🔙 Quay lại trang tải sách pdf ebook Bài Tập Vật Lí Lớp 11 Ebooks Nhóm Zalo -UDNG DUYEN BJNH - VU QUANG (ddng Chu bien) td NGUYI N XUA N CHI - BUI QUANG HAN DOAN DUY HINH m P S £ • 1 RV ^^^m NHA XUAT BAN GIAO DUC VIET NAM LUONG DUYfiN BINH - VU QUANG (dong Chu bien) NGUYfiN XUAN CHI - BUI QUANG HA N - DOAN DUY HINH IBdi tap (Tdi bdn ldn thd tU) NHA XUAT BAN GIAO DUC VIET NAM Ban quyen thu6c Nha xuat ban Giao due Viet Nam 01-2011/CXB/826-1235/GD Ma so : CB106T1 ij4ANMOT:D€ Bfll ^httcfng DIEN TICH DIEN TRl/dNG Bai 1. DIEN TICH. DIN H LUAT CU-LONG 1.1. Nhiem difn cho mot thanh nhua roi dua no lai gdn hai vat M va N. Ta tha'y thanh nhua hut ca hai vat M va A^. Tinh hu6'ng nao dudi day chdc chdn khong the xay ra ? A. M va JV nhiSm di6n cung da'u. B. M va N nhidm difin trai da'u. C. M nhiem dien, con A^ khdng nhiSm dien. D. Ca M va A^ diu kh6ng nhiim dien. 1.2. M6t he c6 lap g6m ba dien tich didm, co kh6'i lugfng khOng dang ki, nam can bang v6i nhau. Tinh huO'ng nao du6i day co the xay ra ? A. Ba dien tich ciing da'u nam of ba dinh ciia mot tam giac diu. B. Ba dien tich ciing da'u ndm tren m6t ducmg thdng. C. Ba dien tich khdng ciing da'u ndm tai ba dinh cua m6t tam giac diu. D. Ba dien tfch kh6ng cung da'u ndm tren m6t ducmg thdng. 1.3. Ne'u tang khoang each giiia hai dien tich di^m len 3 ldn thi luc tuong tac tinh dien giiia chiing se A. tang len 3 Mn. B. giam di 3 ldn. C. tang len 9 ldn. D. giam di 9 ldn. 1.4. Do thi nao trong Hinh 1.1 co thi bieu dien su phu thudc ciia lue tucmg tac giiia hai dien tich diem vao khoang each giiia chiing ? Fk Fi A. C. D. Hinh l.I 1.5. Hai qua cdu A va fi co khdi lucmg Wj va m2 duoc treo vao mot didm O bdng hai soi day each dien OA va AB (Hinh 1.2). Tich dien cho hai qua cdu. Su"e cang T ciia soi day OA se thay doi nhu the' nao so vdi luc chiing chua tich dien ? A. T tang neu hai qua edu tich dien trai ddu. B. T giam neu hai qua cdu tich dien ciing ddu. C. T thay ddi. D. T khdng doi. Ol Hinh 1.2 1.6. a) Tinh luc hiit tinh dien giiia hat nhan trong nguyen tit heli vdi mdt electron trong Idrp vo nguyen tu. Qjo rdng electron nay ndm each hat nhan 2,94.10"^'m. b) Neu electron nay chuydn ddng tron deu quanh hat nhan vdi ban kinh quy dao nhu da cho 6 tren thi td'c dd goc eua no se la bao nhieu ? e) So sanh luc hut tinh dien vdi luc hdp ddn giiia hat nhan vd electron. Dien tich eua electron : -1,6.10" C. Khd'i luong eiia electron : 9,1.10~ kg. •> —27 • ' Khdi lucmg cua hat nhan heli : 6,65.10 kg. Hang sd hap dan : 6,67.10"''m^/kg.sl 1.7. Hai qua cdu nho gid'ng nhau bdng kim loai, eo khdi lucmg 5 g, dugc treo vao cung mot diem O bdng hai sgi chi khdng dan, dai 10 cm. Hai qua cdu tie'p xuc vdi nhau. Tieh dien eho mdt qua edu thi thdy hai qua cdu ddy nhau cho de'n khi hai day treo hgp vdi nhau mdt goc 60 . 2 Tfnh dien tich ma ta da truyen cho cae qua cdu. Ldy g=lO m/s . 1.8. Mdt he dien tfch cd cau tao gom mdt ion duong +e va hai ion am gid'ng nhau ndm can bdng. Khoang each giua hai ion am la a. Bo qua trgng lugng ciia cac ion. a) Hay cho bie't cdu triic cua he va khoang each giiia ion duong va ion am (theo a). b) Tfnh dien tfch eua mdt ion am (theo e). 1.9. Mdt he gom ba dien tfch duomg q gid'ng nhau va mdt dien tfch Q ndm can . bdng. Ba dien tfch q ndm tai ba dinh cua mdt tam giac ddu. Xae dinh ddu, dd Idfn (theo q) va vi trf ciia dien tfch Q. 1.10. Hai qua cdu kim loai nhd, gid'ng het nhau, chiia cac dien tfch ciing da'u q^ va q2, dugc treo vao chung mdt didm O bdng hai sgi day chi manh, khdng dan, dai bdng nhau. Hai qua edu ddy nhau vd gdc giiia hai day treo la 60 . Cho hai qua cdu tie'p xiic vdi nhau, roi tha ra thi chung ddy nhau manh hon va gdc giiia hai day treo bay gid la 90°. Tfnh ti sd — • ?2 Bai 2. THUYET ELECTRON. DJNH LUAT BAO TOAN DIEN TICH 2.1. Mdi trudng nao dudi day khong chiia dien tfch tu do ? A. Nude bidn. B. Nude sdng. C. Nudc mua. D. Nudc cdt. 2.2. Trong trucmg hgp nad dudi day se khong xay ra hien tugng nhidm dien do hudng ling ? Dat mdt qua edu mang dien d gdn ddu ciia mdt A. thanh kim loai khdng mang dien. B. thanh kim loai mang dien dUdng. C. thanh kim loai mang dien am. D. thanh nhua mang dien am. 2.3. Vdo mua hanh khd, nhidu khi keo do len qua ddu, ta thdy cd tie'ng no laeh tach. Dd la do A. hien tugng nhidm dien do tie'p xiie. B. hien tugng nhidm dien do eg xdt. C. hien tugng nhidm dien do hudng iing. D. ca ba hien tugng nhidm dien neu tren. 2.4. Dua mdt qua cdu kim loai A nhidm dien duong lai gdn mdt qua cdu kim Ioai B nhidm dien ducmg. Hien tugng nao dudi day se xay ra ? A. Ca hai qud cdu ddu bi nhidm dien do hudng iing. B. Ca hai qua cdu ddu khdng bi nhidm dien do hudng iing. C. Chi cd qua cdu B bi nhidm dien do hudng iing. D. Chi ed qua cdu A bi nhidm dien do hudng ting. 2.5. Mudi an (NaCl) kdt tinh la dien mdi. Chgn cau dung. A. Trong mud'i an kdt tinh cd ion duong tu do. B. Trong mud'i an kdt tinh ed ion am tu do. C. Trong mud'i an ket tinh cd electron tu do. D. Trong mud'i an ket tinh khdng cd ion va electron tu do. 2.6. Hai qua cdu kim loai nhd A va fi gid'ng het nhau, dugc treo vao mdt didm 0 bdng hai sgi ehi dai bdng nhau. Khi can bdng, ta thdy hai sgi chi lam vdi dudng thdng diing nhiing gde a bdng nhau o (Hinh 2.1). Trang thai nhidm dien cua hai qua cdu se la trang thai nao dudi day ? / A. Hai qua cdu nhidm dien ciing ddu. ^ B. Hai qua cdu nhidm dien trai ddu. A C. Hai qua cdu khdng nhidm dien. Hinh 2.1 D. Mdt qua edu nhidm dien, mdt qua edu khdng nhidm dien. 2.7. Hay giai thfch tai sao d eae xe xi tee chd ddu ngudi ta phai ldp mdt chide xich sdt cham xud'ng da't. 2.8. Treo mdt sgi tdc trude man hinh eua mdt may thu hinh (tivi) chua hoat ddng. Ddt nhien bat may. Quan sat hien tugng xay ra dd'i vdi sgi tdc, md ta va giai thfch hien tugng. 2.9. Cd ba qua cdu kim loai A, B, C. Qua edu A tfch dien dudng. Cac qua edu fi va C khdng mang dien. Lam the' nao dd eho qua edu B tich thudn tuy dien duomg va qua cdu C tfch thudn tuy dien am ma khdng hao hut dien tfch duong cua qua cdu A ? 2.10. Dat hai hdn bi thep nhd khdng nhidm dien, gdn nhau, trdn mat mdt ta'm phang, nhdn, ndm ngang. Tich dien cho mdt hdn bi. Hay doan nhan hien tugng se xay ra va giai thfch, n^u : a) Tdm phang la mdt ta'm kim loai. b) Tdm phang la mdt tdm thuy tinh. Bai 3. DIEN TRUONG VA CUdNG DO DIEN TRUdNG. DUdNG SOC DIEN 3.1. Tai didm nao dudi day se khdng cd dien trudng ? A. O ben ngoai, gdn mdt qua edu nhua nhidm dien. B. O ben trong mdt qua cdu nhua nhidm dien. C. O ben ngoai, gdn mdt qua cdu kim loai nhidm dien. D. O ben trong mdt qua cdu kim loai nhidm dien. 3.2. Q6 thi nao trong Hinh 3.1 phan anh su phu thude ciia cudng dd dien trudng eua mdt dien tfch didm vao khoang each tut dien tfch dd ddn didm ma ta xet ? Ek EL Ei Ei A. B. C. D. Hinh 3.1 3.3. Dien trudng trong khf quydn gdn mat ddt cd cudng dd 200 V/m, hudng thang diing ttt tren xudng dudi. Mdt electron (-e = -1,6.10 C) d trong dien trudng nay se chiu tdc dung mdt luc dien cd cudng dd va hudng nhu thd nao ? A. 3,2.10 ^' N ; hudng thang diing tur tren xue>ng. -.-21 B. 3,2.10 N ; hudng thang diing tut dudi len. 3.4. C. 3,2.10 N ; hudng thang dumg tii tren xud'ng D. 3,2.10"'^ N ; hudmg thdng diing td dudi ien. Nhiing dudng siic dien nao ve d Hinh 3.2 la dudng siic cua dien trudng ddu ? a) A. Hinh 3.2a. "> "' ""^ B. Hinh 3.2b. C. Hinh 3.2e. D. Khdng ed hinh ndo. 3.5. Hinh anh dudng siie dien nao ve d Hinh 3.2 iing vdi cac dudng siic ciia mdt dien tfch didm am ? A. Hinh anh dudng siic dien d Hinh 3.2a. B. Hinh anh dudng siic dien d Hinh 3.2b. C. Hinh anh dudng siie dien d Hinh 3.2e. D. Khdng cd hinh anh nao. 3.6. Tren Hinh 3.3 cd ve mgt sd dudng siic eua he thd'ng hai dien tfch didm A va B. Chgn cau diing. A. A la dien tfch duong, B la dien tfch am. B. A la dien tfch am, B la dien tfch duong. C. Ca A vd fi la dien tfch duong. D. Ca A va fi la dien tieh am. Hinh 3.3 3.7. Badien tfch didm ^1 =+2.10 C ndm tai diem A ; ^2 =+4-10 C nam tai didm B va q^ ndm tai diem C. He thd'ng ndm can bang trong khdng khi. Khoang each AB = 1 cm. a) Xac dinh dien tich q^ va khoang each BC. b) Xae dinh eudng dd dien trudng tai eae didm A, S va C. 3.8. Mdt qua edu nhd tfch dien, ed khdi lugng m = 0,1 g, dugc treo d ddu mdt sgi chi manh, trong mdt dien trudng ddu, cd phucmg ndm ngang va cd cudng dd dien trudng E= 1.10^ V/m. Day ehi hgp vdi phuong thang diing mdt gdc 10°. Tfnh dien tieh cua qua cdu. Ldy g= 10 m/s . 3.9. Mdt gigt ddu hinh cdu, cd ban kfnh R, ndm lo limg trong khdng khf trong dd cd mdt dien trudng ddu. Veeto cudng dd dien trudng hudng thdng dumg tii tren xudng dudi va cd dd ldm la E. Khdi lugng rieng eua ddu la p^, cixa khdng khf la p^. Gia tdc trgng trudng la g. Tim cdng thiie tfnh dien tfch cua qua edu. 3.10. Mdt electron chuydn ddng vdi van td'c ban ddu 1.10 m/s dgc theo mdt dudng siic dien eua mdt dien trudng ddu dugc mdt quang dudng 1 cm thi dtoig lai. Xdc dinh cudng dd dien trudng. Dien tfch eua electron la -1,6.10 C ; khd'i lucmg cua electron la 9,1.10"^' kg. Bai 4. CONG CUA LUC DIEN 4.1. Mdt vdng trdn tam O ndm trong dien trudng eiia mdt dien tfch didm Q. M vaN la hai didm tren vdng trdn dd (Hinh 4.1). Ggi A^JN, >iM2N ^^ -^MN la cdng ciia luc dien tdc dung len dien tfch didm q trong eae dich chuydn dgc theo cung MIN, M2N va day cung MN. Chgn didu khang dinh diing : ^ - '^MIN < ^M2N B. Aj^N nhd nhdt. C. A|^2N ^ ^ nha't. D- ^MlN = ^M2N - ^MN 4.2. Cdng eua lue dien tdc dung len mdt dien tfch didm q khi di chuydn td didm M de'n didm N trong dien trudmg A. ti le thuan vdi chieu ddi dudng di MN. B. ti le thuan vdi dd ldm cua dien tfch q. C. ti le thuan vdi thdi gian di chuydn. D. ca ba y A, B, C ddu khdng diing. 4.3. Cdng ciia luc dien tac dung len mdt dien tfch didm q khi di chuydn tur didm M de'n didm N trong mdt dien trudng, thi khong phu thude vao A. vi trf ciia cac didm M, N. B. hinh dang ciia dudng di MN. C. dd ldn cua dien tfch q. D. dd ldm ciia cudng dd dien trudng tai cac didm tren dudng di. 4.4. Mdt electron (-e = -1,6.10"'^ C) bay tii ban duomg sang ban am trong dien trudng ddu cua mgt tu dien phdng, theo mdt dudng thang MN dai 2 cm, cd phuomg lam vdi phUdng dudng siie dien mdt gdc 60°. Bidt cudng dd dien trudng trong tu dien la 1 000 V/m. Cdng ciia luc dien trong dich chuydn nay la bao nhieu ? A. « +2,77.10"^^ J. B. « -2,77.10"'^ J. C. +1,6.10"'^! D. -1,6.10"'^ J. 4.5. Dat mot dien tfch didm Q dUdng tai mdt didm O.MvaN la hai diem ndm dd'i xiing vdi nhau d hai beri didm O. Di chuydn mdt dien tfch didm q dUdng tii M de'n N theo mdt dudng cong bdt ki. Ggi Ay^^ la cdng eua luc dien trong dich chuydn nay. Chgn cau khang dinh dung. A. Aj^jsj 5^ 0 va phu thude vao dudng dich chuydn. B. Ayo^ ^ 0, khdng phu thudc vao dudmg dich chuydn. C. A^Q;^ = 0, khdng phu thude vao dudng dich chuydn. D. Khdng thd xdc dinh dugc Aj^j^j. 4.6. Khi mdt dien tfch q di chuyen trong mdt dien trudng tii mgt diem A de'n mdt diem B thi lue dien sinh cdng 2,5 J. Ne'u thd nang cua q tai A la 2,5 J, thi the' nang eua nd tai B la bao nhieu ? A. - 2,5 J. B. - 5 J. C.