Điện tử - Viễn thông chuyên ngành Tiếng Anh: Phần 1

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Tài liệu Tiếng Anh chuyên ngành Điện tử - Viễn thông được viết theo dạng song ngữ Anh – Việt, gồm 20 bài lựa chọn theo những chủ đề cơ bản của chuyên ngành Điện tử - Viễn thông. Nội dung các bài đều hướng vào phát triển kỹ năng đọc hiểu và kỹ năng dịch chuyên ngành. Các bài giới thiệu ngữ pháp được trình bày bằng tiếng Việt giúp cho sinh viên hệ thống hoá hoặc bổ sung những nội dung ngữ pháp cơ bản, thường gặp trong văn phong khoa học - như câu điều kiện, mệnh đề quan hệ, câu bị động... Tài liệu được chia thành 2 phần, sau đây là phần 1, mời các bạn cùng tham khảo.

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Nội dung Text: Điện tử - Viễn thông chuyên ngành Tiếng Anh: Phần 1

N G U Y E N C AM T H A N H - 0 A N G OIJC C U & N G - V U O N G O A O V Y TIENG ANH CHUYEN NGANH BlEN TlH - VllN THONG ■ (Tai ban Ian 1) English for Electronics and Telecommunications (Second Edition) NHA XUAT BAN BUU OIEN Ha Noi, thang 12 - 2007
LCJI n h A x u a t ban 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 hu 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. Nhdm 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 Nhd xuat ban Bifu dien da xuat ban cuon sach "Tieng A n h chuyen nganh Dien 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 co 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. Nhd xuat ban Bifu dien rat mong nhan duoc nhitng y kien dong gop cua quy vi. Moi v kien dong gop xin gin ve N hd xu a t ban B u u dien, 18 N guyen Du, 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 BU U D I E N
LCJI NOI DAU Cuon sach “ T ien g A n h chuyen n ganh D ien tu - Vien th o n g ” la tai lieu hoc tap danh cho cho sinh vien nganh Dien tir -Vi6n thong va Cong nghe th on g tin, d u p e bien soan chu yeu phuc vu cho doi tupng sinh vien nam thu hai, hoac toi thieu da hoan thanh chuo ng trinh tieng Anh trlnh do E lem entary. Cuon sach gom 20 bai lira chon theo nhung chu de c o ban cua c h u y e n ngan h Dien tir - Vidn thong. Noi dung cac bai deu hua ng vao phat trien ki nang doc hieu va ky nang dich chuyen nganh. Cac bai gioi thieu ngir phap (L an g u a g e fo c u s ) du pe trinh bay bang tieng Viet giup cho sinh vien he thong hoa hoac b6 sung nhung noi d u n g n g u ph ap co ban, thirong gap trong van phong khoa hoc - nh u can dieu kien, menh de quan he. can bi dong v.v... Ngoai ra, cuon sach con cung cap cac bai kiem tra giua va cu6i kh o a hoc, cac bai dich mau cung nh u phan giai dap cac bai tap cua tung bai trong phan phu luc giu p cho sinh vien tir danh gia ket qua hoc tap cua m lnh va tra cuu nhung doa n dich m ^u khi can. Nhan dip ra m i t lan dau cuon sach “Tieng A n h chuyen nganh Dien tu - Vien thong ” nhom tac gia xin chan thanh cam an 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 riron g D ai hoc K h o a hoc Tir n h ien d a tao m o i d i e u k ie n tot nha t de c u o n s ac h d u p e ho a n tha nh. C h u n g toi c u n g xin giii loi c a m a n d a c biet ta i ca nh an TS. Le The Que, TS. Tran Qu a ng Vinh, TS. N g u y e n Chi Dung, ThS. T r an Thi Nga. cac giang vien Ng uy6n T h a n h Tu ng va Nguygn N h u Q u y n h vi nhSng qu a n tarn va don g gop co ng sue cho tai lieu nay kip hoan tat du ng thai gian quy dinh. Tro ng qua trinh bien soan cuon sach, cac tac gia da co ga ng toi da n h a m dat du a c nhung muc tieu de ra. Tu y nhien, cac thieu sot la kho ng the’ tranh khoi. C h u n g toi rat m o n g nhan dup e y kien do ng gop cua cac nha c hu ye n mon, d o n g ng hi e p va tat ca nhung ai quan tarn de tiep tuc hoan thien cuon sach. Xin tran trong cam an. Tluiy m at nliom bien soan P G S .T S . Virang D uo Vy
