Tiếng Anh chuyên ngành điện tử viễn thông

N h u vdy thong tliao tieng Anh chuyen nganh Dien t i t - Vien thong la mot trong cac yen can ccf ban doi voi nhitng ai lam viec, hoc tap va nghien cihi khoa hoc trong linh vitc nay.. Cu

Ngay nay Dien tif - Vien thong co toe do phat trien rat nhanh De tie'p can duoc sit phat trien do ddi hoi nhitng ngifcfi quan tarn vita phai co kien tliitc ve ky thuat vita phdi co trtnh do ngoai ngit tieng Anh chuyen nganh tot N h u vdy thong tliao tieng Anh chuyen nganh Dien t i t - Vien thong la mot trong cac yen can ccf ban doi voi nhitng ai lam viec, hoc tap va nghien cihi khoa hoc trong linh vitc nay N hdm cung cap von tif vitng, cac ky nang doc hieu, ky nang dich tieng Anh chuyen nganh cua linh vuc Dien tif - Vien thong den ban doc, ndm 2005 N hd xuat ban Bifu dien da xuat ban cuon sach

"T ieng A n h chu yen nganh D ien tit - V iin th o n g ” Cuon sach ra dcri da dap ifng ditoc mong moi cua nhieu ban doc muon trau ddi va nang cao trinh do tieng Anh chuyen nganh Dien tie - Vien thong Voi muc dich phuc vu ban doc tot hon nita, Nha xuat ban Buu dien phoi hop voi cac tac gia chinh si(a bo sung, tai ban cuon sach nay Cuon sach duoc vie't theo dang song ngu Anh - Viet, gom 20 bdi duoc lua chon sat voi chit de co ban c ia nganh Dien tif - Vien thong Cuoi moi bai deu co phan bdi tap, mot so phan gioi thieu ngi? phap c o ban thuong gap trong van phong khoa hoc nhu can dien kien, menh de quan he, menh de thdi gian, menh de danh tif, can bi dong, Ngodi ra, cuon sach con cung cap cac bdi kiem tra giifa va cuoi khoa hoc,

t dc bdi dich man cung nhu phan giai dap cac bdi tap ciia titng bdi trong phan phu luc giiip cho ban doc tif danh gia k it qua hoc tap c ia minh va tra cifu nhitng doan dich man khi can Phan Phu luc tap hop cac thuat ngif cung nhu cac tif vie't tdt thong dung

ve chuyen mon ma cac bdi hoc tren da de cap.

Cuon sach la tai lieu hoc tap cho hoc sinh, sinh vien cac trudng dai hoc, cao dang chuyen nganh Dien tit - Vien thong mong muon trau doi von tieng Anh chuyen nganh va tif nghien cifu tai lieu chuyen nganh bdng tieng Anh Ngodi ra cuon sach con Id tdi lieu tif ddo tqo, boi ditdng tieng Anh cho cac can bo ky thuat, ky sit, can bo cdng nhan vien hien dang cong tac trong linh vuc Dien tif - Vien thong va Cong nghe thong tin.

Trong Ian xuat ban nay, cuon sach da duoc chinh sifa va bo sung, hodn thien hon N hd xuat ban Bifu dien rat mong nhan duoc nhitng y kien dong gop cua quy vi

M oi v kien dong gop xin gin ve N h d x u a t ban B u u dien, 18 N gu yen D u, H a Noi; dien thoqi: (04) 5772142; Fax: (04) 5772037.

Tran trong cam on.

H a N oi, thang 12 ndm 2007

N H A X U A T B A N B U U D I E N

LCJI NOI DAU

C u o n sach “T ien g A n h ch u yen n g a n h D ien t u - V ien th o n g ” la tai lieu hoc tap

d a nh c h o c ho sinh vien n g a nh Di en tir -Vi6n th on g va C o n g nghe t h o n g tin, d u p e bien soan chu yeu phuc vu c h o doi tu pn g sinh vien n a m t h u hai, h oa c toi t hieu da h o an t hanh

c h u o n g trinh tieng A n h trlnh do E lem entary.

Cu on sach g o m 20 bai lira c h on theo n h u n g chu de c o ban c u a c h u y e n n g a n h Di en tir - Vidn thong Noi d u n g cac bai deu h u a n g vao phat trien ki n a n g d o c hieu va ky na ng dich c h u y e n nganh Cac bai gioi thieu ngir p ha p (L a n g u a g e fo c u s ) d u p e trinh bay bang tieng Viet giup c ho sinh vien he th on g hoa hoac b6 s ung n h u n g noi d u n g n g u p h a p c o ban, thirong g a p t rong van pho ng k ho a hoc - n h u can dieu kien, m enh de quan he can

bi dong v.v

N go ai ra, c u o n s ach c o n c u ng c ap c ac bai k i e m tra gi ua va c u6i k h o a hoc, cac bai dich m a u c u n g n h u p ha n giai d a p cac bai tap c u a t ung bai t rong p ha n ph u luc g i u p c h o sinh vien tir d a n h gia ket q u a hoc tap c u a m l n h va tra c uu n h u n g d o a n d i c h m ^ u khi can

Nhan dip ra m i t lan dau cuon sach “Tieng A n h chuyen nganh D ien tu - Vien th o n g ”

n h o m tac gia xin c ha n t hanh c a m a n Ban G ia m hieu, P h o n g D a o tao va Bo m on

N g o a i ngir T riro n g D a i h o c K h o a h oc Tir n h ie n d a t a o m o i d i e u k i e n tot n h a t de

c u o n s a c h d u p e h o a n t h a n h C h u n g toi c u n g xi n giii loi c a m a n d a c bi et t a i ca n h a n

TS Le Th e Q ue , TS Tr an Q u a n g Vinh, TS N g u y e n Chi Dung , ThS T r a n T h i Nga cac

g ia ng vien N g u y 6 n T h a n h T u n g va N g u y g n N h u Q u y n h vi n h Sn g q u a n tarn va d o n g g o p

c o n g sue c ho tai lieu n ay kip ho an tat d u n g thai gian q u y dinh

T r o n g q u a trinh bien soan c u on sach, cac tac gia d a c o g a n g toi d a n h a m dat d u a c

n h u n g m u c tieu de ra T u y nhien, cac thieu sot la k h o n g the’ t ra n h khoi C h u n g toi rat

m o n g n h an d u p e y ki en d o n g g o p c u a cac n ha c h u y e n m o n , d o n g n g h i e p va tat ca

n h u n g ai q u a n tarn de tiep tuc h oa n thien c u o n sach

Xin tran t rong c a m an

Tluiy m at nliom bien soan

P G S T S Virang D uo Vy

ATOMS AND THE DEFINITION OF ELECTRICITY

El e m e n t s are a r ra n ge d by their basic properties, as being metals, etc on a chart

k n o w n as the periodic chart o f the elements

So me o f the m or e c o m m o n e le me nt s are carbon, copper, o x y g e n and a l u m i n u m

E l e me n t s m a y exist alone, or they m a y exist in clusters, or mo le cul es , a long with other

e lements For e x a m p l e , a piece o f co pp er wire is solely m a d e up o f the c op pe r element

By c o mp a r i s o n , wa t er is a c omb in a ti on o f two different e lements : o x y g e n and hydrogen

An e l e m e n t c an be b roken d o w n into even smal l er particles, called atoms An

a tom is the s mal lest unit into which an e l ement can be broken d o w n and still retain its original c har acteris tics The atom re se mb le s a little universe T he c e n t e r o f this universe, call ed the nucleus, is ma d e up o f parts k n o w n as protons and neutrons

A r o u n d the nuc leus , tiny little particles are c onstantly rotating in an orbit W e call these particles electrons

Th e a t om is far too smal l to be seen, even with the aid o f the m os t powerful

mi c ro sco pe H o we v e r , we d o have a vast a m o u n t o f k n o w l e d g e about the a to m and its inner parts T h e pro ton differs fr om the electron both electri cally and physically Electrically, the proton is positively c har ged, and is about 1850 times as he avi er than the electron Th e o rbi t in g electron, on the other hand, is m u c h lighter, a nd is said to be negati vely c h a r g e d Th e neutron c an effectively be thou gh t o f as c o n s is t in g o f both a

proton and an el ec tro n It has the s ame a ppr ox ima t e weight as the proton: howe ver, it is neutral in c ha r ge T h is is b e ca us e the positive c har ge o f the proton c a n c el s out the

negative c h a r g e o f the electron

A t o m s a l w a y s have the s am e parts, but not a l way s in the s a m e a m o u n t s or

co nfi gu ra ti ons A t o m s with m or e protons and electrons, o f course, must be larger and heavier U n d e r n o r m a l c i r c u ms t a nc es , a t oms seek to be neutral in c h ar g e , and so will have an e q u a l a m o u n t o f e lec trons and protons So if an a tom like c op pe r has 29 protons

in its center, it will also have 29 electrons Because these e l ec tr on s are r otating in an

6 Tieng A n h chuyen nganh Dien tu" - Vien thong

orbit, having too m a n y electrons in a given orbit could c aus e th em to c rash into e a ch

other So m o t h e r nature placed them in different orbits on diff er ent levels W e call

th em layers or rings.