+5J. D. OJ. 4.7. Mdt dien tfch q = +4.10 C di chuydn trong mdt dien trudng ddu cd cudng dd £• = 100 V/m theo mdt dudng gdp khiic ABC. Doan AB dai 20 cm va vectd dd ddi AB lam vdi cae dudng siic dien mdt gdc 30°. Doan BC ddi 40 cm va vectd do ddi BC lam vdi cdc dudng sire dien mdt gde 120°. Tfnh cdng eiia luc dien. 4.8. Mdt dien tfch q di chuydn trong mdt dien trudng tii mdt didm M de'n mdt didm N theo mdt dudng cong. Sau dd nd di chuydn tie'p tit N vi M theo mdt dudng cong khae. Hay so sanh cdng ma luc dien sinh ra tren cac doan dudng dd (A^N va A^M). 10 4.9. Mdt electron di chuydn trong dien trudng ddu E mdt doan 0,6 cm, til didm M den didm A'^ dgc theo mdt dudng siic dien thi luc dien sinh cdng 9,6.10"'^ J. a) Tfnh cdng ma luc dien sinh ra khi electron di chuydn tiep 0,4 cm tur didm A^ de'n diem P theo phucmg va ehidu ndi tren. b) Tfnh van td'c ciia electron khi nd den didm P. Bie't rang, tai M, electron khdng ed van td'c ddu. Khdi lugng cua electron la 9,1.10 kg. 4.10. Xet ede electron chuydn ddng quanh hat nhan cua mdt nguyen td. a) Cudng do dien trudng eiia hat nhan tai vi trf cua cae electron ndm cdng xa hat nhan thi cang ldm hay cang nhd ? b) Electron ndm cang xa hat nhan thi cd the' nang trong dien trudng cua hat nhan cang ldm hay cang nhd ? Bai 5. DIEN THE. HIEU DIEN THE 5.1. Bidu thiic nao dudi day bidu didn mdt dai lugng ed dom vi la vdn ? A. qEd. B. qE. C. Ed. D. Khdng cd bidu thiic ndo. 5.2. The nang ciia mdt electron tai diem M trong dien trudng ctia mdt dien tfch didm la -32.10 J. Dien tfch ciia electron la -e = -1,6.10" C. Dien thd tai diem M bdng bao nhieu ? A. +32 V. B. -32 V. C. +20 V. D. -20 V. 5.3. Mdt electron (-e = -1,6.10" C) bay tiir didm M de'n didm A^ trong mdt dien trudng, giiia hai diem cd hieu dien the' U^^. = 100 V. Cdng ma luc dien sinh ra se la : A.+1,6.10~'^J. B.-1,6.10"'^ J. C. +1,6.10"''^ L D.-1,6.10"^^ J. 5.4. Tha mdt ion duong eho chuydn ddng khdng van td'c ddu tur mdt diem bdt ki trong mdt dien trudng do hai dien tfch didm duong gay ra. Ion dd se chuydn ddng 11 A. dgc theo mdt dudng siic dien. B. dgc theo mdt dudng nd'i hai dien tfch didm. C. tii didm ed dien thd cao den didm cd dien thd thdp. D. tur diem cd dien the' thdp ddn didm cd dien thd cao. 5.5. Hieu dien thd giiia hai didm M, A^ la C/jyi^ = 40 V. Chgn cau chdc chdn diing. A. Dien thd d M la 40 V. B. Dien thd d N bdng 0. C. Dien the' b M CO gid tri duomg, b N co gia tri am. D. Dien the d M eao hom dien thd d Af 40 V. 5.6. Mdt hat bui nhd ed khd'i lugng m = 0,1 mg, ndm Id limg trong dien trudng giiia hai ban kim loai phang. Cdc dudng siie dien cd phuong thdng dumg va ehidu hudng tur dudi len tren. Hieu dien the' giiia hai ban la 120 V. Khoang cdch giiia hai ban la 1 cm. Xac dinh dien tfch eua hat bui. Ldy g = 10 m/s . 5.7. Mdt qua edu nhd bdng kim loai dugc treo bdng mdt sgi day chi manh giiia hai ban kim loai phdng song song, thdng diing. Ddt nhien tfch dien cho hai ban kim loai dd tao ra dien trudng ddu giita hai ban. Hay du doan hien tugng xay ra va giai thfch. Cho rdng, liic ddu qua cdu ndm gdn ban duong. 5.8. Bdn mdt electron vdi van td'c ddu rdt nhd vao mdt dien trudng ddu giiia hai ban kim loai phdng theo phucmg song song vdi cdc dudng siie dien (Hinh 5.1). Electron duge tang td'c trong dien trudng. Ra khdi dien trudng, nd ed van tdc 1.10 m/s. a) Hay cho bie't ddu dien tfch eua cdc ban A va fi eiia tu dien. B ^ • ^ r-, Hinh 5.1 5.9. 12 b) Tinh hieu dien thd f/^B gi""^ hai ban. Dien tfch eua electron : -1,6.10"'^ C. Khd'i lugng ciia electron : 9,1.10"^' kg. d sdt mat Trdi Ddt, vecto eudng do dien trudng hudng thdng diing tur tren xud'ng dudi vd cd do ldn vdo khoang 150 V/m. a) Tfnh hieu dien thd giiia mdt didm d dd cao 5 m vd mat ddt. b) Cd thd diing hieu dien thd ndi tren dd thdp sang den dien dugc khdng ? 5.10. Bdn mdt electron vdi van td'c VQ vdo dien trudng | •). + •)• + + •i.Tn ddu giiia hai ban kim loai phdng theo phuong song * 7*" song, cdch ddu hai ban kim loai (Hinh 5.2). Hieu „, , . ^ dien the giiia hai ban la U. a) Electron se bi lech vd phfa ban duong hay ban am ? Hinh 5.2 b) Bie't rdng electron bay ra khdi dien trudng tai didm ndm sdt mep mdt ban. Viet bidu thiic tfnh cdng cua lue dien trong su dich chuydn ciia electron trong dien trudng. e) Viet cdng thiie tfnh ddng nang ciia electron khi bdt ddu ra khdi dien trudng. Bdi 6. TU DIEN 6.1. Chgn eau phdt bidu diing. A. Dien dung cua tu dien phu thudc dien tfch ciia nd. B. Dien dung cua tu dien phu thudc hieu dien the giua hai ban ciia nd. C. Dien dung ciia tu dien phu thudc ea vao dien tfch ldn hieu dien the' giiia hai ban ciia tu. D. Dien dung ciia tu dien khdng phu thudc dien tfch va hieu dien the giiia hai ban ciia tu. 6.2. Chgn cau phdt bidu diing. A. Dien dung ciia tu dien ti le vdi dien tfch ciia nd. B. Dien tfch cua tu dien ti le thuan vdi hieu dien thd giOa hai ban eiia nd. C. Hieu dien the' giita hai ban tu dien ti le vdi dien dung eua nd. D. Dien dung eua tu dien ti le nghich vdi hieu dien the' giiia hai ban eua nd. 6.3. Hai tu dien chiia ciing mdt lugng dien tfch thi A. chiing phai ed cung dien dung. B. hieu dien the' giiia hai ban cua mdi tu dien phai bdng nhau. C. tu dien nao ed dien dung ldn hom, se cd hieu dien thd giiia hai ban ldn hon. D. tu dien nao ed dien dung ldn hon, se cd hieu dien the giiia hai ban nhd hon. 13 6.4. Trudng hgp nao dudi day ta ed mdt tu dien ? A. Mdt qua edu kim loai nhidm dien, dat xa edc vat khae. B. Mdt qua cdu thuy tinh nhidm dien, dat xa cae vat khae. C. Hai qua cdu kim loai, khdng nhidm dien, dat gdn nhau trong khdng khf. D. Hai qua cdu thuy tinh, khdng nhidm dien, dat gdn nhau trong khdng khf. 6.5. Don vi dien dung cd ten la gi ? A. Culdng. B. Vdn. C. Para. D. Vdn tren met. 6.6. Mdt tu dien cd dien dung 20 ^iF, dugc tfch dien dudi hieu dien the 40 V. Dien tich ciia tu se la bao nhieu ? A. 8.10^ C. B. 8C. C. 8.10"^C. D. S.IO^'^C. 6.7. Mdt tu dien phdng khdng khf cd dien dung 1 000 pF va khoang each giira hai ban la.d= I mm. Tfch dien cho tu dien dudi hieu dien the'60 V. a) Tfnh dien tfch eiia tu dien va cudng do dien trudng trong tu dien. b) Sau dd, ngdt tu dien ra khdi ngudn dien va thay ddi khoang cdch d giiia hai ban. Hdi ta se td'n cdng khi tang hay khi giam d ? 6.8. Mdt tu dien khdng khf ed dien dung 40 pF va khoang each giiia hai ban la 1 cm. Tfnh dien tfch tdi da cd thd tfch eho tu, bie't rdng khi eudng do dien trudng trong khdng khf len den 3.10 V/m thi khdng khf se trd thanh ddn dien. 6.9. Tfch dien cho tu dien C^, dien dung 20 |a,F, dudi hieu dien thd 200 V. Sau dd nd'i tu dien Cj vdi tu dien C2, cd dien dung 10 nF, chua tfch dien. Sit dung dinh luat bao toan dien tfch, hay tfnh dien tfch va hieu dien thd giiia hai ban ciia mdi tu dien sau khi nd'i vdi nhau. 6.10. Mdt gigt ddu ndm Id limg trong dien trudng cua mdt tu dien phang. Dudng kfnh eua gigt ddu la 0,5 mm. Khd'i lugng rieng ciia ddu la 800 kg/m . Khoang each giiia hai ban tu dien la 1 cm. Hieu dien the' giira hai ban tu dien la 220 V ; ban phia tren la ban duong. a) Tfnh dien tfch cua gigt ddu. b) Dot nhien ddi ddu eua hieu dien the. Hien tugng se xay ra nhu the' nao ? 2 Tfnh gia td'c cua gigt ddu. Lay g = 10 m/s . 14 BAI TAP eud i CHirONG I I.l. Chi ra cdng thtic dting cua dinh luat Cu-ldng trong chan khdng. A. F = ^ M B. F = -t'M^ r r C.F = k\^ . D.F^^ . f.2 kr 1.2. Trong cdng thtic dinh nghia cudng do dien trudng tai mdt diem (IJ thi F va ^ la gi ? A. F la tdng hgp cdc Itic tdc dtang len dien tfch thit; ^N > 0- D. VN > V^M > 0. 15 1.5. Bidu thufc nao dudi day la bidu thiic dinh nghla dien dung eua tu dien ? A. ^ . q a - 5' - § 1.6. q la mdt tua gidy nhidm dien duong ; q' la mdt tua gia'y nhidm dien am. K la mdt thudc nhita. Ngudi ta thdy K hiit duge ea q iSn q\ K duge nhidm dien nhu the' nao ? A. K nhidm dien duong. B. K nhidm dien am. C. K khdng nhidm dien. D. Khdng thd xay ra hien tugng nay. 1.7. Tren Hinh Ll cd ve mdt sd' dudng stic ciia he thd'ng hai dien tfch. Cae dien tfch dd la A. hai dien tfch duong. B. hai dien tfch am. C. mdt dien tfch duomg, mdt dien tfch am. D. khdng thd ed eae dudng stic cd dang nhu the'. Hinh I.l 1.8. Tti dien ed dien dung Cj cd dien tfch ^j =2.10~^C. Tu dien cd dien dung CJ cd dien tich ^2 =1.10"^ C. Chgn khdng dinh diing vd dien dung cac tu dien. A. q > CJ. B. CJ = C2. c. q < C2. D. Ca ba trudng hgp A, B, C ddu cd thd xay ra. 1.9. Di chuydn mdt dien tfch q td didm M de'n didm N trong mdt dien trudng. Cdng Ajyij,^ cua lite dien se cang ldm neu A. dudng di MN cang dai. B. dudng di MN cang ngdn. 16 I.IO. C. hieu dien the' f/p^ cang ldm. D. hieu dien the (/^ N cang nhd Hay chgn cau dting. a) U Gt c) U b) Hinh 1.2 Do thi nao tren Hinh 1.2 bidu didn stJ phti thudc cua dien tfch cua mdt tu dien vao hieu dien the giiia hai ban ciia nd ? A. Dd thi a. B. D6 thi b. C. Dd thi c. D. Khdng cd dd thi nao. 1.11. Cd mdt he ba dien tfch didm : q^ - 2q, dat tai didm A ; q-, = q dat tai didm B, vdi q duomg ; va ^3 = ^Q ^^^ tai didm C, vdi q^ am. Bd qua trgng lugng cua ba dien tfch. He ba dien tfch nay ndm can bdng trong chan khdng. a) Cdc dien tfch nay phai sdp xe'p nhu the nao ? b) Bidt AB = a. Tfnh BC theo a. c) Tfnh q theo q^. 1.12. Cho rdng mdt trong hai electron cua nguyen tii heli chuydn ddng tron deu quanh hat nhan, tren quy dao cd ban kfnh 1,18.10" m. a) Tfnh lite hut eua hat nhan len electron nay. b) Tfnh chu ki quay cua electron nay quanh hat nhan. Cho dien tich cita electron la -1,6.10" C ; khd'i lugng cua electron : 9,1.10"^' kg. 1.13. Mdt dien tfch didm q^ = +9.10"^ C ndm tai diem A trong chan khdng. Mgt dien tfgh didm khae ^2 = -16.10"^ C ndm tai diem B trong chan khdng. Khoang each AB la 5 cm. 17 2A-BTV*TLV1 1 a) Xae dinh eudng do dien trudng tai didm C vdi CA = 3 em va Cfi = 4 cm. b) Xac dinh didm D ma tai dd cudng dd dien trudng bdng 0. 1.14. Electron trong den hinh vd tuye'n phai cd ddng nang vao ed 40.10" J thi khi dap vao man hinh nd mdi lam phdt quang ldp bdt phat quang phu d dd. De tang td'c electron, ngudi ta phai eho electron bay qua dien trudng ciia mdt tti dien phang, doe theo mdt dudng stic dien. 6 hai ban eua tti dien cd khoet hai Id trdn ciing true va cd ciing dudng kfnh. Electron chui vao trong tu dien qua mdt Id va chui ra d Id kia. a) Electron bdt ddu di vao dien trudng cua tii dien d ban duomg hay ban am? b) Tfnh hieu dien the' giiia hai ban cua tu dien. Bd qua ddng nang ban ddu cua electron khi bdt ddu di vao dien trudng trong tii dien. Cho dien tfch ciia electron la -1,6.10" C. c) Khoang each giua hai ban tu dien la 1 cm. Tfnh cudng do dien trudng trong tii dien. 1.15. De ion hoa nguyen tit hidrd, ngudi ta phai td'n mdt nang lugng 13,53 electron vdn (eV). Ion hod nguyen tur hidrd la dua electron cua nguyen tix hidrd ra vd cue, bie'n nguyen tit H thanh ion H^. Electron vdn (eV) la mdt don vi nang lugng. Electron vdn cd do ldm bdng cdng eua luc dien tac dung len dien tfch +1,6.10" C lam cho nd dich chuydn giita hai didm ed hieu dien thd 1 V. Cho rdng nang lugng toan phdn eua electron d xa vd cue bdng 0. a) Hay tfnh nang lugng toan phdn cua electron cita nguyen tit hidrd khi nd dang chuydn ddng tren quy dao quanh hat nhan. Tai sao nang lugng nay ed gid tri am ? b) Cho rdng electron chuyen ddng trdn ddu quanh hat nhan tren quy dao cd ban kfnh 5,29.10" m. Tfnh ddng nang cua electron va thd nang tUdng tac eua nd vdi hat nhan. c) Tfnh dien the' tai mdt didm tren quy dao cita electron. 