E-Book2 Electricity and electronics, Exercises of Social Work

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2014 ELECTRICITY AND

ELECTRONICS

Marija Krznarić

TEHNIČKO VELEUČILIŠTE U ZAGREBU

ELEKTROTEHNIČKI ODJEL

Nakladnik

Tehničko veleučilište u Zagrebu

Elektrotehnički odjel

Autor

Marija Krznarić

Recenzenti

Prof. dr. sc. Sejid Tešnjak

Prof. dr. sc. Krešimir Meštrović,

Mirjana Milotić-Pejnović, prof.

Objavljivanje je odobrilo Stručno vijeće Tehničkog veleučilišta u Zagrebu

odlukom broj: 803-7/09 od 21.04.2009.godine

Skripta

ISBN 978-953-7048-44-

Foreword

Some parts of this manual have been already used for several years but lately, the material has been re-written and improved to provide entry- and advanced-level competencies, for the students of the Department of electrical engineering. It consists of instructional materials for the career-oriented students who have learned English for eight years before joining the Department of Electrical Engineering. The texts are structured to provide an introduction to the broad subject called electricity and electronics. Although no prior formal training in electricity is assumed, it is very unlikely that a student has not been exposed to the world of electricity and electronics. For this reason, certain words associated with electricity are expected to have already entered the students’ vocabulary. Nevertheless, strict technical definitions are used throughout the manual which may help some students rid themselves of misconceptions learned earlier. Both texts and exercises are meant to develop greater students’ sensitivity to the way of thinking in engineering and to the way of presenting and expressing such thoughts in technical English. Since the level of the students’ knowledge of English might be rather different, certain grammatical categories have been revised and added in order to target students’ attention to the technical English.

This manual is divided into 6 parts:

1. texts for reading and reproduction
2. hints how to write a job application, a summary and a business letter
3. some cultural and communication aspects
4. grammar revision and exercises
5. glossary: terms and definitions
6. Irregular verbs.

For those who like surfing the Internet, I recommend pages a4esl.org and www.englishpage.com where explanation, exercises and key to exercises can be found. Although these exercises are written for universal use, i.e. you will not find problems with which Croatian students have to “fight”, they are a recommended self-study practice course. As for examination material for each term, it can be found on our web site. This truly is the age of electricity and electronics, computer science and communications. The solid foundation provided by these simple texts is likely to prove useful, whether a student intends to pursue a career in electricity and electronics or simply needs the material as background information for other purposes. The author welcomes comments and suggestions from teachers as well as from students. For future engineers of a small country, like Croatia, it is extremely important to master at least one foreign language since their mobility and employability in the European Union depend greatly on their knowledge of a foreign language, preferably English. Materials given in this manual will be of considerable help for those who intend to revise and improve their knowledge.

And finally I would like to thank Professor Sejid Tešnjak PhD from the Faculty of Electrical Engineering and Computing in Zagreb and the head of the Electrical Engineering Department, University of Applied Sciences in Zagreb, Professor Krešimir Meštrović PhD, for reading the manual and correcting it from the technical point of view. Special thanks to my colleague, Mrs. Mirjana Milotić-Pejnović from University College for Applied Computer Engineering for giving valuable suggestions and advice and for using this material in its different forms for the past ten years.

I would also like to thank Mr. Rade Buinac, MEng EE for help with the text processor.

