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6.	switch	f)	the ability of a system to store an electric charge
7.	terminal	g)	an electrical device consisting of a length of wire arranged in a coil
			for converting the level of a voltage
8.	transmission	h)	a point of connection for closing an electric circuit
	line

Ex.5. Translate the words given in the box into English and fill in the blanks with the appropriate word. Translate the sentence into Russian.

выход	клеммы	закон сохранения энергии	источник
индуктивность	катушка	линия передачи	напряжения
переменные	конденсатор		переключатели

1. An electric circuit is an "open circuit" if it lacks a complete path between the positive and negative … of its power source. 2. The total loss of power in a … is often specified in decibels per metre (dB/m), and usually depends on the frequency of the signal. 3. The energy stored in a … is equal to the work done to charge it. 4. An "ideal inductor" has …, but no resistance or capacitance, and does not dissipate or radiate energy. 5. Automatically operated … can be used to control the motions of machines. 6. In a closed-loop control system, a sensor monitors the … (the vehicle's speed) and feeds the data to a computer. 7. An inductor is usually constructed as a … of conducting material, typically copper wire. 8. Much of the basic theory for which we use … today, such as school geometry and algebra, was developed thousands of years ago. 9. No real … is ideal; all have a non-zero effective internal resistance, and none can supply unlimited current. 10. The … states that the total amount of energy in a closed system remains constant.

Read and translate the text using a dictionary if necessary.

E L E C T R I C C I R C U I T

An electrical network is an interconnection of electrical elements such as resistors, inductors, capacitors, transmission lines, voltage sources, current sources, and switches.

An electrical circuit is a network that has a closed loop, giving a return path for the current. A network is a connection of two or more components, and may not necessarily be a circuit.

Electrical networks that consist only of sources (voltage or current), linear lumped elements (resistors, capacitors, inductors), and linear distributed elements (transmission lines) can be analyzed by algebraic and transform methods to determine DC response, AC response, and transient response.

Because the relationship between voltage, current, and resistance in any circuit is so regular, we can reliably control any variable in a circuit simply by controlling the other two. The easiest variable in any circuit to control is its resistance. This can be done by changing the material, size, and shape of its conductive components.

Special components called resistors are made for the purpose of creating a precise quantity of resistance for insertion into a circuit. They are typically constructed of metal wire or carbon, and engineered to maintain a stable resistance value over a wide range of environmental conditions. Unlike lamps, they do not produce light, but they do produce heat as electric power is dissipated by them in a working circuit. Typically, though, the purpose of a resistor is not to produce usable heat, but simply to provide a precise quantity of electrical resistance.

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The most common schematic symbol for a resistor is a zig-zag line:

Capacitors have thin conducting plates (usually made of metal), separated by a layer of dielectric, then stacked or rolled to form a compact device.

Many types of capacitors are available, with capacitance ranging from the picofarad, microfarad range to more than a farad, and voltage ratings up to hundreds of kilovolts. In general, the higher the capacitance and voltage rating, the larger the physical size of the capacitor and the higher the cost.

Circuits consisting of just one battery and one load resistance are very simple to analyze, but they are not often found in practical applications. Usually, we find circuits where more than two components are connected together.

An inductor or a reactor is a passive electrical component that can store energy in a magnetic field created by the electric current passing through it. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries. Typically an inductor is a conducting wire shaped as a coil, the loops helping to create a strong magnetic field inside the coil due to Faraday's law of induction. Inductors are one of the basic electronic components used in electronics where current and voltage change with time, due to the ability of inductors to delay and reshape alternating currents.

To design any electrical circuit electrical engineers need to be able to predict the voltages and currents at all places within the circuit. Linear circuits, that is, circuits with the same input and output frequency, can be analyzed by hand.

Ex.6. Match the halves of the sentences together.

	A		B
1.	The movement of charge constitutes …	a)	algebraic and transform methods.
2.	The physical parameters governing this	b)	the material, size, and shape of its
	transport …		conductive components.
3.	Electrical networks can be	c)	a precise quantity of electrical
	analyzed …		resistance.
4.	To control resistance of the circuit one	d)	the larger the physical size of the
	can change …		capacitor.
5.	Resistors produce heat …	e)	depend upon the material.
6.	The purpose of a resistor is	f)	the voltages and currents at all places
	to provide …		within the circuit.
7.	The higher the capacitance and voltage	g)	an electric current.
	rating, …
8.	To design any electrical circuit one	h)	as electric power is dissipated by them
	needs to be able to predict …		in a working circuit.

Ex. 7. Translate the following word combinations from Russian into English.

