English for electrical engineering.pdf

7/24/2019 English for electrical engineering.pdf

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DRW - STTH

ENGLISH FOR

ELECTRICAL ENGINEERING



ELECTRICAL CONDUCTOR

Electrical conductor is any material that offers little resistance to the flow

of an electric current. The difference between a conductor and an insulator,

which is a poor conductor of electricity or heat, is one of degree rather than kind,

because all substances conduct electricity to some extent. A good conductor of

electricity, such as silver or copper, may have conductivity a billion or more times

as great as the conductivity of a good insulator, such

as glass or mica. A phenomenon known as

superconductivity is observed when certain

substances are cooled to a point near absolute zero,

at which point their conductivity becomes almost

infinite. In solid conductors the electric current is

carried by the movement of electrons; in solutions

and gases, the electric current is carried by ions.

Exercise

1. Property of any object or substance to resist or oppose the flow of an electrical

current is called ______________1.

2.

Phenomenon displayed by certain substances that conduct electricity but

demonstrate no resistance to the flow of an electric current is called

____________2.

3. _____________ is the lowest temperature theoretically possible, characterized by

complete absence of heat (thermal energy).

4. __________, in chemistry, are homogeneous (uniform) mixtures of two or more

substances.



ELECTRIC INSULATION

The perfect insulator for electrical applications would be a material that is

absolutely nonconducting; such a material does not exist. The materials used as

insulators, although they do conduct some electricity, have a resistance to the

flow of electric current as much as 2.5 × 1024 greater than that of good electrical

conductors such as silver and copper.

Materials that are good conductors have a large number of free electrons

(electrons not tightly bound to atoms) available to carry the current; good

insulators have few such electrons. Some materials such as silicon and

germanium, which have a limited number of free electrons, are semiconductors

and form the basic material of transistors. In

ordinary electric wiring, plastics are commonly used

as insulating sheathing for the wire itself. Very fine

wire, such as that used for the winding of coils and

transformers, may be insulated with a thin coat of

enamel. The internal insulation of electric equipment

may be made of mica or glass fibers with a plastic

binder.

Electronic equipment and transformers may

also use a special electrical grade of paper. High-voltage power lines are insulated

with units made of porcelain or other ceramic, or of glass. The specific choice of

an insulation material is usually determined by its application. Polyethylene and

polystyrene are used in high-frequency applications, and mylar is used for

electrical capacitors. Insulators must also be selected according to the maximum

temperature they will encounter.

Teflon is used in the high-temperature range of 175° to 230° C (350° to450° F). Adverse mechanical or chemical conditions may call for other materials.

Nylon has excellent abrasion resistance, and neoprene, silicone rubber, epoxy

polyesters, and polyurethanes can provide protection against chemicals and

moisture.



Exercise

1. What would a perfect insulator be like?

2. What characterizes good insulators?

3. What materials are used as insulating sheathing for wire?4. What materials are used for insulation of electronic equipment?

5. What determines the choice of an insulation material?

Exercise

Find out the similar meanings from the text

1. Complete =

2. Positively =

3.

Live =4. Fundamental =

5. Seperated =

6. Particular =

7. Choose =

8. Meet =

9.

Substantial =

10. Supply =



SIMPLE PAST TENSE VS PAST CONTINUOUS

Simple past tense

We use the simple past to describe things that happened in the past and finished

at a specific time.

Example: He started the company in 1969.

They didn’t make a profit in the first year.

Did she work there in 1975?

We often use a time reference which refers to the finished event. E.g. yesterday,

last week, last night, three years ago, in 1969, in the first year.

Form

verb stem + ed

Positive and Negative

I/ you/ she/ he/ it/ we/ they Arrived Didn’t arrive

Question

Did I/ you/ she/ he/ it/ we/ they Arrive?

The verb to be

Positive and Negative

I/ he/ she Was Was not/ wasn’t

You/ they/ we Were Were not/ weren’t

Past continuous

Use ________ Was/Were + V(ing)

We use the past continuous to talk about:

Things which were happening at the time of speaking.

Example: I was trying to call Geoff Peters.

He was n’t working today.



