pHAM DLfC CLfdNG (Chu bien) E TAN Rl - BUI IRAN DLfC ANH THAI, THAN THANH SANG 530.076 L527TH CAC DANG BAI TAP TQ CAC D E THI QUOC GIA (TOT NGHIE P - T U Y E N kINH) VAT^Y / ^ C a c de c h i n h thiic v a de l u y ^ n t a p p a n va thang diem ciia B Q Giao due va Dao tao (Tai b a n , svfa chvTa v a bo sung) Cho mach dien xoay chieu nhif h i n h ve Bi^t cuon day c6 dien t r d khong ~ dang ke K h i khoa k dong dong dien qua mach cham pha hofn dien ap hai _ d^u mach la — K h i khoa k md dong dien qua mach nhanh pha i :4„: ,,_4_.i horn dien ap hai dau mach la — Moi lien he giOfa cam dung khang Zc cua ma -|i4 A Z L = (V3 + DZc D V L C Z: = ^ D ZL = M 1 (73- DZC NHA XUAT BAN DAI HOC Si/ PHAM PHAM DLfC CLfdNG (Chu bien) LE TAN Ri - BUr TRAN DISC ANH THAI - THAN THANH SANG LUYEN THI CAP TOC • CAC DANG BAI TAP TlT CAC OE THI QUOC GIA (^at nqklift - ^tufln dnh) VAT L Y Cac de chinh thCfc va de luyen tap Dap an va thang diem cua Bg Giao due va Dao tqo (Tdi ban, sura chufa va bd sung) THt; V i a ; TNVH BiNH VHUAW NHA XUAT BAN DAI HQC Si/ PHAM MUC L U C Phan 1: Tom tat giao khoa 49 53 53 54 56 B Phan rieng cho chirong trinh nang cao Dpng lyre HQC vat ran Con lac v§t K Hi?u img Dop-ple Thuyet tuong doi h^p Thuyet Big bang 13 17 25 31 37 43 A Phan chung cho cce ban va nang cao Dao dpng ca Song ca Dao dpng di^n tir - song difn tir Dong di?n xoay chieu Song anh sang Lugng tir anh sang H^t nhan nguyen tir Tir vi mo den vT mo Phan 2: Kien thirc can nhor 77 80 80 80 82 B Phan rieng cho chirong trinh nang cao Ca hpc v^t ran Con lac v§t li Hi?u irng Dop-ple Quang di$n Tia X (Ronghen) 58 64 66 69 70 73 74 A Phan chung cho co ban va nang cao Dao dpng CO Song ca Dong di?n xoay chieu Dao dpng di^n tu Song anh sang Quang di^n Vat li h^t nhan Phan 3: Dap an va huoTig dan giai cac de on luyfn Tu Tai Phan 4: Dap an va hv&ng dan giai cac de on luyf n Dai h9c - Cao dang 83 190 ^han t: Phan TdM T A T G I A O K H O A chujif cho ban of ban ad ndn^ eao DAO DONG CQ I Dao d9ng dien hoa : * Dao dpng tuan hoan la dao dpng ma trang thai chuyen dpng cua vat dupe l$p lai nhu cij sau nhung khoang thai gian bSng * Chu ky la khoang thai gian ngan nhat de tr^ng thai dao dpng cua v^t l^p l^i nhu cu hay thai gian thvrc hi?n dao dpng toan phan * Dao dpng dieu hoa la dao dpng dupe mo ta bang djnh lu^t dang cos hoae sin: X = Acos(cot+ (p) Vai: + X la li dp ciia dao dpng (khoang each dgi sS tir vat den v/ tri can bdng) + A la bien dp cua dao dpng, don vj : m; em (A = + /x„a.x/) CO la tan so goc ciia dao dpng, don vj : rad/s (co cho biit dao dpng nhanh hay chants co Id toe dp bien doi ciia goc phaj + (cot + cp) la pha dao dpng t^i thai diem t, pha chinh la doi s6 cua ham cosin va la mpt goc (Pha dao d0ng cho ta biet v/ tri vat dao d^ng, gid tri vd each bien thien cua vgn toe va gia toe vat dao dgng Pha dao dgng xde dfnh trgng thai vat dao dqng) + (p la pha ban dau ciia dao dpng (Pha ban ddu xde dinh trgng thai ban ddu ciia vgt dao d(>ng, ph^i thuQc each chgn goc tog dp vd goc thai gian) + Vgn toe va gia toe v|it dao dpng dieu hoa bien thien cung tan so vai tan so v^t dao dpng + V$n toe nhanh pha ^ so vai li dp x + Gia toe ngupc pha so vai li dp x * Lye tac diing lam vat dao dQng dieu hoa: + C6d9ngF = - k