Unit 1

Некоммерческое акционерное общество

АЛМАТИНСКИЙ ИНСТИТУТ ЭНЕРГЕТИКИ И СВЯЗИ

Кафедра «Иностранные языки»

АНГЛИЙСКИЙ ЯЗЫК

Методические указания для развития умений аудирования

на основе текстов для студентов специальностей 050717 – Теплоэнергетика, 050718 – Электроэнергетика

Алматы 2009

СОСТАВИТЕЛЬ: А.У. Жусупова. Английский язык. Методические указания для развития умений аудирования на основе текстов (для студентов специальностей 050717 – Теплоэнергетика, 050718 – Электроэнергетика – Алматы. АИЭС, 2009. – 26 с.

Данные методические указания предназначены для студентов второго курса всех форм обучения для развития умений аудирования на основе текстов по специальности теплоэнергетика и электроэнергетика. В метод разработке содержатся аутентичные тексты и аудиотексты английской научно-технической литературы из разных источников.

Unit 1

Energy

Vocabulary

Source – источник

Obtain – получать

Fossil fuel – твердое топливо

To generate – вырабатывать, производить

Conventional – общепринятый, обычный

Nuclear power – ядерная энергия

To convert – превращать, обращать

Supply - запас

Solar power - энергия солнца

1.1 Energy sources

Read and translate the text

At present most of the power is obtained mainly from two sources. One is from burning fossil fuels that is coal, natural gas and oil. The second way of producing electricity is by means of generators that get their power from steam or water turbines. It should be noted however, that the generation of electricity by these conventional processes is highly uneconomic. Besides, the world resources of fossil fuels are not everlasting. Actually, only about 40 per sent of heat in the fuel is converted into electricity.

On the other hand, the power produced by hydroelectric plants, even if increased many times, will be able to provide for only a small fraction of the power required in the near future. Therefore much effort is being given to other means of generating electricity.

Using atomic fuel for the production of electricity is highly promising. It is well known fact, that one pound of uranium contains as much energy as three million pounds of coal, so cheap power can be provided wherever it is required.

However, scientists all over the world are doing their best to find more efficient ways of generating electricity directly from the fuel. They already succeeded in developing some processes which are much more efficient, as high as 80 per cent, and creating a number of devices capable of giving a higher efficiency. Scientists are hard at work trying to solve these and many other problems.

Listening

Tapescript 1.1 (According to the Disk: Track 1, unit 23. Energy sources)

In this dialogue an energy specialist is answering questions about different sources of energy. He compares how long 10 kilograms of different kinds of fuel will last. Listen to this dialogue and write down the length of time for each type of energy source/process.

Energy generation per 10 kgs in a 2 million kilowatt power station

Fuel/Process	Running time per 10 kgs
Nuclear Power
Hydrogen Fusion Reactor
Fast Reactor
Natural Uranium
Oil
Coal

Tapescript 1.2 (According to the Disk: Track 2, unit 9 (C), Input.)

Energy divisions

a) Listen to the text and complete the gaps.

How does modern _________ get the huge supplies of ___________ it needs? Here’s how the energy cake has been divided up since 1925. As you can see, __________ was the most widely used ___________ before the middle of this century. However, since the 1950s the use of coal has declined rapidly, and ___________ and _____________ have gradually replaced it as the main energy ___________. They now provide about three quarters of the world industrial energy ____________.

The chart also shows that the use of ______________ grew between 1925 and 1955, but since then it has stayed at a figure of 6%. ___________ power provided only a fraction of the industrial energy supplies in 1970, but it now meets 10% of the need.

In the last 60 years the world’s ______________ demand has increased by 800%, and this trend is likely to continue. Since fuels such as oil and gas will run out during the next 50 years, we will have to find new ways of getting the energy we need. The energy pie of 2025 will probably include a large slice of ______________.

b) Read and translate the text.