18 2B-BTVATLyii thuang II DONG DIEN KHONG DOI Bai 7. DONG DIEN KHONG DOI. NGUON DIEISl 7.1. Ddng dien chay trong maeh dien nao dudi day khong phdi la ddng dien khdng ddi ? A. Trong maeh dien thdp sang den cua xe dap vdi ngudn dien la dinamd. B. Trong mach dien kfn eiia den pin. C. Trong maeh dien kfn thdp sdng den vdi ngudn dien la acquy. D. Trong mach dien kfn thdp sang den vdi ngudn dien la pin mat trdi. 7.2. Cudng do ddng dien khdng ddi dugc tfnh bdng cdng thiic nao ? A./=^ . B.I = qt. t C.I = q^t. D./-^ . 7.3. Didu kien dd cd ddng dien la A. chi cdn ede vat ddn dien ed ciing nhiet do nd'i lidn vdi nhau tao thanh maeh dien kfn. B. ehi cdn duy tri mdt hieu dien the' giiia hai ddu vat ddn. C. chi can CO hifu dien thd. D. chi pan e@ ngudn dien. 7.4. Mifu ^i#n the' \ V dugc dat vao hai ddu dien trd 10 Q trong khoang thdi gian Id io s. Lugng dien tfch dich chuydn qua dien trd nay khi dd la bao nhieu ? 19 A. 200 C. B. 20 C. C. 2C. D. 0,005 C. 7.5. Sudt dien ddng cua ngudn dien la dai lugng dac trung cho kha nang A. tao ra dien tfch duomg trong mdt giay. B. tao ra cac dien tfch trong mdt giay. C. thuc hien cdng cua ngudn dien trong mdt giay. D. thtic hien cdng cita ngudn dien khi di chuydn mdt ddn vi dien tich duong ngugc ehidu dien trudng ben trong ngudn dien. 7.6. Don vi do sudt dien ddng la A. ampe (A). B. vdn (V). C. culdng (C). D. oat (W). 7.7. Cd thd tao ra mdt pin dien hod bdng each ngam trong dung dich mudi an A. hai manh ddng. B. hai manh nhdm. C. hai manh tdn. D. mdt manh nhdm va mdt manh kem. 7.8. Hai ctic cua pin Vdn-ta dugc tfch dien khdc nhau la do A. cdc electron dich chuydn tit cue ddng tdi cite kem qua dung dich dien phan. B. chi cd cac ion dUdng kem di vao dung dich dien phan. C. chi cd cac ion hidrd trong dung dich dien phan thu ldy electron eua cue ddng. D. cdc ion duong kem di vdo dung dich dien phan va ca cac ion hidrd trong dung dich thu ldy electron ciia cue ddng. 7.9. Didm khae nhau chii ydu giiia acquy va pin Vdn-ta la A. sii dting dung dich dien phan khdc nhau. B. chdt diing lam hai ctic khdc nhau. C. phdn ting hod hgc d trong acquy cd the xay ra thuan nghich. D. sti tfch dien khdc nhau d hai cue. 7.10. Cudng dd ddng dien khdng ddi chay qua day tdc cua mdt bdng den la / = 0,273 A. a) Tfnh dien lugng dich chuydn qua tidt dien thdng ciia day tdc trong 1 phut. 20 b) Tinh sd electron dich chuydn qua tidt dien thdng cua day tdc trong khoang thdi gian ndi tren. —19 Bie't dien tfch cua mdt electron la -1,6.10 C. 7.11. Sudt dien ddng cua mdt acquy la 6 V. Tfnh cdng ctia lue la khi dich chuydn lugng dien tfch la 0,8 C ben trong ngudn dien tur ctic am tdi cue duomg cua nd. 7.12. LiJc la thuc hien mdt cdng la 840 mJ khi dich chuyen mdt lugng dien tfch —2 7.10 C giiia hai cue ben trong mdt ngudn dien. Tfnh sudt dien ddng ciia ngudn dien nay. 7.13. Pin Vdn-ta cd sudt dien ddng la 1,1 V. Tfnh cdng ciia pin nay san ra khi cd mdt lugng dien tfch +54 C dich chuydn d ben trong va giiia hai cue eua pin. 7.14. Pin Lo-elang-se san ra mdt cdng la 270 J khi dich chuydn lugng dien tfch la +180 C d ben trong va giiia hai ctic cua pin. Tfnh sudt dien ddng cita pin nay. 7.15. Mdt bd acquy cd sudt dien ddng la 6 V vd san ra mdt cdng la 360 J khi dich chuydn dien tfch d ben trong va giiia hai cue ctia nd khi acquy nay phat dien. a) Tfnh lugng dien tfch dugc dich chuydn nay. b) Thdi gian dich chuydn lugng dien tfch nay la 5 phiit, tfnh eudng dd ddng dien chay qua acquy khi dd. 7.16. Mdt bd acquy ed thd cung edp mdt ddng dien 4 A lien tue trong 1 gid thi phai nap lai. a) Tfnh cudng dd ddng dien ma acquy nay cd the cung cdp neu nd dugc sif dung lien ttic trong 20 gid thi phai nap lai. b) Tfnh sudt dien ddng ciia acquy nay ne'u trong thdi gian hoat ddng tren ddy nd san sinh ra mdt cdng la 86,4 kJ. Bai 8. DIEN NANG. CONG SUAT DIEN 8.1. Dien nang bidn ddi hoan toan thdnh nhiet nang d dung eu hay thie't bi dien nao dudi day khi chiing hoat ddng ? A. Bdng den day tdc. B. Quat dien. C. Am dien. D. Acquy dang dugc nap dien. 21 8.2. Cdng sudt ciia ngudn dien dugc xac dinh bdng A. lugng dien tfch ma ngudn dien san ra trong mdt giay. B. cdng ma lue la thuc hien khi dich chuydn mdt don vi dien tfch duong ngugc ehidu dien trudmg ben trong ngudn dien. C. lugng dien tfch chay qua ngudn dien trong mdt giay. D. cdng cua lite dien thuc hien khi dich chuydn mdt dom vi dien tfch duong chay trong mach dien kin trong mdt giay. 8.3. Bdng den 1 cd ghi 220 V - 100 W va bdng den 2 cd ghi 220 V - 25 W. a) Mde song song hai den nay vao hieu dien thd 220 V. Tfnh dien trd /?i va /?2 tuong iing eua mdi den va cudng do ddng dien /, va Ij chay qua mdi den khi dd. b) Mde nd'i tidp hai den nay vao hieu dien the' 220 V va cho rdng dien trd cua mdi den vdn ed tri so nhu d cau a. Hdi den nao sang hon va cd cdng sudt ldn gdp bao nhieu ldn cdng sudt eua den kia ? 8.4. Gia sit hieu dien thd dat vao hai ddu bdng den cd ghi 220 V - 100 W ddt ngdt tang len tdi 240 V trong khoang thdi gian ngdn. Hdi cdng sudt dien eua bdng den khi dd tang len bao nhieu phdn tram (%) so vdi cdng sudt dinh miic cua nd ? Cho rdng dien trd eua bdng den khdng thay ddi so vdi khi hoat ddng d che' do dinh miic. 8.5. Mdt dm dien duge diing vdi hieu dien the' 220 V thi dun sdi dugc 1,5 1ft nudc tit nhiet do 20°C trong 10 phiit. Bidt nhiet dung rieng cita nudc la 4 190 J/(kg.K), khdi lugng rieng cua nude la 1 000 kg/m va hieu suat cita dm la 90%. a) Tfnh dien trd cua dm dien. b) Tfnh cdng suat difn ciia dm nay. 8.6. Mdt den dng loai 40 W duge chd tao de cd cdng sudt ehidu sang bang den day tdc loai 100 W. Hdi neu sti dting den dng nay trung binh mdi ngay 5 gid thi trong 30 ngay se giam duge bao nhieu tidn dien so vdi sit dting den day tdc ndi tren ? Cho rdng gia tidn dien la 700 d/(kW.h). 8.7. Mgt ban la dien khi dugc sit dting vdi hieu dien the' 220 V thi ddng dien chay qua ban la cd cudng dd la 5 A. a) Tfnh nhiet lugng ma ban la toa ra trong 20 phiit theo don vi jun (J). b) Tfnh tien dien phai tra cho viec sif dung ban la nay trong 30 ngay, mdi ngay 20 phiit, cho rang gid tidn dien la 700 d/(kW.h). 22 8.8. Mdt acquy cd sudt dien ddng la 12 V. a) Tfnh cdng ma acquy nay thue hien khi dich chuydn mdt electron ben trong acquy tuf cite duomg tdi cue am eiia nd. ' 18 b) Cdng sudt cua acquy nay la bao nhieu neu cd 3,4.10 electron dich chuydn nhu tren trong mdt giay ? Bdi 9. DjNH LUAT OM DOI vdl TOAN IVIACH 9.1. Ddi vdi mach dien kfn gdm ngudn dien vdi maeh ngoai la dien trd thi cudng dd ddng dien chay trong maeh ) A. ti le thuan vdi dien trd mach ngodi. B. giam khi dien trd mach ngoai tang. C. ti le nghich vdi dien trd maeh ngoai. D. tang khi dien trd mach ngodi tang. 9.2. Hien tugng doan mach eua ngudn dien xay ra khi A. sur dting cac day ddn ngan de mdc mach dien. B. ndi hai cue cita mdt ngudn dien bdng day ddn cd dien trd rdt nhd. C. khdng mde edu ehi cho mdt mach dien kfn. D. diing pin hay acquy dd mdc mdt maeh dien kfn. 9.3. Cho mach dien cd sd dd nhu trenf Hinh 9.1, trong dd ngudn dien ed sudt dien ddng ^= 12 V va cd dien trd trong rdt nhd, edc dien trd d maeh ngoai la/?i = 3Q,/?2 = 4Qva/?3 = 5Q. _ ^ 1 a) Tfnh cudng dd ddng dien chay trong maeh. b) Tfnh hieu dien thd giiia hai ddu dien trd Rj. c) Tfnh cdng eua ngudn dien san ra trong > ^3 ZZZl «2 10 phut va cdng sudt toa nhiet d dien trd R^. Hinh 9.1 9.4. Khi mdc dien trd /?i = 4 Q vao hai cite cua mdt ngudn dien thi ddng dien trong mach ed cudng dd I^ = 0,5 A. Khi mdc dien trd i?2 = 10 Q thi ddng dien trong mach la Ij = 0,25 A. Tfnh sudt dien ddng W va dien trd trong r cua ngudn dien. 9.5. Mdt dien trd R^ duge mdc vao hai cue cua mdt ngudn dien cd dien trd trong r = 4 Cl thi ddng dien chay trong mach cd cudng dd la /i = 1,2 A. 23 Neu mdc them mdt difn trd /?2 = 2 Q nd'i tiep vdi difn trd /?, thi ddng difn chay trong mach cd cudng dd la /j = 1 A. Tfnh tri sd eua difn trd Ry. 9.6. Khi mdc dien trd R^ = 500 Q vao hai cue cua mdt pin mat trdi thi hifu difn the' mach ngoai la t/j = 0,10 V. Ndu thay difn trd R^ bang difn trd /?2 = 1000 Q thi hieu dien the mach ngoai bay gid la Uj = 0,15 V. a) Tfnh sudt difn ddng ^va dien trd trong r cua pin nay. •> 2 b) Dien tich eua pin la 5 = 5 cm va nd nhan dugc nang lugng dnh sang vdi cdng suat tren mdi xentimet vudng difn tfch la vv = 2 mW/cm . Tfnh hifu suat H cua pin khi chuydn tii nang lugng dnh sang thanh nhift nang d dif n trd ngoai i?2- 9.7. Mdt dien trd /? = 4 Q dugc mdc vao ngudn difn ed sudt difn ddng f- 1,5 V de tao thanh mach dien kfn thi cdng sudt toa nhift d dien trd nay la 9^ = 0,36 W. a) Tfnh hifu difn thd giua hai ddu difn trd R. b) Tfnh difn trd trong cita ngudn dien. 9.8. Mdt ngudn difn cd sudt difn ddng ^ = 2 V va difn trd trong r = 0,5 Q dugc mdc vdi mdt ddng co thanh mach difn kfn. Ddng co nay nang mdt vat cd trgng lugng 2 N vdi van tdc khdng ddi v = 0,5 ni/s. Cho rdng khdng cd sti mdt mat vi toa nhift d edc day nd'i va d ddng cd. a) Tfnh cudng dd ddng dien / chay trong mach. b) Tfnh hifu difn thd giiia hai ddu cua ddng co. c) Trong cac nghiem ciia bai toan nay thi nghifm nao cd lgi hom ? Vi sao ? Bai 10. DOAN IVIACH CHQA NGUON DIEN. GHEP CAC NGUON DIEN THANH BO 10.1. Ghep mdi ndi dung d cdt ben trdi vdi mdt ndi dung phii hgp d edt ben phai. 1. Mdt mach dien cd chiia ngudn a) — ldn difn trd trong cita mdt dien ndu , , ngudn dugc ghep trong bg. 24 2. Bd ngudn ghep nd'i tie'p cd dien trd trong la 3. Bd ngudn gdm n ngudn nhu nhau ghep song song cd dien trd trong bdng 4. Bd ngudn ghep nd'i tidp ed sudt difn ddng la 5. Bd ngudn gdm n ngudn nhu nhau ghep song song cd sudt difn ddng la b) tdng cac sudt dien ddng ciia cae ngudn cd trong bd. c) ddng dien chay qua nd cd ehidu di ra tur ctic dudng va di tdi cue am. d) sudt difn ddng cua mdt ngudn cd trong bd. e) tdng difn trd trong cua cac ngudn dugc ghep trong bd. 10.2. Mdt doan mach cd ehiia ngudn difn (ngudn phdt difn) khi ma A. ngudn difn dd tao ra cdc dien tfch duomg va day cac difn tfch nay di khdi cue duomg cita nd. B. ddng difn chay qua nd cd ehidu di vao cue am va di ra tit ctic duomg. C. ngudn dien nay tao ra cac difn tfch am va ddy cac difn tfch nay di ra khdi cue am ciia nd. D. ddng difn chay qua nd cd ehidu di vao cite duomg va di ra tii cue am. 10.3. Hai ngudn difn cd sudt difn ddng nhu nhau '1' 1 "2. 1-2 ^1 - ?2 = 2 V va ed dif n trd trong tuong iing la > R rj = 0,4 Q vd r2 = 0,2 Q dugc mdc vdi difn trd Hinh 10.1 R thdnh mach difn kfn ed so dd nhu Hinh 10.1. Bidt rdng, khi dd hifu difn thd giiia hai cue cua mdt trong hai ngudn bdng 0. Tfnh tri sd eiia difn trd/?. 