x + Lvrc luon huang ve VTCB nen dupe gpi la \\fc keo ve (hay lye hoi phye) * Dao dpng eiia lac 16 xo la mpt dao dpng dieu hoa co chu ky: * Voi goc l^ch nho, dao dgng ciia lac don la mpt dao dgng dieu hoa c6 chu ky: T= n Vg * H f dao dQDg: + thvrc hi^n dao dpng t\ dupe gpi la hf dao dpng + Dao dpng t\ la dao dpng xay duoi tac d\ing ciia npi l\rc (Noi each khdc dao dgng tir c6 chu ky chi phu thuQC cac dgc tinh ciia h^, khong phu thuQC cdc yeu to ben ngoai) + Chu ky cua dao dpng t\ gpi la chu ky rieng Vidu: + Con lac Id xo la rnqt h^ dao dgng (c6 chu ki chiphy thuQC vao m va k), l\cc dan hoi tac dung vac vgt la ngi l\rc + Con lac dcm va Trdi ddt (hay lac vgt It vd Trdi ddt) Id h? dao n Cor nSng: Do v^t n^ng iSc 16 xo chju tac dyng ciia l\rc dan hoi va iSc don la trpng lyc nen ca nang ciia v$t dupe bao toan vi l^rc dan hoi va trpng Ivrc la nhung \\fc the * Co' nang dao d$ng dieu hoa: + The nang: E, = ^ kx^ = ^ kA^cos^(cot + cp) + Dpng nang: Ea = ^ mv^ = ^ kA^sin^((ot + 9) + Ca nSng toan phan: E = E, + E^ = — kA^ =—mco^ = const V$y suot qua trinh dao dpng dieu hoa c6 s\f chuyen hoa nSng lupng gi&a the nSng va dpng nSng nhung ca nSng khong doi va ti I9 vai binh phuang bien dp dao dpng III Dao dgng t^t dan: Dao dpng tat dan la dao dpng c6 bien dp giam dan theo thai gian tac dyng ctia ma sat nhot * D^c diem: + Dao dpng tat dan noi chung khong c6 tinh dieu h6a nhung xet thai gian ngin ta c6 the coi la dao dpng dieu hoa vai chu ki rieng va tan so rieng + L\rc can moi truang cang Ian (hay moi triwng cdng nhot) dao dpng tat dan cang nhanh + Dp nhot cua moi truong tang theo thu t\r: khong khi, nuac, dau, dau rat nhot T I V Dao d^ng tri: Dao dpng dupe cung cap nSng lupng de bu l^i phan nSng lupng mat di ma sat ma khong lam thay d6i chu ki rieng cua no gpi la dao dpng tri * Dao dpng tri eo ngo^i l^rc tac dyng, ngo^i l^rc dupe dieu khiSn + de C O t i n so goe bSng tan so goc dao dpng t\ cua h? + boi chinh dao dpng ky qua mpt ca cau nao * Tan so va bien dp dao dpng tri v i n bSng nhu h$ dao dpng t\ V Dao d^ng cir&ng birc: la dao dpng dupe tri tac dyng cua mpt ngo^ii l^rc bien doi dieu hoa: F = FoCosQt + Dao dpng cu&ng buc la dao dpng dieu hoa + Tan so dao dpng eixong buc bSng tan so ngo^i Ivrc + Bien dp dao dpng cuong buc ti I9 vai bien dp Fo cua ngo^i lyre va phy thupc tan so cuong buc D cua ngoai l\rc ( AQQ e | Q - CO| ) VI S y C9ng hirong: + Hi?n tupng bien dp dao dpng cu&ng buc tang nhanh den mpt gia trj eye d^i tan so f cua lyc cir&ng buc bang tan so rieng cua v^t dao d9ng gpi la hi$n tupng cpng huong + Bien dp dao dpng d^t den gia trj khong doi va eye toe dp tieu hao nSng lupng ma sat bSng toe dp cung cap nSng lupng cho h^ + Bien dp eye d^i ciia dao dpng cpng huong phy thupc ma sat moi truong: ma sat giam thi gia trj eye d^i bien dp ting * Phan bi?t dao dpng cv&ng birc vol dao d9ng tri: + Dao dpng cu&ng buc la dao dpng xay dudi tac dyng ciia ngo^i lyc tuan hoan C O tan s6 goc Q bat ki Khi on djnh dao dpng cuong buc c6 tan so biing tan so ngo^i lyc + Dao dpng tri cung xay dudi tac dyng ngo^i lyc nhung ngo^i lyc dupe dieu khien (boi ehinh dao dpng ay) de c6 tan so goc bang tan so goc ciia dao dpng ty ciia h? VII Tong h(fp dao d^ng: * Xet hai dao dpng dieu hoa cung