Unit 2

Electricity

Vocabulary

Conductor – проводник

Complete circuit – замкнутая цепь

Electromotive force – электродвижущая сила

Direct current – постоянный ток

Alternating current – переменный ток

Voltage – напряжение

Wire – провод

A bare wire – оголенный провод

Fuse – предохранитель

Rubber – резина

Insulator – изолятор

Terminal – зажим, вывод, клемма

Pivoted – вращающийся

To deflect – отклонять, отклонить

To charge – заряжать

Bulb – лампочка

Copper – медь

Horseshoe – подкова

Ammeter – амперметр

To rotate – вращаться

To repel – отталкивать

2.1 Electric current

Read and translate the text

Electric current is a form of energy carried by certain particles of matter (electrons and protons), used for lighting and heating and for making machines work. A current heats a conductor, it has a chemical action when it passes through a solution, and it can produce a magnetic effect. The practical unit of a current is called the Ampere.

A complete circuit and electromotive force cause an electric current to flow. The practical unit of electromotive force is the Volt.

There are two types of current: direct and alternating.

A direct current flows through a conducting circuit in one direction only. The simplest source of power for direct current is a battery, for a battery pushes the electrons in the same direction (i.e. from the negatively charged terminal to the positively charged terminal.

An alternating current is a current that changes its direction of flow through circuit. Current flows first in one direction and then in opposite one. It is easy to transform alternating current power from one voltage to another by a transformer. When necessary alternating current can be changed into direct current, but this is seldom necessary.

It is possible to have a strong shock from the electric wires in a house. The wire seldom carry current at a high voltage than 220, and a person who touches a bare wire or terminal may suffer no harm if the skin is dry. But if the hand is wet, he may be killed. Water is a good conductor of electricity. When we deal with wires and fuses which carry and electric current, it is best to wear rubber gloves. Rubber is a good insulator and will not let the current pass to the skin.

We all use electric current in our homes every day but sometimes forget that it is a form of power and may be dangerous. It can burn and kill, but it will serve us well if we use it wisely.

Listening

Tapescript 2.1 (According to the Disk: Track 3, unit 6, Input)

Oersted ‘s Experiment

a) Listen to the text and complete the gaps

In the winter of 1819 – 20 Christian Oersted was doing ____________ to find links between electricity,____________, light and heat. One of these experiments was very important, as it was the first step towards the ____________ of the generator or dynamo.

Oersted’s apparatus was very simple. He took a piece of ___________ and bent it to make a kind of bridge. The ends of the wire could be connected by leads to the terminals of an electric ___________. The only other piece of equipment was a pivoted magnet, like a compass needle.

It had long been known that magnets have two ___________ – north and south. Unlike poles attract and like poles ____________. Oersted also knew that there was a relationship between _____________ and magnetism, and he showed this by placing the magnetic needle below the wire, then connecting the wire to the battery. The needle was deflected by the ____________ in the wire. The wire was acting like another magnet and influencing the magnetic needle below it. What made the experiment so important was the next stage: when he placed the needle above the wire the needle was again deflected, but this time in the opposite direction.

Oersted concluded that there must be some sort of circular power or __________ around the wire. This force made the magnet move in opposite directions depending on its position relative to the electricity __________ wire.

b) Read and translate the text.

Listening

Tapescript 2.2 (According to the Disk: Track 3, unit 6, Step 6.)

a) Listen and make a list of the inventors, dates, and inventions.

1._________________________________________________

2._________________________________________________

3._________________________________________________

4._________________________________________________

5._________________________________________________

6._________________________________________________

b) Complete the paragraph using the correct prepositions.

______ one of Faraday’s experiments, he placed a copper wheel ______ the poles ______ a horseshoe magnet. ______ the centre and ______ the edge ______ the wheel there were electrical contacts. These were connected ______ the terminals ______ an ammeter. When the wheel rotated ______ the poles of the magnet, an electric current was shown ______ the ammeter. When the wheel was rotated ______ the opposite direction, the needle ______ the ammeter was deflected _______ the opposite direction, too.