10.4. Hai ngudn difn ed sudt dien ddng va difn trd trong tuong ting la ^i = 3 V ; r, = 0,6 Q va ?2 = 1,5 V ; r2 = 0,4 Q duge mdc vdi difn trd /? = 4 Q thanh mach difn kfn cd sd dd nhu Hinh 10.2. a) Tfnh cudng dd ddng difn chay trong maeh. b) Tfnh hifu dien the' giua hai cue ciia mdi ngudn. ^1 '-1 —ii- % 2i ' 2 -c R Hinh 10.2 10.5. Hai ngudn difn ed eiing sudt difn ddng ? va difn trd trong /- dugc mdc thanh bd ngudn va dugc mdc vdi dien trbR = ll Q. nhu sd dd Hinh 10.3. 25 Trong trudng hgp Hinh 10.3a '^) Cr , r b) ^f thi ddng difn chay qua R cd i —IJH cudng do /i = 0,4 A ; edn trong trudng hgp Hinh 10.3b thi ddng difn chay qua R ed eudng do Ij = 0,25 A. Tfnh sudt difn ddng ^ va difn trd trong r. %.r R Hinh 10.3 10.6. Hai ngudn difn cd sudt difn ddng vd dien trd trong nrong iing la ?, = 4 V ; /-j = 2 Q va ^2 = 3 V ; rj = 3 Q dugc mdc vdi bie'n trd R thanh mach difn kfn theo Sddd nhu Hinh 10.4. Bie'n trd phai ed tri sd RQ la bao nhieu dd khdng .'1 P2| ' 2 ed ddng dien chay qua ngudn ^2 ? Hinh 10.4 10.7. Mdt bd ngudn gdm 20 acquy gid'ng nhau, mdi acquy cd sudt difn ddng ^'o = 2 V va difn trd trong KQ = 0,1 Cl, dugc mdc theo kidu hdn hgp ddi xiing. Difn trdi? = 2 Q duge mde vao hai cue eua bd ngudn nay. a) Dd ddng difn chay qua difn trd R ed cudng do ctic dai thi bd ngudn nay phai gdm bao nhieu day song song, mdi day gdm bao nhieu acquy mde nd'i tidp ? b) Tfnh cudng dd ddng dien cue dai nay. e) Tfnh hifu sudt ciia bd ngudn khi dd. 10.8. Cd n ngudn difn nhu nhau cd ciing sudt difn ddng f va difn trd trong r. Hoac mdc nd'i tiep hoae mdc song song tdt ca eae ngudn nay thdnh bd ngudn rdi mde dien trd R nhu so dd Hinh 10.5a va 10.5b. Hay ehiing minh rdng trong ea hai trudng hgp, ndu R = r thi ddng difn chay qua R eo eiing cudng do. n -*^ ^ 1 ' • -C R a) Hinh 10.5 26 Bai n . PHUONG PHAP GIAI MOT SO BAI TOAN VE TOAN MACH 11.1. Cho maeh dien ed so dd nhu Hinh 11.1, trong dd ngudn difn cd sudt difn ddng ^ = 30 V vd difn trd trong r = 3 Q, cac Rl difn trd /?, = 12 Q, /?2 = 27 Q, /?3 = 18 Q, vdn ke' V ed dien trd rdt ldm. a) Tfnh dien trd tuomg duong R^ cita . maeh ngoai. b) Xde dinh sd chi cua vdn ke. H®- Ri D Hinh 11.1 11.2. Mdt day hgp kim cd dien trd la i? = 5 Q dugc mde vao hai ctic cua mdt pin difn hod cd sudt difn ddng va difn trd trong la ^= 1,5 V, r = 1 Q. Difn trd eua edc day nd'i la rdt nhd. a) Tfnh lugng hod nang duge chuydn hod thanh difn nang trong 5 phiit. b) Tfnh nhiet lugng toa ra d difn trd R trong khoang thdi gian da cho tren day. c) Giai thfch sti khae nhau giiia cac ke't qua tfnh dugc d cau a vd b tren day. 11.3. Cho mdt ngudn difn ed sudt difn ddng ?"= 24 V vd difn trd trong /• = 6 Q. a) Cd thd mde nhidu nhdt bao nhieu bdng den loai 6 V - 3 W vao ngudn difn da cho tren day dd eae den sdng binh thudng ? Ve so dd each mdc. b) Neu chi ed 6 bdng den loai tren day thi phai mdc chting vao ngudn difn da cho theo so dd nao dd ede den sang binh thudng ? Trong cac each mdc nay thi each nao lgi hom ? Vi sao ? 11.4. Cd A^j bdng den ciing loai 3 V - 3 W va A/^2 ngudn difn cd cung sudt difn ddng ^0 = 4 V vd difn trd trong rQ= I Q. dugc mdc thanh bd ngudn hdn hgp dd'i xiing. a) Ndu sd bdng den la ATj = 8 thi cdn sd ngudn ft nhdt (A^2 "li") ^^ bao nhieu dd ede den nay sang binh thudng ? Ve so dd ede each mdc ngudn va den khi dd va tfnh hieu sudt cita bd ngudn trong tumg trudng hgp. b) Ndu sd ngudn la Nj = 15 thi ed the thdp sang binh thudng sd den ldn nha't (A^i max) la bao nhieu ? Ve so dd tat ca cac each mdc ngudn va den khi dd vd tfnh hifu sudt cua bd ngudn dd'i vdi timg each mdc dd. 27 BAI TAP CUOI CHl/ONG II 11.1. Ghep mdi ndi dung d cdt ben trai vdi mdt ndi dung d cdt ben phai dd thanh mdt cau cd ndi dung dting. 1. Trong mach difn kfn don gian, eudng do ddng difn bdng 2. Sudt difn ddng eua ngudn difn dac trung cho 3. Sudt dien ddng cua bd ngudn mde nd'i tiep bdng 4. Acquy la ngudn difn hod hgc cd thd dugc nap lai dd sit dting nhidu ldn la do 5. Ddng difn khdng ddi la 6. Sti tfch difn khdc nhau d hai / cue cita pin difn hod dugc duy tri la do 7. Ddng difn chay qua doan mach chtia ngudn phat difn thi 8. Dd giam difn the tren mdt doan maeh la 11.2. Ghep dai lugng, dinh luat d cdt ben d cdt ben phai cho phii hgp. 1. Dinh luat 6m ddi vdi mach difn kfn dom gian 2. Sudt difn ddng eiia ngudn difn 3. Cudng do ddng difn khdng ddi 4. Hifu difn the' (/^g giiia hai ddu eua doan mach cd chtia ngudn dien, trong dd A ndi vdi cue duong cua ngudn difn 28 a) tac dung hod hgc. b) tac dung cua phan ting hda hgc thuan nghich. c) tfch cita cudng dd ddng difn chay qua doan maeh dd va difn trd eua nd. d) thuong sd giiia sudt difn ddng eiia ngudn difn va difn trd toan phdn ciia mach. e) kha nang thtic hifn cdng cua ngudn difn. g) tdng cae sudt difn ddng cita cdc ngudn difn thanh phdn. h) ed ehidu di tdi cue am va di ra tit cue dUdng eua dung cu nay. i) ddng difn ed ehidu va eudng dd khdng thay ddi theo thdi gian. trdi vdi cdng thiic, hf thtic tuong iing a) f'b = ^1 + ^2 + ^3 + - + ^n b)[/AB=^-/( ^ + '-)- 5. Sudt difn ddng cita bd ngudn N o^^ ji mde ndi tie'p ^ 6. Sudt dien ddng cua bd ngudn g)W= I(R + r). mdc song song don gian 11.3. Cae Itic la ben trong ngudn difn khong ed tac dung A. tao ra vd duy tri hifu difn the giiia hai cue cita ngudn difn. B. tao ra vd duy tri sti tfch dien khdc nhau d hai cue cua ngudn difn. C. tao ra cae dien tfch mdi cho ngudn difn. D. lam ede difn tfch duong dich chuydn nguge chieu difn trudng ben trong ngudn difn. 11.4. Trong cac pin difn hod khong co qua trinh nao dudi day ? A. Bie'n ddi hod nang thanh difn nang. B. Bie'n ddi ehdt nay thanh ehdt khae. C. Lam eho eae cure cua pin tfch difn khae nhau. D. Bidn ddi nhift nang thanh difn nang. 11.5. Dat hifu dien the U vao hai ddu mdt dien trd R thi ddng dien chay qua cd eudng dd /. Cdng sudt toa nhift d difn trd nay khong the tfnh bdng cdng thiie nao ? A. 3^„h = i^f^- c. 9^nh = ui^- B-^nh=W. D ^ - ^ 11.6. Dd'i vdi mach difn kfn gdm ngudn difn vdi mach ngoai la difn trd thi hieu difn thd maeh ngodi A. tl le thuan vdi eudng dd ddng difn chay trong mach. B. tang khi cudng do ddng difn chay trong maeh tang. C. giam khi eudng dd ddng difn chay trong mach tang. D. ti If nghich vdi cudng dd ddng difn chay trong mach. 11.7. Sudt difn ddng cita mdt acquy la 12 V. Lue la thuc hifn mdt cdng la 4 200 J. Tfnh difn lugng dich chuydn giiia hai ctic eua ngudn difn khi dd. 29 11.8. Cho mach dien cd so dd nhu Hinh II.l, trong dd bd ngudn cd sudt difn ddng ^j, = 42,5 V va difn trd trong r^ = 1 Q, dien trd /?i = 10 Q, Rj = 15 Q. Difn trd cita cae ampe kd va eua cdc day nd'i khdng dang ke. a) Biet rdng bd ngudn gdm cac pin gid'ng nhau mdc theo kidu hdn hgp dd'i xiing, mdi pin cd sudt difn ddng ^Q = 1,7 V va difn trd trong KQ = 0,2 Cl. Hdi bd ngudn nay gdm bao nhieu day song song, mdi day gdm bao nhieu pin mdc nd'i tidp ? b) Biet ampe ke Aj chi 1,5 A, hay xac dinh sd ehi cita ampe ke'A2 vd tri sd cua difn trd R. 11.9. Cd 36 ngudn gid'ng nhau, mdi ngudn ed sudt difn ddng ^ = 12 V va difn trd trong r = 2 Q dugc ghep thanh bd ngudn hdn hgp dd'i xtimg gdm n day song song, mdi day gdm m ngudn ndi tiep. Mach ngoai cua bd ngudn nay la 6 bdng den gid'ng nhau dugc mde song song. Khi dd hifu difn thd mach ngoai laU = 120 V va cdng sudt mach ngodi la ^^ = 360 W. a) Tfnh dien trd cita mdi bdng den. b) Tfnh sd day n va sd ngudn m trong mdi day eua bd ngudn nay. c) Tfnh cdng sudt vd hifu sudt eua bd ngudn trong trudng hgp nay. 30 K^huang III DONG DEN TRONG CAC MOI TRLfC5NG Bai 13. DONG DIEN TRONG KIM LOAI 13.1. Ghep ndi dung d cdt ben trdi vdi ndi dung thieh hgp d edt ben phai. 1. Ban chat cua ddng difn trong kim loai dugc neu rd trong mdt If thuydt ggi la 2. Cac electron hod tri sau khi tach khdi nguyen tii, trd thanh 3. Cdc electron tu do chuydn ddng nhift hdn loan trong toan mang tinh thd kim loai, tao thanh 4. Khf electron chuydn ddng trdi ngugc ehidu dien trudng ngoai, tao thanh 5. Nguyen nhan gay ra difn trd cita kim loai la 6. Nhiing ehdt ddn difn td't va cd difn trd sudt kha nhd (khoang 10 4- 10 Q.m), thudng la cdc a) hf sd nhift difn trd. b) suat difn ddng nhift difn. e) thuyet electron. d) khf electron (difn tit) tti do. d) ehdt sieu ddn. e) kim loai. 31 7. Cae hat mang difn tham gia vao qua trinh ddn dien dugc ggi la 8. Hf sd xac dinh su phu thudc cua difn trd suat vao nhiet do dugc ggi la 9. Chdt cd difn trd sudt giam ddt ngdt xudng gia tri bdng khdng khi nhift do giam thdp hon nhift do tdi han T^ cua nd duge ggi la 10. Bd hai day ddn khae loai cd hai ddu han-ndi vdi nhau thanh mdt maeh kfn ggi la cap nhift difn. Sudt difn dgng xudt hien trong cap nhift difn khi giiia hai mdi han ciia nd cd mdt dd chenh If ch nhift do ggi la 13.2. He so nhiet dien trd a cd don vi do la g) ddng difn. h) su mdt trat tti eua mang tinh thd. i) cdc electron tu do. k) cac hat tai dien. A. Q '. C. Q.m. B. K -1 D. V.K -1 13.3. Ne'u ggi PQ la difn trd sudt cua kim loai d nhift do ban ddu IQ thi difn trd sudt p cita kim loai phii thugc nhift do t theo cdng thtic nao dudi day ? A. p = PQ+ a(t - IQ) ; vdi aid mdt hf so cd gid tri dUdng. B. p- PQ[1 + a(t - to)] ; vdi a la mdt hf sd ed gid tri am. C. p = PQ[1 + a(t - IQ)] ; vdi a la mdt hf sd ed gid tri duong. D. p = PQ+ a(t - to) ; vdi a la mdt hf so cd gia tri am. 13.4. Hf so nhift difn trd a eua kim loai phti thude nhiing yeu td nao ? A. Chi phii thudc khoang nhift do. B. Chi phu thudc do sach (hay do tinh khiet) eiia kim loai. C. Chi phti thudc che' do gia cdng eua kim loai. D. Phti thude ca ba ye'u td neu tren. 32 13.5. cau ndo dudi day ndi vd tfnh chat dien cua kim loai la khong diing ? A. Kim loai la ehdt ddn difn. B. Dien trd sudt eiia kim loai khd ldm, ldm hom 10 Q.m. C. Difn trd sudt cita kim loai tang^theo nhift dd. D. Cudng dd ddng difn chay qua day kim loai tuan theo dting dinh luat 6m khi nhiet do eiia day kim loai thay ddi khdng dang ke. 13.6. Mdt day bach kim d 20°C cd difn trd suat PQ = 10,6.10"^ Q.m. Tfnh dien trd sudt p cita day bach kim nay d 1120°C. Gia thidt dien trd sudt ciia day bach kim trong khoang nhift do nay tang bae nhat theo nhift do vdi hf so nhiet difn trd khdng ddi la or = 3,9.10 K . A. « 56,9.10"^ Q.m. B. » 45,5.10"^ Q.m. C. « 56,1.10"^ Q.m. D. « 46,3.10"^ Q.m. 13.7. Nd'i cap nhift ddng - eonstantan vdi mdt milivdn kd thanh mdt mach kfn. Nhiing mdi han thti nhdt vao nude da dang tan va mdi han thit hai vao hoi nudc sdi, milivdn kd chi 4,25 mV. Tfnh hf so nhift dien ddng «j cua cap nhift nay. A. 42,5 (iV/K. B. 4,25 ^V/K. C. 42,5mV/K. D. 4,25 mV/K. 13.8. Chumg minh cdng thiie xae dinh cudng do ddng difn I chay qua day ddn kim loai ed dang / = enSv, trong dd e la do ldm cua difn tfch electron, n la mat do, 5 la tidt difn cita day kim loai va v la td'c do trdi cita electron. 13.9. Dua vao quy luat phu thudc nhift dd eiia difn trd suat cua day kim loai, tim cdng thtic xdc dinh sti phti thude nhift do cua dien trd R cixa mdt day kim loai cd dd ddi / va tidt dien ddu 5. Gia thiet trong khoang nhift do ta xet, dd dai vd tie't difn ciia day kim loai khdng thay ddi. 13.10. Mdt bdng den 220 V - 40 W cd day tdc lam bdng vonfam. Dien trd cua day tdc den d 20°C la RQ = 121 Q. Tfnh nhift do t cixa day tdc den khi sang binh thudng. Gia thie't difn trd cua day tdc den trong khoang nliiet do nay tang bae nhdt theo nhiet dd vdi hf sd nhiet difn trd « = 4,5.10"^ K~'. 