phuong, cung ikn so: X ] = Aicos(cot + cpi); X2 = A2cos(cot + 92) Tong hpp hai dao dpng dieu hoa cung phuong, cung t i n so la mpt dao dpng dieu hoa cung phucmg, cung tan so voi hai dao dpng phan + Bien dp hai dao dpng tong hpp: A = ^Aj + Aj + Pha ban dau hai dao dpng tong hpp la 9, voi: t a i K p ^ Aisincpi + A^sincp; AiCOSCpi + A2C0S(P2 +2AiA2COs(92 + Neu hai dao dOng phan cung pha: 92 - (Pi = 2kn => A = A , + A2 ; (() = (pi = 92 + Neu hai dao dgng phan ngirgrc pha: 92 - (Pi = (2k + )7t A = Noi chung : A | - A2 ; cp = (pi neu Ai > Aj A, - A < A < A , + A SONG c a I Song ca: + Song CO hpc la nhCrng dao dpng co Ian truyen mOt moi truong + Song CO du(?c t ^ nha lyc lien ket dan hoi giira cac phan tir ciia moi tmong truyen dao dpng di Cac phan tir cang a xa tam dao dpng cang tre pha hon + Khi song truyen chi c6 trang thai dao dpng (pha dao dgng) truyen di ban than cac phan tOr vat chat chi dao dpng t^i cho * Song ngang: + Co phuong dao dpng vuong goc vai phuong truyen song + Truyen moi truong c6 l^rc dan hoi xuat hi?n bj bien dang l?ch (Vd: Song truyen tren mat nuac, spi day dan hoi, tam kim lo^i mong ) + Song tren m§t chat long la hpp lyc c5ng mat ngoai va trpng lyc c6 tac dyng giong nhu lyc dan hoi * Song d9c: + Co phuong dao dpng trung vai phuong truyen song + Truyen moi truong c6 lyc dan hoi xuat hi^n bj bien dang nen, dan (Vd: Song truyen tren 16 xo 16 xo nen va dan ) II Cac dai lirQiig dac trirng ciia song : * Chu ky, tan so ciia song: la chu ky, tan so dao dpng chung ciia cac phan tii v^t chat CO song truyen qua va bang chu ky, tan so ciia nguon song =:> Chu ki va tan so khong doi song truyen * Toe d9 truyen song: la toe dp truyen pha dao dpng Trongrnqtmoi tru&ng toe dQ truyen song khong doi) * Buoc song X: Buac song la khoang each giua hai diem gan nhat tren Cling mpt phuang truyen song va dao dpng ciing pha voi Buoc song cung la quang duong ma song truyen dupe mpt chu ky song X = vT = ^ f * Bien d9 song: Bien dp song t^ii mpt diem la bien dp dao dpng cua phan t i i vat chat tai diem c6 song truyen qua * Nang liTQTig cua song: Qua trinh truyen song la qua trinh truyen nang lugng Nang lugng song tai moi diem t i I9 v a i binh phuomg bien dp song tai diem M p t phan tir v$t chat dang dumg yen c6 song truyen den se dao dpng, nghia la phan tur da nh$n dupe nang lugng tir song Vay qua trinh truyen song cung la qua trinh truyen nang lupng I I I PhiroTig t r i n h song : Xet song truyen tir nguon O den diem M each O mpt doan O M = x Gia sOr phuorng trinh dao dpng t ^ i nguon O la : UQ = Acoscot Song truyen tir O den M mat thai gian to = — Phuong trinh dao dpng tai M each O doan d la: Uyj = UMCO = Uo(t - to) Acos(©t-^) hay U M = A c o s c o t - Y ' ' ) (*) ( • ) cho ta xac djnh l i dp ciia phan tur song t ^ i diem M bat k i tren ducmg truyen song, gpi la la phuong trinh song * Neu song truyen nguQc chieu vai chieu dircmg true Ox thi phmxng trinh song CO dgng: = A c o s ( — t + — x) Tir (*) ta thay song c6 hai tinh chat: + Tinh tuan hoan theo thoi gian: K h i xet mpt diem P tren song c6 toa dp x = d Ta thay l i dp u cua P bien thien theo ham cos => chuyen dpng cua diem P la mpt dao dpng tuan hoan vai chu k i T = — (0 + Tinh tuan hoan theo khong gian: K h i