Unit 1 ATOMS AND THE DEFINITION OF ELECTRICITY Elements are arranged by their basic properties, as being metals, etc. on a chart known as the periodic chart of the elements. Some o f the more c om m on elements are carbon, copper, oxyge n and aluminum. Elements may exist alone, or they may exist in clusters, or molecules, along with other elements. For ex ample, a piece of copper wire is solely made up of the copper element. By comparison, water is a combination of two different elements: oxygen and hydrogen. An element can be broken down into even smaller particles, called atoms. An atom is the smallest unit into which an element can be broken down and still retain its original characteristics. The atom resembles a little universe. The center of this universe, called the nucleus, is made up of parts known as protons and neutrons. Around the nucleus, tiny little particles are constantly rotating in an orbit. We call these particles electrons. The atom is far too small to be seen, even with the aid of the most powerful microscope. However, we do have a vast amount of know led ge about the atom and its inner parts. The proton differs from the electron both electrically and physically. Electrically, the proton is positively charged, and is about 1850 times as heavier than the electron. The orbiting electron, on the other hand, is muc h lighter, and is said to be negatively charged. The neutron can effectively be thought of as consisting of both a proton and an electron. It has the same approximate weight as the proton: however, it is neutral in charge. T h is is because the positive charge of the proton cancels out the negative charg e of the electron. A to m s alw ays have the same parts, but not always in the same am ounts or configurations. A to m s with more protons and electrons, o f course, must be larger and heavier. U n d e r normal circumstances, atoms seek to be neutral in charge, and so will have an equal am ount of electrons and protons. So if an atom like copper has 29 protons in its center, it will also have 29 electrons. Because these electrons are rotating in an
6 Tieng A nh chuyen nganh Dien tu" - Vien thong orbit, having too ma ny electrons in a given orbit could cause th em to crash into each other. So mother nature placed them in different orbits on different levels. W e call them layers or rings. Depending on which ring we are discussing, each ring has a m a x i m u m a m ou nt ot electrons which it can hold, without having to form another ring. For instance, the first ring can only hold 2 electrons. So if we have an atom with 3 protons. (As in the case of Lithium) it must also have 3 electrons. Since it can only hold 2 electrons in the n u m b e r 1 ring, it is forced to create a second ring, with only 1 electron in it. In the case of Lithium, this 1 electron is said to exist in the outer ring, or the valence ring. In Electronics, we are mainly concerned with this valence ring, be cau se it is here that the magic o f Electronics takes place. If a given ring is shy o f being full, it wants to “ borr ow ” an electron from so mew he re else. If an atom has one too m a n y electrons, it pushes the “ex tra ” electron way out on a ring of its own. and tries to “ loan" it to another atom. Electronics, in its purest form, is the study of the mo v e m e nt of electrons from one atom to another. Usually, this takes place by borrowing and loaning (tem po rarily ) of electrons. While we can not actually see this going on, we c an m o n it o r its effects, which can be amazing! (Text taken from http-.llwM-M scie n c e -e b o o k s.c o m edited by W illiam H. Boos» Words and expressions aid (n) sir trp giup approximate (adj) xap xi, khoang atom (n) nguyen tir characteristic (n) dac tfnh, tinh chat charged (adj) (dupe) tfch dien, mang dien tich , create (v) tao ra elem ent (n) nguyen to exist (v) ton tai level (n) mire (nang lirpng ...) loan (v) cho mupn, cho vay molecule (n) phan tir neutral (adj) trung hoa. trung tinh orbit (n) quy dao orbiting electron electron quy dao particle (n) hat, tieu phan periodic chart bang tuan hoan
