of a material, giving it a negative (–) charge. Atoms on the surface of another material that have lost one or more of their electrons are called positive (+) ions. 4____. Static electricity is caused by rubbing the two different materials together. Since opposite charges attract, there is a tendency for the electrons to attract toward the positive ions, resulting in static electricity.

In a metal or other conducting material, electrons will flow from an area of excess negative (–) charges to an area of positive (+) charges. 5____. If the opposite charges are constant, such as with the terminals in a battery, the current is called direct current or DC electricity, because it is going in one direction. If the terminals constantly switch their polarity from (+) to (–) and back again, the direction of the electrons alternates and is called alternating current or AC electricity. 6____.

DC can be created by a battery or DC generator. AC requires an AC generatorforitscreation.DCisusedinmanydevicesthatdonotrequire high voltages for their operation, such that batteries are used for power. AC can be used in higher voltages. 7____. AC is required for many electronic devices.

45

Use of English 1: vocabulary

6. Make pairs of words by matching a word in column A to a word in column B. Then complete the sentences 1–6 with each pair.

AB

1A __________ drive, sometimes called an electronic disk, is a data storage device that uses __________ memory to store persistent data with the intention of providing access in the same manner of a traditional hard disk drive.

2When __________ – ​both in vacuum and metals – ​move, they produceanetflowofchargecalledanelectriccurrent,whichgenerates a magnetic field.

3According to modern atomic theory, the nucleus of an atom has a

__________becauseofitsprotons,andinthenormalatomthereare enough extra-nuclear electrons to balance the nuclear charge so that the normal atom as a whole is neutral.

4The Greeks discovered __________ when working with magnetized rocks and tree resin.

5 The electric charge flows in a constant direction, distinguishing

__________ from alternating current.

6The voltage of an __________ can be changed by a transformer. With direct current it is not possible to use a transformer to change voltage.

Use of English 1: grammar

The Participle

7. Choose the correct form of the Participle.

1The problem may be considered ______. a solving b being solved c solved

46

6He found it difficult to understand the language __________ at the conference.

a spoken b speaking c having been spoken

7 The engine __________ required further improvement. a testing b having tested c tested

8The quantity of electricity __________ is directly related to the amounts of material transformed at the electrodes.

a flowing b being flown c having been flown

Reading 2

8. Read the text and complete the sentences according to the information given in the text.

1 Electromagnetism is responsible for…

2 James Clerk Maxwell was the first to describe…

3 In the 19th century electricity and magnetism…

4 However, electric and magnetic forces…

5 Electric forces are produced by…

6 Magnetic forces are produced by…

7 Electric and magnetic fields are regions…

8 Michael Faraday discovered that…

9 James Clerk Maxwell deduced that…

10The science of electricity is concerned with…

11The fundamental concepts of the science of electricity are…

12A common problem in electricity is…

47

Electromagnetism is responsible for interactions between charged particles that occur because of their charge, and for the emission and absorption of photons (electromagnetic radiation). The phenomena of electricity and magnetism are consequences of this force, and the relationships between them were first described by James Clerk Maxwell in the 1860s. The physical description of electromagnetism has since been combined with quantum mechanics into the theory of quantum electrodynamics. The electromagnetic force is about 1036 times as strong as the gravitational force.

Electricity and magnetism were long thought to be separate forces. It was not until the 19th century that they were finally treated as interrelated phenomena. In 1905 Albert Einstein’s special theory of relativity established beyond doubt that both are aspects of one common phenomenon. At a practical level, however, electric and magnetic forces behavequitedifferentlyandaredescribedbydifferentequations.Electric forces are produced by electric charges either at rest or in motion. Magnetic forces, on the other hand, are produced only by moving charges and act solely on charges in motion.

Electric and magnetic forces can be detected in regions called electric and magnetic fields. These fields can exist in space far from the charge or current that generated them. Remarkably, electric fields can produce magnetic fields and vice versa, independent of any external charge. A changingmagneticfieldproducesanelectricfield,astheEnglishphysicist Michael Faraday discoveredinworkthat formsthebasis ofelectricpower generation. Conversely, a changing electric field produces a magnetic field, as the Scottish physicist James Clerk Maxwell deduced.

Animportantaspectofelectromagnetismisthescienceofelectricity,which is concerned with the behaviour of aggregates of charge, including the distribution of charge within matter and the motion of charge from place to place. Different types of materials are classified as either conductors or insulators on the basis of whether charges can move freely through their constituent matter. Electric current is the measure of the flow of charges; the laws governing currents in matter are important in technology, particularly in the production, distribution, and control of energy.

The concept of voltage, like those of charge and current, is fundamental to the science of electricity. Voltage is a measure of the propensity of

48

charge to flow from one place to another; positive charges generally tend to move from a region of high voltage to a region of lower voltage. A common problem in electricity is determining the relationship between voltage and current or charge in a given physical situation.

Use of English 2: vocabulary

9. Match the words with their definitions.

49

Use of English 2: grammar

The Participle

10. Translate the words in brackets using the appropriate form of the Par- ticiple. Use conjunctions (when, if, unless, as) if necessary.

1 We read the article (написанную) by our professor attentively.

2The conference (проходящая сейчас) in our city is devoted to the problems of renewable energy sources.

3(Будучи) a good engineer he didn’t manage to perform the task in a short space of time.

4Most laboratories (оборудованных) with the latest apparatus are housed in the main building.

5 He was tired (проработав) on his report for the whole day.

6 (Как видно) from the article these jet engines are produced in Russia.

7 (Если не испытана) the machine must not be put into operation. 8 (При нагревании) the polymer changed its properties completely.

9(Послетогокакнебылапринята)bypublishersseveraltimes,the article was accepted by another journal.

10The power plant (снабжающая) a large area with electricity was built 50 years ago.

Reading 3

11. Read the text and answer the questions. Then retell the text using the questions as a plan.

1 When and where did James Clerk Maxwell live?

2 What was his most significant achievement?

3Which Maxwell’s work was called the “second great unification in physics”?

4 What other discoveries did he make?

5Maxwell’s contribution to the development of science was highly praised, wasn’t it?

50