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B.For more than 100 years imperial units of measure have not been the only units of measurement in the United Kingdom.

5.A. He was thrown backward by the force of the explosion.

B.The effect will be to increase unemployment and force down wages.

6.A. Rivers flow into the sea.

B.He struggled to swim against the flow of the water.

7.A. We can supply the goods from our main store.

B.The nation's fuel supplies will not last forever.

8.A. I will do everything in my power to help you.

B.This boat is powered with the latest improved model of our engine.

9.A. When the plug is inserted in the socket, the lamp can be lighted.

B.Your phone can be plugged into the cigarette lighter socket in your car.

10.A. The dollar has been steadily increasing in value. B. Shelly valued her privacy.

Ex. 12. Translate the following sentences from English into Russian.

1. Incandescent bulbs are made in a wide range of sizes and voltages, from 1.5 volts to about 300 volts. 2. The money that has been collected will be distributed among all the children's hospitals in the area. 3. The company makes devices for separating metal from garbage. 4. In electromagnetism and electronics, capacitance is the ability of a body to hold an electrical charge. 5. Capacitance is also a measure of the amount of electric charge stored (or separated) for a given electric potential. 6. Although early batteries were of great value for experimental purposes, in practice their voltages fluctuated and they could not provide a large current for a sustained period. 7. Electromotive force in electrostatic units is the statvolt (in the centimeter gram second system of units equal in amount to an erg per electrostatic unit of charge). 8. He read through the article, and liked it so much that he made copies of it to distribute around the hospital. 9. Power supply unit in computer converts alternating current to direct current and provides different voltages to different parts of the computer. 10. Newton's law of universal gravitation states that every object in this universe attracts every other object with a force which is directly proportional to the product of their masses and inversely proportional to the square of distance between their centres. 11. Water flowed from the pipe. 12. He struggled to swim against the flow of the water. 13. The price the meat is sold for has no relation to the price the farmer receives. 14. We can measure the energy that food provides in calories. 15. The measure is given in centimeters. 16. Tell me in what direction to look. 17. I had never in my life been to a political meeting or demonstration organized by the revitalized feminist movement. 18. The whole horizon glowed with the light of the great fire. 19. The bridge isn't strong enough to allow the passage of heavy vehicles. 20. A problem must be stated in order to be solved. 21. Approximately 90% of the power consumed by an incandescent light bulb is emitted as heat, rather than as visible light.

Ex.13. In the following sentences use Passive instead of Active.

1. They directed the attacks against the enemy's seaports. 2. They stated the contents of the deed falsely. 3. We can supply the goods from our main store. 4. No wonder the lamp didn’t come on, they didn’t plug it in! 5. They valued Jan for her hard work. 6. They should distribute water not only to every house, but to every floor. 7. The loss of money forced her to sell her house. 8. They quantified the damage caused to the tourist industry. 9. They measured the rainfall over a three-month period. 10. The latest improved model of our engine powers this

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boat. 11. They relate the rise in crime to an increase in unemployment. 12. One large central light lit the room. 12. They stated the contents of the deed falsely. 13. They replaced the broken window. 14. Two points determine a straight line. 15. You have to carry a mobile so that they can call you in at any time.

Ex.14. Match the words on the left with their definitions on the right.

Ex.15. Choose the best alternative to complete the sentences and translate them from English into Russian.

1. The metallic substances differ from all other materials by the fact that the outer shells of their atoms are bound rather loose / loosely, and often let one of their electrons go free. 2. Electric currents in solids typically flow very slow / slowly. 3. The high speed of electromagnetic waves is rough / roughly analogous to the speed of sound in a gas; while the random / randomly motion of charges is analogous to heat - the thermal velocity of random / randomly vibrating gas particles. 4. A flow of positive / positively charge gives the same electric current as an opposite flow of negative charge. 5. Electric current can be directly measured with a galvanometer. 6. Circuit performance depends strong / strongly upon the designed current level, and the current density then is determined by the dimensions of the conducting elements. 7. At high / highly current densities the material forming the interconnections actual / actually moves. 8. The electrical resistance of an object is a measure of its opposition to the passage of a steady / steadily electric current. 9. There are fixed energy levels which the electrons can occupy, and values in between these levels are impossible / impossibly. 10. Simple ohmmeters cannot measure low resistances accurate / accurately because the resistance of their measuring leads causes a voltage drop that interferes with the measurement.

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

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

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

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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 is called direct current (DC). Current that flows back and forth, reversing direction again and again, is called alternating current (AC). 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.

In electrical circuits, Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and inversely proportional to the resistance between them.

The mathematical equation that describes this relation is:

RI = V.

where V is the potential difference measured across the resistance in units of volts; I is the current through the resistance in units of amperes

and R is the resistance of the conductor in units of ohms.