33 3A-BTVATLyi1 13.11*. Day tdc bdng den 220 V - 100 W khi sang binh thudng d 2485°C cd difn trd ldm gdp « = 12,1 ldn so vdi difn trd ciia nd d 20°C. Tfnh hf sd nhift difn trd a va difn trd RQ eua day tdc den d 20°C. Gia thidt rdng difn trd eiia day tdc den trong khoang nhift dd nay tang bae nhdt theo nhift dd. 13.12*. Can cii cae sd Ufu trong bang dudi day, hay ve dd thi bidu didn sti phu thudc ciia sudt difn ddng nhift difn ^vao hifu nhift dd (Tj - T-^ giiia hai mdi han cita cap nhiet difn sdt - eonstantan. Tfnh hf sd nhift difn ddng o^ cita cap nhiet nay. (ri-r2)(K) ^(mV) 0 0 10 0,52 20 1,05 30 1,56 40 2,07 50 2,62 60 3,10 70 3,64 Bai 14. DONG DIEN TRONG CHAT DIEN PHAN 14.1. Ghep ndi dung d edt ben trai vdi ndi dung thfch 1. Lf thuydt giai thfch sti ddn difn eua ede dung dich axit, bazo va mud'i ggi la 2. Cdc dung dich va edc chat ndng chay trong dd cac hgp chdt nhu axit, bazo va mud'i bi phan li thanh cac ion tti do dugc ggi la 3. Binh dung chdt dien phan cd hai difn cue nd'i vdi hai cue dudng va am cua ngudn difn ggi la 4. Ion am chuydn ddng vd andt (cue duong) eua binh difn phan ggi la 5. Ion duomg chuydn ddng vd catdt (cue am) cita binh difn phan ggi la 34 hgp d cdt ben phai. a) cation (ion duong). b) dinh luat Fa-ra-day thii nhdt vd difn phan. c) thuye't dien li. d) duomg lugng difn hod eua ehdt gidi phdng ra d difn cue d) duong lugng gam cua nguyen td. 6. Ddng difn trong long chdt difn phan la e) dinh luat Fa-ra-day ddng chuydn ddng cd hudmg theo hai ehidu thti hai vd difn phan. ngugc nhau eua 7. Hifn tugng ddng difn phan tfch cdc hgp g) cdng thirc Fa-ra-day ehdt hod hgc chtia trong dung dich thanh vd difn phan. edc hgp phdn (nhu phan tfch H2O thanh H2 va O2) ggi la 8. Hifn tugng difn phan xay ra khi chdt h) qnion (ion am), difn phan la mud'i cita kim loai diing lam i) mdt duomg lugng gam andt va andt bi tan ddn vao dung dich ctia chdt dd. ggi la 9. Dinh ludt m = kq cho bidt khdi lugng m k) sd Fa-ra-day. ciia cha't giai phdng ra d difn cue, ti If vdi difn lugng q chay qua binh difn phan ggi la 10. He sd ^ = — cho bie't khd'i lugng cua /) hifn tugng duomg cue tan ehdt giai phdng ra d difn cue khi ed mdt don vi difn lugng chay qua binh difn phdn ggi la A 11. Dai lugng — xae dinh bdi ti sd giiia ,,^ . ,' " ,,....,. . m) binh dien phan. khoi lugng moi nguyen tu A voi hoa tri n cita mdt nguyen td hod hgc ggi la 1 A 12. Dinh luat k = —— cho bie't duong n) cae ion duong va ion lugng difn hod cua nguyen td giai phdng ra d dien cue cita binh dien phan, ti If vdi duomg lugng gam eua nguyen td dd, ggi la 13. Dai lugng F = 96 494 « 96 500 C/mol, o) hifn tugng difn phan. ggi la 14. Sd Fa-ra-day cd gia tri bdng difn lugng p) chdt difn phan. chay qua binh difn phan dd giai phdng ra d difn cue mdt lugng chdt bang 14.2. cau nao dudi day ndi vd ban chdt ddng difn trong chdt difn phan la dting ? A. La ddng electron ehuydn ddng nguge hudmg difn trudng. B. La ddng ehuydn ddng cd hudmg ddng thdi eiia cac ion duomg theo ehidu difn trudng va ddng ion am eiing vdi cdc electron ngugc ehidu dien trudng. 35 C. La ddng chuyen ddng ed hudmg ddng thdi cita cae ion duomg theo ehidu difn trudng vd eiia edc electron ngugc ehidu difn trudng. D. La ddng chuydn ddng cd hudng ddng thdi eiia cae ion duomg theo ehidu difn trudng va cita ede ion am ngugc ehidu difn trudng. 14.3. Ggi m la khd'i lugng cua chdt giai phdng d difn cue, / la cudng dd ddng difn, t la khoang thdi gian cd ddng difn chay qua chdt difn phdn, F la sd Fa-ra-day, A la khd'i lugng moi nguyen tit va n la hod tri eua nguyen td giai phdng ra d difn cue. Hay vidt cdng thtic Fa-ra-day vd difn phan. 1 A A. m = It, trong dd m tinh ra gam va F « 96 500 C/mol. F n I A I B. m = //, trong dd m tinh ra kildgam va — « 96500 C/mol. F n r A C. m = F—It, trong dd m tinh ra gam vd F « 96 500 C/mol. n 1 n D. m - ——It, trong dd m tinh ra gam va F « 96 500 C/mol. F A 14.4. Mdt binh difn phan chtia dung dich mudi niken vdi hai difn cue bdng niken. Dudng lugng difn hod cua niken la ^ = 0,30 g/C. Khi eho ddng difn eudng dd / = 5 A chay qua binh nay trong khoang thdi gian t = I gid thi khdi lugng m ciia niken bam vdo catdt bang bao nhieu ? A. 5,40 g. B.'^40mg. C. l,50g. D. 5,40 kg. 14.5. Mdt binh difn phan chtia dung dich ddng sunphat (CUSO4) vdi hai difn cue bdng ddng (Cu). Khi eho ddng difn khdng ddi chay qua binh nay trong khoang thdi gian 30 phut, thi thdy khdi lugng ciia catdt tang them 1,143 g. Khdi lugng moi nguyen tit eua ddng la A = 63,5 g/mol. Ld'y sd Fa-ra-day F « 96500 C/mol. Ddng difn chay qua binh difn phan cd cudng dd / bdng bao nhieu ? A. 0,965 A. B. 1,93 A. C. 0,965 mA. D. 1,93 mA. 14.6. Mdt binh difn phan chtia dung dich bae nitrat (AgN03) cd difn trd la 2,5 Q. Andt cua binh bdng bae (Ag) va hifu difn thd dat vdo hai difn cue eiia binh la 10 V. Sau 16 phiit 5 giay, khd'i lugng m ciia bae bam vao catdt bdng bao nhieu ? Bae cd khd'i lugng moi nguyen tuf la A = 108 g/mol. 36 A. 2,16 g. B.4,32mg. C.4,32g. D.2,16mg. 14.7*. Dua vao cdng thtic Fa-ra-day vd difn phan, tfnh difn tfch nguyen td e. Cho bie't sd Fa-ra-day F « 96 500 C/mol. 14.8*. Mdt vat kim loai dugc ma niken ed difn tfch S = 120 em . Ddng dien chay qua binh difn phan cd eudng dd / = 0,3 A va thdi gian ma la ? = 5 gid. Tfnh dd ddy h ciia ldp niken phu ddu tren mat cua vat dugc ma. Niken cd khdi lugng moi nguyen tit la A = 58,7 g/mol; hod tri n = 2 vd khdi lugng rieng yO= 8,8.10^ kg/m^ Bai 15. DONG DIEN TRONG CHAT KHI 15.1. Ghep ndi dung d cdt ben trdi vdi ndi dung thfch hgp d cdt ben phai. 1. Nggn lita ga, tia tit ngoai,... cd tdc a) hifn tugng nhan sd hat diing lam tang mat dd cac hat tai difn tai difn. (gdm ion duomg, ion am va electron tu do) trong chdt khf, nen duge ggi la 2. Ddng difn trong ehdt khf la ddng b) hd quang difn. chuydn ddng cd hudmg theo hai ehidu ngugc nhau cua 3. Qud trinh ddn difn (phdng difn) cita c) bugi ddng ed nd, thie't ehdt khf chi tdn tai khi phun (dua) cae bi tao dzdn,... hat tai difn vao khd'i khf d gifia hai ban cue va bidn mdt khi ngumg dua edc hat tai difn vao trong dd, ggi la 4. Khi phdng difn tu luc, quan hf phu d) tdc nhan ion hoa. thudc cua cudng dd ddng difn trong chdt khf vao hifu difn thd (dd sut the) giiia hai difn cue khdng tuan theo 5. Hifn tugng tang mat dd hat tai difn d) qua trinh ddn difn hi luc. trong ehdt khf do ddng difn chay qua nd gay ra, ggi la 37 6. Qud trinh ddn difn ciia chat khf ed thd tu duy tri, khdng cdn phun (dua) lien tuc cac hat tai difn vao trong nd, ggi la 7. Qud trinh phdng dien tu Itic trong chdt khf khi gifla hai difn cue ed difn trudng du manh lam ion hod chdt khf, bidn phan tit khf trung hod thanh ion ducmg va electron tu do, ggi la 8. Tia difn dugc iimg dting trong 9. Qua trinh ddn difn tu lue trong chdt khf d dp sudt thudng hay dp sudt thdp khi giiia hai difn ctic cd hifu difn thd khdng ldm, kem theo toa nhift va toa sang rdt manh, ggi la 10. Hd quang difn dugc umg dung trong e) may han difn, Id nung chay mdt sd vat Ufu,... g) cac ion duomg, ion am vd electron tu do. h) dinh luat Om. i) tia lita difn (tia difn). k) qua trinh ddn difn (phdng difn) khdng tu luc. 15.2. cau nao dudi day ndi vd qua trinh ddn difn khdng tu luc ciia ehdt khf la dting ? A. Dd la qua trinh ddn difn trong ehdt khf, khdng edn lien tiic tao ra cac hat tai difn trong khd'i khf. B. Dd la qua trinh ddn difn cita chdt khf nam trong mdt trudng du manh. C. Dd la qua trinh ddn difn dugc iing dung trong bugi cua ddng cd nd. D. Dd la qua trinh ddn difn trong ehdt khi ehi tdn tai khi lien tuc tao ra cdc hat tai difn trong khdi khf. 15.3. Cau nao dudi day ndi vd su phti thude eiia eudng dd ddng difn / vao hifu difn thd U trong qud tiinh ddn difn khdng tu luc cita ehdt khf la khong dung ? A. Vdi mgi gia tri eua U : cudng dd ddng difn / ludn tang ti If thuSn vdi U. B. Vdi U nhd : cudng dd ddng difn / tang theo U. C. Vdi t/ dit ldm : cudng do ddng difn / dat gia tri bao hoa. D. Vdi U qua ldm : eudng dd ddng difn / tang nhanh theo U. 38 15.4. cau ndo dudi day ndi vd hifn tugng nhan sd hat tai difn trong ehdt khf la khong dung ? A. Dd la hifn tugng tang mat dd hat tdi difn trong ehdt khf do d gifta hai dien cue cd difn trudng du manh dd ldm ion hod ehdt khf. B. Dd la hifn tugng tang mdt dd hat tai difn trong chdt khf ehi bdng each diing nggn lira ga dd dd't ndng khd'i khf d giiia hai difn cite. C. Dd la hifn tugng tang mat dd hat tai difn trong ehdt khf do ddng difn chay qua. D. Dd la hifn tugng tang mat dd hat tai difn trong chdt khf theo kidu "tuydt Id", ttic la mdi electron, sau khi va cham vdi phan tit khf, se nang sd hat tai len thanh 3 (gdm 2 electron va 1 ion duong). 15.5. cau nao dudi day ndi vd qua trinh ddn difn tu Itjc eua chdt khf la khong dUng ? A. Dd la qud trtnh ddn difn trong chdt khf xay ra khi ed hifn tugng nhan hat tai difn. B. Dd Id qud tnnh ddn difn trong ehdt khf xay ra vd duy tri duge ma khdng cdn phun lien tvie cdc hat tai difn vdo. C. Dd la qua trinh ddn difn trong ehdt khf xay ra ehi bang each dd't ndng manh khdi khf d giiia hai difn cue dd tao ra cac hat tai difn. D. Dd Id qua trinh ddn difn trong chdt khi thudng gap dudi hai dang : tia lifa difn vd hd quang difn. 15.6. cau nao dudi day ndi vd hd quang difn la khdng diing ? A. Dd la qua trinh phdng difn tu liie trong chat khf ma hat tai difn mdi sinh ra la electron tu do thoat khdi catdt do phat xa nhift electron. B. Dd la qua trtnh phdng difn tu luc trong ehdt khf xay ra khdng cdn ed hifu difn thd ldm, nhung edn cd ddng difn ldm dd ddt ndng catdt d nhift dd cao. C. Dd la qua trinh phdng difn tu lue trong ehdt khf khi cd difn trudng dii manh d giiia hai difn cue dd lam ion hod ehdt khf. D. Dd la qua trinh phdng difn tu lue trong ehdt khf, dugc sit dung trong may hdn difn, trong Id dun chay vat lifu. 15.7. cau nao dudi day ndi vd tia lita difn la khong dung ? A. Dd la qua trtnh phdng difn tu ItJc trong chdt khi khi cd difn trudng dii manh dd ldm ion hod ehdt khf d giiia hai difn cue. 39 B. Dd la qua trinh phdng difn khdng tu luc trong ehdt khf ma hat tai difn mdi sinh ra la electron tti do thoat khdi catdt khi ion duomg tdi dap vao catdt. C. Dd la qua trinh phdng difn tu luc trong ehdt khf cd thd tii duy tri, khdng cdn lien tuc phun hat tai difn vdo. D. Dd la qua trinh phdng difn tu Itic trong ehdt khf duge six dung trong bugi (bd phan danh lita) de ddt hdn hgp nd trong ddng eo nd vd thidt bi tao khf dzdn. 15.8. Tai sao d didu kifn thudng, ehdt khf lai khdng ddn difn ? Trong ki thuat, tfnh chat nay ciia khdng khf dugc sit dting dd lam gi ? 