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413.Учебные задания по английскому языку

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2865
МИНОБРНАУКИ РОССИИ
Федеральное государственное бюджетное образовательное учреждение
Высшего профессионального образования
«ЛИПЕЦКИЙ ГОСУДАРСТВЕННЫЙ ТЕХНИЧЕСКИЙ УНИВЕРСИТЕТ»
Кафедра иностранных языков
УЧЕБНЫЕ ЗАДАНИЯ
ПО АНГЛИЙСКОМУ ЯЗЫКУ
ДЛЯ СТУДЕНТОВ 2 КУРСА
СПЕЦИАЛЬНОСТИ «ЭЛЕКТРОЭНЕРГЕТИКА И ЭЛЕКТРОТЕХНИКА»
3 СЕМЕСТР
Составители: Ламанская О.П.
Хаустов О.Н.
Фадина Е.Ю.
Липецк
Липецкий государственный технический университет
2012
Copyright ОАО «ЦКБ «БИБКОМ» & ООО «Aгентство Kнига-Cервис»
ББК Ш 13 (англ) я 7
Л 211
Рецензент: канд. филолог. наук, доцент Н.В. Барышев
Л211. Ламанская, О.П. Учебные задания по английскому языку для студентов 2
курса специальности «Электроэнергетика и электротехника», 3 семестр/
О.П. Ламанская, О.Н. Хаустов, Е.Ю. Фадина - Липецк: Издательство ЛГТУ,
2012.-45с.
Целью данных учебных заданий является дальнейшее ознакомление
студентов с лексикой по специальности на базе текстов средней степени
сложности, развитие навыков перевода, реферирования и аннотирования, а
также активизация и накопление терминологической лексики.
Материал разбит на четыре модуля, каждый из которых состоит из двухтрех
текстов
объединенных
общей
тематикой,
серии
упражнений,
направленных на усвоение терминологической лексики и развитие навыков
устного высказывания в виде презентации на заданную тему и письма.
© ФГБОУ ВПО «Липецкий государственный
технический университет, 2012
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MODULE I
UNIT ONE
ELECTRICITY
READING
1. Read the text and answer the questions.
a. What is electric charge? What are the types of electric charges?
b. How does electrical activity manifest itself in the universe?
c. Is electricity a many-sided form of energy? How does it make our life
comfortable?
d. What are the two forms of electric charge?
e. What is the difference between positively charged objects and negatively
charged objects?
f. Can an object be uncharged?
Electricity is one of the basic forms of energy. Electricity is associated with electric
charge, a property of certain elementary particles such as electrons and protons, two
of the basic particles that make up the atoms of all ordinary matter. Electric charges
can be stationary, as in static electricity, or moving, as in an electric current.
Electrical activity takes place constantly everywhere in the universe. Electrical
forces hold molecules together. The nervous systems of animals work by means of
weak electric signals transmitted between neurons (nerve cells). Electricity is
generated, transmitted, and converted into heat, light, motion, and other forms of
energy through natural processes, as well as by devices built by people.
Electricity is an extremely versatile form of energy. It can be generated in many
ways and from many different sources. It can be sent almost instantaneously over
long distances. Electricity can also be converted efficiently into other forms of
energy, and it can be stored. Because of this versatility, electricity plays a part in
nearly every aspect of modern technology. Electricity provides light, heat, and
mechanical power. It makes telephones, computers, televisions, and countless other
necessities and luxuries possible.
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Electricity consists of charges carried by electrons, protons, and other particles.
Electric charge comes in two forms: positive and negative. Electrons and protons
both carry exactly the same amount of electric charge, but the positive charge of the
proton is exactly opposite the negative charge of the electron. If an object has more
protons than electrons, it is said to be positively charged; if it has more electrons than
protons, it is said to be negatively charged. If an object contains as many protons as
electrons, the charges will cancel each other and the object is said to be uncharged, or
electrically neutral.
VOCABULARY PRACTICE
1. Match each word from the box with one of the definitions.
neuron charge molecule proton atom energy particle matter electron cell
a. a very small piece of matter, part of an atom;
b. the smallest unit, consisting of a group of atoms, into which a substance
can be divided without a change in its chemical nature;
c. a very small piece of matter with a positive electric charge that forms
part of the nucleus of an atom;
d. physical substance in general that everything in the world consists of;
e. a cell that carries information within the brain and between the brain
and other parts of the body;
f. the smallest part of a chemical element that can take part in a chemical
reaction;
g. the ability of matter or radiation to work because of its mass, movement,
electric charge, etc.;
h. the smallest unit of living matter that can exist on its own;
i. a very small piece of matter with a negative electric charge, found in all
atoms;
j. the amount of electricity that is carried by a substance.
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2. Use the correct form of the words from the text to complete the chart.
Noun
Adjective
1. versatility
versatile
2. …………
necessary
3. …………
electric
4. element
……………..
5. station
……………..
6. nature
……………..
7. neutron
……………..
8. difference
……………..
3. Find English equivalents to the following words and word combinations.
a. механическая энергия;
b. простое вещество;
c. вырабатывать электроэнергию;
d. предметы первой необходимости;
e. накапливать электричество;
f. основные виды энергии;
g. неподвижный заряд;
h. удерживать молекулы.
UNIT TWO
STATIC ELECTRICITY
READING
1. Read the text. The beginnings of some sentences have been removed. Match
the beginnings A-H to sentences 1-7. There is one beginning which you do not
need to use.
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Electricity occurs in two forms: static electricity and electric current. Static electricity
consists of electric charges that stay in one place. An electric current is a flow of
electric charges between objects or locations.
(1)_________________________ by rubbing together two objects made of
different materials. Electrons move from the surface of one object to the surface of
the other if the second material holds onto its electrons more strongly than the first
does. The object that gains electrons becomes negatively charged, since it now has
more electrons than protons. (2)_________________________becomes positively
charged. For example, if a nylon comb is run through clean, dry hair, some of the
electrons on the hair are transferred to the comb. The comb becomes negatively
charged and the hair becomes positively charged. The following materials are named
in decreasing order of their ability to hold electrons: rubber, silk, glass, flannel, and
fur (or hair). If any two of these materials are rubbed together, the material earlier in
the list becomes negative, and the material later in the list becomes positive. The materials
should be clean and dry.
(3)__________________________in either of two ways: by contact or by
induction. A charged object transfers electric charge to an object with lesser charge
if the two touch. When this happens, a charge flows from the first to the second
object for a brief time. Charges in motion form an electric current. When charge
flows between objects in contact, the amount of charge that an object receives
depends on its ability to store charge. The ability to store charge is called
capacitance and is measured in units called farads.
(4)______________________________ by touching an uncharged electroscope
with a charged comb. An electroscope is a device that contains two strips of metal
foil, called leaves, that hang from one end of a metal rod. A metal ball is at the other
end of the rod. When the charged comb touches the ball, some of the charges on the
comb flow to the leaves, which separate because they now hold like charges and
repel each other. (5)____________________, the leaves remain apart because they
retain their charges. The electroscope has thus been charged by contact with the
comb.