Unit 1 7 retain (n) duy tri, giuf lai rotate (v) quay, xoay temporarily (adv) (mot cach) tarn thdi universe (n) vu tru valence ring vong (I6p) hoa trj 1. M ain idea W hich sta tem en t best expresses the m ain idea o f the text? W hy did yo u elim inate the other c h o ice s? 1. Atom s are m a de up o f protons, neutrons and electrons. 2. The electron is the most important part of an atom. 3. Electronics studies the movement of electrons between atoms. 2. Q u estio n s A n sw e r th e fo llo w in g questions. 1. What are electrons? 2. In what way are the neutron and the proton similar? 3. W hy are electrons of an atom placed in different orbits? 4. What is Valence Ring? 5. W h e n does the loaning of electrons happen? 3. U n d er sta n d in g the passage D ecide w h eth er th e fo llo w in g statem ents are true or fa lse (TIF ) by referrin g to the in fo rm a tio n in th e text. T h en m ake the necessary changes so th a t the fa lse statem ents becom e true. 1 It is impossible to split an atom into smaller parts. 2 The atom is so far that people can not see it with their naked eyes. 3 The electron differs from the proton in that it is n e g a t i v e l y c har ged and not so heavy as the proton. 4 Configurations of atoms of different e lements can be different. 5 W e can see electrons moving from one atom 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 revie w M atch a word/phrase in colum n A with an appropriate phrase in co lu m n B. A B 1. nucleus a. a very small piece of matter moving around the nucleus 2. element b. together with a neutron to form the nucleus 3. electron c. the central part of an atom 4. electric charges d. they are either positive (+) or negative (-) 5. proton e. a chemical substance consisting of atoms of only one kind 6. E n g l is 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 Vietnam ese, basing on the in fo rm a tio n in the text. 1. The single most important characteristic of an atom is its a t o m i c n u m b e r , which is defined as the nu m ber o f units of positive charge in the nucleus. 2. The atomic nu m be r determines the kinds of molecules that can be formed and their binding energy. Hence, the atomic nu m be r determines an atom's characteristics as an element.
Unit 1 9 7. V ietn am ese - E nglish translation Translate the fo llo w in g sentences into English, basing on the inform ation in the text. !. D ie n tir co the bi keo khoi quy da o c ua no qua nh hat nhan bai mot ngoai luc nao do. 2. M6i lop dien tu co kha nang giu' duoc mot so luong toi da cac dien tu ma khong tao ra lap moi. 3. Trong dien tu hoc chung ta chu yeu quan tarn den lop dien tu hoa tri. vi day chinh la noi di6n ra didu ky dieu cua mon khoa hoc nay. S. Bai dich th a m khao Nguyen tif va djnh nghla ve dien Cac nguye n to duoc sap xep theo nhung thuoc tinh co ban cua chung. vi du nhu cac kim loai va cac nguyen to khac trong bang tuan hoan cac nguyen to. Mot so ngu ye n to pho bien hon la cac-bon, dong, o-xi, nhom. Cac nguyen to co the ton tai doc lap hoac duai dang hop chat hay phan tu cung voi nhung nguy en to khac. Thi du mot maiu soi dong chi gom nguyen to don g tao thanh. Trong khi do nuoc la su ket hop cua hai nguyen to khac nhau: O-xi va hi-dro. Mot ngu ye n to co the duoc phan chia thanh nhung hat nho hon goi la cac nguven tir. N gu ye n tu la d on vi nho nhat ma mot nguyen to co the phan chia ra va no van con giu' duoc ban chat cua nguyen to do. Nguyen tu giong nhu mot vu tru nho. T a m cua vu tru goi la hat nhan duofc tao boi cac no-tron va pro-ton. Xung quanh hat nhan co nhung hat rat be quay lien tuc tren quy dao duoc goi la cac dien tu hay electron. N guy en tu la qua nho de ta co the’ nhin thay duoc. ngay ca khi co su tr a 2iup cua kinh hie'n vi cuc manh. Tuy vay. chung ta da co d ua c su hieu biet nhieu ve n s u v e n tu va phan ben trong cua no. Pro-ton khac vai electron ca \ e dien hoc va \ e vat lv hoc Ve dien hoc. pro-ton m a n g dien tich d u a n g va nang han electron 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 quy da o lai nhe hon nhi6u va ma ng dien tfch am. No-tron co the xem nhu bao gom ca pro-ton va electron. N o co trong luong xap xi pro-ton. tuy nhien lai trung hoa v£ dien. So d! nhu vay la vi dien tich duon g cua proton da triet tieu voi dien tich am cua electron. Nguyen tu bao gio c ung co cac thanh phan nhu nhau nhung kh ong phai luon luon co cung mot so luong cac hat hoac cung mot cau h'inh. Cac nguyen tu co nhieu pro-ton va electron hon, hien nhien phai