15.9. Ddng difn trong ehdt khf duge tao thanh bdi nhiing loai hat tai difn ndo ? Cac loai hat tdi difn nay chuydn ddng theo ehidu ndo trong difn trudng d giiia hai difn cue ciia dng phdng difn ? Ke't luan vd ban ehdt ddng difn trong ehdt khf. Bai 16. DONG DIEN TRONG CHAN KHONG 16.1. Ghep ndi dung d cdt ben trai vdi ndi dung 1. Mdi trudng da dugc ldy di tdt ea ede phan tit khf chtia trong nd, ggi la 2. Bdng den thuy tinh ben trong la chan khdng va cd hai difn ctic (catdt la day tdc vonfam, andt la ban kim loai), ggi la 3. Cac electron phdt ra tii catdt bi nung ndng d nhift dd eao trong didt chan khdng, ggi la 4. Chiim tia phdt ra tit catdt trong didt chan khdng, ggi la 5. Tia am cue hay tia catdt thtic chdt la ddng 6. Ddng difn trong didt chan khdng la ddng ehuydn ddng ed hudng ciia cae electron (nhift) theo ehidu tur 40 thfch hgp d cdt ben phai. a) tia am cue hay tia catdt. b) catdt ddn andt. e) tfnh chinh luu ddng dien. d) cae electron nhift. d) dao ddng kf difn tit, may thu hinh. e) sting electron hay sting difn tit. 7. Tfnh ehdt cua didt chan khdng ehi g) dng phdng difn tur. cho ddng difn chay qua nd theo mdt ehidu tur andt de'n catdt, ggi la 8. Ong phdt ra chilm tia electron va h) chan khdng. trong dng cd edc difn ctjc diing tao ra cdc difn trudng vudng gdc vdi nhau va vudng gdc vdi chiim electron, ggi la 9. Ong phdng difn tu dugc su dung i) didt chan khdng. trong cae dting cu nhu : 10. Trong dng phdng difn tit va den k) cae electron bay tu do hinh, bd phan dung dd tao ra chiim tia trong didt chan khdng. electron la 16.2. cau nao dudi day ndi vd didu kifn dd cd ddng difn chay qua didt chan khdng la dung ? A. Chi cdn dat hifu difn thd f/^K ^^ 8^^ t^ duomg va khd ldm giiia andt A vd catdt K cua didt chan khdng. B. Phai nung ndng catdt K bdng ddng difn, ddng thdi dat hifu difn thd f/^K CO gid tri am gifla andt A va catdt K cita didt chan khdng. C. Chi cdn nung ndng catdt K bdng ddng difn va ndi andt A vdi catdt K cua didt chan khdng qua mdt difn kd. D. Phai nung ndng catdt K bdng ddng difn, ddng thdi dat hifu difn thd C/AK '^d gia tri dUdng gifla andt A va catdt K cua didt chan khdng. 16.3. Cau ndo dudi day ndi vd mdi lien hf eiia eudng dd ddng difn Ip^ chay qua didt chan khdng vdi hifu difn thd f/^K gi^^ a^^t A va catdt K la khong dung ? A. Khi catdt K khdng bi nung ndng, thi /^ = 0 vdi mgi gid tri duong cua Up^. B. Khi catdt K bi nung d nhift dd cao, tM /^ ^^ 0 vdi mgi gia tri cua f/^K C. Khi catdt K bi nung ndng d nhift dd cao, thi /^ tang theo cdc gid tri duomg cua I/^K D. Ndu catdt bi nung nong d nhift dd cao va tang ddn. (/^K ^^ 0 ^^ i"9t gid tri duong ndo dd thi /^ se tang ddn tdi gid tri khdng ddi 7^, ggi la ddng bao hod. 41 16.4. Hinh ndo trong Hinh 16.1 md ta dang dae tuydn vdn-ampe ciia didt chan khdng ? u u B. u C. D. Hinh 16.1 16.5. Cau ndo dudi day ndi vd ban chdt cua lia catdt la diing ? A. La chiim ion am phdt ra tfl catdt bi nung ndng d nhift dd cao. B. La chum ion duong phat ra tfl andt eua didt chan khdng. C. La chum electron am phdt ra tfl catdt bi nung ndng d nhift dd cao. D. La chum tia sang phat ra tfl catdt bi nung ndng d nhift dd cao va lam huynh quang thanh dng thuy tinh dd'i difn vdi catdt. 16.6. Cau nao dudi day ndi vd tinh chdt cua tia catdt Id khong dUng ? A. Phat ra tfl catdt, truydn ngugc hudmg difn trudng gifla andt va catdt. B. Mang nang lugng ldm, ed thd lam den phim anh, lam phdt huynh quang mdt sd tinh thd, lam kim loai phat tia X, lam ndng cac vat bi nd rgi vao,... C. La ddng edc electron tu do bay tfl catdt ddn andt. D. La ddiig cac ion am bay tfl catdt ddn andt. 16.7. cau nao dudi day ndi vd dng phdng difn tfl va den hinh la khong diing ? A. Trong dng phdng difn tfl, chum tia electron di qua khoang gifla hai cap ban ctic vudng gde (X^Xj) va (YyYj), rdi hdi tu tren man huynh quang tao ra mdt vdt sang. B. Trong den hinh, chum tia electron di qua khoang giiia hai cudn day ed dang dac bif t (X) va (Y), rdi hdi tu tren man huynh quang tao ra mdt vdt sang. 42 C. Trong dng phdng difn tfl, vifc lam Ifch chum tia electron dugc didu khidn bdng difn trudmg gifla hai cap ban cue vudng gdc (X^Xj) va (l'i72)- D. Trong den hinh, vifc ldm Ifch chum tia electron cung dugc didu khidn bdng difn trudng gifla hai cudn day ed dang dac bift (X)va(Y). 16.8. Electron cd khd'i lugng m vd nang lugng chuydn ddng nhift eiia nd d nhift do T 3kT la s = ——, vdi k la hdng sd Bdn-xo-man. Hdi tdc do ehuydn ddng nhift u cua electron khi nd vfla bay ra khdi catdt trong didt chan khdng d nhift dd T dugc tfnh theo cdng thflc nao ? 2kT \2kT „ \?,kT A. u= J . B. M = J . m \ m V /n C. M = yjSkTm. D.u = 2kT m 16.9. Electron cd khd'i lugng m va difn tfch la e. Ndu bd qua tdc do chuydn ddng nhiet eua electron khi nd vfla bay ra khdi catdt trong didt chan khdng, thi tdc dd trdi V cua electron trong difn trudng giua andt vd catdt khi hieu difn thd gifla hai dien cue nay la U dudc tfnh theo cdng thflc nao ? _ \2eU ^ mU C.v = J . D. i; = d-r—. \ m \ 2e 16.10. Sd electron A^ phat ra tfl catdt trong mdi giay khi ddng difn trong didt chan khdng cd gid tri bao hod /^ = 12 mA la bao nhieu ? Bie't difn tfch electron la -e = -1,6.10"^^ C. A. 7,5.10^^ electron. B. 7,5.10^^ electron. C. 75.10^^ electron. D. 75.10^^ electron. 16.11*. Tai sao khi hifu difn thd (7^^; B^^^ hai cue andt A va catdt K ciia didt chan khdng ed gia tri am vd nhd, thi eudng dd ddng dien /^ chay qua didt nay lai khae khdng va khd nhd ? 16.12*. Tai sao khi hifu difn the' {7^^ Si^a hai cue andt A va catdt K eua didt chan khdng tang ddn mdt gid tri duong du ldn, thi eudng dd ddng difn /^ chay qua didt nay khdng tang nfla va dat gid tri bao hod ? 43 16.13. Tfnh tdc dd chuydn ddng nhift u cua electron d nhift dd T = 2500 K. Cho bidt electron cd khdi lugng m = 9,1.10"^* kg va nang lugng chuydn ddng nhift cua nd d nhift dd T Id £ = f!lL^ ydi k = 1,38.10 J/K Id hdng sd Bdn-xo-man. 16.14. Tfnh tdc dd trdi v ciia electron trong difn trudng gifla andt A va catdt K trong didt chan khdng khi gifla hai difn cue ndy cd mdt hifu difn thd U = 2 500 V. Bd qua tdc dd ehuydn ddng nhift eua electron khi nd vfla bay ra khdi catdt. Difn tfch cua electron Id - e = - 1,6.10"^^ C. Bai 17. DONG DIEN TRONG CHAT BAN DAN 17.1. Ghep ndi dung d cdt ben trdi vdi ndi dung thfch hgp d cdt ben phai. 1. Cae vat lifu cd difn trd sudt giam manh a) electron ddn. khi tang nhift dd, hoac pha them tap cha't, hoac bi ehidu sang hay bi tac dung ciia cae tdc nhan ion hod khae, ggi la b) electron din va Id trdng. c) tranzito (ludng cue) n-p-n. d) ldp chuydn tidp p-n. d) tap nhan hay tap axepto. e) chdt bdn ddn. 44 2. Trong tinh thd silic, cac mdi lien kdt gifla hai Nguyen tfl canh nhau dugc thuc hifn bdng each 3. Electron d mdi lien ke't gifla hai nguyen tfl silic vfla bi phd vd (diit) se chuydn ddng tu do vd trd thanh hat tai difn, ggi Id 4. Mdi lien kdt gifla hai nguyen tfl silic vfla bi phd vd (dflt) se thidu mdt electron nen mang difn duong, ggi Id 5. Chdt ban ddn cd mat dd electron ddn bang mat dd Id trdng, ggi Id 6. Mdi nguyen tfl tap chdt nhu phdtpho (P), asen (As),... cd hod tri 5, khi lien kdt vdi bdn nguyen tfl silic bao quanh nd trong tinh thd se cho mdt electron du (electron ddn), nen ggi la 7. Chdt ban ddn trong dd cdc hat tai difn g) ban ddn loai n. chit ydu la cac electron ddn, dugc ggi la 8. Mdi nguyen tfl tap ehdt nhu bo (B), h) Id trd'ng. nhdm (Al), gali (Ga)... cd hod tri 3, khi lien ke't vdi bd'n nguyen tfl silic bao quanh nd trong tinh thd se cd mdt mdi lien kdt bi thidu electron, do dd cdn phai nhan them mdt electron tfl mdt nguyen tfl khae d lan can dd bu vao, nen goila 9. Chdt ban ddn trong dd cdc hat tai difn i) tap cho hay tap ddno. chu ydu la eae Id trdng, dugc ggi la 10. Chd giao nhau ctia hai midn mang tfnh k) ban ddn loai p. ddn p va tfnh ddn n tao ra tren mdt tinh thd bdn ddn, ggi la 11. Linh kien ban ddn dugc cdu tao tfl l) gdp ehung electron thanh mdt ldp chuydn tidp p-n va ed dae tfnh tucng cap. chi cho ddng difn chay qua nd theo mdt ehidu xde dinh, ggi la 12. Linh kifn bdn ddn duge cdu tao tfl m) didt (chinh luu) ban ddn. mdt tinh thd ban ddn pha tap dd tao ra mdt midn p mdng kep gifla hai midn n va cd dac tinh khuech dai cac tfn hieu ..^ •. „ • , • n) ban dan tinh khiet. difn, ggi la 17.2. Cau ndo dudi day ndi vd tfnh ehdt eua cdc chat ban ddn la khong diing ? A. O nhift dd thdp, difn trd suat eua ban ddn tinh khidt cd gid tri rdt ldm. B. Difn trd sudt eua ban ddn giam manh khi nhift dd tang, nen hf sd nhift difn trd eua ban ddn cd gia tri am. C. Difn trd sudt cua ban ddn cung giam manh khi dua them mdt lugng nhd tap chdt (10~^% -^10"Vo) vao trong ban ddn. D. Difn trd sudt cua ban ddn tang khi nhift dd tang, nen hf sd nhift difn trd cua bdn ddn cd gid tri duong. 45 17.3. cau nao dudi day ndi vd cdc Ioai chdt ban ddn Id khong dUng ? A. Ban ddn tinh khiet la chdt ban ddn, trong dd mat dd «; cua cdc electron ddn dung bdng mat dd p^ ciia cdc Id trd'ng : «, = pj. B. Ban ddn tap ehdt la chdt bdn ddn trong dd mat dd cac nguyen tfl tap chat ldm hon rat nhidu so vdi mat dd cdc hat tai difn. C. Bdn ddn loai n la chat ban ddn trong dd mat dd «„ cua ede electron ddn ldn hom rdt nhidu so vdi mat dd p^ eua cac Id trdng : «„ ^ Pn • D. Bdn ddn loai p la chdt ban ddn trong dd mat dd p^ eua cap Id trd'ng ldn hdn rdt nhidu so vdi mat dd «„ eiia cdc electron ddn :/?»« . 17.4. Cau nao dudi day ndi vd cac hat tai difn trong chdt bdn ddn Id dung ? A. Cdc hat tai difn trong bdn ddn loai n chi la cac electron ddn. B. Cae hat tai difn trong bdn ddn loai p ehi la edc Id trd'ng. C. Cac hat tai difn trong eae ehdt bdn ddn ludn bao gdm ca hai loai : electron ddn va Id trd'ng. D. Electron ddn vd Id trd'ng ddu mang difn tfch am va ehuydn ddng ngugc ehidu difn trudng. 17.5. Cau nao dudi day ndi vd tap ddno vd tap axepto trong ban ddn la khong dUng ? A. Tap ddno la nguyen tfl tap chdt lam tang mat do electron ddn. B. Tap axepto la nguyen tfl tap ehdt lam tang mat dd Id trdng. C. Trong ban ddn loai n, mat dd electron ddn ti If vdi mat dd tap axepto. Trong ban ddn loai p, mat do Id trd'ng ti If vdi mat do tap ddno. D. Trong ban ddn loai n, mat dd electron ddn ti If vdi mat dd tap axepto. Trong bdn ddn loai p, mat do Id trdng ti If vdi mat dd tap ddno. 17.6. cau ndo dudi day ndi vd ldp ehuydn tidp p-n la khong dUng ? A. Ldp chuyen tidp p-n la chd tidp xuc cua hai midn mang tfnh ddn p va tfnh ddn n dugc tao ra tren mdt tinh thd ban ddn. B. Difn trudmg trong ldp chuydn tiip p-n hudng tfl midn p sang midn n. C. Difn trudng trong ldp chuydn tidp p-n ddy ede hat tai dien ra xa chd tie'p xtic gifla hai midn p vd n va tao ra mdt ldp ngheo hat tai difn. D. Ddng difn chay qua ldp ngheo phu thudc vao ehidu cua hifu dien the' dat tren ldp ehuydn tidp p-n. 46 17.7. Cau ndo dudi day ndi vd tfnh chdt cua didt ban ddn la khong diing ? A. Didt bdn ddn la Unh kifn ban ddn dugc tao bdi mdt ldp chuydn tiip p-n. B. Didt bdn ddn chi eho ddng difn chay qua nd theo ehidu tfl midn p sang midn n. C. Didt ban ddn bi phan ctic thuan khi midn n dugc nd'i vdi ctic duomg vd midn p dugc ndi vdi cue am ctia ngudn difn ngodi. D. Didt ban ddn thudng dugc dung dd bidn ddng difn xoay ehidu thanh ddng difn mdt ehidu. 