2.2 The Electric motor

Read and translate the text

In an electric motor an electric current and magnetic field produce a turning movement. This can drive all sorts of machines, from wrist-watches to trains. The motor shown in Picture 1 is for a washing machine. It is a universal motor, which can run on direct current or alternating current.

An electric current running through a wire produces a magnetic field around the wire. If an electric current flows around a loop of wire with a bar of iron through it, the iron becomes magnetized. It is called an electromagnet; one end becomes a north pole and the other a south pole, depending on which way the current is flowing around the loop.

Picture 1

If you put two magnets close together, like poles-for example, two north poles-repel each other, and unlike pole attract each other.

In a simple electric motor, like the one shown in Picture 2, a piece of iron with loops of wire round it, called an armature, is placed between the north and south poles of a stationary magnet, known as the field magnet. When electricity flows around the armature wire, the iron becomes an electromagnet.

Picture 2

The attraction and repulsion between the poles of this armature magnet and the poles of the field magnet make the armature turn. As a result, its north pole is close to the south pole of the field magnet.

Then the current is reversed so the north pole of the armature magnet becomes the south pole. Once again, the attraction and repulsion between it and the field magnet make it turn. The armature continues turning as long as the direction of the current, and therefore its magnetic poles, keeps being reversed.

To reverse the direction of the current, the ends of the armature wire are connected to different halves of a split ring called a commutator. Current flows to and from the commutator through small carbon blocks called brushes. As the armature turns, first one half of the commutator comes into contact with the brush delivering the current, and then the other, so the direction of the current keeps being reversed.

Unit 3

Fuses

Vocabulary

Over current – перенапряжение

Short circuit – короткое замыкание

Plug – штепсельная вилка

Appliance – приспособление, прибор

3.1 Fuses

Read and translate the text

Fuses are used as protection devices. They are utilized in various circuits, electrical equipments and installations. Fuses serve to protect them against over currents and short circuits.

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

Fuses are commonly used in low-voltage industrial installations rated up to 1,000 V.

Fuses protection is based on a very simple principle: in case of a short-circuit or over current, when the maximum value of current has been exceeded, the fusible link of a fuse is heated to its melting point. This opens the circuit and disconnects the circuit from the power source. In case of a fault, one should replace the faulty fusible element by a new one.

Fuses are used both in direct current and alternating current circuits.

Listening

Tapescript 3.1 (According to the Disk: Track 3, unit 6 (B), Input).

Safety with fuses

a) Listen to the text and fill in the gaps.

If an ____________ such as a light or heater stops working, it is probably because the ___________ has blown. There are three main types of fuse in use today – cartridge, rewirable and the most modern type, miniature circuit breakers. Some appliances have their own fuses (usually in the plug), so this should be checked first. Otherwise, check whether the main fuse has gone.

The main fuses are normally in a switch box or fuse box at the point where the mains electricity ____________ cable enters the building, usually near the front door. Before checking these fuses, turn off the main ___________. Remove and examine the fuses one by one. With the ____________ the simplest thing to do is to take out the old fuse and try a substitute fuse – of the correct amp rating, of course. Then test the appliance.

With ____________ look for wire breaks or scorch marks on the fuse carriers. Remove the old wire, fit new wire round the retaining screws and tighten the screws. Replace the fuse carrier and see if the appliance works.

If the fuse continues __________, do not fit another fuse, but get an ____________ to check the appliance and the ___________ for possible faults. Never attempt to use a fuse of a higher rating.

Picture 3

b) Read and translate the text.

Listening

Tapescript 3.2 (According to the Disk: Track 3, unit 6 (B), Step 5)

a) What size of fuse should you fit for each of the appliances in this list?

Appliances		Fuse ratings
Colour television	Refrigerator	(amps)
Cooker	Clock	3
Shower	Fan	5
Table lamp	Unit air-conditioner	13
Room heater	Black and white television	15/20
Lighting circuit	Freezer	45
Iron	Stereo

b) Listen to the information on the cassette and check your answers.