D e p en d i n g on wh ic h ring we are d is cus sing, e ac h ring has a m a x i m u m a m o u n t ot

e lectrons w hi ch it c an hold, without having to form a no ther ring For instance, the first ring can only hold 2 electrons So if we have an atom with 3 protons ( As in the c as e o f

L i t hi um) it mus t also have 3 electrons Since it c an only hold 2 e l e c t r o n s in the n u m b e r

1 ring, it is forced to create a s ec ond ring, with only 1 e lectron in it In the case o f

Li th ium, this 1 el ec tr on is said to exist in the o ut er ring, or the valence ring

In El ectronics, w e are ma i n l y c o nc e r n e d with this valence ring, b e c a u s e it is here that the m a g i c o f El ec tronic s takes place If a given ring is shy o f b e i ng full, it w a n t s to

“ b o r r o w ” an el ec tr on fr om s o m e w h e r e else If an a t om has one too m a n y e le ct ron s, it

pu sh es the “e x t r a ” el ec tr on wa y out on a ring o f its own and tries to “ l oa n" it to a n ot he r atom

Electronics, in its purest form, is the study o f the m o v e m e n t o f e l e c t r o n s from one atom to another Usually, this takes place by b or r owi n g and l oaning ( t e m p o r a r i l y ) of electrons W h i l e we c a n not actually see this g oi ng on, we c a n m o n i t o r its effects,

w hi ch c an be amazing!

(T ext taken from http-.llwM-M sc ie n c e -e b o o k s.c o m ed ited by W illia m H Boos»

W ords and expressions

nguyen toton taimire (nang lirpng .) cho mupn, cho vay phan tir

trung hoa trung tinh quy dao

electron quy dao hat, tieu phan bang tuan hoan

retain (n) duy tri, giuf lai

rotate (v) quay, xoay

tem porarily (adv) (mot cach) tarn thdi

1 A t o m s are m a d e up o f protons, neutrons and electrons

2 T he e lec tr on is the mo st important part o f an atom

3 El ec troni cs studies the m o v e m e n t o f electrons be twee n atoms

2 Q u e stio n s

A n sw e r th e fo llo w in g questions.

1 W h at are e lec tr on s?

2 In what wa y are the neutron and the proton similar?

3 W h y are e l ec t ro ns o f an atom placed in different orbits?

4 W h at is V a l e n c e Ri ng?

5 W h e n d oe s the lo ani ng o f e lectrons ha ppen?

3 U n d e r st a n d in g the passage

D ecide w h e th er th e fo llo w in g sta tem en ts are true or fa ls e (TIF ) by refe rrin g to the

in fo rm a tio n in th e text T h en m a ke the necessary ch a n g es so th a t th e fa ls e statem en ts becom e true.

1 It is impos si ble to split an atom into s ma l le r parts

2 T h e a tom is so far that people can not see it with their na k ed eyes

3 Th e e lec tron differs from the proton in that it is n e g a t i v e l y c h a r g e d and

not so heavy as the proton

4 C o n f ig ur a t i on s o f a t o ms o f different e l e m e n t s c an be different

5 W e c an see e lec trons m o vi ng from one a to m to another

8 Tieng A n h chuyen nganh Dien tit - Vien thong

4 C o n t e x t u a l r e f e r e n c e

W hat does each word in bold refer to?

1 it (para 4)

2 T h i s (para 4)

3 t h e m (para 5)

4 t h e m (para 5)

5 it (para 6)

5 C o n t e n t r e v i e w

M atch a w ord/phrase in co lu m n A with an appropriate ph ra se in c o lu m n B.

1 nucleus a. a very small piece of matter moving around the nucleus

2 el ement b. t ogether with a neutron to form the n uc leus

3 electron c. the central part of an atom

4 electric c har ges d. they are either positive (+) or negati ve (-)

5 proton e. a chemical substance consisting of atoms of only one kind

6 E n g l i s h - V i e t n a m e s e t r a n s l a t i o n

Translate the fo llo w in g sentences into V ietnam ese, basing on th e in fo rm a tio n in

th e text.

1 The single mos t important characteristic of an a tom is its a t o m i c n u m b e r , whi ch is defi ned as the n u m b e r o f units of positive c ha r ge in the nucleus

2 The at omic n u m b e r d e te r mi n e s the ki nds o f mo l e c u l e s that can be f or med and their bi ndi ng energy He nce , the a tomi c n u m b e r de te r mi ne s an a tom' s characterist ics as an e lement

7 V ie tn a m ese - E nglish translation

Translate the fo llo w in g sentences into English, basing on the inform ation in the text.

! D i e n tir c o the bi k eo khoi q u y d a o c u a no q u a n h hat n ha n bai mot n go ai luc

n a o do

2 M6i lop dien tu c o k ha nang giu' du oc mot so luong toi da cac dien tu ma khon g tao ra l ap moi

3 T r o n g di en t u hoc c h u n g ta chu yeu qu an tarn den lop dien tu hoa tri vi da y chinh

la noi di6n ra didu ky dieu cua m o n kh oa hoc nay

S Bai dich th a m k h a o

Nguyen tif va djnh nghla ve dien

Cac n g u y e n to d u o c sap xep theo nh un g thuoc tinh c o ban cua c hu ng vi du nhu

c ac kim loai va c ac n g u y e n to k hac trong bang tuan hoan cac n g u y e n to

M ot so n g u y e n to pho bien hon la cac-bon, do ng , o-xi, n hom Cac n g u y e n to co the ton tai d o c lap h o a c d u a i d a ng h o p chat ha y phan tu c u ng voi n h u n g n g u y e n to khac Thi du mot maiu soi d o n g chi g o m ngu ye n to d o n g tao thanh T r o n g khi d o nu oc la su ket h op c ua hai n g u y e n to k ha c nhau: O-xi va hi-dro

Mot n g u y e n to co the d u oc phan chia thanh n h u n g hat n ho hon goi la cac n g uv e n tir N g u y e n tu la d o n vi nho nhat m a mot n g u y en to co the phan chia ra va no van con giu' d u o c ban chat c u a n g u y e n to do N g u y e n tu gi on g n h u mot vu tru nho T a m c ua vu tru goi la hat n ha n duofc tao boi cac no-tron va pro-ton X u n g q u a n h hat nha n co nh un g hat rat be q u a y lien tuc tren q uy d a o d u o c goi la cac dien tu hay electron

N g u y e n tu la q u a nho de ta co the’ nhin thay duoc nga y ca khi c o su t r a 2iup cua kinh hie'n vi c uc m a n h T u y vay c h u n g ta da co d u a c su hieu biet nhieu ve n s u v e n tu va phan ben t rong c ua no Pro-ton k ha c vai electron ca \ e dien hoc va \ e vat lv hoc Ve

di en hoc pro- ton m a n g dien tich d u a n g va na ng h a n e lec tron k h o a n s 1850 lan T r o n °

10 Tieng A n h chuyen nganh Dien tic - Vien thong

khi do, electron q u y d a o lai nhe hon nhi6u va m a n g dien tfch am N o -t r o n c o the x em

n h u bao go m ca pro-ton va electron N o c o t rong luo ng xa p xi pro-ton tuy nhien lai trung hoa v£ dien So d! n h u vay la vi dien tich d u o n g c ua proton d a triet tieu voi dien tich am c ua electron

N guy en tu bao g io c u n g co cac t hanh phan n h u nhau n hu n g k h o n g phai luon luon

co c u ng mot so luong cac hat hoac c u ng mot cau h'inh C ac n g u y e n tu c o nhieu pro-ton

va electron hon, hien n hien phai Ion hon va n ang hon T r o n g dieu kien binh thu dn g cac

n g uye n tir co xu h u d n g tim kie m sir t rung hoa ve dien va n h u vay se c o so luon g cac pro-ton va so luong electron bang nhau C ho nen, neu mot n g u y e n tu n h u n g u y e n tu

d o n g co 29 pro-ton d tam thi no c u ng se co 29 electron Vi c ac di en tu nay q u a \ tren mot q u y d a o va viec co q u a nhieu electron tren c u ng q u y d a o nay c o the g a y nen su va

c h a m giua ch un g N h u vay, cac electron tren n h u n g q uy d a o k h a c nha u va 6 n h u n g mure

na ng luong kha c nha u la ban cha't tu nhien c ua cac n g u y e n to T a goi c h u n g la c ac lop hoac cac vong

T u y theo lop na o d u o c x e m xet, m6i lop vong de u co c h u a mo t lu on g e le ct ro n toi

da m a k h o ng dan toi viec tao ra lop moi Vi du, lop da u tien chi c o the c h u a 2 electron Neu mot n g u ye n tu co 3 pro-ton (vi du n g uy en tu Liti) thi no c u n g phai c o 3 electron