Соединение электрических элементов, проводящие пластины, созданный электрическим полем, имеющий форму катушки, задерживать и менять форму переменных токов, линейные цепи, входная и выходная частота, максимально допустимое напряжение, сделанный из металлического провода или углерода, цепь замыкания, нагрузочное сопротивление.

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Ex.8. Choose the best alternative to complete the sentences.

1.	An electrical network is a(n) … of electrical elements.
a) joint		b) link	c) interconnection
2.	An electrical circuit is a network that has a closed …, giving a return path for the
	current.
a) circle		b) loop	c) net
3.	They do not produce …, but they do produce heat as electric power is dissipated by
	them in a working circuit.
a) light		b) energy	c) power
4.	Circuits consisting of just one battery and one ... resistance are very simple to analyze.
a) unload		b) load	c) loaded

5.An inductor or a … is a passive electrical component that can store energy in a magnetic field created by the electric current passing through it.

a) capacitor		b) sensor	c) reactor
6.	An inductor is a conducting wire shaped as a ….
a) coil		b) ring	c) loop
7.	Linear circuits are circuits with the same input and output ….
a) resistance		b) power	c) frequency

8.To design any electrical circuit electrical engineers need to be able to predict the voltages and currents at all places within the….

a) circuit

b) device

c) wire

Ex.4. Answer the following questions to the text.

1.What elements can be interconnected in an electrical circuit?

2.How can a circuit be analyzed?

3.What purpose are the circuits analyzed for?

4.Why can one control any variable in a circuit by controlling the other two?

5.What purpose are resistors made for?

6.What kind of materials are resistors typically made of?

7.What elements does a capacitor consist of?

8.What types of capacitors are available?

9.What purpose are inductors made for?

10.How an inductor's ability to store magnetic energy is measured?

11.What do electrical engineers need to be able to predict to design any electrical circuit?

U N I T 5

Ex. 1. Copy and memorize the following terms.

Glossary

branch – ветвь на схеме разводки lead(s) – электропроводка

parallel – соединённый параллельно series – соединённый последовательно

Ex 2. Copy the following words and memorize the meanings.

9chain – цепочка

9clockwise – по часовой стрелке

9common – общий

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9counter-clockwise – против часовой стрелки

9on the one hand ... on the other hand – с одной стороны ..., с другой стороны

9rate – скорость

9to diminish – уменьшать, уменьшаться

Ex.2. Translate the following sentences from English into Russian.

1. Despite the increase in supply voltage, the ratio between any branch current and the total current remains unchanged. 2. The lead is a wire used to connect a piece of electrical equipment to the power supply. 3. The lead is a wire that conveys electric current from a source to an appliance, or that connects two points of a circuit together. 4. If we are able to identify which parts of the circuit are series and which parts are parallel, we can analyze it. 5. They formed a human chain to move the equipment.6. A sudden drop on Wall Street can set off a chain reaction in other financial markets. 7. The Sun, the Moon, the planets and stars seem to move clockwise across the northern sky. 8. Turn the lid anticlockwise. 14. We are working together for a common purpose. 9. These drugs diminish blood flow to the brain. 10. I'd like to eat out, but on the other hand I should be trying to save money. 11. Nuclear power is relatively cheap. On the other hand, you could argue that it's not safe.

	Ex.3. Match the words in column A with their definitions in column B.
	A		B
1.	branch	a)	side by side and having the same distance continuously between
			them
2.	leads	b) the speed with which something moves
3.	parallel	c)	a feature or quality belonging typically to a thing and serving to
			identify it
4.	series	d)	the course or direction in which a thing is moving
5.	rate	e)	a wire used to connect a piece of electrical equipment to the power
			supply
6.	to diminish	f)	a number of things of a similar kind coming one after another
7.	characteristic	g)	a smaller less important part of a circuit that leads away from the
			larger more important part of it:
8.	clockwise	h) make or become less
9.	path	i)	corresponding in direction to the movement of the hands of a clock

Ex.4. Practice the reading of the following word combinations. You are to copy them and memorize their meanings.

Basic way, defining characteristic, series circuit, counter-clockwise direction, amount of current, path for electrons to flow, the rate of flow, set of electrically common points, to determine the relationships.

Read the text and translate it using a dictionary if necessary.