Unit 4

Heat Engines

Vocabulary

Jet engine – реактивный двигатель

Petrol engine – бензиновый двигатель

Compress – сжимать

Combustion chamber – камера сгорания

Exhaust gases – выхлопные газы

Nozzle – сопло

To expand – расширять

Equipment – оборудование

Alternator – генератор переменного тока

Spark – искра

To ignite – зажигать, загораться

Fuel – топливо

Piston – поршень

Crankshaft – коленчатый вал

Listening

Tapescript 4.1 (According to the Disk: Track 4, unit 3 (A), Input)

a) Listen to the text about the Petrol Engine and The Jet Engine. Listen to the text once more and fill in the gaps.

The ______ and air ________ enters the cylinder. The ________ rises and it _________ the mixture. The compressed mixture is __________ by the _________. As the combustion gases ________ they push the piston down, and the _________ turns. On an ___________ the crankshaft is connected to the propeller. In a car it transmits the power to the wheels.

The compressor sucks air into the _______, and compresses it. Then the compressed air mixes with fuel and this mixture is burnt in the ___________. The combustion gases drive the _________. This drives the compressor. The __________ escape from the engine through the nozzle. This pushes the _________ forwards.

b) Translate the text.

4.2 Engines systems

Read and translate the text

Engines work by burning fuel. So they produce heat. If an engine produces too much heat, it will get damaged and eventually explode. A cooling system is needed to prevent the engine from overheating.

There are two types of cooling systems used in cars.

1) Water –cooled. The engine has hollow walls – known as an engine jacket. Water passes through the jacket absorbing the heat from the engine. The water heats up, and is passed into a radiator. Air blowing over the radiator cools the water down again; then it goes back into the engine jacket. Most cars have a water – cooled engine.

2) Air – cooled.

Air is blown over the engine to cool it. This type is normally used on motorbikes, where the engine is open to the air.

Technical information

Pressure affects temperature. At high pressure, water needs a higher temperature to boil. The radiator cap keeps the water under pressure.

Engines operate best at a temperature close to boiling point. The thermostat stops the water circulating when the engine is cold to maintain the optimum temperature.

The water would flow round the system naturally by convection. (Heat rises). But this is too slow, so the cooling system has a pump to push the water round faster.

A car’s heaters use the hot water from the engine jacket. This is not an essential part of the cooling system.

The water is cooled by running down through the radiator. The radiator fins increase the surface area and so make the heat disperse more quickly. Copper is used for this, because it conducts heat very easily.

The engine is connected to the radiator by two rubber hoses. When the car is moving forwards air automatically flows over the radiator.

A fan helps to suck air through the radiator to cool the water. The fan is driven by a belt connected to the crankshaft in the engine. The fan is needed, because when the car is not moving, no air will flow over the radiator.

Listening

Tapescript 4.2 (According to the Disk: Track 5, unit 3 (B), Step 6)

a) Sometimes a car’s cooling system breaks down and the engine overheats.

Listen and write down

a) What you should do

b) What you should not do if this happens

4.3 Portable generator

Read and translate the text

Although most electricity comes from power stations, power can also be generated by far smaller means. Nowadays, electricity generators can be small enough to hold in the hand.

Portable generators are made up of two main parts: an engine, which powers the equipment, and an alternator, which converts motion into electricity.

In a typical four-stroke engine, when the piston descends, the air inlet valve opens and a mixture of air and petrol is sucked in through a carburetor.

The valve closes, the piston rises on the compression stroke and a spark within the upper chamber ignites the mixture. This mini-explosion pushes the piston back down, and as it rises again the fumes formed by the ignition are forced out through the exhaust valve.

This cycle is repeated many times per second. The moving piston makes the crankshaft rotate at great speed.