Vi no chi g iu d u oc 2 e lectron d lop t h u nhat, no buoc phai tao ra lop t h u hai d6 s ap xep

th e m 1 electron c on lai T r on g tru dn g h op n g uy en tu Liti, 1 e lec tr on nay ton tai a lop ngoai hay c on goi la lop hoa tri

T r o n g dien tu hoc, c h u n g ta c hu yeu q u an t am de n lop hoa tri nav boi vi dav

c hinh la noi xa y ra dieu ky dieu c ua dien tu hoc N eu mot lop na o d o c h u a c h u a d a \ electron, no co xu the " m u o n" mot e lectron tir mot noi khac N eu n g u y e n tir thira 1 dien tir thi no se daiy e lec tron "ngoai lai" nay ra khoi lop c u a no va c o g a n g de c h o mot

n g u ye n tir k h a c "vay"

D i e n tu hoc, 6 d a n g t h u a n tuy nhat ciia no la bo m o n n gh ie n c uu ve su di c h u v e n ciia cac dien tir tir n g u y e n tir nay sang n g u ye n tir khac T h o n g thu dn g q u a trinh nav xav

ra th on g q u a viec " m u o n " va "cho vay" ( mot cach tam thefi) cac elec tron T r o n s khi

c h u n g ta k h o n g the true tiep nhin thay n hu n g di^n bien nay c h u n g ta van co the 21a m sat d u o c n h u n g hieu irng co the’ la mot dieu d a n g kinh ngac ciia q ua trinh d o 1

ELECTRICITY AND ELECTRONICS

Volta m a d e his e x p er i me nt a l cell in 1800, p ro du ci ng for the first time a steady, reliable electric current Durin g the nineteenth century, the d e v el o pm e nt o f practical

a pplications o f electrical e n e r gy a dvanced rapidly The first ma jor uses o f electricity were in the field o f c o m m u n i c a t i o n s - first for the telegraph and then the telephone

T h e y used not o nl y electric current but also e l e ct ro ma gn e ti c effects.

T h o m a s E d i s o n ’s invention o f the electric light bulb was perhaps the most

impor tant d e v e l o p m e n t o f all, because it led to the creation o f an electric powe r s ystem

which has since r e ac h e d into nearly every c orner o f the world The applications o f electricity have g r o w n to the point where most o f us lead “electrified life” , s u r roun de d

by a variety o f de v ic es that use electric energy

It is quite r e m a r k a b l e that so m u c h o f this rapid d eve lopm ent o f electrical devices took place d u r i n g the n ineteenth century, when the nature o f electri city was not

c o m pl e t e l y und er s to od W e have obs er ved that for a long time, but it was incorrectly believed that c ur re nt flowed from positive to negative It w'as not until 1897 that the British scientist J os ep h T h o m s o n a n n o u n ce d his discovery o f the electron

T h o m s o n ’s d i s co ve r y led to further e x pe r ime nt a ti on into the structure o f the atom

W i t h i n the field o f electricity, his wo rk led to the creation o f the s cience of electroni cs

T h e r e is so m u c h c o n f us i o n in current usage b et wee n the terms “e l ec t ri c it y” and

“ e l e c t r o n i c s ” that we s hould attempt to m a k e s ome sort o f distinction b e t w e e n them

Electricity g e ne ra ll y refers to the flow o f free electrons t hr o u g h a c o n du ct o r , in

ot he r words, to a c urre nt o f electricity The term includes the electric p ow er is supplied

by g ene ra to rs and the distribution s y st e ms which transmit it to h o me s, offices, and

factories

Electronics, on the o t he r hand, deals with the m o v e m e n t o f free e l ec t ro ns in a

v a c u u m or in s em i c o n d u c t o r W h e n the term first c a m e into use it referred to the

b e ha vi ou r o f free e l ec tr ons in v a c u u m tubes like those used to transmit or detect radio waves Since then it has been e x t e n d e d to include the m o v e m e n t o f e l ec t r o ns in gases, liquids, and solids

12 Tieng A n h chuyen nganh Dien tit - Vien thong

Reg ard le ss o f the distinction m a d e b e t w ee n the t wo fields, both mus t be understood by t o d a y ’s electrical and electroni c engineers Even an e n g i n e e r w o r k i n g on the design o f the n ewes t c o m p u t e r s mus t have k n o w l e d g e o f circuits and

e l ec tr omagne ti c effects Electricity and e lectroni cs are really indivisible: e ac h one forms part o f the other

(Text adapted from The language o f E lectrical an d E lectronic Engineering in English by Eugene J Hall)

Words and expressions

advance (n/v) tien bo

announce (v) thong bao, cong bo

application (n) s i/ urig dung

circuit (n) mach, mach dien

confusion (n) s i/ Ian Ion, nham Ian

design (n/v) thiet ke, s i/th ie t ke

development (n) su phat trien

discovery (n) su kham pha, su phat hien

distinction (n) su phan biet

electricity (n) dien, dien hoc

electrom agnetic effects hieu ilrng dien ti/

electronics (n) dien tif (hoc)

indivisible (adj) khong the chia, khong the tach rdi

invention (n) phat minh, s u p h a t minh

liquid (n) chat long

observe (v) quan sat

reliable (adj) (dang) tin cay

solid (n) chat ran

steady (adj) khong doi, on dinh

supply (v) cung cap

transm it (v) phat (song )

vacuum tube (n) den dien tir

2 People had been able to m a k e good use o f electricity before they fully unde rs to od its nature.

3 A l th o u g h both "electricity" and "electronics" refer to the m o v e m e n t o f tree electrons, they m e a n different things

2 Q u e stio n s

A n s w e r th e fo llo w in g q uestion s

1 W h at were the first m a j o r uses o f electricity in practical applications'.’

2 W h y was the invention o f the electric light bulb perhaps the most important event?

3 W h at impor tant event took place in 1897?

4 W h a t d oe s e lectri city deal with? W h at does electronics refer to?

5 W h y must t o d a y ’s electrical and electronic e ng inee rs k n ow both o f the fields?

3 U n d e r st a n d in g the passage

D ecide w h e th e r th e fo llo w in g statem ents are true or fa ls e (TIF ) by referrin g to the

in fo rm a tio n in th e text T h en m a ke the necessary ch a n g es so th a t the fa lse sta tem en ts becom e true.

1 T he d e v e l o p m e n t o f practical applications o f electrical e n e r gy a d v a n c e d veryfast d u r i n g the ni ne te enth century

2 T h a n k s to E d i s o n ’s invention o f the electric light bulb, an e le ct ro n ic po we r

s y st e m has n o w been created almost e v e r y wh e re in the world

3 J os ep h T h o m s o n di scove re d the electron in order to improve e lec troni c

e n g i n e e r i n g in Engl and

4 El ec tro ns are not able to flow in liquids or solids.

5 G e n e r a l l y spea ki ng , electricity and elec tro ni cs do not have significantdiff er en ces

14 Tieng A n h chuyen nganh Dien tit - Vien thong

4 C o n tex tu a l referen ce

W hat do the words in bold refer to?

T hey (para 1)

it (para 2)

them (para 4)

it ( para 5)

the term ( para 6)

5 C on ten t review Use the in fo rm a tio n in the text to com plete the fo llo w in g su m m a ry. V o l t a ’s invention o f ( 1 ) in 1800 o pe ned up the w ay for practical applications o f electricity Early main uses o f electricity we re in the field ot (2) The i ncandescent light bulb, which was de vel op ed by T homas Edi son caused an ( 3 ) to be created With this system, electric e ner g\ has been delivered to homes, offices, and factories In 1897 Sir J ose ph T h om s on a nn ou nc ed his discovery o f ( 4 ) and he is c onsi de re d to be the founder of the science o f (5) Unlike electricity w hi ch m e a n s the How of electrons through a (6) electronics refers to the m o v e m e n t of free electrons in a ( 7 ) or in ( 8 )

6 English - V ietn a m ese translation

Translate the fo llo w in g sentences into V ietnam ese, basing on the in fo rm a tio n in the text.

1 The mo le cules of a liquid are held t oget her t ighter than those o f a gas

2 The resistance o f a s emi c on du ct or material is greater than that of a c o n d u c t o r like copper and less than that of an insulator like glass

3 The r emote control unit contai ns keys and el ectroni cs c o m p o n e n t s s imi la r to those

o f a calculator

4 Or bi t i ng e lect rons are called planet ary electrons, and those that have been pulled

a w a \ are k n ow n as free electrons

7 V ie tn a m e s e -E n g lish tran slation

Translate the fo llo w in g sentences into English, basing on the inform ation in the text.