T Y P E S O F E L E C T R I C A L C I R C U I T S

There are two basic ways in which to connect more than two circuit components: series and parallel. First, an example of a series circuit:

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Here, we have three resistors (labeled R1, R2, and R3), connected in a long chain from one terminal of the battery to the other. The defining characteristic of a series circuit is that there is only one path for electrons to flow. In this circuit the electrons flow in a counter-clockwise direction, from point 4 to point 3 to point 2 to point 1 and back around to 4. The basic idea of a "series" connection is that components are connected end-to-end in a line to form a single path for electrons to flow: The first principle to understand about series circuits is that the amount of current is the same through any component in the circuit. This is because there is only one path for electrons to flow in a series circuit, and because free electrons flow through conductors, the rate of flow at any point in the circuit at any specific point in time must be equal. In series circuits a trouble in one component results in no current in the whole circuit.

Now, let's look at the other type of circuit, a parallel configuration:

Again, we have three resistors, but this time they form more than one continuous path for electrons to flow. There's one path from 8 to 7 to 2 to 1 and back to 8 again. There's another from 8 to 7 to 6 to 3 to 2 to 1 and back to 8 again. And then there's a third path from 8 to 7 to 6 to 5 to 4 to 3 to 2 to 1 and back to 8 again. Each individual path (through R1, R2, and R3) is called a branch.

The defining characteristic of a parallel circuit is that all components are connected between the same set of electrically common points. Looking at the schematic diagram, we see that points 1, 2, 3, and 4 are all electrically common. So are points 8, 7, 6, and 5. Note that all resistors as well as the battery are connected between these two sets of points. The basic idea of a "parallel" connection, on the other hand, is that all components are connected across each other's leads. In a purely parallel circuit, there are never more than two sets of electrically common points, no matter how many components are connected. There are many paths for electrons to flow, but only one voltage across all components. In summary, a parallel circuit is defined as one where all components are connected between the same set of electrically common points. Another way of saying this is that all components are connected across each other's terminals. From this definition, three rules of parallel circuits follow: all components share the same voltage; resistances diminish to equal a smaller, total resistance; and branch currents add to equal a larger, total current. Total parallel resistance is less than any one of the individual branch resistances because parallel resistors resist less together than they would separately: Total parallel conductance is greater than any of the individual branch conductances

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because parallel resistors conduct better together than they would separately: In parallel circuits a trouble in one branch results in no current in that branch only, a trouble in the main line results in no current in the whole circuit.

We can have circuits that are a combination of series and parallel, too:

In this circuit, we have two loops for electrons to flow through: one from 6 to 5 to 2 to 1 and back to 6 again, and another from 6 to 5 to 4 to 3 to 2 to 1 and back to 6 again. Notice how both current paths go through R1 (from point 2 to point 1). In this configuration, we'd say that R2 and R3 are in parallel with each other, while R1 is in series with the parallel combination of

R2 and R3.

If we are able to identify which parts of the circuit are series and which parts are parallel, we can analyze it in stages, approaching each part one at a time, using the appropriate rules to determine the relationships of voltage, current, and resistance.

Ex.2. Choose the best alternative to complete the sentences.

1.	In a series circuit, all components are connected ….
	a) across each other.	b) end-to-end.
2.	In a parallel circuit, all components are connected ….
	a) across each other.	b) end-to-end.
3.	A parallel circuit has ….
	a) parallel branches only.	b) the main line and parallel branches.

4.A parallel circuit is used in order ….

a)to have the same value of current in all the elements.

b)to have the same value of voltage in all the elements.

5.A series circuit is used in order ….

a)to have the same value of current in all the elements.

b)to have the same value of voltage in all the elements.

6.Total parallel resistance is ….

a)more than any one of the individual branch.

b)less than any one of the individual branch.

7.Total parallel conductance is ….

a)greater than any of the individual branch.

b)smaller than any of the individual branch.

8.We can analyze series-parallel circuits ….

a) as a whole.

b) in stages.

Ex.3. Consult the text and complete the sentences according to the model: Model: Conductors have a low resistance … →

Conductors have a low resistance while insulators have a high resistance.

1.Resistors connected in series have different values of voltage while ….

2.Resistors connected in series have the same value of current, while ….

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3.In order to have the same value of current in all elements, a series circuit is used, while ….

4.in series circuits components are connected end-to-end in a line to form a single path for electrons to flow, while ….

5.A trouble in one component of a series circuit results in no current in the whole circuit, while …..

6.No current in a parallel circuit results from a trouble in the main line, while….

Ex.4. Answer the following questions to the text.

1.How are the components connected in a series circuit?

2.How are the components connected in a parallel circuit?

3.What is the defining characteristic of a series circuit?

4.What is the defining characteristic of a parallel circuit?

5.What is the rate of flow at any point in a series circuit at any specific time?

6.In what kind of circuit is total parallel resistance less than any one of the individual branch resistances?

7.What type of circuit has the main line and parallel branches?

8.What type of circuit is used to have the same value of current in all the components?