The crankshaft extends directly to an alternator, which consists of two main sets of windings -coils of insulated copper wire wound closely around an iron core. One set, called stator windings, is in a fixed position and shaped like a broad ring. The other set, the armature windings, is wound on the rotor which is fixed to the rotating crankshaft. The rotor makes about 3,000 revolutions per 25 minute.

The rotor is magnetized and as it spins round, electricity is generated in the stator windings through the process of electromagnetic induction. The electric current is fed to the output terminals or sockets.

This type of generator can produce a 700 watt output, enough to operate lights, television, and some domestic appliances. Larger versions provide emergency power to hospitals and factories.

Unit 5

Central Heating

Vocabulary

Steam engine – паровой двигатель

Pump – насос, помпа, качать накачивать, откачивать

Pump piston – поршневой насос

To mount – устанавливать

Tank – бак, резервуар

To attach – прикреплять, присоединять

Pivoted – стержневой

Beam – балка, балансир

Shaft – вал

To contract – сжимать, сужать, сокращаться

Boiler – котел

5.1 Gas central heating

Read and translate the text

Most gas central heating works on the 'wet' system of heat transfer between water flowing through pipes. A typical system includes a boiler, a network of pipes, a feed, an expansion tank, radiators, and a hot water storage system.

In conventional boilers, water is heated by gas burners. It is then pumped around the central heating system and the hot water storage cylinder. The flow of gas to the burner is controlled by a valve (or valves) which can be operated by a time switch or by a boiler thermostat, hot water cylinder thermostat, or by a thermostat located in one of the rooms.

Air is necessary for complete combustion and is supplied to the burners either from inside the house, when adequate ventilation must be ensured, or directly from outside through a balanced flue.

Water is circulated through a heat exchanger above the burner. The heat exchanger is made of tubes of cast iron or copper, which resist corrosion. Both types use fins to increase the surface area in contact with water, which improves the transfer of heat. A thermostat located in the boiler causes the gas control valve to shut off when the water temperature reaches the pre-set level.

After being pumped through a diverter or priority valve, water circulates around either one of two loops of pipe work, which act as heat exchangers. One loop passes through the inside of the hot water storage cylinder in a coil arrangement. Heat is transferred to the surrounding water, which can then be drawn off from this cylinder from various hot taps in the house when required. The loop then returns to the boiler for re-heating.

The other loop of the circuit passes to the radiators, which provide room heating. Several radiators are generally connected, where one pipe provides the hot water input and the other carries the cold water back to the boiler. In this way, all radiators receive hot water directly from the boiler.

Listening

Tapescript 5.1 (According to the disk Track 6, unit 8 (A), Input)

Newcomen’s steam-atmospheric pump

The Industrial Revolution depended on the development of steam power. How does steam provide power?

a) Listen to the text and fill in the gaps.

James Watt is normally credited with inventing the first modern _____________. In fact, he got the idea for his steam engine from a primitive steam driven pump, which had been built by Tomas Newcomen in 1712 for ____________ water out of tin mines in S W England.

Newcomen’s pump had two main parts, positioned either side of a wall. There was a pump mechanism on one side of the wall and a simple engine on the other. These two parts were connected by a large pivoted beam. Attached to each end of the beam was a ___________ on a chain: the pump piston hung down inside a mine shaft, while the engine piston sat inside a cylinder, which was mounted on top of a ____________. Above the cylinder was a tank containing cold _______________.

The system worked as follows. The weight of the pump piston pulled the beam down. ____________ from the boiler _____________ and filled the cylinder. Then cold water was let into the cylinder. The steam cooled and contracted. The ____________ inside the cylinder was now lower than the atmospheric pressure outside. Air pressure on the top of the engine piston pushed it down. The beam was thus pulled down at the ____________ end and the pump piston came up the shaft, brining water with it. The cycle was then repeated.

b) Read and translate the text.

Glossary of engineering terms

Alternator – a type of generator producing alternating current.

Armature – the moving part of an electric motor which comprises a piece of iron with loops of wire running round it; the current through the wire is reversed to provide the changes in magnetic fields required to make the motor run.