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This flow of charge between objects with different amounts of charge will occur
whenever possible. However, it requires a pathway for the electric charge to move
along. Some materials, called conductors, allow an electric current to flow through
them easily. (6)_______________________, strongly resist the passage of an electric
current.
Under normal conditions, air is an insulator. However, if an object gains a large
enough charge of static electricity, part of the charge may jump, or discharge, through
the air to another object without touching it directly. (7)____________________, the
air becomes a conductor. Lightning is an example of a discharge.
A Objects become electrically charged
B Other materials, called insulators
C Charging by contact can be demonstrated
D As a result
E Static electricity can be produced
F When the charge is large enough
G If the comb is removed
H The object that gives up electrons
VOCABULARY PRACTICE
1. Explain the words and the word combinations in bold in the text.
2. Complete each sentence with one of the names of materials from the box.
hair
flannel
nylon
rubber
glass
silk
fur
a. When travelling in Malaysia, we saw a lot of ________plantations.
b. The sable is hunted for its _______.
c. ________trousers are used for summer sports and games.
d. A cat with a fine coat of ______ sat graciously beside me, purring.
e. It is better to keep beer in ______ bottles than in plastic ones.
f. Beginners are usually advised to play the guitars with _______ strings.
g. She felt comfortably cool in her _______ blouse.
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3. Complete each sentence (a-f) with one of the endings (1-6).
a. An electroscope is used…
b. In simplified form the electroscope consists of…
c. The amount of the charge…
d. Electric charges are conducted…
e. The capacitance of a capacitor…
f. The capacitance depends only on…
1. …is measured in farads.
2. …two lightweight conductors suspended in a glass container.
3. …to detect the presence of electric charges.
4. …the thickness, area, and composition of the capacitor’s dielectric.
5. …is calculated by measuring the distance the leaves are forced
apart.
6. …to the leaves at the bottom via the metal support.
4. Write out the passage using the correct form of the verbs in brackets.
COULOMB’S LAW
Objects with opposite charges (1)_______(attract) each other, and objects with
similar charges (2)_______(repel) each other. Coulomb’s law, (3)_______(formulate)
by French physicist Charles Augustin de Coulomb during the late 18th century,
(4)________(quantify) the strength of the attraction or repulsion. This law states that
the force between two charged objects (5)____(be) directly proportional to the
product of their charges and inversely proportional to the square of the distance
between them. The greater the charges on the objects, the larger the force between
them; the greater the distance between the objects, the lesser the force between them.
The unit of electric charge, also (6)______(name) after Coulomb, is equal to the
(7)_______(combine) charges of 6.24 × 1018 protons (or electrons).
If two (8)______(charge) objects in contact have the same capacitance, they
(9)______(divide) the charge evenly. Suppose, for example, that one object
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(10)_____(have) a charge of +4 coulombs and the other a charge of +8 coulombs.
When they (11)_____(touch), charge (12)_____(flow) from the 8-coulomb object to
the 4-coulomb object until each (13)____(have) a charge of +6 coulombs. If each
object originally had a charge of +6 coulombs, no charge (14)_____( flow) between
them.
5. Complete the text with words formed from the words in capitals.
An electrical (1)___________ is any material that offers little
CONDUCT
(2)_______________to the flow of an electric current. The
RESIST
(3)___________ between a conductor and an insulator, which
DIFFER
is a poor conductor of (4)__________or heat, is one of degree
ELECTRIC
rather than kind, because all (5)_________conduct electricity
SUBSTANCE
to some extent. A (6)_______ conductor of electricity, such as
GOOD
silver or copper, may have a (7)_______________ a billion or
CONDUCT
more (8)_____________as great as the conductivity of a good
TIME
(9)_________, such as glass or mica. A phenomenon known as
superconductivity is (10)_____when certain substances, cooled to
zero, have nearly (11)___________conductivity.
INSULATE
OBSERVE
FINITE
UNIT THREE
CHARGING BY INDUCTION
READING
1. Scan the first paragraph of the article and describe the procedure of a neutral
object being charged by induction.
2. Scan the second paragraph of the article and explain the reason for a charged
object and a neutral object to be attracted.
3. Read the text and mark the statements as TRUE or FALSE. Correct the
FALSE ones.
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a. A neutral object may be charged without contact.
b. The positive object induces a negative charge on the far side of the neutral
object.
c. The negatively charged side of the neutral object repels the positive object.
d. A negatively charged object and a neutral object cannot be attracted.
e. A neutral object may only be charged by induction permanently.
f.
A metal wire helps the electrons of a neutral object flow out into the
ground.
g. Earth is a neutral object.
h. When the wire is disconnected, object B may become neutral again.
A charged object may induce a charge in a nearby neutral object without touching it.
For example, if a positively charged object is brought near a neutral object, the
electrons in the neutral object are attracted to the positive object. Some of these
electrons flow to the side of the neutral object that is nearest to the positive object.
This side of the neutral object accumulates electrons and becomes negatively
charged. Because electrons leave the far side of the neutral object while its protons
remain stationary, that side becomes positively charged.
Since the negatively charged side of the neutral object is closest to the positive
object, the attraction between this side and the positive object is greater than the
repulsion between the positively charged side and the positive object. The net effect
is an attraction between the objects. Similarly, when a negatively charged object is
brought near a neutral object, the negative object induces a positive charge on the
near side of the neutral object and a negative charge on the far side. As before, the net
effect is an attraction between the objects.
The induced charges described above are not permanent. As soon as the
charged object is taken away, the electrons on the other object redistribute themselves
evenly over it, so that it again becomes neutral.
An object can also be charged permanently by induction. If a negatively charged
object, A, is brought near a neutral object, B, the electrons on B are repelled as far as
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possible from A and flow to the other side of B. If that side of B is then connected to
the ground by a good conductor, such as a metal wire, the electrons flow out through
the wire into the ground. The ground can receive almost any amount of charge
because Earth, being neutral, has an enormous capacitance. Object B is said to be
grounded by the wire connecting it to Earth.
If this wire is then removed, B has a positive charge, since it has lost electrons to
Earth. Thus B has been permanently charged by induction. Even if A is subsequently
removed, B still remains positive because the wire has been disconnected and B
cannot regain electrons from Earth to neutralize its positive charge.
VOCABULARY PRACTICE
1. Explain the words and word combinations in bold in the text.
2. Complete each sentence with an appropriate form of one of the verbs from the
box.
accumulate
ground
redistribute
disconnect
repel
induce
flow
attract
neutralize
regain
a. This can prevent air from ________ freely to the lungs.
b. You may be __________ if you do not pay the bill.
c. They had to _________ the money among schools in the area.
d. This rod ________ the electrical equipment.
e. He did not ________ consciousness for several days.
f. A magnet __________ steel.
g. By investing wisely she _____________ a fortune.
h. ________ magnetism is possible by holding a piece of iron near a magnet.
i. This drug should __________ the poison.
j. The reptile’s prickly skin __________ nearly all of its predators.
3. Find English equivalents to the following words and word combinations.
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a. равномерно перераспределяться;
b. притягиваться к положительно заряженному предмету;
c. отсоединить провод;
d. аналогично, подобным образом;
e. отдавать электроны земле;
f. сообщать заряд;
g. быть заземлённым;
h. перетекать (об электронах).