Ion hon va nang hon. Tr ong dieu kien binh thudng. cac nguyen tir co xu hudng tim kiem sir trung hoa ve dien va nh u vay se co so luong cac pro-ton va so luong electron bang nhau. Cho nen, neu mot ngu ye n tu n hu nguyen tu dong co 29 pro-ton d tam thi no cung se co 29 electron. Vi cac dien tu nay q u a \ tren mot quy dao va viec co qua nhieu electron tren cung quy dao nay co the gay nen su va cham giua chung. N h u vay, cac electron tren nhung quy dao khac nhau va 6 nh ung mure nang luong khac nhau la ban cha't tu nhien cua cac nguyen to. Ta goi c h u n g la cac lop hoac cac vong. Tuy theo lop nao duoc xem xet, m6i lop vong deu co chua mot luong electron toi da ma khong dan toi viec tao ra lop moi. Vi du, lop dau tien chi co the c hu a 2 electron. Neu mot nguyen tu co 3 pro-ton (vi du nguyen tu Liti) thi no cung phai co 3 electron. Vi no chi giu duoc 2 electron d lop thu nhat, no buoc phai tao ra lop thu hai d6 sap xep them 1 electron con lai. Trong trudng hop nguyen tu Liti, 1 electron nay ton tai a lop ngoai. hay con goi la lop hoa tri. Tr ong dien tu hoc, ch ung ta chu yeu quan tam den lop hoa tri nav. boi vi dav chinh la noi xay ra dieu ky dieu cua dien tu hoc. Neu mot lop nao do chu a ch ua da \ electron, no co xu the "muon" mot electron tir mot noi khac. Neu ng uy e n tir thira 1 dien tir thi no se daiy electron "ngoai lai" nay ra khoi lop cua no va co ga ng de c h o mot nguyen tir khac "vay". Dien tu hoc, 6 dan g thuan tuy nhat ciia no. la bo mon nghien cuu ve su di ch uv en ciia cac dien tir tir nguy en tir nay sang nguyen tir khac. Thong thudng. qua trinh nav xav ra thong qua viec "muon" va "cho vay" (mot cach tam thefi) cac electron. T r o n s khi chung ta kho ng the true tiep nhin thay nhung di^n bien nay. chung ta van co the 21 am sat duoc nh ung hieu irng. co the’ la mot dieu dang kinh ngac ciia qua trinh d o 1
Unit 2 ELECTRICITY AND ELECTRONICS Volta made his experimental cell in 1800, producing for the first time a steady, reliable electric current. During the nineteenth century, the development of practical applications of electrical energy advanced rapidly. The first major uses of electricity were in the field of commun ications - first for the telegraph and then the telephone. T h ey used not only electric current but also electromagnetic effects. Th o m as E d i s o n ’s invention of the electric light bulb was perhaps the most important develo pm ent of all, because it led to the creation of an electric power system which has since reached into nearly every corner of the world. The applications of electricity have gro wn to the point where most of us lead “electrified life” , surrounded by a variety of devices that use electric energy. It is quite rem ar ka ble that so muc h of this rapid development of electrical devices took place during the nineteenth century, when the nature of electricity was not completely understood. We have observed that for a long time, but it was incorrectly believed that current flowed from positive to negative. It w'as not until 1897 that the British scientist Joseph Th om so n announced his discovery of the electron. T h o m s o n ’s discovery led to further e xperimentation into the structure of the atom. Within the field of electricity, his work led to the creation of the science of electronics. There is so m u c h confusion in current usage between the terms “electricity” and “electronics” that we should attempt to make some sort of distinction between them . Electricity generally refers to the flow of free electrons through a conductor, in other words, to a current of electricity. The term includes the electric power is supplied by generators and the distribution systems which transmit it to homes, offices, and factories. Electronics, on the other hand, deals with the movement of free electrons in a vacuum or in semiconductor. W he n the term first came into use. it referred to the behaviour of free electrons in vacuum tubes like those used to transmit or detect radio waves. Since then it has been extended to include the move me nt of electrons in gases, liquids, and solids.