Brushes – spring-loaded carbon blocks which carry the electric current to the commutator of an electric motor.

Carburetor – a device where air and petrol are mixed in an internal combustion engine.

Charger – a device which contains a unit for converting mains power to direct current at a suitable voltage for charging batteries.

Circuit breaker – an electrical switch fitted with an overload protection cut out.

Commutator – the part of the armature of an electric motor which is in contact with the brushes; it reverses the flow of current through the armature.

Compressed air – air at higher than atmospheric pressure; used to power pneumatic devices such as drills.

Compression – the effect of forces which act to squash a structure.

Conductor – a material which will transmit electricity or heat.

Crankshaft – the main shaft of an engine which carries the cranks for the pistons.

Diverter valve – a valve used in central heating to redirect the flow of hot water from radiators to water heating and vice versa.

Engine – a device which converts fuel into work.

Field magnet – a magnet for producing and maintaining the magnetic field in a generator or electric motor.

Fuel cell – a cell which converts the chemical energy of a fuel to electrical energy.

Generator – a machine converting mechanical energy into electricity.

Heat exchanger – the part of a boiler where the water is heated.

Ignition – the circuit which allows high-tension current to pass to the sparking plugs in an internal combustion engine.

Insulator – a substance which will not transmit electricity or heat.

Pilot light – a small flame used to ignite the main burners in a gas-fired heating boiler.

Plant – the machines in a factory and all the buildings.

Revolve – turn, rotate.

Rotor – rotating part of a generator.

Stator – stationary part of a generator.

Thermostat – a control device which operates at a pre-set temperature.

Transformer – a device for stepping up or down the voltage of an electric current

Turbine – a machine which produces power when steam, gas or what is passed over the blades attached to the rotating drive output shaft.

Tapescripts

Unit 1

T 1.1

A: Well, what do you want to know about energy generation?

B: We hear so much these days about different fuels and processes. We are told that nuclear power is more efficient than conventional fossil fuels. And we know that fossil fuels are limited. How can we compare the efficiency of the different fuels and processes?

A: Well, first of all, what types of fuel do you know?

B: Conventional fossil fuels — that is, oil, gas and coal — and nuclear fuels — that is, uranium and plutonium.

A: Right, and what processes do we use?

B: Well, I know that there are different nuclear reactors and different conventional processes.

A: Well, let's imagine a bucket of fuel.

B: What exactly do you mean? How much does a bucket hold?

A: Let's say a bucket holds 10 kilograms.

B: So how long does a bucket last?

A: Well now, that depends on the type of fuel and the type of process. And let's look at a 2 million kilowatt power station.

B: How many megawatts does that make?

A: 2 million kilowatts make 2000 megawatts. OK?

B: OK. So which fuel produces the most energy?

A: Well, that's nuclear fuel.

B: And which process does it use?

A: It uses the most efficient nuclear process, which converts all the matter in this fuel into energy.

B: So how long will it last?

A: Well, you may be surprised when I tell you that it will last eight and a half years. In

fact you will be very surprised if you compare it with a hydrogen fusion reactor. B: How long does a bucket of fuel last using that process?

A: Only 2 weeks.

B: Only 2 weeks. That's certainly an incredible difference.

A: And there's more to come.

B: What do you mean?

A: Well, the next process is a fast reactor.

B: Yes. When will that need more fuel?

A: After just a week. And now we come on to natural uranium.

B: And when will that fuel stop producing energy?

A: After 3 days. Now let's look at conventional fossil fuels, shall we? How long do you think a bucket of oil will last?

B: One hour?

A: Well ... nearly. In fact it will last one eighteenth of a second! And the same goes for coal.

B: So which country today produces most electricity using nuclear energy? A: Well, in Europe, France is top and then West Germany.