9.What type of circuit is used to have the same value of voltage in all the components?

10.What does a trouble in the main line result in?

11.What does a trouble in a branch result in?

Ex.5. Translate the following sentences from Russian into English.

1. Последовательное и параллельное соединение – это два основных способа соединения элементов электрической цепи. 2. При последовательном соединении все элементы связаны друг с другом так, что включающий их участок цепи не имеет ни одного узла. 3. При параллельном соединении все входящие в цепь элементы объединены двумя узлами и не имеют связей с другими узлами. 4. При последовательном соединении проводников сила тока во всех проводниках одинакова. 5. При параллельном соединении падение напряжения между двумя узлами, объединяющими элементы цепи, одинаково для всех элементов. 6. При этом величина, обратная общему сопротивлению цепи, равна сумме величин, обратных сопротивлениям параллельно включенных проводников. 7. При последовательном соединении проводников сила тока во всех проводниках одинакова.

C H A P T E R T W O P O W E R S U P P L Y

U N I T 1

Ex. 1. Copy and memorize the following terms.

Glossary

cell – гальванический элемент dioxide – двуокись

dry-cell battery – галетная сухая батарея (из плоских элементов) lead-acid storage battery – батарея свинцово-кислотных аккумуляторов nickel-cadmium battery – никель-кадмиевая батарея

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Ex. 2. Copy the following words and memorize their meanings:

9benefit – выгода; польза; прибыль; преимущество beneficial – выгодный, полезный; прибыльный

9to convert – преобразовывать, трансформировать convertible – трансформируемый

9to immerse – погружать

9lack – недостаток, отсутствие;

to lack smth. - нуждаться в (чём-л.); не иметь что-то

9portable – переносный, передвижной

9portability – портативность

9to rely on smth. – полагаться, надеяться на что-то reliability – надёжность

reliable – надёжный

9seal – затвор

to seal – запечатывать; заклеивать; плотно закрывать sealed – герметизированный; герметичный; запаянный

9span – период времени

Ex. 2. Translate the following sentences from English into Russian

1. Cycling is highly beneficial to health and the environment. 2. The new credit cards will be of great benefit to our customers. 3. They would benefit by reducing their labour costs. 4. If two chemicals are put together and heated, they can be converted into a completely different substance. 5. The rooms are equipped with bathrooms and convertible sofas for parents who want to stay with their children 6. A portable computer program can be used on different computer systems. 7. The principle advantage of a portable computer versus a laptop or other mobile computer is the use of standard motherboards or backplanes providing plug-in slots for add-in cards. 8. Over a span of ten years, the company has made great progress. 9. The doorway had been sealed up with bricks. 10. All medical instruments should be immersed in a suitable disinfectant. 11. The town relies on the seasonal tourist industry for jobs. 12. He will not lack for advisers. 13. In Africa, cellular phones are often the only reliable way of communicating.

Ex. 3. Suffixes change the class of the root word. They can tell you if a word is a noun, adjective, verb or adverb.

-er (manufacturer)

-eer (engineer)

-or (operator) -ant (assistant) -ian (electrician) -ist (scientist)

-ion (creation)

-ment (development) -ity (purity)

-able (programmable)

N o u n s u f f i x e s ( j o b s ) :

The fridge was sent back to the manufacturers. He trained as an electrical engineer.

Hello, operator? Could you put me through to Room 31? The laboratory assistant was very helpful.

An electrician maintains electrical equipment. Our scientists made several important discoveries.

N o u n s u f f i x e s ( s t a t e , a c t i v i t y )

The motorway should aid the creation of new business in the area.

How slow is the development of heat? There was a purity and a peace in his life.

A d j e c t i v e s u f f i x e s :

A programmable machine can be given instructions so that it will do something automatically.

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-ible (convertible) -ful (powerful) -less (careless)

-ize / -ise (specialize)

Ice is convertible into water.

Charlie Chaplin had a long and colorful career. Thousands of people have been made homeless.

V e r b s u f f i x e s :

DDT is a pesticide that was first synthesized in 1874.

Ex. 3 Complete the sentences using the word in brackets with an appropriate suffix. Consult a dictionary. Translate the sentences.

1.Most library databases are … via the Internet. (ACCESS)

2.The growth of the Internet has increased the need for effective data …. (SECURE)

3.What was Alfred Nobel’s greatest …? (ACHIEVE)

4.I’d like to invent something that is … to people in developing countries like a water purification system. (BENEFIT)

5.Recent … in medicine are helping people live longer and healthier lives.

6.Leonardo da Vinci was an artist and also a brilliant …. (INVENT)

7.For every problem, there is usually a …. (SOLVE).