RI = V = V/I and I = V/R. If any two of the quantities are known, the third can be calculated. For example, if a potential difference of 110 volts sends a 10-amp current through a conductor, then the resistance of the conductor is R = V/I = 110/10 = 11 ohms. If V = 110 and R = 11, then I = V/R = 110/11 = 10 amp.

Ex. 61. Choose the best alternative to complete the sentences.

1.DC is a current that ….

a)changes its direction of flow

b)flows in one direction….

2.AC flows….

a)back and forth

b)in the same direction

3.When two objects with different charges touch ….

a)an electric current flows from one object to the other

b)an electric current flows in the opposite direction

4.When a light bulb is connected to an electric battery ….

a)current flows current flows the battery and wires

b)current flows current flows wires and the bulb

5.Ohm's law states that ….

a)that the current through a conductor between two points is directly proportional to the potential difference across the two points

b)that the current through a conductor between two points is inversely proportional to the potential difference across the two points

Ex.2. Solve the following problems using the formulas of Ohm’s. Model: V= 50V I = 5amp R=?

Current equals 5amp; voltage equals 50 volts. How much is resistance? Resistance equals voltage divided by current. It equals 10 ohms.

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Ex. 3. Fill in the blanks with the words given in the box. Translate the sentences.

An electric (1) … is formed when a conductive path is created to allow free electrons (2) … to continuously move. This continuous (3) … of free electrons through the conductors of a circuit is called a (4) … and it is often referred to in terms of "flow". The force motivating electrons to flow in a circuit is called (5) …. . It is a specific measure of potential energy that is always relative between two points. When we speak of a certain (6) …. of voltage being present in a circuit, we are referring to the measurement of how much (7) … exists to move electrons from one particular point in that circuit to another particular point. Without reference to two particular points, the (8) … "voltage" has no meaning.

Free electrons tend to move through conductors with some degree of (9)..., or opposition to motion. This opposition to motion is more properly called (10) … The amount of current in a circuit depends on the amount of voltage available to motivate the electrons, and also the amount of resistance in the circuit to oppose electron (11) ….. just like voltage, resistance is a quantity relative between two points. For this reason, the (12) …. of voltage and resistance are often stated as being "between" or "across" two points in a circuit.

Ex.4. Translate the following sentences from Russian into English.

1.Электрический ток – это движение заряженных частиц.

2.Направлением электрического тока – это направление движения положительно заряженных частиц.

3.Закон Ома формулируется так: сила тока в участке цепи прямо пропорциональна напряжению, иобратнопропорциональнаэлектрическомусопротивлению.

4.Сила тока на участке цепи равна отношению напряжения на этом участке к его сопротивлению.

5.Закон Ома является фундаментальным (основным) и может быть применён к любой физической системе, в которой действуют потоки частиц или полей, преодолевающие сопротивление.

6.Постоянный электрический ток - электрический ток, не изменяющийся с течением времени по силе и направлению.

7.Переменный электрический ток – это электрический ток, периодически изменяющий свое направление в цепи так, что среднее значение силы тока за период равно нулю.

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U N I T 3

Ex. 1. Copy and memorize the following terms.

Glossary

conductivity – электропроводность, удельная проводимость density – плотность; концентрация

doping – допирование (введение примесей) frequency – частота

impurity – примесь

insulator – диэлектрик; изолятор

net current – результирующий поток, полный ток resistivity – удельное сопротивление semiconductor – полупроводник

solid – твёрдое тело solution – раствор velocity – скорость

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

9gradient – отклонение

9imposition – приложение

9interstitial – промежуточный

9negligible – незначительный

9random – случайный, произвольный

9response – реакция

9thereby – таким образом

9to constitute – составлять

9to dissolve – растворять

9to hop – скакать, прыгать

9to occur – происходить

Translate the following sentences from English into Russian.

1. The conditions of equal densities and equal velocities imply that the current densities of electrons and ions have equal magnitude but opposite direction. 2. Volunteers constitute more than 95% of the center's work force. 3. Sugar dissolves in water. 4. The path becomes very rough as the gradient increases. 5. She and some friends hopped a train for Liverpool. 6. The law was passed in response to public pressure. 7. The disease occurs chiefly in tropical climates. 8. He became a citizen in 1978, thereby gaining the right to vote. 9. Sound could at last be recorded with incredible ease and at negligible cost. 10. The company has introduced random drug testing of its employees. 11. Helicopters will fly overhead, and police robots will be available to handle suspicious packages that might contain explosives.12. All natural minerals contain impurities. 13. A semiconductor is a material that has an electrical resistivity between that of a conductor and an insulator.

Ex.2. Fill in the blanks with the words given in the box. Translate the sentences.