T 1.2

Energy division

How does modern industry get the huge supplies of energy it needs? Here’s how the energy cake has been divided up since 1925. As you can see, coal was the most widely used fuel before the middle of this century. However, since the 1950s the use of coal has declined rapidly, and oil and natural gas have gradually replaced it as the main energy source. They now provide about three quarters of the world industrial energy supplies.

The chart also shown that the use of hydroelectricity grew between 1925 and 1955, but since then it has stayed at a figure of 6%. Nuclear power provided only a fraction of the industrial energy supplies in 1970, but it now meets 10% of the need.

In the last 60 years the world’s industrial energy demand has increased by 800%, and this trend is likely to continue. Since fuels such as oil and gas will run out during the next 50 years, we will have to find new ways of getting the energy we need. The energy pie of 2025 will probably include a large slice of solar power.

Unit 2

T 2.1

Oersted ‘s Experiment

In the winter of 1819 – 20 Christian Oersted was doing experiments to find links between electricity, magnetism, light and heat. One of these experiments was very important, as it was the first step towards the invention of the generator or dynamo.

Oersted’s apparatus was very simple. He took a piece of wire and bent it to make a kind of bridge. The ends of the wire could be connected by leads to the terminals of an electric battery. The only other piece of equipment was a pivoted magnet, like a compass needle.

It had long been known that magnets have two poles – north and south. Unlike poles attract and like poles repel. Oersted also knew that there was a relationship between electricity and magnetism, and he showed this by placing the magnetic needle below the wire, then connecting the wire to the battery. The needle was deflected by the current in the wire. The wire was acting like another magnet and influencing the magnetic needle below it. What made the experiment so important was the next stage: when he placed the needle above the wire the needle was again deflected, but this time in the opposite direction.

Oersted concluded that there must be some sort of circular power or force around the wire. This force made the magnet move in opposite directions depending on its position relative to the electricity charged wire.

T 2.2

Electrical inventions are all around us nowadays – batteries electric motors and generators, light bulb, and so on. Who were the inventors that we have to thank for all this? Well, in most cases we are pretty certain who invented what, but it’s true to say that now and then more than one person had the same bright idea. The picture is something like this:

In 1800 the Italian Alessandro Volta produced the first battery. By 1831 the English scientist Michael Faraday had built the first generator of electric current. Not long after, in 1835, Thomas Davenport, an American, invented the first DC electric motor (that is, one working from a direct current supply). The first electric telegraph started working in 1837, made by Samuel Morse, in the United States.

The first electric light bulb was made in 1860 by Sir Joseph Swan in England.

This invention was developed commercially by Thomas Edison in the United States twenty years later.

The world’s first public electricity supply was set up by Edison in 1882 in Pearl Street, New York.

Unit 3

T 3.1

Safety with Fuses

Fuses are used as protection devices. They are utilized in various circuits, electrical equipments and installations. Fuses serve to protect them against over currents and short circuits.

If an appliance such as a light or heater stops working, it is probably because the fuse has blown. There are three main types of fuse in use today – cartridge, rewirable and the most modern type, miniature circuit breakers. Some appliances have their own fuses (usually in the plug), so this should be checked first. Otherwise, check whether the main fuse has gone.

The main fuses are normally in a switch box or fuse box at the point where the mains electricity supply cable enters the building, usually near the front door. Before checking these fuses, turn off the main switch. Remove and examine the fuses one by one. With the cartridge fuses the simplest thing to do is to take out the old fuse and try a substitute fuse – of the correct amp rating, of course. Then test the appliance.

With rewirable fuses look for wire breaks or scorch marks on the fuse carriers. Remove the old wire, fit new wire round the retaining screws and tighten the screws. Replace the fuse carrier and see if the appliance works.

If the fuse continues to blow, do not fit another fuse, but get an electrician to check the appliance and the circuit for possible faults. Never attempt to use a fuse of a higher rating.