12 Tieng A nh chuyen nganh Dien tit - Vien thong Regardless of the distinction made between the two fields, both must be understood by t o d a y ’s electrical and electronic engineers. Even an engineer working on the design of the newest computers must have know led ge of circuits and electromagnetic effects. Electricity and electronics are really indivisible: each one forms part of the other. (Text adapted from The language o f E lectrical and Electronic 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 cell (n) pin 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 electromagnetic effects hieu ilrng dien ti/ electronics (n) dien tif (hoc) indivisible (adj) khong the chia, khong the tach rdi invention (n) phat minh, su 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 transmit (v) phat (song...) vacuum tube (n) den dien tir 1. M ain idea W hich sta tem en t best expresses the m ain idea o f the text? W hy did yo u elim inate th e other choices? 1. Electricity has mod ernized our lives.
Unit 2 13 2. People had been able to make good use of electricity before they fully understood its nature. 3. Although both "electricity" and "electronics" refer to the mo ve me nt of tree electrons, they m ean different things. 2. Q u estion s A n sw e r th e fo llo w in g questions 1. What were the first major uses o f electricity in practical applications'.’ 2. W hy was the invention of the electric light bulb perhaps the most important event? 3. What important event took place in 1897? 4. What does electricity deal with? What does electronics refer to? 5. W h y must t o d a y ’s electrical and electronic engineers know both of the fields? 3. U n d er sta n d in g the passage D ecide w h eth er th e fo llo w in g statem ents are true or fa lse (TIF) by referring to the in fo rm a tio n in th e text. T hen m ake the necessary changes so that the fa lse sta tem ents becom e true. 1 The develo pm ent of practical applications of electrical energy adv anc ed very fast d uri ng the nineteenth century. 2 Thank s to E d i s o n ’s invention of the electric light bulb, an electronic power system has now been created almost everywhere in the world. 3 Joseph T h o m s o n discovered the electron in order to improve electronic engin eer ing in England. 4 Electrons are not able to flow in liquids or solids. 5 Generally speaking, electricity and electronics do not have significant differences.
14 Tieng A n h chuyen nganh Dien tit - Vien thong 4. C ontextual reference W hat do the words in bold refer to? They (para 1) ................................... it (para 2) ................................... them (para 4) ................................... it (para 5) ................................... the term ( para 6) ................................... 5. C ontent review Use the info rm a tio n in the text to com plete the fo llo w in g sum m ary. V olt a ’s invention of ( 1 ) .................................in 1800 opened up the way for practical applications of electricity. Early main uses of electricity were in the field ot (2) .................................. The incandescent light bulb, which was developed by Thomas Edison caused an ( 3 ) .................................to be created. With this system, electric energ\ has been delivered to homes, offices, and factories. In 1897 Sir Joseph Thomson announced his discovery of ( 4 ) .................................and he is considered to be the founder of the science of (5) .................................. Unlike electricity which means the How of electrons through a (6) .................................. electronics refers to the mo ve me nt of free electrons in a ( 7 ) .................................or in ( 8 ) ................................... 6. English - V ietnam ese translation Translate the fo llo w in g sentences into Vietnam ese, basing on the in fo rm a tio n in the text. 1. The molecules of a liquid are held together tighter than those o f a gas. 2. The resistance of a semiconductor material is greater than that of a con du cto r like copper and less than that of an insulator like glass. 3. The remote control unit contains keys and electronics co mp on ent s similar to those of a calculator. 4. Orbiting electrons are called planetary electrons, and those that have been pulled a w a\ are known as free electrons.