Marija Krznarić

• Foreword
• PART
  • YOUR CAREER AS AN ELECTRICAL ENGINEER
  • THE BOLOGNA PROCESS IN THE DEPARTMENT OF ELECTRICAL ENGINEERING
  • THE ENGINEERING PROFESSION
  • THE STRUCTURE OF MATTER
  • THE ELECTRIC CURRENT
  • THE EFFECTS OF AN ELECTRIC CURRENT
  • ELECTRIC CIRCUITS
  • CONDUCTORS, INSULATORS, SEMICONDUCTORS
  • BATTERIES and CAPACITORS
  • PROCESS CONTROL SYSTEMS
  • MACHINE TRANSLATION – YES or NO
  • FROM CAMERA TO SCREEN
  • THE CATHODE RAY TUBE
  • RADIO COMMUNICATIONS
  • HOW ROBOTS MAKE OUR LIVES EASIER
  • CIRCUIT BREAKERS, FUSES AND SWITCHES
  • POWER ENGINEERING
  • TELECOMMUNICATIONS
  • OPTICAL FIBERS
  • NIKOLA TESLA - THE GENIUS WHO LIT THE WORLD..........................................................................
  • NANOTECHNOLOGY
• PART
  • HOW TO WRITE A JOB APPLICATION
  • HOW TO WRITE A SUMMARY............................................................................................................
  • HOW TO WRITE A POWER POINT PRESENTATION
  • HOW TO WRITE A BUSINESS LETTER
• PART
  • WHEN IN ROME, DO AS THE ROMANS DO
  • POLITICALLY CORRECT LANGUAGE – HE vs. SHE
  • A HANDSHAKE, A BOW OR AN EMBRACE
  • SOME HINTS ABOUT SUCCESSFUL NEGOTIATIONS
• PART
  • IS GRAMMAR IMPORTANT?
• TALKING ABOUT THE PRESENT........................................................................................................
  • PRESENT CONTINUOUS - PRESENT SIMPLE
• WORD ORDER
• TALKING ABOUT THE PAST
  • PAST SIMPLE - PAST CONTINUOUS
• TALKING ABOUT THE FUTURE
  • GOING TO - PRESENT CONTINUOUS - WILL – FUTURE - PRESENT SIMPLE
• ARTICLES
  • THE INDEFINITE ARTICLE
  • THE DEFINITE ARTICLE
• TALKING ABOUT THE PAST
  • PAST PERFECT SIMPLE & CONTINUOUS - FUTURE IN THE PAST
• COMMANDS
• PRESENT PARTICIPLE
• TALKING ABOUT THE PRESENT PERFECT
  • PRESENT PERFECT SIMPLE : PRESENT PERFECT CONTINUOUS
• DEFECTIVES......................................................................................................................................
• CONDITIONALS - TYPE 0 & TYPE
  • TYPE
  • TYPE
• CRIB NOTES......................................................................................................................................
  • ACTIVE
  • PASSIVE
• TALKING ABOUT THE PASSIVE VOICE
  • THE PASSIVE VOICE......................................................................................................................
  • PAST PARTICIPLE..........................................................................................................................
• INDIRECT SPEECH
  • STATEMENTS
• WH-QUESTIONS...............................................................................................................................
• YES - & NO - QUESTIONS
• CONDITIONALS
  • CONDITIONALS TYPE 0 & TYPE
  • CONDITIONALS - TYPE 2 & TYPE
• THE UNREAL PAST
• CAUSATIVE "HAVE" or "GET"...........................................................................................................
• REVISION OF THE VERBAL FORMS...................................................................................................
• PART
  • GLOSSARY
• PART
  • IRREGULAR VERBS

WRITE DOWN THREE REASONS WHY YOU HAVE CHOSEN THIS STUDY COURSE

1. ________________________________________________________________________________

2. ________________________________________________________________________________

3. ________________________________________________________________________________

DISCUSS WITH YOUR NEIGHBOUR THE ABOVE REASONS, ADD HIS or HERS AND WRITE THEM DOWN

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A Bachelor of Engineering degree, BSc in other countries includes

BSc in the Department of electrical engineering, The Polytechnic of Zagreb includes

Electrical engineering Electronic and Electrical Engineering Electronic engineering Microelectronic and Electrical Engineering Electronics and Telecommunication Engineering

Control and computer engineering in automation ( AiPR )

Electrical power engineering ( EE )

Communication and computer technology ( KiRT )