xet tat ca cac diem tren song vao thai diem to, (*) " M = Acos( Y to - Y x) Ta thay l i dp u cua cac diem tren song bien thien tuan hoan theo l i dp x => hinh dang song (hinh sin) tai thai diem to : cu sau mpt buac song thi song lai C O hinh dang nhu truac D^c bift: + NhiJng diem tren phuong truyen song dao dgng cung pha v a i nguon k h i — x = 2k7i=> x = kX v a i Ikl =0,1,2, + N h u n g diem tren phuang truyen song dao dpng ngugc pha v a i nguon — x = ( k + 1)71=^ x = (k + - ) X A I V P h a n x a song: Song dang truyen mpt moi truong ma g^p v§t can thi bj phan x^ Song phan X c6 ciing tan so va buac song ciia song t a i Neu v^t can tyr thi song phan x? luon luon ciing pha v a i song t a i a d i l m phan x^ + Neu v$t can c6 djnh thi song phan x^ luon luon ngugc pha v a i song tai a diem phan x^ + V Song d i r n g : Song dCmg la song c6 nhCrng diem dung yen (nut song) va nhOng diem dao dgng v a i bien dp c^rc d^i (byng song) khong gian Dac d i l m : V j tri cac nut va cac byng la c6 djnh + Song diing la svr giao thoa giua song t a i va song phan x^ tren cdng phuang + V j t r i cac byng luon each dau c6 djnh nhung khoang bSng mpt so le l4n mpt phan t u buac song - V j t r i cac nut luon each d i u c6 djnh nhirng khoang bSng mpt so nguyen Ian nua buac song - 3l + Khoang each giua hai nut (ho$c hai byng) ke dfiu bSng — Dieu kif n c6 song dirng: - K h i hai dau day c6 djnh: De c6 song dung, chieu dai spi day b^ng so nguyen \kn nua buac song ^ = k | (vai k = 1,2, ; => tren day c6 so byng bang so bo bang k, so nut lak+ - K h i mpt dau day t y va mpt dau day c6 djnh: De c6 song dung, chieu dai spi day bang so nguyen le Ian mpt phan t u buac song l = m— (vai m = 1, 3, ) => tren day c6 so bung bang so nut bangn = ~~~ -^on so bo Ian -1 ifng dyng cua song dirng: Do v$n toe truyen song VI Giao thoa song: * Hai nguon dao dpng cung tin s6 va c6 dp i?ch pha khong doi gpi la hai ngu6n ket hgrp Song ma chiing t^o dugc gpi la song ket hgrp * Giao thoa la s\c t6ng hgp cua hai song ket hgrp khong gian, c6 nhixng cho c6 djnh ma bien dp song dugc tang cucmg ho^c bj giam bat * Dieu kif n c6 giao thoa: Hai song la hai song ket hgrp va dao dpng cung phuong * Ly thuyet ve giao thoa: Gia sir A va B la hai ngu6n ket hgrp c6 cung phuorng trinh dao dpng la: U A = U B = Acoscot Xet diSm M bat ky moi truong each A mpt doan di va each B mpt doan d2 Phuorng trinh dao dpng t^i M song tCr A den: ui = Acos(cot - ) Phuorng trinh dao dpng t^i M song tir B den: U = Acos(cot - ) K Dao dpng t^i M la tong hpp cua hai dao dpng tren 2nd,, , , - ) + Acos(cot u = u, + U2 = Acos(cot o 7t(d2-d,) u = 2Acos—^^^^ *^cos c o t - 7t(d2 2nd,, -) +d,) V$y dao dpng t^i M la dao dpng dieu hoa voi bien dp : A ^2 A cosTa thay A phy thupc vj tri cua diem M Nhir vay: * T^ii M CO bien dp c\rc d^i - 2A (hai dao dpng phdn ciingpha : = 2kK) : cos t ( d - d i ) = o Vay: Tai nhirng diem M c6 hi^u dircmg di b§ng so nguyen Ian birffc song thi bien dao d9ng tong h9rp c^c dai va hpp mpt hp cac duong hyperbol nh?in A va B lam tieu diem (ke ca duong trung tr\rc cua AB) dj - d, = kA, voi k = 0, ±1, ±2, k = l k =0 k = -l k = -2 k =2 k'=-2 k-=o k'=-l Cau 16 MQt dif n tra thuan R mac vao m^ch di^n xoay chieu tan so f Muon dong di?n