1 M a y dien thoai va m a y dien b a o la hai ung d u n g qu an trong dau tien c ua dien hoc trong linh vuc th on g tin lien lac

2 Di en hoc va di en tu hoc la hai linh vuc k h o n g the tach rdi va vi vav, ngudi kv su dien t u can phai hieu biet ca hai linh vuc do

8 Bai d ich th a m k h a o

N a m 1800, lan dfiu tien Volta da tao d uo c mot pin thi n gh ie m c h o mot d o n g dien

dn dinh T r o n g suot the ki X IX viec phat trien cac ung d u n g thuc tien c ua na ng luong

di en d a tang nh anh Ung d u n g chu yeu dau tien cua dien la d trong linh vuc truven thong Thoa t d a u la di en bao va sau do la dien thoai Hai p hu o ng tien nay k ho n g chi sir

d u n g d o n g dien m a c on d u n g ca cac hieu ung dien tir

Phat m in h c u a T h o m a s Edi son ve bong den dien co le la phat mi nh qu an trong nhat vi no d a n toi viec tao ra mot he tho ng dien nang nav da vuon tdi d u o c hau hot moi noi tren the gidi N h u n g ung d u n g ve dien da phat trien tdi m u c m a hau het c h u n g ta d£u d a n g s ong mot c u o c s on g "dien khi hoa", bao q u a n h bdi n h u n g thiet bi su d un g

d i e n nang

D ie u d a n g ghi nh an la sir phat trien n ha nh c h o n g ve cac thiet bi dien tir da dit!n ra

t r on g suot the ky XI X khi m a con ngudi c hu a hieu biet day du ve ban chat c ua dien hoc Ma c du da q u a n sat t rong mot thdi gian dai s ong hoi do ngudi ta van tin r ang d on g

d i e n c ha v tu c u c d u o n g sang circ am Mai d e n n a m 1897 nha bac hoc ngudi A n h J ose ph

T h o m s o n mdi c d n g bo phat m in h cua o n g ve dien tu (electron)

Phat m in h c u a T h o m s o n da m d dirdng c h o n hu n g thi n gh i e m tiep the o ve cau true ciia n g u v e n tir T r o n g linh virc dien hoc cac c o ng trinh nghien cuu c ua o ng d a da n de n

su ra ddi cua n g a n h di en tu hoc Hien nay co qua nhieu su nhiim liin t r on a viec sii d u n e

c a c thuat ngir "dien h o c " va "dien tir hoc" vi vay ta can c o g a n g p ha n biet hai khai

n i e m nay

16 Tieng A n h chuyen nganh Dien ttf - V len thong

Dien hoc noi c h u n g d£ cap toi d on g dien tu tu d o di qu a mot vat dim noi c ac h khac de cap den d on g dien Thuat n g u nay h am c hua ca dien n a ng d u o c c u n g c a p boi cac m a y phat dien va cac he thong phan phoi dan dien den tirng nha tirng c o n g no va tirng xi nghiep

Tren mot binh dien khac "dien tu h o c ” lien q u an den su c h u y e n d o n g c u a dien tu

tu d o trong moi trudng chan khong hoac trong chat ban dan Khi thuat ngur n a \ d u o c su

d u n g Ian dau no am chi thuoc tinh c ua cac dien tu tu do trong c ac o n g c h a n khong giong n h u nhu ng ong d u oc su dung de truven hay do song radio Tir d o ve sau thuat

n g u nay da d u pe m o rong de bao ham ca s u c h uy en d on g c ua di en tu t r ong chat khi chat long, va chat ran

Mac dii co su k hac nhau giiira dien hoc va dien tu hoc cac ky su d i e n va dien tu ngav nay can phai hieu biet ca hai linh vuc nay Ng ay ca mot ky su t h a m gia thiet ke

n hu n g m a u m a y tinh moi nhat cung phai c o kien thuc ve m a c h dien va hieu ung dien tir Dien hoc va dien tir hoc thuc chat la hai linh vuc k h o n g the tach roi: linh vuc nay la bo phan ciia linh vuc kia

PASSIVE VOICE

1 D efin ition

Th e bi d o n g (pa ssive voice) la mot p h a m tru cua d o n g tir tieng A n h doi lap voi the chu d o n g (active voice). T r o n g cau bi dong, chu n g u cua cau k ho n g phai la chu the (hay tac n h an ) c ua h a nh d on g, m a c hinh la ddi tuo ng tiep nhan hanh d o n g do

C a n bi d o n g d irac sir d u n g t ro n g n h u n g t r u d n g hap:

• Khi khong can thiet p hai nhac den chit the ciia hanh dong, (n h u vi du tren);

• Khi m uon ifit tien nhan mqnh doi tucmg c ia hanli dong (difa doi tirang c ia lidnh dong ten dau edit);

Vi du: The perio d ic chart o f the elem ents, which was pro p o sed by M endeleev, is still com m only used.

T r o n g t r u d n g h a p t hu hai, ta d u n g gidi tir by + chu the hanh dong.

2 S tru ctu r e

2.1 Cciu trite co' ban c i a edit bi dong:

Be + past particip le

T r on g c au true nay be co vai tro la m ot t r a d o n g tu l^ ° nen cac thi khac nhau nhu:

• P r esen t sim p le : a m /is/a re + past particip le

Vf du 1: O xygen is co m b in e d with hydrogen to fo rm water.

• P resen t perfect: h a v e /h a s been + past p articip le

Vi du 2: E a ch ch e m ic a l elem en t h a s b een g iv e n an a to m ic n u m b e r

• Past sim p le : w as/ w ere + past particip le

18 Tieng A n h chuyen nganh Dien tif - Vien thong

2.2 Hinh thuc hi dong co clang nguyen the khi cau true tren cli sau cac dong tif tinh that

• M od al verb (can, will, may ) + be + past particip le

Vi du 4: An elem ent can be broken down into even sm aller particles.

2.3 Cau hi dong hay gap trong cac tinh huong leri not gidn tiep, lam cho p hat ngon co tinh kliacli quan nhieu lurn:

• It + p a ssive + th a t-c la u se

• S u b je c t (not it) + p a ssiv e + to -in fin itiv e

Vi du 5: It was incorrectly believed th at current flo w e d fro m positive to negative.

C urrent was incorrectly believed to flo w fro m po sitive to negative.

Mot so d o n g tu hay d uo c d u n g trong cau true nay: rep o rt, say, understand, assume, believe, consider, kn o w, observe, think .

2.4 Khi dich sang tieng Viet, edit bi dong co xu the chuyen sang dang cau chit dong

Vi du, ca hai cau tren deu co the dich Id:

(Thdi do) ngudi ta tin tucmg mot cach sai lech la dong dien di tifcifc difcmg sang cut dm

3 Practice

A C hange the follow ing sentences into passive a n d translate them into Vietnamese.

1 W e can break d o w n an e l emen t into e ven s ma l le r particles, cal l ed a toms

2 E ve r y b o d y k n o w s that wa ter consists o f o x y g e n a nd h y d r o g e n

3 T h e y say that the orbit ing e l ec ti on is ne gat i vel y c har ged

4 In the nineteenth century people did not completely understand the nature o f electricity

5 T od a y ' s electrical and e l e c t r o n i c - e n g i n e e r s mu st un de rs tan d both electricity and electronics

6 Volta m a d e the first cell in 1880.

7 It was not until 1897 that Joseph T h o m s o n a n no un ce d the d is co ve r y o f the electron

8 El ectricity has m o d e r n i z e d o ur life

9 W e c an no t see the electron because it is too small

10 T h e y say that the el ec tr on exists in the outer ring

B P u t the verbs in brackets in the passive.

M a n y h u n d r e d s o f years after the p h e n o m e n o n o f static electricity( 1 ) (discover), scientists found that there were t wo kinds o f electricalchar ges T he s e t w o ki nds o f c har ges (2) (call) positive and negative

M u c h later it (3) (learn) that the m o v e m e n t o f tiny particles o f m a tt e r

-e l -ec tr ons c a u s-e d -el-ectricity Th-e -el-ectron is v-ery light in w-eight and can (4) ( dr aw ) out o f its orbits around the m u c h heavier nucleus Electronsorbiting farthest from the nucleus most easily ( 5 ) (dr aw) away Orbiti ng

e lectrons (6) (call) planet ary electrons and the e lectrons w hi c h (7) (pull) a w a y ( 8 ) (know) as free electrons

Unit 3

RESISTORS AND RESISTANCE

Ma nuf ac tu re d circuit c o m p o n e n t s w hi ch contai n definite a m o u n t s o f resistance are called resistors In simplest terms, resistors resist, or o pp os e, the fl ow o f electrons through a circuit Every material off ers s ome resistance, or oppos ition, to the flow of electric current t hrough it G oo d condu ct or s, such as copper , silver, and aluminum, offer very little resistance Poor co nd uct or s, or insulators, such as glass, wood, and paper, offer a high resistance to current flow

The size and type o f material o f the wires in an electric circuit are c h o s e n so as to keep the electrical resistance as low as possible In this way c ur re nt c an How easily through the c onductor s, just as wa ter flows thr ough the pipe b e t w e e n t w o tanks If the water pressure r e ma ins constant, the flow o f wa ter in the pipe will d e p e n d on how far the valve is opened The s mal ler the opening, the greater the o p po s i t io n to the flow, and the lower the rate o f flow in ga llons -per -s econd

The s ame is true in electrical circuits: the larger the d i a m e t e r o f the w ires, the lower their electrical resistance (opposition) to the flow o f c u rr ent t h r o u g h the m In the water analogy, pipe friction oppos es the flow o f wa ter b e t w e e n the tanks T h i s friction

is similar to electrical resistance The resistance o f the pipe to the flow' o f w a t er through

it d e p en d s upon

• the length o f the pipe;

• the d ia m e t e r o f the pipe; and

• the nature o f the inside w-alls (r ou gh or s mo o th )

Similarly, the electrical re sista nc e o f c o n d u c t o r s d e p e n d s upon

• the length o f the wires;

• the d i a m e t e r o f the wires; and,

• the material of the wires (copper, a l u m i n u m , etc.)