WRITE A SHORT ESSAY - HOW I SEE MY FUTURE EMPLOYMENT

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

AND A JOKE

YOU MIGHT BE AN ENGINEER IF… … the only jokes you receive are through e-mail. … you can’t write unless the paper has both horizontal and vertical lines. … you order pizza over the Internet and pay for it with your home banking software. … all your sentences begin with “what if”. … at Christmas, it goes without saying that you’ll be the one to find the burnt-out bulb in the string. … buying flowers for your girlfriend or spending the money to upgrade your RAM is a moral dilemma. … people groan at the party when you pick out the music. … you are always late to meetings. … you are at an air show and know how fast the skydivers are falling.

THE BOLOGNA PROCESS IN THE DEPARTMENT OF ELECTRICAL ENGINEERING

The Department of Electrical Engineering is a continuation of the three-year Technical College founded in Zagreb in 1962 and almost four decades later, in 1998, it became one of the departments of the Polytechnic of Zagreb. The academic year 2005/2006 was the implementation of the Bologna process or the Bologna Declaration requirements in the Department of Electrical Engineering. Since a three- year bachelor degree (180 ECTS) should give students broad professional basic knowledge and competencies, their mobility and later on employability depend greatly upon and rely on cross- disciplinary qualifications where foreign languages play an important role. Along with these indispensable cross-disciplinary qualifications and competences, regardless of the profile of each study course or higher education institution, in most EU countries compulsory knowledge of one or more foreign languages is required. Discussing the Bologna Process with the special accent on employability of graduates, UNICE (Union of Industrial and Employers’ Confederation of Europe, in 2007 renamed BUSINESSEUROPE) emphasizes that a bachelor should have:  an appropriate level of verbal and written articulacy in the national language  an appropriate level of verbal and written articulacy in at least one foreign language (preferably English for non-native speakers)  ability to work in a team, etc.

Having all this in mind, it is an imperative for Croatian graduates to have a fluent foreign language competence, in both the oral and the written language. They should also master the particular language of their specialty.

To meet all these requirements and as computer skills are compulsory for all university graduates, the software for learning and testing English in a computer laboratory in the Department of Electrical Engineering has been created and different types of drills and tests have been prepared for students. These tests may also be used for self-study together with drills and tests on our web sites.

To familiarize the students with certain new terms concerning the Bologna process, the first year courses are listed here as well as the names for different types of courses, such as compulsory or basic (all first year courses, except the foreign language which is compulsory elective), electives (which students choose themselves), etc.

After you have passed the prescribed university entrance exam, you will have to deal with the following compulsory basic and compulsory elective courses in your first year:

1 st^ term ECTS 2 nd^ term ECTS

fundamentals of electrical engineering 1 8 fundamentals of electrical engineering 2 9 mathematics 1 7 mathematical tools for electrical engineering

physics 5 mathematics 2 9 materials in electrical engineering 4 electronic components 6 personal computer applications 5 English in Electrical Engineering 1 2 technical documentation 3 physical education 1 physical education 1 First year total ECTS 62

During the last term, students have practical training and write their final thesis. They are assigned a mentor who suggests which electives they should choose and approves the subject of the final thesis.