4. Fill in the correct preposition.
A charged object will induce a charge __ a nearby conductor. __ this example, a
negatively charged rod pushes some of the negatively charged electrons __ the far
side __ a nearby copper sphere because like charges repel each other. The positive
charges that remain __ the near side __ the sphere are attracted __ the rod. If the
sphere is grounded so that the electrons can escape altogether, the charge __ the
sphere will remain if the rod is removed.
5. Match each adjective (a-f) with one of the explanations (1-6). Use them in
sentences of your own.
a. Negative_____________
b. Enormous____________
c. Near_________________
d. Positive______________
e. Neutral_______________
f. Possible______________
1. that can exist or happen;
2. of the sort of electricity produced by rubbing glass with silk;
3. very great, immense;
4. having no definite characteristics;
5. of that kind of electricity produced by rubbing wax, vulcanite, etc.
6. close to.
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SPEAKING
1. Speak on the role electricity plays in modern world.
WRITING
1. You are going to give a talk on static electricity. Make notes which may help
you to explain the differences between charging by contact and charging by
induction.
MODULE I ASSESSMENT
Translate from English into Russian in writing.
The ancient Greeks observed that amber, when rubbed, attracted small, light objects.
About 600 BC Greek philosopher Thales of Miletus held that amber had a soul, since
it could make other objects move. In a treatise written about three centuries later,
another Greek philosopher, Theophrastus, stated that other substances also have this
power.
For almost 2,000 years after Theophrastus, little progress was made in the study of
electricity. In 1600 English physician William Gilbert published a book in which he
noted that many substances besides amber could be charged by rubbing. He gave
these substances the Latin name electrica, which is derived from the Greek word
elektron (which means “amber”). The word electricity was first used by English
writer and physician Sir Thomas Browne in 1646.
The fact that electricity can flow through a substance was discovered by 17th-century
German physicist Otto von Guericke, who observed conduction in a linen thread.
Von Guericke also described the first machine for producing an electric charge in
1672. The machine consisted of a sulfur sphere turned by a crank. When a hand was
held against the sphere, a charge was induced on the sphere. Conduction was
rediscovered independently by Englishman Stephen Gray during the early 1700s.
Gray also noted that some substances are good conductors while others are insulators.
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MODULE II
UNIT ONE
ELECTRIC CURRENT
READING
1. Read the text and complete statements 1-6 with the best ending A, B or C.
1) According to the text a copper wire…
A does not let electric current flow through it.
B allows charge to flow easily.
C is a poor conductor.
2) Direct current…
A is used in electric cells.
B flows between two objects.
C is of a much wider application than alternating current.
3) Alternating current…
A is employed in a great number of electrical appliances.
B is easy to understand.
C flows in one direction.
4) Ohm’s law…
A quantifies and compares electric currents.
B shows what voltage and resistance are.
C states relations between current, voltage and resistance in circuits.
5) Materials that do not let electric current flow through them are called…
A conductors.
B dielectrics.
C capacitors.
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6) The charge can arc through an insulator from one object to another when the
object has…
A a positive charge.
B a great charge.
C a negative charge.
An electric current is a movement of charge. When two objects with different charges
touch and redistribute their charges, an electric current flows from one object to the
other until the charge is distributed according to the capacitances of the objects. If
two objects are connected by a material that lets charge flow easily, such as a copper
wire, then an electric current flows from one object to the other through the wire.
Electric current can be demonstrated by connecting a small light bulb to an electric
battery by two copper wires. When the connections are properly made, current flows
through the wires and the bulb, causing the bulb to glow.
Current that flows in one direction only, such as the current in a battery-powered
flashlight, is called direct current. Current that flows back and forth, reversing
direction again and again, is called alternating current. Direct current is used in most
battery-powered devices. Alternating current is used in most devices that are
“plugged in” to electrical outlets in buildings.
Other properties that are used to quantify and compare electric currents are the
voltage (also called electromotive force) driving the current and the resistance of the
conductor to the passage of the current. The amount of current, voltage, and
resistance in any circuit are all related through an equation called Ohm’s law.
Electric current is measured in units called amperes (amp). If 1 coulomb of
charge flows past each point of a wire every second, the wire is carrying a current of
1 amp. If 2 coulombs flow past each point in a second, the current is 2 amp.
Conductors and Insulators
Conductors are materials that allow an electric current to flow through them easily.
Most metals are good conductors.
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Substances that do not allow electric current to flow through them are called
insulators, nonconductors, or dielectrics. Rubber, glass, and air are common
insulators. Electricians wear rubber gloves so that electric current will not pass from
electrical equipment to their bodies. However, if an object contains a sufficient
amount of charge, the charge can arc, or jump, through an insulator to another object.
For example, if you shuffle across a wool rug and then hold your finger very close to,
but not in contact with, a metal doorknob or radiator, current will arc through the air
from your finger to the doorknob or radiator, even though air is an insulator. In the
dark, the passage of the current through the air is visible as a tiny spark.
VOCABULARY PRACTICE
1. Explain the words and word combinations in bold in the text.
2. Replace the words underlined with the most appropriate adjective from the
box.
sufficient
alternating
visible
common
direct
tiny
different
a. The eclipse will be clearly seen in Western Europe.
b. I hope $10 is enough for the expenses of your journey.
c. He showed his movement in a straight line.
d. The two boys are not the same in their tastes.
e. Lightning is a usual phenomenon in many parts of the world.
f. Electrons are really small particles.
g. Most devices use current that repeatedly reverses its direction at regular
intervals.
3. Fill in the correct preposition.
Battery, also electric cell, is a device that converts chemical energy ___ electricity.
Strictly speaking, a battery consists ___ two or more cells connected ___ series or
parallel, but the term is also used ___ single cells. All cells consist ___ a liquid, paste,
or solid electrolyte and a positive electrode, and a negative electrode. The electrolyte
is an ionic conductor; one ___ the electrodes will react, producing electrons, while
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the other will accept electrons. When the electrodes are connected ___ a device to be
powered, called a load, an electrical current flows.
Batteries ___ which the chemicals cannot be reconstituted ___ their original
form once the energy has been converted (that is, batteries that have been discharged)
are called primary cells or voltaic cells. Batteries ___ which the chemicals can be
reconstituted ___ passing an electric current ___ them ___ the direction opposite that
___ normal cell operation are called secondary cells, rechargeable cells, storage cells,
or accumulators.
4. Complete the text with words formed from the words in capitals.
(1)___________ is a property of any object or substance to resist or
RESIST
oppose the flow of an (2)__________current. The quantity of resistance ELECTRIC
in an electric circuit determines the amount of current (3)___________
in the circuit for any (4)_________voltage applied to the circuit.
The resistance of an object is (5)___________by the nature of
FLOW
GIVE
DETERMINE
the substance of which it is composed, known as the (6)__________,
the dimensions of the object, and the (7)_________. The term resistance
is also used when the flow of a fluid or heat is impeded. The (8)______of
RESIST
TEMPER
FORCE
friction provide the resistance to the flow of a fluid in a pipe, and (9)____INSULATE
provides (10)________resistance that reduces the flow of heat from
a (11)_______to a lower temperature.