Unit 2 15 7. V ietn a m ese -E nglish translation Translate the fo llo w in g sentences into English, basing on the inform ation in the text. 1. May dien thoai va m a y dien bao la hai ung dung quan trong dau tien cua dien hoc trong linh vuc thong tin lien lac. 2. Dien hoc va dien tu hoc la hai linh vuc khong the tach rdi. va vi vav, ngudi kv su dien tu can phai hieu biet ca hai linh vuc do. 8. Bai dich th am k h ao Dien ■ hoc ■ va dien ■ ta hoc ■ N a m 1800, lan dfiu tien Volta da tao duoc mot pin thi nghiem cho mot dong dien dn dinh. Tr ong suot the ki XIX viec phat trien cac ung dung thuc tien cua nang luong dien da tang nhanh. Ung dung chu yeu dau tien cua dien la d trong linh vuc truven thong. Thoat dau la dien bao va sau do la dien thoai. Hai phuong tien nay khong chi sir d un g do ng dien ma con du ng ca cac hieu ung dien tir. Phat minh cua T h o m a s Edison ve bong den dien co le la phat minh quan trong nhat. vi no d an toi viec tao ra mot he thong dien nang. nav da vuon tdi duoc hau hot moi noi tren the gidi. N h u n g ung dung ve dien da phat trien tdi muc ma hau het ch un g ta d£u dang song mot cuo c song "dien khi hoa", bao quanh bdi nhung thiet bi su dung dien nang. Dieu da n g ghi nhan la sir phat trien nhanh chong ve cac thiet bi dien tir da dit!n ra trong suot the ky XIX. khi ma con ngudi chua hieu biet day du ve ban chat cua dien hoc. Mac du da qua n sat trong mot thdi gian dai. song hoi do ngudi ta van tin rang dong dien chav tu cuc d u o n g sang circ am. Mai den nam 1897 nha bac hoc ngudi An h Joseph T h o m so n mdi cd ng bo phat minh cua ong ve dien tu (electron) . Phat minh cua T h o m s o n da m d dirdng cho nhung thi nghiem tiep theo ve cau true ciia nguven tir. T ro ng linh virc dien hoc. cac cong trinh nghien cuu cua ong da dan den su ra ddi cua nganh dien tu hoc. Hien nay co qua nhieu su nhiim liin trona viec sii du n e cac thuat ngir "dien hoc" va "dien tir hoc" vi vay ta can co ga ng phan biet hai khai nie m nay.
16 Tieng A nh chuyen nganh Dien ttf - Vlen thong Dien hoc noi chung d£ cap toi dong dien tu tu do di qua mot vat dim. noi cach khac. de cap den dong dien. Thuat ngu nay ham chua ca dien nang duoc cu ng ca p boi cac may phat dien va cac he thong phan phoi dan dien den tirng nha. tirng c ong no va tirng xi nghiep. Tren mot binh dien khac. "dien tu h o c ” lien quan den su chuy en dong c ua dien tu tu do trong moi trudng chan khong hoac trong chat ban dan. Khi thuat ngur na \ duoc su dung Ian dau. no am chi thuoc tinh cua cac dien tu tu do trong cac ong chan khong. giong nhu nhung ong duoc su dung de truven hay do song radio. Tir do ve sau. thuat ngu nay da dupe m o rong de bao ham ca su chuyen dong cua dien tu trong chat khi. chat long, va chat ran. Mac dii co su khac nhau giiira dien hoc va dien tu hoc. cac ky su dien va dien tu ngav nay can phai hieu biet ca hai linh vuc nay. Ngay ca mot ky su tha m gia thiet ke nhung mau may tinh moi nhat cung phai co kien thuc ve mach dien va hieu ung dien tir. Dien hoc va dien tir hoc thuc chat la hai linh vuc khong the tach roi: linh vuc nay la bo phan ciia linh vuc kia.