17.8. Hinh nao trong Hinh 17.1 md ta dung sti hinh thdnh difn trudng E^ trong ldp chuyen tie'p p-n do qud trtnh khudeh tan cac Ioai hat tai difn ? n P -:+ _ . n -1 + B. D. Hinh 17.1 P n -i+ 1 « - |+ - |+ - i+ ' 17.9. Hinh nao trong Hinh 17.2 md ta dung sd dd mdc didt bdn ddn khi ldp ehuydn tidp p-n phan cure thuan va ehidu ddng difn / chay qua didt theo ehidu thuan ? A. -Kl- + -!>- + I'^j ——/ _ r^ i^ — • / Hinh 17.2 47 a. D. 17.10. Hinh ndo trong Hinh 17.3 md ta dung dae tuydn vdn-ampe cua didt ban ddn ? u u B. C. D. Hinh 17.3 17.11. Hinh nao trong ffinh 17.4 md ta dting ten cua cdc difn ctic E, B, C tuomg ling vdi cdu tao cua tranzito n-p-n, trong dd E Id cue phat (emito), B la ctic day (bazo) vd C la cue gdp (colecto) ? C. D. Hinh 17.4 17.12. Ve SO dd maeh chinh luu ddng difn dung bd'n didt mdc thdnh cdu chinh luu, trong dd ghi ro ehidu eua cac ddng dien chay qua mdi didt va qua difn trd tai. 17.13. Ve md hinh cdu true n-p-n va kf hifu cua tranzito luong cue n-p-n. Giai thfch tai sao tranzito nay lai cd tfnh chdt khudeh dai ddng dien. 48 K^huangIV Tt/TRaClNG Bai 19. TU TRUONG nui¥e ''i.r,:2i^s9^^is^xF.-:t:.'0 •^v a) b) Hinh 22.1 q<0 22.5. So sdnh trgng lugng vd dd ldn cua lue Lo-ren-xo cd phuomg thang dflng •J 7 tdc dung len mdt electron chuyen ddng vdi van td'c i; = 2,5.10 m/s trong mdt den hinh tivi, tai dd cam flng tfl fi = 2.10 T ed phuomg vudng gdc vdi van td'c v cua electron. 22.6. Hat prdtdn bay vdi van td'c ddu VQ vao mdt midn : Cd difn trudng deu E Cd tfl trudng deu B 1. VQ t t E 2.VQLE 3. dQ,E = 30° 1. 00 ^1^ B 2. UQ JL fi 3. ijQ,B = 30° Vdi mdi trudng hgp tren, hay neu len : a) Dang quy dao eua prdtdn. b) Su bie'n thien van td'c ciia prdtdn. 22.7. Hat electron vdi van td'c ddu bdng 0, duge gia tdc qua mdt hifu difn thd 400 V. Tidp dd, nd dugc ddn vao mdt midn cd tfl trudmg ddu vdi cam flng tfl B vudng gde vdi van td'c v eua electron. Quy dao cua electron trong dd la mdt dudng trdn ban kfnh /?"= 7 em. Xde dinh cam flng tfl B. 22.8. Mdt prdtdn chuydn dgng theo mdt quy dao trdn ban kfnh 5 em trong mdt tfl trudng ddu fi= 10"^ T. a) Xdc dinh van td'c cita prdtdn. -,-27 b) Xdc dinh chu ki chuyen ddng ciia prdtdn. Khd'i lugng prdtdn la 1,672.10 ^' kg. 22.9. Mdt prdtdn khdng cd van td'c ddu, dugc gia td'c qua mdt hifu difn thd 100 V. Sau dd prdtdn bay vao mdt midn cd tfl trudng ddu theo hudng vudng gdc vdi ede dudng sflc. Khi dd quy dao ciia prdtdn la dudng trdn ban kfnh 7?i = 30 em. Ne'u thay thd prdtdn bdng mdt hat nhan heli vdi cung nhflng didu kifn ban ddu nhu tren thi ban kfnh quy dao hat nhan heli bdng bao nhieu ? 55 Cho bie't cae khdi lugng : prdtdn : 1,672.10"^^ kg ; hat nhan heli : 6,642.10"^^ kg. 22.10. Mdt khdi phd ke cd bd phan "lgc van td'c" bao gdm mdt tfl trudng ddu ed cam ling tfl fi = 0,04 T vudng gdc vdi mdt dien trudng ddu 5,00.10 V/m. Mdt ion Li^ cd khdi lugng 1,16.10 kg dugc gia tdc qua difn trudng rdi chuyen ddng trdn dudi tdc dung ciia tfl trudng. Xdc dinh ban kfnh quy dao eiia ion Li dd. 22.11. Hat tfch difn +1,0.10~^ C chuydn ddng vdi van tdc 500 m/s theo mdt dudng thang song song vdi mdt day ddn thdng dai vd han tai khoang each 100 mm ; trong day cd ddng difn 2 A chay theo ehidu chuyen ddng cua hat. Xae dinh hudmg vd dd ldn ciia liic tfl tac dting len hat dd. BAI TAP CUOI CHl/ONG IV IV.l. Chgn cac ndi dung tuong ting nhau d edt phai va cdt trdi. 1. Cam ling tfl eua ddng dien thang dai. 2. Cam ling tfl cua ddng difn trdn. 3. Cam flng tfl ciia dng day difn hinh tru. 4. Lue Lo-ren-xo. 5. Luc Lo-ren-xo tac dung len electron ehuydn ddng thang ddu. , IV.2. Ba ddng difn eung cudng dd /j , Ij, 12, chay trong ba day ddn thang dai ddng phang song song each ddu nhau theo eung mdt ehidu. a) Xae dinh liic tfl tac dung len mdt doan cua ddng d giua Ij. b) Neu ddi ehidu /2 thi luc dd thay ddi thd ndo ? 56 7 A^ a) 4;r.l0"^—/ b)10"^ -r 0 10"l2;r ^ R d) Id ufi sin or e) ^ok^sina iM '2J\ '3/ V < Hinh rv.l IV.3. Hai dong dien cudng dd / chay theo mdt khung day ddn kin ndm trong mdt mat phdng vudng gdc vdi eae dudng sflc cua mdt tfl trudng ddu. Chiing minh rdng lire tfl tdng hgp tac dung ien khung dd bdng 0. Xet hai trudng hgp : a) Khung day hinh vudng. b) Khung day hinh tam giac ddu. IV.4. Ddng dien cudng dd /j chay trong day ddn trdn cd dinh tam Oj ; ddng difn cudng do Ij chay trong day ddn thang dai di qua O] va vudng gdc vdi mat phdng chfla /j . Xac dinh luc tfl tUdng tac gifla hai ddng dien a'y. IV.5. Hai ddng difn cung cudng dd /j = Ij chay trong hai day ddn thang ddi, ddng phang hgp vdi nhau gde 2a. Xac dinh quy tfch nhflng didm tai dd fi = 6. 57 Chuang V CAM ONG DI£N TC; Bai 23. TU THONG. CAM UNG DIEN TU 23.1. Dinh luat Len-xd la hf qua cua dinh luat bao todn A. ddng difn. B. difn tfch. C. ddng lugng. D. nang lugng. 23.2. Trong nhiing phat bidu sau, phat bidu nao dung, phat bidu ndo sai ? s D 1. Tfl thdng Id mdt dai lugng ludn ludn duong vi nd ti If vdi sd dudng sflc di qua difn tfch cd tfl thdng. 2. Tfl thdng la mdt dai lugng ed hudmg. 3. Tfl thdng la mdt dai lugng vd hudmg. 4. Tfl thdng qua mdt mat chi phu thude vao dd Idm cua difn tfch ma khdng phti thudc vdo do nghieng cua mat. 5. Tfl thdng cd thd duong, am hoae bdng khdng. 6. Tfl thdng qua mdt mat kfn ludn bdng khdng. 7. Ddn vi tfl thdng la T.m^ = Wb. D D D D D D D D D D D D D D 23.3. Mdt nfla mat cdu (mat bdn cdu) dudng kfnh 2/? dat trong mdt tfl trudng ddu ed cam flng tfl fl song song vdi true ddi xiing eua mat ban edu dy. Tfnh tfl thdng qua mat ban edu. 23.4. Mdt khdi tfl dif n ddu ACDE canh a dat trong mdt tfl trudng ddu ed vectd cam ting tfl fl song song vdi eanh AC. Tinh tfl thdng qua mat ADE. 23.5. Trong mat phang chfla mdt day ddn thang ddi vd han cd ddng dien /j dat mdt khung day ddn hinh chfl nhat MNPQ trong ed ddng difn Ij, sao cho MN va PQ song song va each ddu day ddn thdng ddi vd han. Chumg td rdng tfl thdng qua MNPQ bdng khdng. 23.6. Tfnh tfl thdng gay bdi mdt tfl trudmg ddu B (B = 0,02 T) qua mdt hinh phang cd chu vi la hinh vudng canh a = 10 em trong cae trudng hgp sau (ffinh 23.1) ; trong mdi trudng hgp mat hinh vudng da dugc dinh hudng : Hinh 23.1 23.7. Trong nhflng phat bidu sau, phdt bidu nao dung, phat bidu nao sai ? 1. Hifn tugng cam flng difn tfl xudt hifn trong mach kfn khi mach kfn chuydn ddng. 2. Hifn tugng earn flng difn tfl xudt hien trong mach kfn khi nam cham chuydn ddng trudc maeh kfn. 3. Hifn tugng cam flng difn tfl xudt hifn trong mach kfn khi tfl thdng qua maeh kfn bidn thien theo thdi gian. 4. Hifn tugng cam ting difn tfl xudt hifn trong mdt mach D D D D s D D D kfn khi maeh kfn dd quay xung quanh mdt true ed dinh trong tfl trudng B ddu sao cho gde a gifla B va phdp tuydn eua mat mach kfn thay ddi. D n 59 23.8. Mdt vdng day ddn kfn (C) dat trude mdt dng day dien hinh trii duge mdc vao mdt maeh difn nhu ffinh 23.2. Xac dinh chieu ddng dien cam iing xuat hifn trong (C) trong hai trudng hgp sau : a) Cho (C) dich chuydn ra xa dng day. b) Cho (C) dflng yen va cho /?i tang len. 23.9. Tren ffiinh 23.3, thanh nam cham song song vdi mat phang chfla vdng day ddn (C). Xae dinh chieu ddng difn cam flng trong (C) khi: a) Nam cham quay 90° de'n vi trf sao eho ctic Nam hudng vao (C). h) Nam cham quay 90° ddn vi tri sao cho cue Bdc hudng vdo (C). c) Nam cham quay deu xung quanh true O cd phucmg song song vdi mat phang chfla (C). 23.10. Mgt khung day ddn khdng bidn dang dugc dat trong mdt tfl trudng ddu B, b VI tri ban dau mat phang khung day song song vdi cac dudng sflc tfl. Cho khung quay 90° ddn vi tri vudng gdc vdi cdc dudng sflc tfl B. Hay xae dinh ehidu ddng difn cam ting xuat hifn trong khung. So sdnh chieu tfl trudng eua ddng difn cam flng vd ehidu eua B. 23.11. Khung day ddn hinh chfl nhat MNPQ dat trong eung mdt mat phang vdi mdt mach difn nhu ve tren ffinh 23.4. Hay xae dinh ehidu ddng dien cam flng xudt hifn trong khung MNPQ trong hai thf nghifm sau : a) Khod K dang ngdt, ddng K. b) Khod K dang ddng, dich eon chay C vd ben phai. 60 Hinh 23.3 K*^ Hinh 23.4 Bai 24. SUAT DIEN DONG CAM QNG 24.1. Hai thanh kim loai song song ndm trong mat phang ngang, ed mdt ddu nd'i vdi nhau bdng day ddn MQNQ ; dugc dat trong tfl trudng ddu, vectd cam ting tfl thang dflng, hudmg len. Thanh kim loai MN tua tren hai thanh kim loai ndi tren, tinh tidn dgc theo hai thanh dd theo phuomg ngang vdi van td'c v khdng ddi (ffinh 24.1). Chting td rdng : a) Trong MN ludn xuat hifn ddng difn cam flng. b) Chidu eua ddng difn cam ting dd ludn khdng ddi. 24.2. Khung day ddn trdn cd thd quay ddu xung quanh mdt trtic cd dinh A thang dflng, trong mdt tfl trudng ddu, vecto B ndm ngang. Ggi a la gdc tao bdi phap tuydn H ciia mat khung va cam ting tfl ^ (Hinh 24.2). Lue t = 0, goc a = 0. Sau dd eho khung quay xung quanh A theo ehidu thuan vdi td'c dd gdc khdng ^j. 2n ddi A OA O A OA Hinh 24.3 61 b) Trong khung xudt hifn ddng difn cam ting. Sudt difn ddng cam limg bidn thien theo dd thi ndo d Hinh 24.4 ? /» 0 J a) b) T ^ t Hinh 24.4 24.3. Mdt khung day ddn cflng hinh chfl nhat cd difn tfch 5 = 200 cm , ban ddu d vi trf song song vdi edc dudng sflc cua mdt tfl trudng ddu fl cd dd ldn 0,01 T. Khung quay ddu trong thdi gian At = 40 % den vi trf vudng goc vdi cdc dudng sflc tfl. Xdc dinh ehidu va do ldn ciia sudt difn ddng cam ting trong khung. 24.4. Mdt dng day hinh tru dai gdm A^ = 10^ vdng day, difn tfch mdi vdng S = 100 em . Ong day cd difn tib R = 16 Cl, hai ddu ndi doan maeh vd duoc dat trong mdt tfl trudng ddu : veeto cam flng fl song song vdi trtic eua hinh tni va dd ldn tang ddu 4.10 T/s. Tfnh cdng sudt toa nhift trong dng day. 24.5. Mdt vdng day ddn difn tfch S = 100 em^ nd'i vao mdt tti difn C = 200 |iF, dugc dat trong mdt tfl trudng ddu, vectd cam ting tfl fl vudng gdc vdi mat phang chfla vdng day, cd do ldn tang ddu 5.10 T/s. Tfnh difn tfch eua tu difn. 24.6. Mdt cudn day ddn det hinh trdn gdm N vdng, mdi vdng cd bdn kfnh R = 10 cm ; mdi met dai ciia day ed difn trd p = 0,5 Q. Cudn day dugc dat trong mdt tfl trudng ddu, vecto cam umg tfl fl vudng gdc vdi cae mat phang chfla vdng day va cd dd ldm fl = 10 T giam ddu ddn 0 trong thdi gian Af = 10 s . Tfnh cudng dd ddng difn xudt hifn trong cudn day dd. 24.7. Mdt dng day ddn hinh tru ddi gdm N = I 000 vdng day, mdi vdng co dudng kfnh 2i? = 10 cm ; day ddn cd difn tfch tiet difn S = 0,4 mm , difn trd suat p = 1,75.10"^ Q.m. Ong day dd dat trong tfl trudng ddu, vecter . cam flng tfl fl song song vdi true hinh tru, ed dd ldm tang ddu vdi thdi A D gian theo quy luat —— = 10" T/s. 62 a) Ndi hai ddu dng day vao mdt tu difn cd C = 10 '^ F, hay tfnh nang lugng tti difn, b) Nd'i doan mach hai ddu dng day, hay tfnh cdng sudt toa nhift trong dng day. Bai 25. TU CAM 25.1. Don vi cua dd tu cam la henry, vdi 1 H bdng A. 1 J.A^. B. 1 J/A I C. 1 V.A. D. 1 V/A. 25.2. Mdt cudn cam ed dd tu cam 0,1 H, trong dd ddng difn bidn thien ddu 200 A/s thi sudt difn ddng tu cam xuat hifn se ed gid tri la bao nhieu ? A. 10 V. B. 20 V. C. 0,lkV. D. 2,0kV. 25.3. Ddng difn trong cudn cam giam tfl 16 A ddn 0 A trong 0,01 s ; sudt dien ddng tu cam trong cudn dd cd gia tri trung binh 64 V ; dd tu cam ed gid tri la bao nhieu ? A. 0,032 H. B. 0,04 H. C. 0,25 H. D. 4,0 H. 25.4. Cudn cam co L = 2,0 mH, trong dd cd ddng difn cudng dd 10 A. Nang lugng tfch luy trong cudn dd la bao nhieu ? A. 0,05 J. B. 0,10 J. C. 1,0J. D. 0,lkJ. 25.5. Ong day difn hinh tru ed ldi chan khdng, chidu ddi / = 20 cm, ed N^ = 1 OCX) vdng, difn tfch mdi vdng S = 100 cm . a) Tfnh dd tu cam L eua dng day. b) Ddng difn qua dng day dd tang ddu tfl 0 ddn 5 A trong 0,1 s, tfnh sudt difn ddng tti cam xudt hifn trong dng day. c) Khi cudng dd ddng difn qua dng day dat tdi gid tri / = 5 A thi nang lugng tfl tfch luy trong dng day bdng bao nhieu ? 