THE ENGINEERING PROFESSION

What is engineering? It offers solutions for real human problems by the development and application of tools, machines, materials, goods, or information in the form of skills, knowledge, processes, blueprints, plans, diagrams, models, formulae, tables, engineering designs, specifications, manuals, or instructions. What is the work of an engineer? An engineer designs, operates , or maintains certain kinds of equipment, deals with the practical application of theoretical findings. Engineers apply the principles of science and mathematics to develop economical solutions to technical problems. Their work is the link between social needs and commercial applications. However, what an engineer did in the past, may seem strange and funny today. You know that in the past engineers did not go to school, don’t you? They just worked for a number of years to be taught certain skills. But, that’s ancient history, times have drastically changed. Today's engineers require at least a three- or five-year university course in order to graduate at a college or to get a bachelor's degree in engineering and become specialists in their fields. This does not mean that, taking their degree, the education is finished. Continuing education , or as it has been called lately lifelong learning , is critical for engineers wishing to enhance their value to employers as technology evolves. They have to cover different fields, incorporate their ideas into the real world, listen to the needs, and be familiar with the global economic situation. Therefore, when engineers start developing a new product, they have to consider many factors. For example, in developing an industrial robot , engineers precisely specify the functional requirements; design and test the robot’s components; integrate the components to produce the final design; and evaluate the design’s overall effectiveness, cost, reliability, and safety. This process applies to the development of many different products, such as chemicals, computers, gas turbines, helicopters, and toys. In addition to design and development, many engineers work in testing, production, or maintenance. These engineers supervise production in factories, determine the causes of component failure, and test manufactured products to maintain quality. They also estimate the time and cost to complete projects. Some move into engineering management or into sales. In sales, an engineering background enables them to discuss technical aspects and assist in product planning , installation , and use. Supervisory engineers are responsible for major components or entire projects. Engineers use computers extensively to produce and analyse designs ; to simulate and test how a machine, structure, or system operates; and to generate specifications for parts. Many engineers also use computers to monitor product quality and control process efficiency. The field of nanotechnology, which involves the creation of high-performance materials and components by integrating atoms and molecules, also is introducing entirely new principles to the design process. Most engineers specialize. Numerous specialties are recognized by professional societies, and the major branches of engineering have numerous subdivisions. Some examples include structural and transportation engineering, which are subdivisions of civil engineering; and ceramic, metallurgical, and polymer engineering, which are subdivisions of materials engineering. Engineers also may specialize in one industry, such as motor vehicles, or in one type of technology, such as turbines or semiconductor materials.

FILL IN THE BLANK SPACES WITH THE CORRESPONDING ENGINEERING PROFESSION:

1. a person whose job involves designing and building of houses, roads, bridges is a ________________ engineer
2. a person who designs and builds machines and systems that use or produce electricity is an ______________ engineer
3. a person whose job is to design, build and repair machines is a ________________ engineer
4. a person who writes computer programs is a ________________ engineer
5. a person who works in a recording or a broadcasting studio and controls the levels and balance of sound is a ___________________ engineer

DISCUSSION QUESTIONS

1. What is engineering?
2. What is the work of an engineer?
3. What is the difference between today’s engineers and those in the past?
4. Why is continuous education an imperative for engineers?
5. What tasks does a supervisory engineer perform?
6. What do engineers use computers for?
7. Where would you like to work?
8. What would you like to specialize in?

TRANSLATE INTO CROATIAN

Engineers trained in one branch may work in related branches and this flexibility allows them to shift to fields with better employment prospects or to those that more closely match their interests. As far as electrical and electronics engineers are concerned, and they are the most important here, there is a certain difference between them. Electrical engineers design, develop, test, and supervise the manufacture of electrical equipment. This equipment includes electrical motors; machinery controls, lighting, and wiring in buildings; automobiles; aircraft; radar and navigation systems; power-generating, -controlling, and -transmission devices used by electric utilities. Although the terms “electrical” and “electronics” engineering are often used interchangeably, electrical engineers have traditionally focused on the generation and supply of power , whereas electronics engineers have worked on applications of electricity to control systems or signal processing. Electrical engineers specialize in areas such as power systems engineering or electrical equipment manufacturing. Electronics engineers are responsible for a wide range of technologies, from portable music players to the global positioning system (GPS). Electronics engineers design, develop, test, and supervise the manufacture of electronic equipment such as broadcast and communications systems. Many electronics engineers also work in areas closely related to computers. However, engineers whose work is related exclusively to computer hardware are considered computer hardware engineers. Electronics engineers specialize in areas such as communications, signal processing, and control systems or have a specialty within one of these areas—industrial robot control systems or aviation electronics, for example. Engineers should be creative, inquisitive, analytical , and detail oriented. They should be able to work as part of a team and to communicate well, both orally and in writing. Communication abilities are important because engineers often interact with specialists in a wide range of fields outside engineering.