Exercise

Change these sentences into positive, negative or introgative sentences

1. We controled the temperature regularly

2. Did he explain the classification of conductor?

3. The current didn’t flow from positive terminal to negative terminal

4. They calculated the energy unit

5. They didn’t use a tester to current supply in electrical circuits

Exercise

MICROSOFT

Thomas (live) in the small town of Brington. He (love) walking through the

beautiful forest that surrounded it. One evening, it (rain) , so he (take) his

umbrella and (go) for a walk in the woods. As he (walk) through the woods, he

(meet) an old man named Frank. Frank (tell) Thomas that if he (want) to become

rich, he should invest in a little known stock called Microsoft. When Thomas

(return) from his walk, he (think) Frank (be) foolish because Microsoft (be) a

computer stock. Everybody (know) that computers (be) just a passing fad. At any

rate, Frank (insist) that Thomas (be) wrong. While they (discuss) the stock, Frank

(draw) a wonderful graph of future possibilities. As Frank (draw) the graph,

Thomas (begin) thinking that maybe Frank (understand) stocks. While he (was) to

work, Thomas (decide) to buy some of these stocks. The next day, he (go) to the

stock broker's and (buy) $1,000 worth of Microsoft stock. That (be) in 1986;

today that $1,000 worth of stock is worth more than.



NUMBERS

I. Match the words with the examples on the right:

1. cardinal numbers a. ¼, 2/3, 28/362. ordinal numbers b. First, second, third, ...

3. decimals c. 1, 2, 3, …

4. fractions d. 12%, 89%...

5. percentages e. 2.3, 4.698

* Each digit after the decimal point is read separately: two point three, four

point six nine eight.

II. Match these written numbers with the way they are read:

1. 60% a. one third

2. 3 ½ b. two fifths

3. 3.4 c. two point eight seven

4. 8.5% d. eight point five percent

5. 1/3 e. three point four

6. 2.87 f. sixty percent

7. 3/4 g. three and a half

8. 2/5 h. three quarters

III. Put these words and phrases into the sentences below:

times/multiplied by, divided by, minus, plus

1. Four________ eighteen equals twenty-two.

2. Seventeen ____________ thirteen equals two hundred twenty-one.

3. Ninety-six _________ four equals twenty-four.

4. Ten ________ nine equals one.



THE EFFECTS OF AN ELECTRIC CURRENT

The effects of an electric current are thermal, luminous, chemical and

magnetic. When a current flows through a conductor it may heat the conductor.

This heat is sometimes undesirable and has to be reduced. For this reason many

electric motors and generators contain a fan. However, domestic appliances, such

as electric cookers, and many industrial processes depend on the heating effect of

an electric current.

The passage of a current may produce light. This can happen in a number

of ways. The heat generated by the current may be so great that the conductor

becomes incandescent. For example, the filament of a light bulb emits intense

white light when heated by a current. Light is also

produced when a current ionises a gas. The

colour of the light will vary according to the gas

used. Mercury vapour lamps give a greenish-blue

light. An electric current can separate a chemical

compound into its components. This is called

electrolysis.

Chlorine is generated by the electrolysis ofsalt water. Electrolysis can also be used to break

down water into hydrogen and oxygen. Because pure water does not conduct well,

sulphuric acid has to be added before the electrolysis takes place.

A current flowing through a conductor creates a magnetic field around it.

This field has three applications. It can magnetize magnetic materials and attract

them to the conductor. The electric relay works on this principle. If the magnetic

field is cut by another conductor, an electromotive force will be induced in that

conductor. For instance, the change in current flowing through the primary of atransformer will induce a current in the secondary. This principle is also used in

generators. Thirdly, if a current carrying conductor is placed in the magnetic

field, a force will e exerted on it. This effect is utilized in the electric motor.



Exercise:

Now study the passage carefully and complete this framework of notes:

Effects of an electric current:

1. Thermal2. …………….

3. …………….

4. Magnetic

1. Heat can be

a. Undesirable, e.g. motor

b. ……....... e.g. cooker

2. light

a. from incandescent conductor e.g. ….....……..

b. from ….....….. e.g. vapour lamp

3. ……....... = breakdown of chemical compound e.g. salt water into chlorine

4. current flowing in conductor ► ….....… round it. Magnetic field has three

applications:

a. ……....... e.g. relay

b. induce emf in another conductor e.g. …….....…..

c. …….....… e.g. motor



HAND TOOLS AND THEIR USES

Nowadays, the speed and productivity are very important, and therefore

many works in the workshop are being done with the power tools and machines.

However, any good craftsman knows that the quality result lies in the balance

between the handwork and machine work. In many cases during the

manufacture, the craftsman has to decide whether some operation will be done

with the hand tools or with the machine. Such decision should always be made

by considering which method is more efficient, which method you are adept to,

which methods produce better work and which method is cheaper.

Always use right hand tool for the job. This way

you get the best job with the least effort, the least

damage to the tool and the least danger to

yourself.

In some cases, hand tools are faster than

the machines. Of course, if many identical parts

need to be cut, hand tools are definitely slower.

But if you work on some unique project, it will

surely be easier to perform some operations with

the hand tools, rather than to waste time to set up and configure your machine.