Te mp e ra t ur e also affects the resistance o f electrical conductors to s o m e c ■ \ [n most c onductor s (copper, a l u m i n u m , iron, etc.) the resistance increases w ith tempv: -• ,:c Carbon is an exception In carbon, the resistance decreases as tempe rat ure

Certain alloys o f metals ( ma nga nin and constantan) have resistance that does not change appreciably with temperature The relative resistance o f several conductor s o f the s ame length and cross section is given in the following list, with silver as a standard o f 1.0 and the r ema in ing metals arranged in order of ascending resistance:

R es is ta nce is m e a s u r e d in o h ms O ne o h m is the resistance o f a circuit or circuit

e l e m e n t that permits a s teady current o f 1 a mpe re (1 c o u l o m b per s ec on d) to flow when

a s teady E M F o f 1 volt is applied to the circuit

(Text taken from http:!/ w w w sc ie iic e -e b o o k s.c o m edited by W illiam H Boos)

W ords and expressions

appreciably (adv) (mot cach) dang ke

arrange (v) sap xep, bo tri

constant (adj) khong doi

cross section tiet dien

decrease (v) giam di, giam xuo'ng

depend ~ on (v) phy thuoc, tuy thuoc (vao .)

ngbai leexception (n)

friction (m) ma sat

increase (v) tang len

measure (v) do, do dac

oppose (v) can trc), chong lai

resistance (n) trd khang

resistor (n) dien trd, con trd

rough (adj) go ghe, tho rap

size (n) kfch thi/dc

smooth (adj) nh3n, trdn

22 Tieng A n h chuyen nganh Dien tit - Vien thong

1 M ain idea

W hich statem ent best expresses the m ain idea o f the te x t? W h y did y o u elim inate the other choices?

1 Different materials offer different resistance to the flow o f electric current through it

2 Resistance is the d eg re e to which materials act against the flow o f electrons

3 The resistance o f electrical c onductor s d epe nds on several factors

2 Q u estio n s

A n sw er the fo llo w in g questions.

1 What are resistors?

2 What is the purpose o f cho osing the size and type of material ol the wires in an electric circuit'1

3 Wh at is the speed o f the water flow through the pipe if the valve is o p en ed far from the source?

4 H o w m a n y factors affect the resistance o f electrical c o n d uc t or s ? W h a t are t h e y 0

5 W h at happen s to the resistance o f a car bon wire whe n its t e mp e r a t u r e r is e s 0

3 U n d er sta n d in g the p assage

D ecide w h eth er the fo llo w in g statem ents are true or fa ls e (TIF) by referrin g to the

in fo rm a tio n in the text T h en m ake the necessary ch a n g es so th a t the fa lse statem ents becom e true.

1 C oppe r is a better electrical c o nd u c t o r than a l u m i n u m

2 Because o f their non-conductivity, glass and pa per are called insulators

3 T he large d i a m e t e r o f the w ire can a cc ou nt for its low resistance

4 Ge ner al ly , t e m pe ra t ur e has a more i nfl uenc e on the resistance than an>

other factor has

5 W h e n te mp e ra t ur e rises, the resistance a l w a y s increases

4 U n d e r sta n d in g v o c a b u la r y

W hich words in th e text can be replaced by the words below? W rite the correct

w ord fr o m the text in each blank.

1 resistor a. the degree to which materials act against the flow o f electrons

2 r esistance b. material which does not allow current to flow

3 c o n d u c t o r c. electronic c o mp on en t for o ppos ing the flow o f charge

4 insulator cl. material which allows current to flow

6 E n glish - V ie tn a m e s e translation

T ran slate th e fo llo w in g sentences into V ietnam ese, basing on the in fo rm a tio n in

th e text.

1 Resistor, an electrical c o mp on en t that opposes the flow of either direct or

a lternat ing current, used to protect, operate, or control the circuit

2 Res is tors can have a fixed value o f resistance, or they can be m a d e variable or

24 Tieng A nh chuyen nganh Dien tit - Vien thong

2 K i- ld- oa t g i a ( K i l o w a t t h o u r ) la d a n vi t h u d n g d u a c sir d u n g khi ngirdi ta ban

n a n g lirgng dien

S Hai dich tliam kh ao

Dien fro va tro khang

Nh un g linh kien m a c h dien co chua mot luong t ra k h a n g nhat d inh d u a c goi la cac dien tra Hieu mot c ac h da n gian nhat, dien trd can trd hoac c h o n g lai d o n g chav cua cac dien tir q u a mot doa n mach Moi vat chat dfiu co trd k h a n g ddi vdi d o n g dien chav q ua no Cac chat dan dien tot nh u dong, bac va n h om co trd k h a n g rat nho Cac chat dan dien kern, hay chat cach dien nhu thuy tinh, go va giay, c o trd k h a n g c ao doi vdi d o n g dien

Kich thudc va loai vat lieu d u n g lam day dan dien trong cac m a c h dien d u a c chon sao c ho bao d a m trd k h a n g ddi vdi d on g dien c ang thap c an g tot T h e o c ac h do dong dien co the c hay qua cac vat dan dien mot cach de dang, giong n h u nu de c h a v q u a ong dan noi giua 2 be chua Neu ap luc nude k h o n g doi thi d o n g nude c h a y t rong ong se phu thuoc vao do m d c ua van ldn hay nho D o m d c ang nhd, thi sir c an trd d o n g nude

c ang ldn va toe do d o n g c hay tinh bang so galon tren giay c ang thap

Mot hien t u a n g t u a n g tu c u ng xay ra trong cac ma ch dien: d u d n g k m h c ua day dan c ang ldn, thi trd k h a n g cua no ddi vdi d o n g dien c ha v q u a c a n g nhd C u n g giong nhu trong trudng h a p d on g nude, m a sat cua ong da n can trd d o n g nude c ha y giiira hai

be chua Ma sat nay t u a n g tu n h u t r a k h an g doi vdi d on g dien T r d k h a n g c ua ong nude doi vdi d o n g nude c hay qu a no phu t huoc vao:

• D o dai cua o n g nude;

• D u d n g k m h cua o ng nude; va

• Ti nh chat thanh trong cua ong (tho rap hay nhan)

T u a n g tir n h u vay trd k h a n g cua cac vat dan dien phu t huoc vao:

• D o dai c ua d ay da n ;

• D u d n g k m h c ua da y dan: va

• Chat lieu cua day d i n (dong n hom v.v )

Nhiet do c u ng anh hud ng len t ra k hang cua vat dan dien a mot c h u n g m u c nhat dinh T r o ng hau het cac vat dan dien (dong, n hom, sat ), t ra k ha ng cua c h u n g tang the o nhiet do C a c b o n la mot trudng h a p ngoai le Doi voi cacbon, dien t ra c ua no giam khi nhiet do tang Mot so h a p kirn (Ma n ga ni n va C onsta nta n) co t r a k h a n g thay doi

k h o n g d a ng ke khi nhiet d p thay doi T r a k h a n g t ua ng doi cua mot so chat dan dien co

c u n g d o dai va c u n g tiet dien d up e liet ke a bang sau vdi bac co trd k h a ng c hu an la 1.0

va n hu n g kim loai c on lai d u a c sap xep t heo t hu tu t r a k ha ng tang dan

D o n g 1,08

V an g 1,4

N h o m 1,8Platin 7.0

Unit 4

CAPACITOR

The capacitor appears to have the effect of passing alternat ing current (AC), while actually not passing anything At the s ame time, it blocks the flow of direct current (DC)

In its most basic form, a capacitor is m a d e up o f 2 plates o f c o n d u c t i n g material

(for instance copper, a l u m i n u m , iron), divided by a piece o f insulative ma te ria l (for instance mica, air, or plastic) If we apply an electric potential to the t w o plates,

electricity will want to attract and flow' from one plate to the oth er, but the insulator

will act as the m e m b r a n e , and block the flow o f electricity For this reason, a capacitor blocks the flow o f DC As power is applied, a certain n u m b e r of e l ec t ro n s on one plate will be attracted to the positive side o f the battery Th e se electrons, leaving the plate

will leave it with a d e fi ci en cy o f electrons, and the plate will be positively char ged.