THE STRUCTURE OF MATTER

Our world consists of many things that we call matter. Matter means anything that has weight and takes up space. It appears in four forms, i.e. the solid state , for example stones, the liquid state , such as water, the gaseous state , air, for example, and plasma , such as electrical arcs produced by tesla coils. This variety represented a puzzle which was difficult to understand and solve. People thought about matter, made experiments but the first theory appeared only at the beginning of the nineteenth century. It was John Dalton , an English scientist, who stated that all matter is made up of small indivisible particles, and he called them atoms. The word atom comes from the Greek word atomos , meaning indivisible. This theory of the atomic nature of matter was true for a long time. Scientists found 92 different atoms from which all matter in nature was composed. Almost a hundred years later, another English scientist, Sir J. J. Thomson developed and published his theory of a subatomic particle. At first it was called a corpuscle but later, G. J. Stoney , an Irish physicist gave it another name, electron. So, if we want to define what an atom is, we may say: an atom is the basic unit of matter and it consists of a nucleus around which smaller particles orbit. These particles are electrons and have a negative electric charge. The nucleus is made up of protons and neutrons. Protons are positively charged whereas neutrons have no net charge. Each atom contains an equal number of electrons and protons but may have a different number of neutrons. Mass number is the sum of protons and neutrons of an atomic nucleus, while atomic number is the number of elementary positive charges in the nucleus when an atom is in its normal condition. The atomic number varies for each element, e.g. it is 1 for hydrogen (the lightest element in nature), and 92 for uranium (the heaviest element in nature) but the number is even higher for the new artificial elements. Copper , for example, which is one of the most important elements in electricity contains 29 e lectrons and 29 protons, and thus its atomic number is 29.

We can compare the structure of an atom to the Solar system. Electrons, which have only a very small mass^4 in comparison to protons and neutrons, orbit at a very rapid speed around the nucleus, somewhat in the same manner as the Earth and the other planets orbit around the Sun. These are planetary electrons and they revolve around the positively charged nucleus of their atom. Fig. 1 represents the theoretical structure of the helium atom. Its nucleus contains two protons and two neutrons. The two planetary electrons revolve in the orbit around the nucleus. But, besides planetary electrons, which are, due to their negative charge strongly attracted to the positively charged nucleus, there is another type of electrons. These are free electrons. They move freely in matter or a vacuum when external electric or magnetic fields act on them. The free electrons are important in electricity and one simple definition for electric current says:

“An electric current is the continuous flow or movement of free electrons.”

(^4) let’s “see” how tiny an electron is: If an ampere is defined as the number of electrons passing through a point in one second, then the number of electrons per ampere is 6.280.000.000.000.000.000 (6.28 x 10^18 )

Figure 1 - Structure of an atom of helium

TERMS AND DEFINITIONS

orbital or planetary electron – an electron that moves in orbit around the nucleus of an atom

atomic number – the number of elementary positive charges in the nucleus of an atom, it is a different number for each element, starting with 1 for hydrogen and going up beyond 103

free electron – an electron that is not constrained to remain in a particular atom, it is therefore able to move freely in matter or a vacuum, when acted on by external electric or magnetic field

subatomic – pertaining to particles smaller than atoms, such as electrons, protons and neutrons

current – the rate of transfer of electricity from one point to another; current is usually a movement of electrons, but may also be a movement of positive and negative ions, or holes

copper – a metallic element that has excellent conductivity of heat and electricity, good ductility and malleability, it is easily alloyed

electron – a subatomic particle with a negative electric charge

conductor – a material which permits the flow of free electrons

generator – an electric machine for generating electromotive force (voltage)

like charges (+ & + and - & - ) – repel each other

unlike charges (+ & -) – attract each other

electron flow – a current produced by the movement of free electrons toward a positive terminal; the direction of electron flow is opposite to that current