Language focus 1 PASSIVE VOICE 1. D efinition The bi dong (passive voice) la mot pham tru cua don g tir tieng Anh doi lap voi the chu dong (active voice). Tr ong cau bi dong, chu ngu cua cau khong phai la chu the (hay tac nhan) cua hanh dong, m a chinh la ddi tuong tiep nhan hanh dong do. Vi du: • T hey arra n g e elem ents in the periodic chart to show tlieir properties, [can chit dong) • E lem en ts are a rra n g e d in the periodic chart to show their properties, (can hi dong) Can bi d o n g dirac sir d u n g trong n h u n g tr ud ng hap: • Khi khong can thiet phai nhac den chit the ciia hanh dong, (nhu 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 periodic chart o f the elements, which was proposed by M endeleev, is still com m only used. Tr ong trudng h a p thu hai, ta du ng gidi tir by + chu the hanh dong. 2. Stru cture 2.1. Cciu trite co' ban c ia edit bi dong: Be + past participle Trong cau true nay. be co vai tro la mot tra dong tu l^ ° nen cac thi khac nhau. nhu: • P resent sim ple: a m /is/are + past participle Vf du 1: O xygen is co m b in ed with hydrogen to fo rm water. • Present perfect: have/has been + past participle Vi du 2: E a ch ch em ica l elem ent h a s been g iven an atom ic n u m b e r. • Past sim p le: w as/ w ere + past participle
18 Tieng A nh 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 odal verb (can, will, may...) + be + past participle 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 phat 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 ssive + to -in fin itiv e Vi du 5: It was incorrectly believed that current flo w ed fro m positive to negative. Current was incorrectly believed to flo w fro m positive to negative. Mot so dong tu hay duoc dung trong cau true nay: report, 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. Change the follow ing sentences into passive and translate them into Vietnamese. 1. We can break down an element into even smaller particles, called atoms. 2. Everybody know s that water consists of oxy ge n and hydrogen. 3. They say that the orbiting election is negatively charged. 4. In the nineteenth century people did not completely understand the nature of electricity 5. Today's electrical and electroni c-e ngi ne er s must understand both electricity and electronics.
Language focus 1 19 6. Volta ma de the first cell in 1880. 7. It was not until 1897 that Joseph T ho m so n announced the discovery of the electron. 8. Electricity has mode rnize d our life. 9. W e cannot see the electron because it is too small. 10. Th ey say that the electron exists in the outer ring. B. P u t the verbs in brackets in the passive. Many hu ndre ds of years after the phen ome non of static electricity ( 1 )........................ (discover), scientists found that there were two kinds of electrical charges. These two kinds of charges (2) .......................... (call) positive and negative. Much later it (3) .......................... (learn) that the movement of tiny particles of matter - electrons caused electricity. The electron is very light in weight and can (4) .......................... (draw) out of its orbits around the much heavier nucleus. Electrons orbiting farthest from the nucleus most easily ( 5 ) ..........................(draw) away. Orbiting electrons (6) .......................... (call) planetary electrons and the electrons which (7) ..........................(pull) away ( 8 ) ............................(know) as free electrons.
Unit 3 RESISTORS AND RESISTANCE Manufactured circuit co mponents which contain definite a m ou nt s o f resistance are called resistors. In simplest terms, resistors resist, or oppose, the flow o f electrons through a circuit. Every material offers some resistance, or opposition, to the flow of electric current through it. Good conductors, such as copper, silver, and aluminum, offer very little resistance. Poor conductors, or insulators, such as glass, wood, and paper, offer a high resistance to current flow. The size and type of material of the wires in an electric circuit are c ho sen so as to keep the electrical resistance as low as possible. In this way. current can How easily through the conductors, just as water flows through the pipe between tw o tanks. If the water pressure remains constant, the flow of water in the pipe will d e p en d on how far the valve is opened. The smaller the opening, the greater the opposition to the flow, and the lower the rate of flow in gallons-per-second. The same is true in electrical circuits: the larger the d ia m e ter o f the w ires, the lower their electrical resistance (opposition) to the flow o f current thro ugh them. In the water analogy, pipe friction opposes the flow of water between the tanks. This friction is similar to electrical resistance. The resistance of the pipe to the flow' of water through it depends upon • the length of the pipe; • the diameter of the pipe; and. • the nature of the inside w-alls (rough or smooth). Similarly, the electrical resistance of cond ucto rs de pen ds upon • the length o f the wires; • the dia meter of the wires; and, • the material of the wires (copper, al um inu m, etc.). Temperature also affects the resistance of electrical conductors to some c ■\ [n most conductors (copper, alu minu m, iron, etc.) the resistance increases w ith tempv: -• ,:c Carbon is an exception. In carbon, the resistance decreases as temperature