THERM
HIGH
5. Put each verb in brackets into a suitable verb form.
ELECTRIC INSULATION
The perfect insulator for electrical applications (1)_____(be) a material that is
absolutely nonconducting; such a material (2)____(not exist). The materials
(3)______(use) as insulators, although they do conduct some electricity, have a
resistance to the flow of electric current greater than that of good electrical
conductors such as silver and copper. Materials that are good conductors
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(4)_____(have) a large number of free electrons (electrons not tightly bound to
atoms) available (5)______(carry) the current; good insulators have few such
electrons.
In ordinary electric (6)________(wire), plastics are commonly used as insulating
(7)________(sheathe) for the wire itself. Very fine wire, such as that used for
(8)_______(wind) coils and transformers, may (9)_________(insulate) with a thin
coat of enamel. The internal insulation of electric equipment may (10)______(make) of
mica or glass fibers with a plastic binder. Electronic equipment and transformers may also
(12)_____(use) a special electrical grade of paper. High-voltage power lines are insulated
with units (13)_______(make) of porcelain or other ceramic, or of glass.
UNIT TWO
VOLTAGE AND RESISTANCE
READING
1. Scan the first paragraph of the article and say what the voltage is and what its
amount depends on.
2. Skim the second paragraph and state the reason for the electric current flow
to be impeded.
3. Read the rest of the text and answer the questions.
a. What is the optimal resistance for conductors? for insulators?
b. How is resistance related to the characteristics of a conductor?
c. What is superconductivity?
Voltage
When the two terminals of a battery are connected by a conductor, an electric current
flows through the conductor. One terminal continuously sends electrons into the
conductor, while the other continuously receives electrons from it. The current flow
is caused by the voltage, or potential difference, between the terminals. The more
willing the terminals are to give up and receive electrons, the higher the voltage.
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Voltage is measured in units called volts. Another name for a voltage produced by a
source of electric current is electromotive force.
Resistance
A conductor allows an electric current to flow through it, but it does not permit the
current to flow with perfect freedom. Collisions between the electrons and the atoms
of the conductor interfere with the flow of electrons. This phenomenon is known as
resistance. Resistance is measured in units called ohms.
A good conductor is one that has low resistance. A good insulator has a very
high resistance. At commonly encountered temperatures, silver is the best conductor
and copper is the second best. Electric wires are usually made of copper, which is less
expensive than silver.
The resistance of a piece of wire depends on its length, and its cross-sectional
area, or thickness. The longer the wire is, the greater its resistance. If one wire is
twice as long as a wire of identical diameter and material, the longer wire offers twice
as much resistance as the shorter one. A thicker wire, however, has less resistance,
because a thick wire offers more room for an electric current to pass through than a
thin wire does. A wire whose cross-sectional area is twice that of another wire of
equal length and similar material has only half the resistance of the thinner wire.
Scientists describe this relationship between resistance, length, and area by saying
that resistance is proportional to length and inversely proportional to cross-sectional
area.
Usually, the higher the temperature of a wire, the greater its resistance. The
resistance of some materials drops to zero at very low temperatures. This
phenomenon is known as superconductivity.
VOCABULARY PRACTICE
1. Explain the words and word combinations in bold in the text.
2. Find English equivalents to the following word combinations.
a. при обычной температуре
b. разность потенциалов
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c. одинакового диаметра
d. электродвижущая сила
e. площадь поперечного сечения
f. пропорционально длине
g. обеспечивать больше пространства
h. падать до нуля
3. Put each verb in brackets into a suitable verb form.
THE DISCOVERY OF SUPERCONDUCTIVITY
Dutch physicist Heike Kamerlingh Onnes sometimes (1)________(call) the
“gentleman of absolute zero” for his (2)_________(pioneer) work in cryogenics, the
study of materials at extremely low temperatures. Onnes (3)______(begin) his lowtemperature work because of his interest in the behavior of gases. He went on
(4)______(become) the first person (5)_______(liquefy) helium and the first
(6)_______(discover) that some metals, when sufficiently (7)______(cool),
(8)______(become) superconductors—that is, materials that have no resistance to the
flow of an electrical current.
4. Complete each sentence (a-g) with one of the endings (1-7).
a. The relationship between current, voltage and resistance…
b. Under normal conditions, resistance…
c. A conductor’s resistance…
d. Energy is required…
e. The rate at which energy is supplied…
f. Superconducting magnets…
g. The discovery of better superconducting compounds…
1…is constant in conductors made of metal.
2…to a device is called power.
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3…is given by Ohm’s law.
4…is a significant step toward a far wider spectrum of applications.
5…to drive an electric current through a resistance.
6…have been used in diagnostic medical equipment.
7…to electric current produces heat.
5. Complete each sentence using one of the words from the box.
induces suspended liquid opposing keeps accordance floats lowered
Levitating Magnet
A small cylindrical magnet (1)______above a high temperature superconductor. The
vapor is from boiling (2)______nitrogen, which (3)______the superconductor in a
zero-resistance state. As the magnet is (4)______toward the superconductor, it
(5)_____an electric current, which creates an (6)______magnetic field in
(7)______with Ampere’s law. Because the superconductor has no electrical resistance,
this induced current continues to flow, keeping the magnet (8)______indefinitely.
UNIT THREE
ELECTRIC CURRENT CONDUCTION
READING
1. Read the text and choose from the list A-I the sentence which best fits each
gap (1-8) in the article. There is one extra sentence which you do not need to use.
All electric currents consist of charges in motion. (1)_________________ When an
electric current flows in a solid conductor, the flow is in one direction only, because
the current is carried entirely by electrons. In liquids and gases, however, a twodirectional flow is made possible by the process of ionization.
Conduction in Solids
The conduction of electric currents in solid substances is made possible by the
presence of free electrons (electrons that are free to move about). Most of the
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electrons in a bar of copper, for example, are tightly bound to individual copper
atoms. (2)________________
Ordinarily the motion of the free electrons is random; that is, as many of them
are moving in one direction as in another. (3)______________________ This end is
said to be at a higher potential and is called the positive end. The other end is said to
be at a lower potential and is called the negative end. The function of a battery or
other source of electric current is to maintain potential difference. A battery does this
by supplying electrons to the negative end of the bar to replace those that drift to the
positive end and also by absorbing electrons at the positive end.
(4)____________________ A perfect insulator would allow no charge to be
forced through it, but no such substance is known at room temperature. The best
insulators offer high but not infinite resistance at room temperature.
Some substances that ordinarily have no free electrons, such as silicon and
germanium, can conduct electric currents when small amounts of certain impurities
are added to them. (5)_____________________ Semiconductors generally have a
higher resistance to the flow of current than does a conductor, such as copper, but a
lower resistance than an insulator, such as glass.
Conduction in Gases
Gases normally contain few free electrons and are generally insulators. When a
strong potential difference is applied between two points inside a container filled with
a gas, the few free electrons are accelerated by the potential difference and collide
with the atoms of the gas, knocking free more electrons. The gas atoms become
positively
charged
ions
and
the
gas
is
said
to
be
ionized.