1. In metals, electrical … decreases with increasing temperature, whereas in semiconductors, electrical conductivity increases with increasing temperature. 2. Electrical … is a measure of how strongly a material opposes the flow of electric current. 3. Devices made of … are essential components of most electronic circuits. 4. In chemistry, a … is a homogeneous mixture composed of two or more substances. 5. For cyclical processes, such as rotation, oscillations, or waves, is … defined as a number of cycles, or periods, per unit time. 6. … is the process of intentionally introducing impurities into an extremely pure semiconductor to change its electrical properties. 7. A very common instrument for the direct measurement of the … of a liquid is the hydrometer. 8. Cotton is a poor ….9. Aluminum and lead … are frequently found in tap water. 10. Matter is generally found in three different forms:… liquid, and gas. 11. The speedboat reached a… of 120 mph.

Ex.3. Translate the following sentences containing a very ‘simple’ word o n e .

1. The second sputnik was launched about a month after the first one. 2. There are many insulating materials from which one may choose. 3. Some substances are efficient conductors, others are poor ones. 4. They are selling their house to move to a smaller one. 5. The old turbine was a water turbine and the new one is a steam turbine. 6. One uses special devices to measure current, voltage and resistance. 7. The new method was much efficient than the old one. 8. One knows that these installations do not operate on nuclear power. 9. One must choose only one of those variants. 10. One should control the chain turbine

Ex.4. Translate the following sentences into Russian paying attention to the construction the … the - чем … тем.

1. The more one studies the nature, the better one knows its laws. 2. The longer one learns, the more one knows. 3. The higher the atmosphere, the less its pressure. 4. The heavier the object, the more work one has to do in order to lift it. 5. The greater the numbers of free electrons in any metal, the higher is its conductivity. 6. The larger the cross-sectional area of the conductor, the more electrons are available to carry the current, so the lower the resistance.

7.The larger the pressure difference between two points the greater the flow between them.

8.The longer the conductor, the more scattering events occur in each electron's path through the material, so the higher the resistance. 9. The higher the value of current, the higher is the temperature of the resistor. 10. The higher the voltage used to charge the capacitor, the more energy it will store. 11. The larger the size of plates and the greater is their number, the more energy it stores. 12. The greater the safety factor, the less efficient the design may be.

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

E L E C T R I C A L C O N D U C T I O N

Electrical conduction is the movement of electrically charged particles through an electrical conductor. The movement of charge constitutes an electric current. The charge transport may result as a response to an electric field, or as a result of a concentration gradient in carrier density, that is, by diffusion. The physical parameters governing this transport depend upon the material.

Conduction in metals and resistors is well described by Ohm's Law, which states that the current is proportional to the applied electric field.

In crystals, electrical current is due to the motion of both ions and electrons. Ions move by hopping occasionally from site to site; all solids can conduct electricity in this manner. When the voltage is zero, there is no net current because the ions hop randomly in all directions. The imposition of a small voltage causes the ions to slightly favour one direction of motion, which leads to a net flow of charge in that direction; this constitutes an electrical current. The electricity conducted by this process is quite small and is usually negligible compared with that carried by the electrons. When an ion hops, it must migrate to a vacant site, which could be either an interstitial or a vacancy. Ionic conductivity can occur because hopping ions cause vacancies to move through the solid. An ion hops to the vacant site, thereby filling the vacancy, while creating a new one at the ion's former site. Repeating this process causes the position of the vacancy to migrate through the crystal. The motion of the vacancy arises from the motion of ions, which carry charge and contribute to electrical conductivity.

•A conductor such as a metal has high conductivity and a low resistivity.

•An insulator like glass or a vacuum has low conductivity and a high resistivity.

•The conductivity of a semiconductor is generally intermediate, but varies widely under different conditions, such as exposure of the material to electric fields or specific frequencies of light, and, most important, with temperature and composition

of the semiconductor material.

The degree of doping in solid state semiconductors makes a large difference in conductivity. More doping leads to higher conductivity. The conductivity of a solution of water is highly dependent on its concentration of dissolved salts and sometimes other chemical species which tend to ionize in the solution. Electrical conductivity of water samples is used as an indicator of how salt-free, ion-free, or impurity-free the sample is; the purer the water, the lower the conductivity (the higher the resistivity).

Ex.1. Translate the words given in the box into English and fill in the blanks with the appropriate word. Translate the sentences into Russian.

1. Electrical conduction is the … of electrically charged particles through an electrical conductor. 2. A conductor such as a metal has high … and a low…. 3. An … hops to the vacant site, thereby filling the vacancy, while creating a new one at the ion's former site. 4. An … like glass or a vacuum has low conductivity and a high resistivity. 5. The electricity conducted by this process is quite small and is usually …. 6. The degree of doping in … state semiconductors makes a large difference in conductivity. 7. The charge transport may result as a … to an electric field. 8. The motion of the … arises from the motion of ions, which carry charge and contribute to electrical conductivity. 9. The imposition of a small voltage causes the ions to slightly favour one direction of motion. 10. The conductivity of a semiconductor varies widely under exposure of the material to electric fields or specific … of light.