DISCUSSION QUESTIONS

1. What is matter?
2. How many states of matter are there?
3. Who was the first author of the theory of matter and when did it appear?
4. What did John Dalton state?
5. Why did he call his particles “atoms”?
6. How many different types of atoms are there?
7. What did J. J. Thomson discover?
8. What other name did Stoney give Thomson’s particle?
9. What is an atom?
10. What does a nucleus consist of?
11. What does the number of protons in a nucleus determine?
12. What are the properties of copper?
13. Why can the structure of an atom be compared to the Solar system?
14. Why are planetary electrons strongly attracted to the positively charged nucleus of their atom?
15. What happens when external electric or magnetic forces act on free electrons?
16. What does the movement of free electrons provide?

The Solar System

Use the following adjectives: big, light, heavy, bright, hot, long

Across

3 Neil Armstrong was the first man to land on the ___________.

6 The Sun is ___________ than other planets. 8 The Sun is the _________ thing in the solar system. 9 There are nine _________ in the solar system. 10 The Earth is heavier than the Moon. The Moon is ___________ than the Earth. 11 Captain Yang Liwei became the _________ Chinese man in space.

Down 1 The first planet is the __________ planet because it is nearest to the Sun. 2 The River Nile is the ___________ river on Earth. 4 The Moon is lighter than the Earth. The Earth is __________ than the Moon. 5 The Earth is __________ than the Moon. 7 Yuri Gagarin was the first man in _________. 12 The __________ is the brightest thing in the Solar system.

COMPARISON - Repeat the rules for comparison of adjectives and complete this table

soft easier the most difficult convenient large farther further

THE ELECTRIC CURRENT

We have already noted that like, or similar charges repel each other, whereas unlike, or opposite charges attract each other. Thus, charged particles within a material are in the state of constant movement. But, when some external forces act on them, these charged particles may be made to move continuously in the same direction for some time. Such continuous movement is an electric current. In 1862, Georg Simon Ohm, a German scientist, first established reliable and experimentally proved facts about electricity. He found the connection between the three values on which the transfer of electricity from one end of the conductor to the other depends. These three values,

electromotive force

current and

resistance

led to the postulation of the fundamental law in electricity: Ohm’s law.

Figure 2 - Difference between amounts of potential energy makes electrons flow through a conductor

Electromotive force (abbreviated EMF ), usually called voltage ( V ), is the force or pressure that moves electrons through a conductor. If electrons are piled at one end of the conductor, and if there are fewer electrons at the other end, the excess of electrons will flow toward the point of deficiency, i.e. the current will flow through the conductor from the negative end to the positive one. The unit of the electromotive force is the volt , V , named after the Italian scientist, Alessandro Volta. The flow of electrons from one end of the conductor to the other is not always the same. On their way, they collide with atoms and molecules, atoms and molecules oppose them and that property of the conductor is called electric resistance. The greater the number of free electrons in the conductor, the lower is its resistance. Most metals are good conductors, but the resistance of a conductor does not depend only on the material of which the conductor is made. It also depends on the cross-section of the conductor. The greater the cross-section, the lower is the resistance of the conductor. The third element is the length of the conductor. The longer the conductor, the greater is its resistance. And at last, there is the temperature of the substance. If the temperature of a metal wire is higher, the resistance will be higher. The unit of the resistance is the ohm , Ω, named in the honour of G. S. Ohm. I stands for intensity , strength or amount of current. It is, in fact, determined by the number or quantity of electrons which pass through the cross-section of a conductor per unit of time. The intensity depends upon the potential difference, and the resistance of the conductor. The greater the potential difference, the larger the quantity of electrons flowing through the conductor – the greater the resistance, the smaller the quantity of electrons. The unit of the intensity is the ampere , A , named for a French scientist, André Ampère. The relationship between the voltage ( V ), the current ( I ) , and the resistance ( R ) is stated in Ohm’s law :