(6)_______________________ An electric current in a gas is composed of these
opposite flows of charges.
Conduction in Liquid Solutions
Many substances become ionized when they dissolve in water or in some other
liquid. An example is ordinary table salt, sodium chloride (NaCl). When sodium
chloride dissolves in water, it separates into positive sodium ions, Na +, and negative
chlorine ions, Cl-. If two points in the solution are at different potentials, the negative
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ions drift toward the positive point, while the positive ions drift toward the negative
point. (7)________________ Thus, while water that is absolutely pure is an insulator,
water that contains even a slight impurity of an ionized substance is a conductor.
Since the positive and negative ions of a dissolved substance migrate to different
points when an electric current flows, the substance is gradually separated into two
parts. (8)____________________
A The electrons move toward the high-potential (more positive) point, while the
ions move toward the low-potential (more negative) point.
B However, if a voltage is applied to the two ends of a copper bar by means of a
battery, the free electrons tend to drift toward one end.
C Such substances are called semiconductors.
D
However, electric current is conducted differently in solids, gases, and
liquids.
E This separation is called electrolysis.
F This phenomenon is widely applied in modern technology.
G As in gases, the electric current is composed of these flows of opposite
charges.
H
Insulators cannot conduct electric currents because all their electrons are
tightly bound to their atoms.
I However, some are free to move from atom to atom, enabling current to flow.
VOCABULARY PRACTICE
1. Match each adjective from the box with one of the definitions.
ordinary
random
infinite
solid
dissolved
individual
ionized
a. not in the form of a liquid or gas;
b. specially for one person or thing;
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free
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c. normal, usual, average;
d. not solid or gaseous;
e. acquiring a liquid state;
f. changed into electrically charged particles when dissolved;
g. unmixed with any other substance;
h. without restraint or control;
i. endless, without limits;
j. without any regular pattern;
k. small; not important.
2. Write out the passage using the most appropriate verb-form from the box in
each gap.
drive (2)
supply
operate
locate
consist
produce
generate
contain
pour
use
SOURCES OF ELECTRIC CURRENT
There are several different devices
that can (1)______the voltage necessary
(2)_______ an electric current. The two most common sources are generators and
electrolytic cells.
Generators use mechanical energy, such as water (3)_______through a dam or
the motion of a turbine (4)_______by steam, to produce electricity. The electric
outlets on the walls of homes and other buildings, from which electricity
(5)_______lights and appliances is drawn, are connected to giant generators
(6)_______in electric power stations. Each outlet (7)_______two terminals. The
voltage between the terminals (8)______an electric current through the appliance that
is plugged into the outlet.
Electrolytic cells (9)______chemical energy (10)_______electricity. Chemical
reactions within an electrolytic cell produce a potential difference between the cell’s
terminals. An electric battery (11)_______of a cell or group of cells connected
together.
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3. Complete the text with a suitable preposition in each space.
ELECTROCHEMISTRY
Electrochemistry is that part (1)___the science (2)___chemistry that deals
(3)___the interrelationship (4)___electrical currents, or voltages, and chemical
reactions, and (5)___the mutual conversion (6)___chemical and electrical energy.
(7)___the broadest sense, electrochemistry is the study (8)___chemical reactions that
produce electrical effects and (9)___the chemical phenomena that are caused
(10)___the action of currents or voltages.
4. Complete the text with words formed from the words in capitals.
ELECTRIC POWER SYSTEMS
Electric power systems are systems for the (1)_______of other types TRANSFORM
of energy into electrical energy and the (2)________ of this energy
TRANSMIT
to the point of (3)___________. The production and transmission of
CONSUME
energy in the form of electricity is (4)__________ efficient and
RELATIVE
(5)___________. Electric power systems make possible the use of
hydroelectric power at a (6)___________from the source.
Waterpower is power (7)________from the fall of water from a higher
to a (8)_________level, and extracted by means of waterwheels or
EXPENSIVE
DISTANT
DERIVE
LOW
hydraulic turbines. Waterpower is a (10)________ resource, available
NATURE
wherever a (11)____________volume of steady water flow exists.
SUFFICE
5. Find English equivalents to the following words and word combinations in
bold.
a. состоять из;
b. обычно;
c. электропроводность;
d. столовая соль;
e. удерживать разность потенциалов;
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f. перемещаться;
g. примеси;
h. тесно связанный;
i. сталкиваться;
j. в движении;
k. постепенно разделяться.
SPEAKING
Make a presentation on a particular source of electric current. Use the following
guidelines.
1. Outline the structure of your presentation.
2. Describe the product features and consumer benefits.
3. Describe the product’s target market.
4. Mention other competing products.
Decide on the structure of your presentation. These phrases will help you order
the information.
THE INTRODUCTION
I’d like to tell you about…
ORDERING INFORMATION
I’ll begin with…
Now I’ll move on to…
Then I’ll turn to…
CHECKING UNDERSTANDING
FINISHING
Is that clear?
Are there any questions?
Are you with me?
Now you are welcome with your
OK so far?
questions.
Thank you very much.
WRITING
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Produce a plan which would help you back up your project of using a particular
electric power system for a certain purpose. Think of the advantages of this
system over other systems.
MODULE II ASSESSMENT
Translate from English into Russian.
OTHER SOURCES OF ELECTRIC CURRENT
There are many sources of electric current other than generators and electrolytic
cells. Fuel cells, for example, produce electricity through chemical reactions. Unlike
electrolytic cells, however, fuel cells do not store chemicals and therefore must be
constantly refilled.
Certain sources of electric current operate on the principle that some metals hold
onto their electrons more strongly than other metals do. Platinum, for example, holds
its electrons less strongly than aluminum does. If a strip of platinum and a strip of
aluminum are pressed together under the proper conditions, some electrons will flow
from the platinum to the aluminum. As the aluminum gains electrons and becomes
negative, the platinum loses electrons and becomes positive.
The strength with which a metal holds its electrons varies with temperature. If
two strips of different metals are joined and the joint heated, electrons will pass from
one strip to the other. Electricity produced directly by heating is called
thermoelectricity.
Some substances emit electrons when they are struck by light. Electricity
produced in this way is called photoelectricity. When pressure is applied to certain
crystals, a potential difference develops across them. Electricity thus produced is
called piezoelectricity. Some microphones work on this principle.
MODULE III
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UNIT ONE
ELECTRIC CIRCUITS
READING
1. Read the text. Match headings A-F to paragraphs 1-5. There is one heading
you will not need to use.
1
An electric circuit is an arrangement of electric current sources and
conducting paths through which a current can continuously flow. In a simple circuit
consisting of a small light bulb, a battery, and two pieces of wire, the electric current
flows from the negative terminal of the battery, through one piece of connecting wire,
through the bulb filament (also a type of wire), through the other piece of connecting
wire, and back to the positive terminal of the battery. When the electric current flows
through the filament, the filament heats up and the bulb lights.
2
A switch can be placed in one of the connecting wires. A flashlight is an
example of such a circuit. When the switch is open, the connection is broken, electric
current cannot flow through the circuit, and the bulb does not light. When the switch
is closed, current flows and the bulb lights.