63 25.6. Mdt cudn cam cd L = 3 H dugc nd'i vdi mdt ngudn difn cd ?^ = 6 V ; /' = 0. Hdi sau thdi gian bao lau tinh tfl lue nd'i vao ngudn difn, cudng dd ddng dien qua cudn cam tang ddn gia tri 5 A ? Gia sfl cudng dd ddng difn tang ddu theo thdi gian. 25.7. Mdt cudn cam cd L = 50 mH cung mdc ndi tiep vdi mdt difn trd R= 20 Cl, nd'i vao mgt ngudn dien ed ^ = 90 V ; r a 0. Xdc dinh tdc do bidn thien eua ddng dien / tai : a) Thdi diem ban ddu flng vdi cudng dd / = 0. b) Thdi diem ma I -2 A. Chii y : Tdc do bidn thien cua / dugc do bang thuong sd — • BAI TAP CUOI CHl/ONG V V.l. Chgn cae ndi dung tuomg ting nhau d cdt phai va cdt trai. 1 2 1. Tfl thdng qua mdt mat difn tich 5 trong tfl trudng deu. a) —Li 1 e' 2. Cdng cua lue tfl khi tfl thdng qua mgt maeh kfn bien thien. b) ^r-pr 3. Cdng cua luc tfl khi ddng difn trong mdt mach kfn bie'n thien. 4. Bieu thflc cua suat dien ddng cam flng. 5. Bieu thflc cua suat difn ddng tti cam. c) /AO d) LiAi e) BScosa 6. Nang lugng dien trudng trong tti difn. g) 7. Nang lugng tfl trudng trong cudn cam. - h) AO Ar -4 At V.2. Mdt dng day dien hinh tru chidu dai 62,8 em quan 1 000 vdng day, mdi vdng day cd difn tfch 5 = 50 cm^. Cudng do ddng difn bdng 4 A. 64 a) Xdc dinh dd ldn cam ting tfl fl trong ldng dng day. b) Xae dinh tfl thdng qua dng day. c) Tfl dd suy ra dd tu cam cua dng day. Ben trong ldng dng day la chan khdng ; difn trd dng day nhd. V.3. 6ng day cd L = 0,01 H dugc nd'i vdo maeh nhu ffinh V.l. Cho biet ^=l,6V;7-= 1Q;/? = 7Q. Khoa K dang ngdt, lue f = 0 ddng K. a) Tfnh eudng dd ddng difn trong maeh ngay khi ddng K (t = 0). b) Sau khoang thdi gian bao lau thi eudng dd ddng difn trong mach bdng 0,2 A ? R •nmr Hinh V.l \ ^ V.4. Ta xet maeh difn tren Hinh V.2 trong dd A^ la mdt den neon. Den nay tao bdi hai difn cure each nhau 1 + 2 mm nam trong khf neon dp sudt thdp. Ndu hifu difn thd hai cue dat tdi 80 V thi den loe sang do cd hifn tugng phdng difn. Tren ffiinh V.2, khi md khod K : den A^ loe sdng trong mdt khoang thdi gian nao ddy. Hay xac dinh khoang thdi gian dd. Cho bidt dng day L, ngudn difn va difn trd R cd gid tri nhu trong bdi V.3. SA-BTVATLVH R +1 -V ^jnr- ^ Hinh V.2 65 C^hucfng VI KHUC XA ANH SANG Bai 26. KHUC XA ANH SANG 26.1. Ghep mdi ndi dung d cdt ben trdi vdi ndi dung tuong iing d cdt ben phai. 1. Tia khue xa Ifch xa phap tuydn hon tia tdi 2. Mgi mdi trudng trong sudt 3. Chie't sudt tuy ft dd'i cua mdt mdi trudng 4. Dinh luat khue xa viet thdnh «j sin J = rt2 sin r a) la chie't sudt ti dd'i cua mdi trudng dd ddi vdi chan khdng. b) khi dnh sang truydn vao mdi trudng chie't quang kem hdn. c) ddu ed chidt sudt tuyf t ddi ldn hom 1. d) la mdt sd khdng ddi. e) cd dang eua mdt dinh luat bao toan. 26.2. Trong mdt thf nghifm vd su khue xa anh sang, mdt hgc sinh ghi lai tren tdm bia ba dudng truydn cua dnh sdng nhu ffinh 26.1, nhung quen ghi chidu truydn. (Cae) tia nao ke sau ed thd la tia khue xa ? A.//?i. B.IRj. C. /i?3. D. /i?i hoac /i?3. Hinh 26.1 26.3. Tidp theo cau 26.2, vdn vdi cac gia thiet da cho, (cdc) tia nao la tia phan xa ? 66 5B-BTVATLVH\ A. //?3. B. //?2. C IR^. D. Khdng cd tia nao. 26.4. Neu tia phan xa vd tia khue xa vudng gdc vdi nhau, mat khdc gdc tdi la 30° thi chiet sudt ti dd'i Uji ed gia tri bao nhieu (tfnh trdn vdi hai ehfl so) ? A. 0,58. B. 0,71. C. 1,7. D. Mdt gid tri khdc A, B, C. 26.5. Tl sd ndo sau day cd gia tri bang chie't sudt ti dd'i n^j ciia mdi trudng (1) dd'i vdi mdi trudng (2) (edc kf hifu cd y nghia nhu thudng dung trong bai hgc) ? A. ^ . B. J-. sinr «2i C. —. D. Bdt ki bidu thflc nao trong sd A, B, C. 26.6. Hay chi ra cau sai. A. Chie't sudt tuyft dd'i cua mgi mdi trudng trong sudt ddu ldn hom 1. B. Chie't sudt tuyft ddi cua chan khdng bdng 1. C. Chie't sudt tuyft ddi eho bidt van td'c truydn anh sang trong mdi trudng cham hon trong chan khdng bao nhieu ldn. D. Chie't sudt tl ddi gifla hai mdi trudng eung ludn ludn ldm hom 1. 26.7. Td'c dd dnh sdng trong chan khdng la c = 3.10 m/s. Kim cuong cd chiet sudt « = 2,42. Td'c dd truydn dnh sang trong kim cuong v (tfnh trdn) la bao nhieu ? c Cho bie't hf thflc gifla chidt sudt vd td'c do truyen dnh sang la « = —. A. 242 000 km/s. B. 124 000 km/s. C. 72 600 km/s. D. Khdc A, B, C. 26.8. Ba mdi trudng trong sud't (I), (2), (3) cd thd dat tidp gidp nhau. Vdi cung gdc tdi / = 60° ; ndu dnh sdng truydn tfl (1) vao (2) thi gde khue xa la 45° ; ne'u dnh sAng tniydn tfl (1) vao (3) thi gde khue xa la 30°. Hdi ndu dnh sdng truydn tfl (2) vdo (3) vdn vdi gdc tdi / thi gdc khue xa la bao nhieu ? 67 26.9. Mdt cdi mang nude sau 30 em, rdng 40 em ed hai thanh ben thang dflng. Dung luc mang can nudc thi ed bdng ram cua thanh A keo dai tdi dung chan thdnh fl dd'i difn (Hinh 26.2). Ngudi ta dd nudc vdo mdng de'n mdt do cao h thi bdng cua thdnh A Hinh 26.2 ngdn bdt di 7 cm so vdi trude. Bidt chidt 4 sudt cua nudc la n = — • Hay tfnh h vd ve tia sang gidi han bdng ram cua thanh mang khi cd nudc. 26.10. Mdt dai sang don sdc song song chidu tdi mat chdt Idng vdi gdc tdi i. Chdt ldng cd chie't sudt n. Dai sang ndm trong mdt mat phdng vudng gdc vdi mat chat long. Bd rdng cua dai sang trong khdng khf Id d. Tim bd rdng d cua dai sang trong chdt ldng. Bai 27. PHAN XA TOAN PHAN 27.1. Ghep mdi ndi dung d cdt ben trai vdi ndi dung tuong flmg d edt ben phdi. 1. Khi cd tia khue xa truydn gdn sdt a) ca hai hifn tugng ddu tuan theo mat phan cdch hai mdi trudng dinh luat phdn xa dnh sang, trong sudt thi cd thd kdt luan b) khdng thd cd phdn xa toan phdn 2. Phdn xa todn phan vd phan xa ^hi dao chidu truydn dnh sang, thdng thudng gidng nhau d dac x .-.^ , •;. ^^' . . ' . ^ ^.& didm sau day : ^^ *®" ^^'^ ^^ ^° P''^^ ^^ ^^ P*^^- 3. Ne'u cd phan xa todn phdn khi d) gdc tdi cd gid tri coi nhu bang dnh sdng truydn tfl mdi trudng gdc gidi han i^^. (1) vdo mdi trudng (2) thi cd thd e) ludn xay ra khdng cdn didu kifn ke't luan vd chidt sudt. 4. Anh sang truydn tfl mdt mdi trudng tdi mdi trudng chidt quang kem hom va gdc tdi ldn hom gde gidi han Id 27.2. Mdt hgc sinh phdt bieu : phan xa toan phdn Id phdn xa anh sang khi khdng cd khue xa. Trong ba trudng hgp truydn dnh sdng sau day (Hinh 27.1), trudng hgp nao cd hien tugng phan xa toan phdn ? 68 111 iTtTi 1111 ^uong phing (1) k tia phan xa ' (2) Hinh 27.1 n2 = n\ (3) A. Trudng hgp (1). C. Trudng hgp (3). B. Trudng hgp (2). D. Khdng trudng hgp nao la phdn xa todn phdn. 27.3. Cd tia sdng truydn tfl khdng khf vdo ba mdi trudng (1), (2), (3) nhu sau (ffiinh 27.2): (cho/-3> r2> ;•]) Hinh 27.2 Phan xa todn phdn cd thd xay ra khi dnh sang truydn tfl mdi trudng ndo tdi mdi trudng ndo ? A. Tfl (2) tdi (1). B. Tfl (3) tdi (1). C. Tfl (3) tdi (2). D. Tfl (1) tdi (2). 27.4. Tidp theo cau 27.3. Phan xa toan phdn khdng thd xay ra khi dnh sdng truydn tfl mdi trudng nao tdi mdi trudng nao ? A. Tfl (1) tdi (2). B. Tfl (2) tdi (3). C. Tfl (1) tdi (3). D. Tfl (3) tdi (1). 69 27.5. Mdt tia sang truydn trong hai mdi trudmg theo dudng truydn nhu ffinh 27.3. Chi ra cau sai. A. a la gdc tdi gidi han. B. Vdi / > a se cd phan xa todn phdn. C. Ndu dnh sang truydn tfl (2) tdi (1) chi ed phan xa thdng thudng. D. A, B, C ddu sai. ® Hinh 27.3 27.6. Ba mdi trudmg trong sudt la khdng khf va hai mdi trudng khdc ed cac chidt sudt tuyft dd'i «i ; ^2 (^di n2 > '^i)- Ldn lugt cho dnh sdng truydn ddn mat phan each cua tdt ea cac cap mdi trudng ed thd tao ra. Bidu thflc nao kd sau khong the la sin cua gde tdi gidi han tgi, dd'i vdi cap mdi trudng tUdng ting ? * 1 T, 1 A. —. B. —. C.^ . D.^ . n "2 "2 "i 27.7. Cd ba mdi trudng (1), (2) va (3). Vdi eung mdt gdc tdi, ndu dnh sang di tfl (1) vdo (2) thi gde khue xa la 30°, ndu anh sdng di tfl (1) vao (3) thi gdc khue xa la 45°. a) Hai mdi trudng (2) vd (3) thi mdi trudng nao chidt quang hdn ? b) Tfnh gdc gidi han phan xa todn phdn gifla (2) vd (3). 27.8. Mdt khdi ban tru cd chidt sudt « = 1,41 ~ v2. Trong mdt mat phang eua tidt difn vudng gde, cd hai tia song song tdi gap mat phang cua ban tru vdi gdc tdi / = 45° d A vdO (ffiinh 27.4). a) Tfnh gdc Ifch flng vdi tia tdi SO sau khi anh sang khue xa ra khdng khf. b) Xdc dinh dudng truydn cua tia tdi SA. Hinh 27.4 70 27.9. Mdt khdi thuy tinh cd tidt difn thdng nhu ffiinh 27.5, dat trong khdng khf (ABCD la hinh vudng ; CDE la tam giac vudng can). Trong mat phdng cua tie't difn thing, chie'u mdt chum tia sdng dom sde hep SI vudng gde vdi DE (IE < ID). Chiit sudt cua thuy tinh Id « = 1,5. Ve dudng di cua tia sang trong khdi thuy tinh. Phucmg cua tia Id lam vdi phdp tuydn eua mat ma tia sdng Id ra mdt gde bdng bao nhieu ? 27.10. Mdt sgi quang hinh tni vdi ldi cd chidt sudt «! = 1,5 va phdn bgc ngoai ed chie't sudt Uj - 1,41. Chum tia tdi hdi tu tai mat trude eua dng vdi gdc 2a (ffiinh 27.6). Hinh 27.5 Xde dinh gdc a dd tdt ca tia sang trong chflm ddu truydn di duge trong dng. Hinh 27.6 BAI TAP CUOI CHl/ONG VI vdi ndi dung tuong flmg d edt ben phai. VI. 1. Ghep mdi ndi dung d edt ben trdi 1. Khi cd khue xa lien tidp qua nhidu mdi trudng ed edc mat phan each song song vdi nhau 2. Khi khdng cd tia khue xa 3. Ndi dung ehung eua dinh luat phan xa anh sdng va dinh luat khue xa anh sang 4. Trong sgi quang chidt sudt eua phdn ldi a) la edc tia sang gdm tia tdi, tia phan xa vd tia khue xa ddu nam trong mat phdng tdi. b) thi dt Id cd phan xa todn phdn. e) thi bidu thflc nsin/ thudc vd cdc mdi trudng ddu cd gid tri bdng nhau. d) ldm hon chidt sudt eua phdn trong sudt xung quanh. e) tia khue xa Ifch gdn phdp tuye'n hon so vdi tia tdi. 71 VI.2. Mdt tia sang truydn trong khdng khf tdi mat thoang eua mgt chdt ldng. Tia phan xa va tia khue xa vudng gde vdi nhau (ffinh VI.1). Trong edc didu kifn dd, gifla cae gdc i va r cd he thflc ndo ? A.i = r + 90" B.i + r = 90". C. / = 180" - r. D. Mdt hf thflc khdc A, B, C VI.3. Tidp eau VI.2. Cho bidt chidt sudt cua chdt ldng la n = 1,73 « >/3 vay gde tdi / cd gid tri nao ? A. 30°. B. 45°. C. 60°. D. Mdt gid tri khdc A, B, C. VI.4. Hai ban trong sudt cd ede mat song song dugc bd trf tiep gidp nhau nhu ffiinh VI.2. Cac ehidt^udt la «j ^ f^. Mdt tia sang truydn qua hai ban vdi gdc tdi /j vd gde Id ij. So sdnh /j vd i^ ta cd kdt qua ndo ? A. ij = 4- B. ij > /j. Hinh VI.2 C. ij < il D. A, B, C ddu ed thd dung tuy theo gid tri cua n^ va Uj. • Anh sang truyen trong moi trudng co chiet suat n^ tdi mat phan each vdi mdi trudng c6 chiet suat HJ vdi gdc tdi / ^ 0. Xet cac dieu kien sau : (1) n2>ny (2) n2-^ . (4) sin/ < Hay chon cac dieu l