At the s ame time, electrons from the negative side o f the battery will see the positive c har ge on the plate, and want to mo ve t oward it As these e l ec tr on s leave the

negative side o f the battery, they will pass th ro u gh our light bulb, and light it We will

notice, ho we v er that it only lights for a m ome n t! W h y ? Because b e t w e e n the t wo plates

o f the c apacitor is an insulator, and while the elec tro ns on the negati ve side m a y be attracted to the plate on the positive side, the electric current can' t pass t hrough the insulator So our light flashes for just a second, and then go es out

Now' if w'e reverse the polarity o f the battery, we see that the s a m e thing happens again, only in reverse As p o we r is applied, the e lec trons on the n o w n e g a t i v e h charged plate ol the c apacitor will be attracted to the positive side o f the battery As these electrons n ow leave the plate, they w ill leave a d ef ic i en c y o f e lec trons , and the formerl) negative plate will b e co m e positively c har ged At the s am e time, the elec tro ns from the negative side o f the battery will move t owa rd the positively c h a r ge d plate until the positive plate s wi n gs negative

Note that in the e x am pl e s , the s c h e m a t i c s y m bo l for the capacitor is ver\ similar

to that ot the battery There is a g ood re aso n for this In a battery, we have 2 (or m o r e )

c o nd uc ti ve plates divided by s o m e kind o f dielectr ic material (usually an acid) In a

capacitor, we have 2 (or m or e ) plates divided by s ome kind o f dielectric material - an insulator A battery has the ability to generate electricity chemi ca ll y, and can store

e n e r g y for long periods o f time While a capacitor does not " g en e r a t e ” electricity, it doe s have s o m e a m a z i n g "storage" capabilities

Recall that w he n we applied power to the c apa citor/la mp circuit, electric current flowed for an instant from one side o f the battery and lit the la mp for a m o m e n t , but then the light went out? W h a t took place was while the electric current was flowing, a potential was b eing built up on the surface o f the plates o f the capacitor As long as the potential kept building, current continued to flow, and the light r ema ined lit At some point, howe ver, the c apa ci tor reaches its m a x i m u m capacity to hold an electric potential In other words, it r eaches its peak voltage limit, and we say the c apacitor is fully c har ged If at this time, we were to r emove the battery from the circuit, the capacitor, in theory, wo u ld r ema in at full c har ge indefinitely

If at this time, we shorted the wires be twee n the capacitor and lamp, such that it

f o r me d a c o m p le t e circuit, the lamp would light for just a second without the battery

W h e r e do es the e n e r g y c o m e from to light the lamp if the battery is not c o n ne ct e d? The

a n s w e r lies in one o f the magical properties o f the capacitor it can store energy! W h e n

e n e r g y is stored in a capacitor, we say it is charged W h e n a c ap ac it or releases its

e ner gy, we say it is dis charging

(Text taken from h ttp :llw w w sc ie n c e -e b o o k s.c o m edited by W illiam H Boos)

W ords and expressions

ability (n) kha nang

battery (n) ac quy

block (v) che, chan, chan

capacitor (n) tu, tu dien

dielectric material vat lieu dien moi

discharge (v) phong dien

flash (v) loe sang, chop sang

indefinitely (adv) vo tan, mai mai

insulative (adj) (co tinh chat) cach dien

membrane (n) mang, mang mong

plate (n) tam, phien, dTa

potential (n) the, dien the

release (v) giai phong, lam thoat ra

remove (v) loai bo, loai tri/

28 Tieng A nh chuyen nganh Dien tit - Vien thong

dien ap

1 M ain idea

W hich statem ent best expresses the m ain idea o f the text? W hy d id y o u elim inate the other choices?

1 The text explai ns the characteristics of the capacitor

2 The text discusses ho w the capacitor lets the A C pass t hrough and bloc ks the flow

3 The text presents the a dvantages o f the capacitor over the battery

2 Q u estio n s

A n sw er the fo llo w in g questions.

1 W h e r e is the position o f the insulative material in a capacitor?

2 How doe s the negative side o f the battery b e co m e positively c h a r g e d ?

3 W h e n doe s the current that m a ke s the la mp light up stop f lowing?

4 Wh at can the battery do that the c apacitor c a n ’t?

5 W h at m a k e s a l a m p light for a s econd without the battery?

3 U n d e r sta n d in g the passage

D ecide w h eth er the fo llo w in g statem ents are true or fa ls e (TIF) by referring to the

in fo rm a tio n in the text T h en m a ke the n ecessary c h a n g es so th a t the fa lse statem ents becam e true.

o f DC

A c apa c it or is a s a nd w ic h ot two plates ot c o n d u c t i n g material separated b\

an insulative material

The negative plate ot the c ap ac i to r b e c o m e s positively char ged before the

e lec tr on s leave it

3 During the alternation o f polarity of the plates, the char ges are displaced

through the dielectric first in one direction and then in the other

4 The e lec trons from the negative side o f the battery will move t oward the

positively c h ar ged plate as long as an electric potential is applied to theplates

5 The ore tic al ly, the capacitor will release its ener gy when the battery is

r e mo v ed from the circuit

2 Its p r i m ar y function is b. consists o f two plates o f c o n du ct i n g

material separated by an insulating material, or dielectric

3 Their capacity to store energy c. to store energy

4 T h e y are used, for e xamp le, cl. m a k es th e m essential c o m p o n e n t s

in digital circuits in m a n y circuits

6 E nglish - V ie tn a m e s e tran slation

T ranslate the fo llo w in g sen tences into V ietn a m ese, basing on the in fo rm a tio n in the text.

1 C a p a c i t o r s are d evices that store electric e ne r gy in the form o f an electric field

ge ne r at e d in the space b et we en two separated, oppositely c ha r ge d electrodes

30 Tieng A n h chuyen nganh Dien tit - Vien thong

2 The no n -c o nd u ct in g properties o f c er ami c s are well k n ow n , a nd s o m e c e r am ic s are ma d e into e x t r e m e l y effective dielectrics

3 Indeed, more than 90 percent o f all capacitors are p r o d uc e d with c er ami c materials serving as the dielectric

7 V ietn a m ese - E nglish translation

Translate the fo llo w in g sentences into E n g lish , basing on the inform ation in the text.

1 Mot thiet bi d u n g de luu tru nang luong dien duoc tao boi hai vat da n dien dal gan nhau va cach dien voi nhau

2 Mot vi du don gian c h o loai thiet bi nay la tu dien co cac ban cuc dat s ong song

3 K ha c voi tu dien ac quy co kha nang tao ra dien ba ng phan ung h oa hoc va co the tfch tru' n ang luong trong thoi gian dai Tu dien c u ng co kha n a ng tfch tru dien song k h o n g the tao ra dien n h u ac quy

8 Bai djch th a m kh ao

Tu dien co ve n h u c ho d o n g dien x oa y chieu ( AC ) di qua n hu n g thuc te no khong

c ho d o n g dien di qua D o n g thoi no con ng an c h a n ca d o n g dien mot chi eu (DC)

0 d a ng c o ban nhat tu dien g o m 2 ban k im loai dan dien (vi du n h u d 6n g nhom sat ) duo'c n ga n c ac h bai mot loai vat lieu c a c h dien (vf du n h u mi ca khon g khi' hoac plastic ) Khi ta dat mot hieu dien the len hai ban c ua tu dien dien co xu the hut n h au

va c h a y tu ban nay sang ban kia n hu n g chat c a c h dien hoat d o n g n h u mot m a n g ngan

va k h o n g c ho d o n g dien c ha v qua Vi ly d o do tu di en ngan d ong dien DC Khi noi

n g u 6 n dien vao tu, mo t so d ie n tu nhat dinh tren mot ban tu se bi hut ve phia cuc duo ng

c u a n gu 6 n dien (ac q uy) Cac dien tir nay khi roi khoi ban tu se gay ra s u thieu hut dien

tu va ban tu se tfch dien du ong

D 6 n g thoi cac dien tu tu cuc am cua nguon dien “ nhan thay” dien tfch d u o n g tren ban tu va co xu the di c huyen ve phia do Khi nhung dien tir nay rdi khoi cuc am ciia ngudn dien c h u ng se di q ua b ong d en va lam b ong den sang len Tuy nhien bong de n chi

s ang trong mot k h oa nh khac Ly do la giCra hai ban tu co chat cach dien va khi nhung dien tir 6 phia cuc a m co the bi hut toi ban 6 phfa cuc duong, thi don g dien k ho n g the

c hay qu a du oc vat c ac h dien N h u the anh sang chi loe len trong giay lat, sau do tat ngay.Bay gi d neu ta d a o c uc ciia ac quy, ta se tha'y rang mot hien tupng tuon g tir lai xay

ra s ong theo chi6u n g u p c lai Khi d up e ca'p n gu 6 n dien cac dien tir tren ban tu tich dien

a m se bi hut ve phia cuc d u o n g ciia ac quy Khi nh un g dien tir nay roi khoi ban tu

c h u n g se ga y ra sir thieu hut dien tir va ban tu a m luc dau se tfch dien duong D o n g thoi

c ac d i e n tir tir cuc a m ciia ac q uy se di c h uy en ve phia ban tu tfch dien d u o n g c ho den khi ban tu tfch dien d u o n g c h u y en sang tich di en am