3
The bulb filament may burn out if too much electric current flows through it. To
prevent this from happening, a fuse (circuit breaker) may be placed in the circuit.
When too much current flows through the fuse, a wire in the fuse heats up and melts,
thereby breaking the circuit and stopping the flow of current. The wire in the fuse is
designed to melt before the filament would melt.
4
The part of an electric circuit other than the source of electric current is called the
load. The load includes all appliances placed in the circuit, such as lights, radios,
fans, buzzers, and toasters. It also includes the connecting wires, as well as switches,
fuses, and other devices. The load forms a continuous conducting path between the
terminals of the current source.
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5
There are two basic ways in which the parts of a circuit are arranged. One
arrangement is called a series circuit, and the other is called a parallel circuit.
A Current transmitting part.
B Simple mechanism of electric light.
C Circuit application.
D Types of electric circuit.
E Precautions.
F Connection and disconnection.
VOCABULARY PRACTICE
1. Explain the words and word combinations in bold in the text.
2. Replace the words underlined with the most appropriate noun from the box.
fuse
terminal connection arrangement source
load
appliance
bulb
a. A faulty connecting point caused the machine to stop.
b. The amount of electrical power supplied is being calculated.
c. Proper order may guarantee good results.
d. There are two points of connection in a battery.
e. This lamp contains three glass parts.
f. Energy can be supplied from different places.
g. This device is designed to prepare food.
h. Check whether a circuit breaker has blown.
3. Put each verb in brackets into a suitable form.
CYLINDRICAL FUSES
A cylindrical fuse (1)______(consist) of a ribbon of fusible metal (2)______(enclose)
in a ceramic or fiber cylinder. Metal end caps fastened over the cylinder
(3)_____(make) contact with the metal ribbon. This type of fuse (4)_____(place) in
an electric circuit so that the current must (5)______(flow) through the metal strip to
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complete the circuit. If excess current (6)_____(surge) through the circuit, the metal
link will heat to its (7)_____(melt) point and break. This action (8)______(open) the
circuit, stop the current flow, and thus protect the circuit. The cylindrical type of fuse
is used mostly (9)______(protect) electrical equipment and appliances.
4. Complete the text with words formed from the words in capitals.
PLUG FUSES
Plug fuses are (1)______________used to protect electric
COMMON
(2)______________in homes. This type also consists of a
WIRE
(3)___________metal strip through which the current must
FUSE
flow to complete the circuit. The strip is, however, (4)______
ENCLOSE
in a plug that can be (5)__________into an ordinary electric
SCREW
receptacle or light socket. Plug fuses (6)_________have a mica
USUAL
window at the (7)_______of the plug so that the condition of the
metal strip can be (8)________at a glance.
BASE
SEE
5. Find English equivalents to the following words and word combinations in
bold.
a. перегорать;
b. постоянно;
c. предотвращать;
d. соединительный провод;
e. нагреваться, накаливаться;
f. последовательная цепь, схема;
g. вентилятор;
h. размыкать цепь.
UNIT TWO
SERIES AND PARALLEL CIRCUITS
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READING
1. Read the text and mark the statements as TRUE or FALSE. Correct the
FALSE ones.
a. In a series circuit the current flows to the negative terminal of the source.
b. The current does not change in a series circuit.
c. The resistances of each object in a series circuit form the total resistance.
d. The more objects are in a series circuit, the less voltage there is in the
circuit.
e. In a parallel circuit the current in each branch and in the source is the
same.
f. The total resistance of parallel objects is the sum of individual resistances.
g. A parallel circuit has only one path for the electric current.
h. The amount of current in a branch depends on the amount of its resistance.
Series Circuits
If various objects are arranged to form a single conducting path between the
terminals of a source of electric current, the objects are said to be connected in series.
The electron current first passes from the negative terminal of the source into the first
object, then flows through the other objects one after another, and finally returns to
the positive terminal of the source. The current is the same throughout the circuit. In
the example of the light bulb, the wires, bulb, switch, and fuse are connected in
series.
When objects are connected in series, the electric current flows through them
against the resistance of the first object, then against the resistance of the next object,
and so on. Therefore the total resistance to the current is equal to the sum of the
individual resistances.
Voltage can be thought of as being used up by the objects in a circuit. The
voltage that each object uses up is called the voltage drop across that object. Voltage
drop can be calculated from the equation V = IR, where V is the voltage drop across
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the object, I is the amount of current, and R is the resistance of the object. In a series
circuit the sum of the voltage drops across the objects always equals the total voltage
supplied by the source.
Parallel Circuits
If various objects are connected to form separate paths between the terminals of a
source of electric current, they are said to be connected in parallel. Each separate path
is called a branch of the circuit. Current from the source splits up and enters the
various branches. After flowing through the separate branches, the current merges
again before reentering the current source.
The total resistance of objects connected in parallel is less than that of any of the
individual resistances. This is because a parallel circuit offers more than one branch
(path) for the electric current, whereas a series circuit has only one path for all the
current.
The electric current through a parallel circuit is distributed among the branches
according to the resistances of the branches. If each branch has the same resistance,
then the current in each will be equal. If the branches have different resistances, the
current in each branch can be determined from the equation I = V/R, where I is the
amount of current in the branch, V is the voltage, and R is the resistance of the
branch.
The total resistance of a parallel circuit can be calculated from the equation
where R is the total resistance and R1, R2, ... are the resistances of the branches.
The greater the resistance of a given branch, the smaller the portion of the
electric current flowing through that branch.
VOCABULARY PRACTICE
1. Find Russian equivalents to the words and word combinations in bold.
2. Complete the text with a suitable preposition in each space.
SERIES-PARALLEL CIRCUITS
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Many circuits combine series and parallel arrangements. One branch ___ a parallel
circuit, ___ example, may have ___ it several objects ___ a series. The resistances of
these objects must be combined according ___ the rules ___ a series circuit. ___ the
other hand, a series circuit may ___ one point divide ___ two or more branches and
then rejoin. The branches are parallel and must be treated ___ the rules ___ parallel
circuits.
3. Put each verb in brackets into a suitable verb form.
(1)___________(complicate) series-parallel circuits may (2)__________(analyze) by
means of two rules called Kirchhoff’s laws. These rules make it possible
(3)_______(find) the amount of electric current (4)________(flow) through each part
of any circuit, as well as the voltage across it. The first of Kirchhoff’s laws
(5)_______(state) that at any junction in a circuit through which a steady current
(6)________(flow), the sum of the currents flowing to the junction is equal to the
sum of the currents flowing away from that point. The second law states that,
(7)_______(start) at any point in a circuit and following any (8)_______(close) path
back to the starting point, the net sum of the voltage encountered (9)______(be equal)
to the net sum of the products of the resistances encountered and the currents flowing
through them. In other words, Ohm’s law (10)_______(apply) not only to a circuit as
a whole, but also to any (11)_______(give) section of a circuit.
4. Write out the passage using one of the adjectives from the box.
positive
opposite
individual
equal
connecting
various
connected
SERIES SOURCES
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Sources of electric current can also be (1)________ in (2)_________ ways. Sources
can be arranged in series by (3)__________ a terminal of one source to the
(4)________ terminal of the next source. For example, if the (5)_________ terminal
of battery A is connected to the (6)_________ terminal of battery B, and the positive
terminal of battery B to the negative terminal of battery C, then batteries A, B, and C
are in series. The load is then placed between the positive terminal of battery C and
the negative terminal of battery A.