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

5.There is no net current because …

a)the ions hop randomly in one direction

b)the ions hop randomly in all directions

6.When an ion hops ….

7.A conductor has ….

a)a low conductivity and a high resistivity

b)a high conductivity and a low resistivity

8.An insulator has ….

a)a low conductivity and a high resistivity

b)a high conductivity and a low resistivity

9.The conductivity of a semiconductor varies widely under ….

a)exposure of the material to electric fields or specific frequencies of light

b)exposure of the material to electric fields or specific frequencies of light and with temperature and because of composition of the semiconductor material

Ex.3. Complete the sentences according to the model consulting the text: Model: Conductors have a low resistance … →

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

1.A conductor has high conductivity while …

2.When the voltage is zero, there is no net current while …

3.More doping leads to higher conductivity while …

4.The purer the water is, the lower the conductivity is while …

5.To make insulators conduct, currents of great values must be applied while …

6.Current passes through insulators with difficulty while …

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Ex.4. Translate the following sentences from Russian into English.

1. Различные материалы по-разному проводят электрический ток. 2. Проводимость всякого материала зависит от количества находящихся в нем свободных, электрически заряженных частиц, переносящих электрические заряды, – электронов и ионов, а также от того, с какой скоростью эти носители электрических зарядов перемещаются. 3. Чем больше в материале имеется носителей зарядов и чем они подвижнее, тем меньше его сопротивление. 4. В нормальных условиях газы не проводят электрический ток. 5. Мера способности вещества проводить электрический ток называется удельной проводимостью. 6. Плотность возникающего тока прямо пропорциональна электрическому полю.

7.Величина, обратная удельной проводимости, называется удельным сопротивлением.

8.Проводник – это вещество, проводящее электрический ток. 9. Среди наиболее распространённых твёрдых проводников известны металлы. 10. Диэлектрик – это материал, плохо проводящий или совсем не проводящий электрический ток. 11. К диэлектрикам относятся воздух и другиегазы, а также стекло, различные смолы и пластмассы.

Ex.5. Answer the following questions to the text.

1.What is electrical conduction?

2.What may the charge transport result in?

3.What do the physical properties governing this transport depend on?

4.What does Ohm’s Law state?

5.What is electrical current in crystals due to?

6.What happens to the net current when the voltage is zero?

7.What kinds of materials have a high conductivity and a low resistivity?

8.What kinds of materials have a low conductivity and a high resistivity?

9.What kind of conductivity does a semiconductor have?

10.What leads to higher conductivity of a semiconductor?

U N I T 4

Ex. 1. Copy and memorize the following terms.

Glossary

capacitor – конденсатор coil – катушка

current source – источник тока inductance – индуктивность inductor – катушка индуктивности switch – выключатель, переключатель terminal – клемма

transmission line – линия электропередачи variable – переменная (величина) voltage source –источник напряжения

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

9application – приложение; применение

9delay – задержка, запаздывание

9input – входной

9layer – слой

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9loop – петля, замкнутая цепь

9lumped – сосредоточенный; концентрированный

9output – выходной

9to dissipate – рассеивать

9to insert – вставлять insertion – включение, вставка

9to predict – предсказывать, прогнозировать

9to stack – комплектовать

9to store – аккумулировать

9transient – переходный

Ex.3. Translate the following sentences from English into Russian

1. The research has many practical applications. 2. If the input data specified it, the file will close and the process terminates. 3. Insert your comments in the space below. 4. Big companies often delay paying their bills. 5. Little by little, the smoke was dissipated by the breeze. 6. Insertion is something that is added to the middle of a document or piece of writing. 7. The moon was shining through a thin layer of cloud. 8. Induction loop is a term used to describe an electromagnetic communicationand detection system, relying on the fact that a moving magnet will induce a electrical current in a nearby conducting wire. 9. In traditional calculus, a function is defined as a relation between two terms called variables because their values vary. 10. Unemployment is predicted to increase to 700,000 by the end of the year. 11. A system is said to be in transient state when a process variable has been changed and the system has not yet reached steady-state. 12. The great water power of the Mississippi at Minneapolis enables the millers there to output some 1,200 tons of flour per day. 13. Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in transmission.14. How much energy can this battery store? 15. The assistants price the items and stack them on the shelves.

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

Electrical network, interconnection of electrical elements, closed loop, return path, voltage source, current source, magnetic field, express purpose, precise quantity, environmental conditions, stable resistance value, store energy, to delay and reshape alternating currents, linear circuit, output capacitance.

Ex.5. Match the words in the A column with their definitions in the B column.