One of the important advantages of hand tools is that they are cheaper

than the power tools, so if in your work you do not have a specific need for this

type of tools, it will be much more cost-effective to buy less expensive hand tool

and use it occasionally, than to buy an expensive power tool which will lay on the

shelf. Besides that, the hand tools are indispensable for the house maintenance.

Various jobs on the house are occasional, so it is not profitable to invest a lot of

money in various power tools. Another great advantage of hand tools is that they

are much safer than the power tools, and this is important for both craftsmen

beginners and for the amateurs, who use hand tools just for quick repairs.



Exercise

Hand tools can be divided into several groups:

Laying out tools – Measuring and marking tools

Impact or striking tools (hammers, mallets and sledges) Twisting tools or fastening tools (wrenches and screwdrivers)

Woodcutting tools (wood saws, planes, wood chisels)

Metal cutting tools (dies, drills, files, punches, reamers, taps)

Holding tools (clamps, pliers, vises)

Safety equipment (goggles, gloves)

Grinding and sharpening tools

Finishing tools and abrasives

Tool storage & accessory containers



PASSIVE VOICE

A. The form of Passive Voice

Passive voice is the We form the passive voice in English with the verb to be as anauxiliary, plus the past participle of the main verb. For every active voice in

English there is a corresponding passive voice.

Formation

Exercise

Change these sentences into passive voice

1. You must leave the message

The message must be left by you

2. The maintenance department regularly services the machine.

……………………………………………

3. You should wear protective clothing in the workshop

…………………………………………….



4. The mechanic wrote a report concerning the failure

………………………………………………

5. The mechanic is checking instrument for measuring

………………………………… 6. we will clean the workshop soon

………………………………

7. He bought a new fork lift for the factory

………………………………

8. You can improve your mechanical engineering knowledge by practicing.

……………………………………

9. The lecturer has devided material into two main classes

…………………………………. 10. Office workers will use Electrician’s Safety Tools

Exercise

Describe the operation of the new speed trap by converting each of these

statements to the Present Passive.

1. The first unit records the time each vehicle passes.

2. It identifies each vehicle by its number plates using Optical Character

Recognition



(OCR) software.

3. It relays the information to the second unit.

4. The second unit also records the time each vehicle passes.

5. The microprocessor calculates the timetaken to travel between the units.

6. It relays the registration numbers on

speeding vehicles to police headquarters.

7. A computer matches each vehicle with

the Driver and Vehicle Licensing Centre

(DVLC) database.

8. It prints off a letter to the vehicle owners

using mailmerge

APPLICATION LETTER

Application letter is also called by A cover letter. Application letter is adocument sent with your resume to provide additional information on your skills

and experience. Business and professional people are hired on the basis of

application letter and interview

General points:



• Keep it brief

• Begin your letter or email ‘Dear Mr /

Mrs/ Msxxxx’ if you know the person’s

name, or ‘Dear Sir or Madam’ if you don’t know their name.

• Short paragraphs.

• Check your spelling, grammar, and

punctuation carefully.

Part of Application Letter

1. Heading

a. Sender's address:b. Date

2. Inside Address

This is the address you are sending your letter to (the company’s address).

Make it as complete as possible. Include titles and names if you know them

3. Salutation

Example: Dear Sir,

4. Body

The body of a good application letter, usually 3 to 4 paragraphs, explains why

the applicant is a good fit for the job, explains relevant experience, and shows

how that experience would be useful if selected for the career opportunity.

5. Closing

Example: Yours sincerely,

6. Signature

Do not followed by punctuation

Consist of application letter

1. Introduction

2. Statement of qualification

3. Reason for applying the job



4. Availability of the applicant

666 Antares Way Ray,

MA 02072

Januari 15, 2016

Ms. Nancy Mary

Human Resources Manager

McKeith & Company, Inc.

Parkinson Park Plaza, dome 2000

Boston, MA 02101

Dear Ms. Mary,

Application for the position of product designer

In reference to the job vacancies you advertised at the Carpenters’ Industrial College career

bazaar, I would like to apply for the position of product designer. I believe that while I am a

recent graduate, I do have some valuable experience that will enable me to be an excellent

addition to your design team.

I recently graduated with a Strata one in graphic design, and the course includes product design

modules. Moreover, I have competed in several design competitions and won a gold medal in a

product design competition in Thailand last year, in which I designed a self- heating mug.

Details of this prize and other prizes that I have won are included in the enclosed curriculum

vitae.

I am looking forward to a positive reply from you. Thank you for your kind consideration and

time.

Yours sincerely,

Almira Aulia

English for electrical engineering.pdf

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