When sources of electric current are connected in series, their (7)_______ voltage is
(8)___________ to the sum of their (9)___________ voltages.
5. Complete the text with words formed from the words in capitals.
PARALLEL SOURCES
Current sources may be arranged in parallel by (1)____________
CONNECT
all the positive terminals together and all the (2)_______ terminals
NEGATION
together. The load is then (3)_______ between the group of positive
PLACE
terminals and the group of negative terminals.
(4)______________ sources in parallel does not increase the
(5)__________. If three 1.5-volt batteries are connected in parallel,
the total voltage is still 1.5 volts. (6)______ should not be connected
ARRANGE
VOLT
BATTERY
in parallel unless they have (7)_______________the same voltage. APPROXIMATE
If a high voltage battery is connected in parallel with a (8)________
LOW
voltage battery, the (9)_______voltage battery will force an electric
HIGH
current through the low voltage battery and damage it.
SPEAKING
Make a presentation on an arrangement of circuit for a particular purpose.
WRITING
Think of a billboard advertising various fuses for particular electrical
appliances.
MODULE
III
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ASSESSMENT
Translate from English into Russian.
Electric circuits are classified in several ways. A direct-current circuit carries current
that flows only in one direction. An alternating-current circuit carries current that
pulsates back and forth many times each second, as in most household circuits. A
series circuit comprises a path along which the whole current flows through each
component. A parallel circuit comprises branches so that the current divides and only
part of it flows through any branch. The voltage, or potential difference, across each
branch of a parallel circuit is the same, but the currents may vary. In a home electrical
circuit, for instance, the same voltage is applied across each light or appliance, but
each of these loads draws a different amount of current, according to its power
requirements. A number of similar batteries connected in parallel provide greater
current than a single battery, but the voltage is the same as for a single battery.
The network of transistors, transformers, capacitors, connecting wires, and other
electronic components within a single device such as a radio is also an electric circuit.
Such complex circuits may be made up of one or more branches in combinations of
series and series-parallel arrangements.
MODULE IV
UNIT ONE
ELECTRIC FIELDS
READING
1. Read the following text. Some phrases have been left out of the text. Choose
from phrases A-I below to complete the gaps. There is one phrase you will not
need.
A single electric charge can attract or repel, and it will demonstrate this ability as
soon as another charge is brought near it. The ability to attract or repel can be thought
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of as being stored in the region around the charge. This region is called the electric
field of force of the charge. All charged objects have electric fields (1)___________.
Lines of Force
An electric field can be visualized as consisting of imaginary lines called lines of
force. Each line corresponds to the path that a positive charge would take if placed
in the field on that line. The lines in the field around a positively charged object
radiate in all directions away from the object, since the object repels positive charges.
Conversely, the lines in the field around a negatively charged object are directed
(2)___________. If a positive and a negative object are placed near each other, their
lines of force connect. If two objects with similar charges are placed near each other,
the lines do not connect. Lines of force never (3)____________each other.
Lines of force are only imaginary. Nevertheless, the idea of lines of force helps
in (4)____________an electric field.
Field Direction
When a charge is placed at any given point in an electric field, it is acted on by a
force that tends to (5)___________it in a certain direction. This direction is called the
direction of the field at that point. The field direction can be represented graphically
by the lines of force near an electric charge.
Field Strength
The strength, or (6)____________, of a field at any point is defined as the force
exerted on a charge of 1 coulomb placed at that point. For example, if a point charge
of 1 coulomb is subjected to a force of 10 newtons, the electric field is 10 newtons
per coulomb at that point. An object with a charge of 5 coulombs would be subjected
to a force of 50 newtons at the same point.
Field strength is represented graphically by the closeness ((7)__________) of
the lines of force. Where the lines are close together, the field is strong. Where they
are (8)____________, the field is weak. Near a charge, the field is strong and the
lines are close together. At greater distances from the charge, the field weakens and
the lines are not as close together. The field strength values that the lines represent
are relative, since a field can be drawn with as many lines as desired.
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A push
B density
C around them
D visualizing
E toward the object
F far apart
G integrity
H cross
I
intensity
VOCABULARY PRACTICE
1. Explain the words and word combinations in bold in the text.
2. Replace the words underlined in each sentence with the most appropriate
verb form from the box.
exert direct attract represent repel draw push weaken cross radiate
a. She asked him to move the table nearer to the wall.
b. This stove sends out sufficient heat.
c. The explosion made the building’s foundations less strong.
d. The new switch is an example of the latest innovations in technology.
e. We are pulled towards the earth by the gravitational force.
f. You’ll have to use all your eloquence to convince her.
g. Make a diagram and show the direction of the electric field.
h. This substance drives away mosquitoes.
i.
He passed from one side of the street to the other side with resolute
steps.
j. Our energies must be turned towards higher productivity.
3. Complete each sentence (a-g) with one of the endings (1-7).
a. A field is an area surrounding an object, in which a gravitational or
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electromagnetic force
b. The concept of fields was first introduced by English physicist Sir
Isaac Newton
c. Gravitational and electromagnetic forces appear
d. Charged particles and massive bodies
e. Massive bodies exert a force
f. The fields exert an electromagnetic or gravitational force
g. The diagram shows that a positive test charge would be pushed
1. … to act at a distance.
2. … away from both charges.
3. … is exerted on other objects.
4. … are said to be the sources of electromagnetic and gravitational
fields.
5. … to explain gravitational forces.
6. … on other objects.
7. … on each other.
4. Complete the text with words formed from the words in capitals.
British (1)___________James Clerk Maxwell, considered one of
PHYSICS
the 19th century’s most (2)___________scientists, was the first to
IMPORTANCE
demonstrate that light (3)____________of electromagnetic waves.
CONSIST
(4)_________upon the ideas of British scientist Michael Faraday,
BUILD
Maxwell (5)______________his electromagnetic theory of light.
DEVELOP
Maxwell’s treatise “A (6)_________________Theory of the
DYNAMIC
Electromagnetic Field” (1864) contains the (7)_____________
(8)____________that describe the electromagnetic field.
FUNDAMENT
EQUATE
5. Write out the passage using one of the words from the box.
scientific
mutual
depends
obvious
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reducing
existence
sensible
magnitude
constituting
The most (1)_________mechanical phenomenon in electrical and magnetical
experiments is the (2)__________action by which bodies in certain states set each
other in motion while still at a (3)_________distance from each other. The first step,
therefore, in (4)________these phenomena into (5)__________form, is to ascertain
the (6)_________and direction of the force acting between the bodies, and when it is
found that this force (7)________in a certain way upon the (8)__________ position
of the bodies and on their electric or magnetic condition, it seems at first sight natural
to explain the facts by (9)_________the (10)_________of something either at rest or
in motion in each body, (11)__________its electric or magnetic state, and capable of
acting at a distance according to mathematical laws.