8.I’d like to be the most famous and respected … in the world. (SCIENCE)

9.I heard this from a very … source. (RELY)

10.Rooms are offered subject to …. (AVALIABLE) 11. It improves the strength and … of joints. (MOBILE)

Ex. 4. Noun phrases are very common in English. Noun phrases often consist of a head noun, which is premodified. It means that the modifier is placed before the noun. They sometimes can be difficult to translate into Russian.

Model: lay-out diagram → diagram (схема) – ключевое слово; lay-out

(расположение) – атрибут → lay-out diagram – схема расположения;

wage rise → rise (повышение) – ключевое слово; wage (зарплата) – атрибут → wage rise – повышение зарплаты;

road vehicle → vehicle (транспортное средство) – ключевое слово; road (дорога) – атрибут → road vehicle – дорожное транспортное средство.

Practice the reading of the following word combinations. You are to copy them and memorize their meanings.

Power supply, circuit components, liquid electrolyte, service life, current availabilities, carbon plate, cell battery, automobile battery, zinc can, storage battery, electrode reaction, oxidation state, current availability, electrolyte paste, lead sulfate, traction system, metro line, power loss, wire damage.

Read the text and translate it using a dictionary if necessary.

B A T T E R Y P O W E R S U P P L Y

A battery is a type of linear power supply that offers benefits that traditional lineoperated power supplies lack: mobility, portability and reliability. A battery consists of multiple electrochemical cells connected to provide the voltage desired.

A wet cell battery has a liquid electrolyte. Wet cells may be primary cells (nonrechargeable) or secondary cells (rechargeable). Wet cells are still used in automobile batteries and in industry for standby power for switchgear, telecommunication or large uninterruptible

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power supplies, but in many places batteries with gel cells have been used instead. These applications commonly use lead-acid or nickel-cadmium cells.

A dry cell has the electrolyte immobilized as a paste, with only enough moisture in the paste to allow current to flow. Compared to a wet cell, the battery can be operated in any random position, and will not spill its electrolyte if inverted.

The most commonly used dry-cell battery is the carbon-zinc dry cell battery. A zinccarbon dry cell battery is packaged in a zinc can that serves as both a container and negative terminal. Dry-cell batteries are made by stacking a carbon plate, a layer of electrolyte paste, and a zinc plate alternately until the desired total voltage is achieved. The most common dry-cell batteries have one of the following voltages: 1.5, 3, 6, 9, 22.5, 45, and 90. During the discharge of a carbon-zinc battery, the zinc metal is converted to a zinc salt in the electrolyte, and magnesium dioxide is reduced at the carbon electrode. These actions establish a voltage of approximately 1.5 V.

The lead-acid storage battery may be used. This battery is rechargeable; it consists of lead and lead/dioxide electrodes which are immersed in sulfuric acid. When fully charged, this type of battery has a 2.06-2.14 V potential. During discharge, the lead is converted to lead sulfate and the sulfuric acid is converted to water. When the battery is charging, the lead sulfate is converted back to lead and lead dioxide.

A nickel-cadmium battery has become more popular in recent years. This battery cell is completely sealed and rechargeable. The electrolyte is not involved in the electrode reaction, making the voltage constant over the span of the batteries long service life. During the charging process, nickel oxide is oxidized to its higher oxidation state and cadmium oxide is reduced. The nickel-cadmium batteries have many benefits. They can be stored both charged and uncharged. They have a long service life, high current availabilities, constant voltage, and the ability to be recharged.

Ex. 5. Go back to the text and translate the following word combinations: cвинцово-кислотный, аккумулятор, резервная мощность, полностью заряженный,

серная кислота, срок службы, слой пастообразного электролита, желаемое напряжение, двуокись магния, угольный электрод, преобразуется в воду, постоянное напряжение.

Ex. 6. Match the halves of the sentences together.

	A		B
1.	A dry-cell battery…	a)	has a liquid electrolyte.
2.	A wet cell battery …	b)	can serve as both a container and negative
			terminal.
3.	A zinc-carbon dry cell…	c)	is rechargeable.
4.	A lead-acid storage battery…	d)	can be stored both charged and uncharged.
5.	A nickel-cadmium battery …	e)	has the electrolyte immobilized as a paste, with
			only enough moisture in the paste to allow
			current to flow.

Ex.3. Answer the following questions to the text.

1.What are the benefits that traditional line-operated power supplies cannot offer?

2.What does the battery consist of?

3.What kind of electrolyte does a wet cell battery have?

4.What kind of electrolyte does a dry cell battery have?

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