Q u a cac vf du ta thay ky hieu tren so do ciia tu dien rat gi ong voi ky hieu ciia ac quy Sau d a y la n g u y e n nh an ciia sir giong nhau nay Tr ong ac q uy ta co hai (hoac nhieu

h on hai) ta'm dan d ie n d u p e phan c ac h boi mot chat dien moi (t hudng la axit) T r o n g tu

di en c u n g co hai ( hoac hon hai) ban tu d up e phan cach boi mot chat dien moi - c hinh la chat c ac h dien Ac q u y c o kha na ng tao ra dien ba ng phan ung hoa hoc va co the tich tru

n a ng lu'png lau dai T r o n g khi tu dien k h o n g co kha nang phat ra dien no lai co mot so

k ha n ang tfch t ru di en ki dieu

Tai sao khi c ap n gu o n c ho m a ch g o m co tu dien va b ong den d o n g dien se chay

q u a ngay tuc thi tir mot cuc ciia ac quy va lam sang den trong c hoc lat va sau do den tat? Ly d o la, khi c o d o n g dien, mot dien the du pe tao ra tren be mat cac ban cuc Chirng nao m a di en the con d up e du y tri, d on g dien con tiep tuc c ha y thi d e n con sang

T u y vay tai mo t thoi d i e m nao do, tu dien dat toi kha nang luu gi u dien the cuc dai Noi

c a ch khac, no dat d u p e gidi han dien ap cao nhat, va ta noi rang tu da d u p e na p day

N eu luc nay ta ngat ac q u y khoi m a c h thi ve p hu o n g dien ly thuyet, tu dien se gi u day

d ie n tich mai mai

Con neu luc na y ta dau da y dan giCra tu va bong de n tao ra mot m a c h dien k he p kin thi den se loe s a ng t r on g giay lat m a k h o n g can ac quy N g u o n na ng luong na o lam

c h o d en s an g neu d e n k h o n g d u p e noi vdi ac q uy ? Cau tra ldi niim d mot i r o n s n h u n °

t h uo c tinh kv di eu c ua tu dien - no co kha nang tich tru nang luong Khi n a n s l u o n s

d u o c tich lai t rong tu dien, ta noi rang tu d u pe nap dien Khi tu dien giai p h o n g n a n s luong, ta noi tu p h o n g dien

Unit 5

AN INTRODUCTION TO THE VACUUM TUBE

The va cuum tube, in it' ve r p r i m i t i \ e tcrrr e \ o l \ e d !rorr ' h e hgh: Ku!b Indented b\ Th o m a s Edison in 1883 the i ncandes cent lamp had 3 basic n ecessiti es to ofxrate the envelope, the filament, and the vacuum

The envelope is basically a sealed container, which complete !; ' i rr u n i '

■envelopes' wha tev er is inside T h e first e n v e l o p e s were rr.ade ot g i a " h o w e \ e r ’here was no written law that the} m u s t be m a d e of glass In fact, man; m o d e r n t u b e s ha%e metal and or cer ami c envelopes

T h e filament, k n o w n as the heater, was the basis o f the light b ul b The idea vms that if a high e n o ug h electrical current flows through a coil of wir e, it g e n e r a t e s light and heat i E d i s o n ' s object was to create a thin e n o u gh piece of wir e, that e \ e n a %er} low current could gener ate a great a m o u n t of light T h e p r o b l e m '.'-a' that he Kepf

b u m m g up the filaments The} w o u l d w o r k t or a m a t t e r of s e c o n d ' , a r i ’.her i e

He e x p e r i m e n t e d with man} d i f f e r e n t f i l a me nt m a t e r i a ! ' Final!', he : ur.d a metal

m a te ri a l that would l a s t - t u n gs t e n M m m o d e m f i l a m e n t ' are m a d e _ r of a t h c n i e d

t u n g ' t e n ma ter ia l

T n e Nacuum w a s a d d e d a l on g the wa% a ' an a t i e m r t t? *ieer the : l a m e r ’ : r ; m

b u r n i n g out It w a s logi cal, that in o r d e r for fire to e x i ' t %ou m j ' t h a - e c x \ £ e n S

E d i s o n a ssu m ed that if all the ox % g e n w e r e r e m o v e d , b* c r e a t i n g a \ a c c u m the

f : l a m e n t ' w o u l d stop b u r n i n g up It h el p ed , but wa> not the s o l u t i o n to the p r o b l e m

He did Iind h o w e v e r , that it a t i l a m e n t w a s e n e r g i z e d w i t h i n a \ a c u u m m a t after

r e a ' h a d o w w o u l d be left on the m s i d e ot the glass, w h i c h r e s e m b l e d the ' h a r t ot

e f i l a me nt H e s u r m i s e d from, t h i ' , that w i t h i n a \ a c u u m p a r t i c l e ' w e r.ow call m e m

these emitted electrons b e co me waste, as they serve no useful purpose The vacuum lube

is howe ver de si gn ed to ma ke use o f these emitted electrons Edison e xper i ment ed b\ placing a s econd e lement, or electrode within the vacuum along with the filament, but not touching it He then c on nec te d an a m m e t er to the second element, and attached the other lead o f the a m m e t e r to the positive terminal o f the battery He found that when, doing this, current would flow t hr ough the ammeter The second element is called the plate

T h e emi tt ed c loud o f electrons, bearing a negative charge, is attracted to the positively c h a r ge d plate It flows through the va cu um toward the plate and is collected

u pon its surface But wh at h appe ns if the plate is c on ne ct e d to the negative side o f the battery? Edi so n di s co v er e d that wh en this is done, no current flows t hrough the

a m m e t e r So electri city flows, within the v a cu u m, in one direction only - from negative

to positive

Edi son fur ther r ea so ne d that since, with the polarity reversed, the negative particles o f electri city d i d n ’t flow from the plate to the filament, that there must be

s o m e outs ide force c a u s i n g the electrons to leave the filament He di scovered that while

he was w o r k i n g w'ith a heated filament, the plate was not heated The heat o f the

f il ament c a u s ed the e l ec t ro ns to be "boiled" off, and freed from the solid ma tt er o f the

fi l ame nt into the s u r r o u n d i n g vacuum O n c e the electrons were freed from the c onfine s

o f the solid matter, they could be attracted to any positively c h ar g ed source w ithin the

v a cu um Thi s is k n o w n as t he rmi oni c emi ssi on, which is the process o f the e lec trons being forced out o f the solid metal via thermal agitation

(Text taken from h tlp l/w n w sc ie n c e -e b o o k s.c o m edited b \ W illiam II Boos)

W ords and expressions

attract (v) hilt, hap dan

ceram ic (adj) (thuoc) gom, lam bang gom

discover (v) kham pha, phat hien

electrode (n) dien ci/c

filam ent (n) sdi nung

incandescent (adj) nong sang

make use of tan dung, sir dung

m atter (n) vat chat

polarity (n) tinh phan ci/c

primitive (adj) so khai, tho sd

process (n) qua trinh

sealed (adj) (dirge) han kin, bit kin

34 Tieng A n h chuyen nganh Dien tu: - Vien thong

substance (n) chat

surface (n) mat, be mat

terminal (n) chan, ci/c

thermal agitation chuyen dong nhiet

1 M ain idea

W hich sta tem en t best expresses the m ain idea o f the text? W h y d id yo u elim inate the other choices?

1 The va cu um tube allows electricity to flow t hrough it in one di re c ti on only

2 In working with the electric light bulb, Edi son d i s cov er ed s o m e important characteristics o f the va cu um tube

3 Edi son effect is the basic operating theory o f the v a c uu m tube

2 Q u estion s

A n sw er the fo llo w in g questions.

1 What is n ece ssa ry for a light bulb to operate?

2 W h y did Edison have to e x pe r ime nt with m a n y different filament ma te ri al s?

3 What ma d e Edison think electrons were e mitted a round the wire?

4 W h y do negatively c ha rge d electrons flow toward the plate'?

5 What is t he rmi oni c e m i ss io n?

3 U n d e r sta n d in g the passage

D ecide w h eth er the fo llo w in g statem ents are true or fa ls e ( TIF) by refe rrin g to the

in fo rm a tio n in the text T h en m a ke the necessary c h a n g es so th a t the false statem ents becom e true.

1 T he v a c u u m tube was d e vel ope d earlier than the light bulb

2 Enve lope s can be m a d e o f different materials

3 The lilament will glow it an electric current is pass ed th ro ug h it

4 The v a c u u m completely ke ep s the f il ament fr om being burnt up

5 T he negative particles o f electricity How from the plate to the l ila me nt wh en

the plate is c o n n ec t e d to the negati ve side o f the battery

Use th e in fo rm a tio n in the text to com plete the fo llo w in g sum m a ry.