T 3.2

Electrical appliances and circuits need fuses or circuit breakers. Of course, not any fuse will do. It has to be one of the right amp rating – the higher the number of watts the appliance uses, the higher the amp rating for the fuse. For example, a 3 amp fuse is suitable for most appliances up to 700 watts – table lamps, a small black and white television, and so on. A lighting circuits needs a 5 amp fuse. Appliances between 700 and 3000 watts – such as room heaters, irons refrigerators, freezers, colour televisions and the like – must have a 13 amp fuse. When you get on to appliances which use a lot of power (usually for some kind of heating) like electric shower heaters and unit air-conditioners, you are talking about a 15 or 20 amp fuse. Then there’s the appliance that consumes the largest amount of power of all, the electric cooker – that needs a 45 amp fuse.

Unit 4

T 4.1

The fuel and air mixture enters the cylinder. The piston rises and it compresses the mixture. The compressed mixture is ignited by the spark. As the combustion gases expand they push the piston down, and the crankshaft turns. On an aircraft the crankshaft is connected to the propeller. In a car it transmits the power to the wheels.

The compressor sucks air into the engine, and compresses it. Then the compressed air mixes with fuel and this mixture is burnt in the combustion chamber. The combustion gases drive the turbine. This drives the compressor. The exhaust gases escape from the engine through the nozzle. This pushes the aircraft forwards.

T 4.2

You are driving along and suddenly you see steam rising from the bonnet of your car. The engine is overheating. What should you do?

The first thing to do is to switch off the engine. If steam is rising from the bonnet, don’t open it. You might get a jet of hot steam in your face.

When it is safe to open the bonnet, you should do so. This will help to cool the engine down. But don’t take the radiator cap off. It could fly up into your face and cover you with boiling water.

Leave the engine to cool down. Never try to cool it faster by throwing cold water over the engine or the radiator.

When the engine is cool throw an old rug, towel or blanket over the radiator. Put on a glove, if you have one and make sure your sleeves are covering your arms. Now slowly undo the radiator cap. Don’t lean over the radiator while you are doing this. Stand to one side.

If the water level in the radiator is low, don’t pour cold water into it, while it is still warm. Use warm water, or wait a bit longer until the radiator is really cool.

Unit 5

T 5.1

Newcomen’s steam-atmospheric pump

James Watt is normally credited with inventing the first modern steam engine. In fact, he got the idea for his steam engine from a primitive steam driven pump, which had been built by Tomas Newcomen in 1712 for pumping water out of tin mines in S W England.

Newcomen’s pump had two main parts, positioned either side of a wall. There was a pump mechanism on one side of the wall and a simple engine on the other. These two parts were connected by a large pivoted beam. Attached to each end of the beam was a piston on a chain: the pump piston hung down inside a mine shaft, while the engine piston sat inside a cylinder, which was mounted on top of a boiler. Above the cylinder was a tank containing cold water.

The system worked as follows. The weight of the pump piston pulled the beam down. Hot steam from the boiler expanded and filled the cylinder. Then cold water was let into the cylinder. The steam cooled and contracted. The pressure inside the cylinder was now lower than the atmospheric pressure outside. Air pressure on the top of the engine piston pushed it down. The beam was thus pulled down at the engine end and the pump piston came up the shaft, brining water with it. The cycle was then repeated.

Список литературы

1. Nick Brieger and Jeremy Comfort. Technical contacts “Materials for developing listening and speaking skills for the students of Technical English”. Prentice Hall International (UK) Ltd. University Press, Cambridge, 1987.

2. Tom Hutchinson and Alan Waters. Interface “English for technical communication”. Longman Group Limited, 1984.

3. Eric H. Glendinning and Norman Glendinning. Oxford English for “Electrical and Mechanical Engineering”. Oxford University Press, 2000.

Содержание

Unit 1…………………………………………………………………………………3

Unit 2…………………………………………………………………………………4

Unit 3…………………………………………………………………………………8

Unit 4………………………………………………………………………………...10

Unit 5………………………………………………………………………………...13

Glossary……………………………………………………………………………...15

Tapescripts…………………………………………………………………………...17

Список литературы…………………………………………………………………22