UNIT TWO
ELECTRICITY AND MAGNETISM
READING
1. Read the text and complete statements 1-6 with the best ending A, B or C.
1) Opposite magnetic poles…
A pull towards each other.
B repel each other.
C are neutral.
2) The strength of the poles…
A does not affect magnetic forces.
B influences magnetic forces.
C is always the same.
3) Electromagnetism shows that electricity and magnetism…
A are interdependent.
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B stand in opposition.
C exist separately.
4) Electric current…
A exists around electric charges.
B consists of magnetic fields.
C produces magnetic fields.
5) The direction of the magnetic field…
A cannot be detected.
B presents circular movement around the conductor.
C coincides with the direction of the current.
6) The motor effect…
A shows the relations between different magnetic fields.
B indicates that magnetic fields are stronger than electric current.
C is not applicable.
Many similarities exist between electric and magnetic phenomena. A magnet has two
opposite poles, referred to as north and south. Opposite magnetic poles attract each
other, and similar magnetic poles repel each other, exactly as happens with electric
charges.
The force with which magnetic poles attract or repel each other depends on the
strength of the poles and the distance between them. This relationship is similar to the
Coulomb’s inverse square law for electric charges.
The similarities between electric
and
magnetic
phenomena indicate that
electricity and magnetism are related. Electricity produces magnetic effects and
magnetism produces electric effects. The relationship between electricity and
magnetism is called electromagnetism.
Magnetic Effects of Electricity
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It has been noted that an electric field exists around any electric charge. If electric
charges are moving, they constitute an electric current. The magnetic effect of
electricity is demonstrated by the fact that a magnetic field exists around any electric
current. The field can be detected when a magnet is brought close to the currentcarrying conductor.
The magnetic field around an electric current can be thought of as lines of
magnetic force that form closed circular loops around the wire that carries the
current. The direction of the magnetic field can be determined by a convenient rule
called the right-hand rule. To apply this rule, the thumb of the right hand is pointed in
the direction in which the current is flowing and the fingers are curled around the
wire. The direction of the fingers then indicates the direction of the lines of magnetic
force. (The right-hand rule assumes that current flows from positive to negative.)
Motor Effect
As already stated, a magnetic field exists around a wire carrying an electric current,
and a magnetic field exists between the two poles of a magnet. If the wire is placed
between the poles, the magnetic fields interact to produce a force that tends to push
the wire out of the field. This phenomenon, known as the motor effect, is used in
electric motors.
VOCABULARY PRACTICE
1. Find English equivalents to the following words and word combinations.
a. составлять;
b. круговые линии;
c. противоположные полюса;
d. выталкивать проводник (из поля);
e. существовать;
f. сходство, сходные характеристики;
g. окружать (проводник);
h. явление;
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i.
магнитный эффект;
j. магнитные силовые линии.
2. Write out the passage using the correct form of the verbs in brackets.
SOLENOIDS
If a wire (1)________(bend) into many continuous loops to form a long spiral coil,
then the magnetic lines of force tend (2)______(go) through the center of the coil
from one end to the other rather than around the individual loops of wire. Such a coil,
(3)_______(call) a solenoid, (4)________(behave) in the same way as a magnet and
(5)____(be) the basis for all electromagnets. The end from which the lines
(6)______(exit) (7)____(be) the north pole and the end into which the lines
(8)_______(reenter) (9)___(be) the south pole. The polarity of the coil can
(10)___________(determine) by (11)________(apply) the left-hand coil rule. If the
left hand (12)______(grasp) the coil in such a way that the fingers (13)______(curl)
around in the direction of the electron current, then the thumb (14)______(point) in
the direction of the north pole.
3. Fill in the correct preposition.
MAGNETISM
Magnetism is an aspect ___ electromagnetism, one ___ the fundamental forces ___
nature. Magnetic forces are produced ___ the motion ___ charged particles such as
electrons, indicating the close relationship ___ electricity and magnetism. The
unifying frame ___ these two forces is called electromagnetic theory. The most
familiar evidence ___ magnetism is the attractive or repulsive force observed to act
___ magnetic materials such as iron. More subtle effects ___ magnetism, however,
are found ___ all matter. ___ recent times these effects have provided important clues
___ the atomic structure ___ matter.
4. Complete the text using one of the words from the box.
placed
discovery
predicted
magnetism
connection
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Hans Christian Oersted (1)__________ in 1813 that a (2)____________would be
(3)__________between
electricity
and
(4)_____________.
In
1819
he
(5)___________a compass near a current-carrying wire and observed that the
compass needle was (6)___________. This (7)___________demonstrated that
electric currents produce magnetic fields.
5. Complete the text with words formed from the words in capitals.
Michael Faraday made (1)__________contributions to the study of
SIGNIFY
electricity and (2)_________. He found that a current flows in a wire
MAGNET
that is moved through a magnetic field. The (3)____________of this
DISCOVER
phenomenon, which is called electromagnetic (4)_____________,
contributed to the (5)________________of Maxwell’s equations,
and led to the (6)___________of the electric generator.
INDUCE
DEVELOP
INVENT
6. Complete each sentence with one of the endings.
a. Compass is an instrument that…
b. Compass enables mariners and navigators…
c. Two fundamental types of compass are used:…
d. In the magnetic compass, directions are obtained by means of…
e. The gyrocompass is…
f.
The magnetic compass…
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g. The gyrocompass was…
1. …one or more magnetic needles.
2. …to get from one place to another.
3. …unaffected by the magnetism of the earth.
4. …indicates direction.
5. …developed at the beginning of the 20th century.
6. …originated in ancient China.
7. …the magnetic compass and the gyrocompass.
SPEAKING
Make a presentation on magnetic effects of electricity. Pay special attention to
the texts of the module. Use additional information and add your own ideas.
WRITING
You are running a firm producing various compasses. Write an advertisement
for a specialized magazine introducing new products.
MODULE IV ASSESSMENT
Translate from English into Russian.
ELECTRIC EFFECTS OF MAGNETISM
If a wire is moved through a magnetic field in such a way that it cuts the magnetic
lines of force, a voltage is created across the wire. An electric current will flow
through the wire if the two ends of the wire are connected by a conductor to form a
circuit. This current is called an induced current, and the induction of a current in this
manner is called electromagnetic induction.
It does not matter whether the wire moves or the magnetic field moves, provided that
the wire cuts through lines of force. If a magnet is moved near a stationary wire, the
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lines of magnetic force are cut by the wire and an electric current is induced in the
wire.
Like any electric current, an induced current generates a magnetic field around it.
Lenz’s law expresses an important fact concerning this magnetic field: The motion of
an induced current is always in such a direction that its magnetic field opposes the
magnetic field that is causing the current.
Редактор Р.А. Черникова
УЧЕБНЫЕ ЗАДАНИЯ
ПО АНГЛИЙСКОМУ ЯЗЫКУ
ДЛЯ СТУДЕНТОВ 2 КУРСА
СПЕЦИАЛЬНОСТИ «ЭЛЕКТРОЭНЕРГЕТИКА И ЭЛЕКТРОТЕХНИКА»
3 СЕМЕСТР
Составители: Ламанская О.П.
Хаустов О.Н.
Фадина Е.Ю.
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