1 W h e n air a nd o th e r ma tt er have be en re mo ve d from a space, a has

b een created

2 are very thin pieces o f wire w hi ch give of f heat or light w h e n acurre nt is p ass ed th ro u gh it

3 Th e p h e n o m e n o n o f a blue glow a ro und the positive pole in a v a c u u m b u l b and a

b la c k e n i n g o f the wire and the bulb at the negative pole is k n o w n as

4 w hi c h is also called the Edi son effect, is the d i s c ha r ge o f e lec trons

fr om heated materials

5 T h e r m i o n i c e m i s s i o n was first observed ( 18 83) by T h o m a s A Edi son as

m o v e m e n t o f electri city from a filament to a o f metal inside an

i n c a nd e sc en t lamp

36 Tieng A n h chuyen nganh Dien tu - Vien thong

6 English - V ie tn a m ese translation

T ranslate th e fo llo w in g sentences into V ietn a m e se, basing on th e in fo rm a tio n in the text.

I , V a c u u m lubes take time, t ho ug h from a few s ec o nd s to several mi nu te s, to heat

up to operating temperature

2 This is at least an inconvenience and in some cases a serious limitation to their use

3 The se s ho rt c omi ng s motivated scientists at Bell La b or at or ie s to seek an alternative to the v a cu um tube and led to the d e ve lo p me nt o f the transist or

7 V ietn a m ese - English translation

Translate the fo llo w in g sentences into English, basing on the inform atio n in the text.

1 Nha vat ly ngudi Anh J.J T h o m s o n xac dinh ( d e t e rm i ne ) rang n g u y e n nhan cua hieu ling Edison la sir phat xa va dich c h u y e n thanh d on g c ua cac di en tu q ua moi trudng chan khong

2 Chac chan Edison la mot trong nhu ng ngudi co nhieu ba ng s a ng c he (patent i nhat tren the gidi

8 Bai dich th a m khiio

Dang so khai c ua de n di en tu la b on g d e n dien D u o c T h o m a s Edi son phat minh vao nam ISS3 bong d e n dien co 3 yeu to can thiet de hoat do ng: vo boc ngoai soi J ot

va chan khong

\ d hoc ngoai la mot binh c hu a d uo c han kin bao boc toan bo moi thu ben trong Cac vo boc ngoai dau n e n d u a c lam b a ng thuy tinh tuv nhien no khong nhat thiet phai

dirge lam hang loai vat lieu nay Tr ong thuc te, nhieu den dien tir hien dai co vo hoc ngoai la kim loai h oac sir hoac vira kim loai vira su.

Sgi dot (sgi n un g) la phan c o ban cua bo ng de n dien Y t u a n g a d a y la neu d ong

d ie n du m a n h c h a y qu a c u on day, thi c uon da y phat sang (va toa nhiet) M u c dich cua

Ed iso n la tao ra mot do an da y du m a n h sao c h o mot d on g dien yeu co the tao ra mot

l u a ng anh sang lan V an de la a c h6 ong luon lam dirt cac sai dot C h u n g chi lam viec

d u a c trong vai giay sau do hi chay Edison da lam thi nghiem vdi nhieu loai vat lieu sai dot k ha c nhau Cuoi c u n g o ng da tlm d u a c mot kim loai cd the sir d u n g d u a c lau dai -

d o la Vont'ram Phan ldn sai dot hien dai ngay nay deu d u a c lam hang vat lieu Von train phu Thori

Ch an k h o n g la mot phan thi nghiem d u a c dua vao nhu mot n6 luc de g iu c ho sai dot k h o n g bi chav Di6u logic la de cd d u a c sir c ha y thi phai cd o x y Vi vay Edison c ho

r ang neu loai bo het o xy ba ng cach tao ra chan k ho n g thi sai dot se k h o n g bi chay Viec lam nay c u ng c d tac d u n g, song c hua phai la giai phap ciia van de

Tu y nhien Edi son d a nhan thay rSng neu cho dong dien chay qua sai dot trong chan, k h o n g thi sau mot thdi gian mot "bong d e n " se xuat hien tren thanh trong cua bong den Bong den nay cd hinh giong n h u hinh ciia sai dot Tir hien t ua ng nay ong cho rang trong c han khong cac hat (nay goi la cac electron) d u a c giai phong ra q uanh sai dot tao thanh mot d a m m a y ha y la dien tich kho ng gian Hieu ung nav d u a c biet den vdi ten goi hieu ung Edison, la ly thuvet c o ban ve hoat d on g ciia tat ca cac den dien tir

T r o n g q ua trinh thi n gh ie m ve bong den dien Edi son nhan thay rang nhieu kim loai phat ra di en tu khi d u a c nung den nhiet do nong sang T r on g b ong den cac dien tir

d u a c phat ra nay se t rd nen vo fch vi chiing k h o n g phuc vu c ho mot m u c dich nao Tu v nhien den dien tu lai d u a c thiet ke nha m tan d u n g cac dien tir d u a c phat ra nav Edison

da lam thi n g h i e m b a ng cach dat the m mot bo phan thu hai goi la dien cuc trong den

di en tir ciing vdi sai dot n hu n g k h o n g c h a m vao nhau Sau d o o ng noi mot A m p e ke vdi dien c uc nay va dat mot c ha n ciia A m p e ke len cuc d u a n g cua ac quy O n g thay rang khi lam n h u vay m ot d o n g dien se di q ua A m p e ke Bo phan t hu hai nav d u a c goi la phien

D a m m a y dien tir phat ra m a n g dien tfch am va bi phien m a n g dien tfch d uo n g hiit No c ha y q u a k h o a n g c han kh on g ve phfa phien va tu lai tren be mat cua phien

D i eu gi se xa y ra neu noi phien vdi cuc am ciia ac q u y? Edi son phat hien rang, khi lam

n h u vay thi k h o n g cd d o n g dien di qua A m p e ke N h u vay d o n g dien chi di q u a c ha n

k h o n g theo mot chiC; u tir cuc am den cuc d u a n g

38 Tieng A n h chuyen nganh Dien tit - Vien thong

Ti ep theo, Edi son nhat xet rang, khi d a o c uc dien, cac hat dien tich a m k ho n g di

c h u ye n tir phien tdi sai nung, n h u vay han phai c o mot ngoai luc na o d o la n g u y e n nhan lam c h o dien t u rdi k hoi sai dot O n g phat hien rang, khi sai dot d u a c n un g n ong thi phien k h o n g n on g len Nhiet c ua sai dot la n g u y en nha n lam c h o c ac dien tir bi "soi" len

va d u a c giai p ho n g tir sai dot vao phan c han k h o n g x u n g qu a nh Mot khi cac dien tu

d u a c giai pho ng khoi giai han ciia chat ran, c h u n g co the d u a c hut tai bat ky n gu on tich dien d u a n g nao trong de n dien tir Hien t u a ng nay d u a c goi la sir phat xa nhiet la qua trinh cac dien tir bi c u a n g buc ra khoi kim loai ran tho ng qu a c h u y e n d o n g nhiet

The light bulb was invented in the 19th centu ry.

The light bulb w as invented when the nature o f electricity wa.\ not com pletely

1 M e n h de thoi gian co the d un g truoc hay sau me n h de chinh Ngoai when, ta con

c o the sir d u n g mot so tir k hac voi nhu ng y nghTa khac nhau

W hen c h o ta biet mot hanh d o n g di£n ra d o n g thoi hoac ngay lap turc sau mot

h an h d o n g khac

A fter d on t huan chi ra 2 hanh d o n g noi tiep nhau

O nce n ha n m a n h r i n g mot hanh d o n g chi co the xay ra sau khi h an h d o n g t hu nhat d a ket thuc

When the ground wave passes over the sand, it loses its energy.

When passing over the sand, the ground wave loses its energy.

40 Tieng A n h chuyen nganh Dien tit - Vien thong

W h e n + V -ing dien ta mot hanh d o n g di£n ra d o n g thoi vdi hanh d on g kia.

\ 7 du 5

When the sky wave strikes the earth, it bounces hack again.

On striking the earth, the sky wave bounces back again.

On + V-ing c ho biet hanh dong thu- hai dien ra ngay lap turc sau hanh d o n g thur nhat

3 Kin dich sang tieng Viet, tuy theo y nghia ciia tirng loai cau c h u n g ta cd the lim mot cach dien dat c ho phu hop:

( \ 7 du 3) C hi khi nao cac dien tir dupe gidi phong ra khoi be m at vat chat thi no mai co the bi hut ve phia nguon mang dien tich duang dat trong chan kliong.

(Vi du 4) Trong klu Ian truyen tren moi trudng cat, song dat bi m at nang luang

( \ 7 du 5) N g a y sau khi va vao trdi dat, song trai dpi tra lai ( tang dien h ).

3 Practice

Translate the fo llo w in g sentences into V ietnam ese.

1 W h e n heated to i nc and es ce nc e, metallic s ub st anc es will emit electrons

2 O nc e the switch is turned off no c urrent Hows t hough the a m me t er

3 On reaching the right side of the screen, the spot of light is blanked and moved back

4 W h e n d is c h a r g i n g too quickly, a cell m a y b e c o m e hot

5 W h e n a d io de is reverse biased, there is no c urrent f lowing t ho u g h it