m^ch som pha hon di?n ap giua hai dau do^n m^ch mpt goc (p^O, nguai ta phai mic noi tiep them vao m^ch mpt A ty di^n B cupn day C di^ntroR' D cupn day thuan cam Cau 17 Chu ki dao dpng lac 16 xo tSng Ian A khoi lugrng v^t n$ng tSng gap Ian B khoi lugng v^t n^ng tang gap Ian C dp cumg 16 xo giam Ian D bien dp tang Ian Cau 18 Trong mpt phan ling h^t nhan t6a nang lupng, d^i lugng nao sau day cua cac h?it sau phan umg Ion hon so vai luc truac phan ung? A Tong vecta dpng lupng cua cac h^t B T6ng so nuclon ciia cac h^t C Tong dp hyt khoi ciia cac h^t D Tong khoi lupng cua cac h^t Cau 19 Mpt m^ch di^n xoay chieu mac noi tiep gom ty d i | n C = \iF, cupn 7t day thu§n cam (c6 dp t^r cam L = — H) va di^n tra thuan R = 100 Q d hai dau n m^ch CO mpt di?n ap xoay chieu u = 200^/2 coslOOTrt (V) Di?n ap hi?u dyng hai dau cupn day bang A 400 V B 200>y2V C IOOV2 D 200 V Cau 20 Song ket hgp la hai song A CO cung tan so, cung bien dp, cung phuong dao dpng B CO cung pha, ciing bien dp, khac tan so C dupe phat tir hai nguon nam tren cung mat phang D CO Cling tan s6 va c6 dp If ch pha khong doi Cau 21 Phat bieu nao sau day la khong dung? A V^t CO nhi?t dp tren 3000° C phat nhieu tia tCr ngoai B Tia tu ngo^i khong bj thiiy tinh hap thy ' C Tia tu ngo^i c6 buac song nh6 hon buac song ciia anh sang D Tia tir ngo^ii c6 tac dyng nhi^t Cau 22 Chpn phat bi^u sai: A D6ng dif n xoay chieu ba pha c6 uu diem Ian la c6 the t^o tir truang quay m^nh B Ho9t dpng cua dpng ca khong dong bp ba pha chi dya tren hi^n tupng cam ung dif n tir C Trong dpng ca khong dong bp ba pha, stato la phan cam D Trong dpng ca di^n xoay chieu, di^n nang dupe bien d6i ca nang 85 Cau 23 Mpt di?n tra R = 800 Q mac noi tiep vai mpt ty c6 di?n dung C = 3,98 \i¥ roi mac vao di^n ap xoay chieu c6 gia trj hifu dyng U, tan so f = 50 Hz H? so cong suat ciia do^n m^ch la A 0,5 B 0,866 C 0,707 D 0,6 Cau 24 Cac h^t nhan dong vj A a cung mpt bang phan lo^ii tuan hoan nen c6 tinh chat v^t h' giong B a cung mpt bang phan lo^ii tuan hoan nen c6 tinh chat hoa hpc giong C luon CO so nucion giong va so proton khac D luon CO so natron giong va so nucion khac Cau 25 Dong di?n xoay chieu qua mpt do^n mach la i = 2cos(314t + —) (A) Phat bieu nao sau day dung? A Dp l^ch pha giCra i va di?n ap hai dau m^ch la — B M^ch c6 tinh dung khang C Dong di?n doi chieu 50 Ian giay D Tan so cua di?n ap hai dau m^ch bang 50 Hz Cau 26 M^ch dao dpng di?n tir LC c6 di?n tra thuan khong dang kk Hi?u di?n the giua hai ban ty di?n bien thien dieu hoa theo thai gian vai tan s6 f Phat bieu nao sau day la sai? A Nang lupng di^n tir bSng nang lupng di^n truong eye d^i B N5ng lupng di^n truong bien thien tuan hoan vai tan so 2f C NSng lupng di?n tir bien thien tuan hoan vai tan so f D N5ng lupng di?n tir bang nang lupng tir truong eye d^i Cau 27 Trong so ciia mpt may phat song v6 tuyen di?n, khong c6 m^ch (tang) A tach song B khuech d?ii C phat dao dpng cao tan D bien di^u Cau 28 Quang ph6 lien tyc cua mpt nguon sang J A khong phy thupc vao phan cau t^o ciia nguon sang J, ma chi phy thupc vao nhi^t dp cua nguon sang B khong phy thupc vao nhi?t dp cua ngu6n sang J, ma chi phy thupc vao phan cau t^o cua nguon sang C khong phy thupc vao ca phan cau t^o va nhi^t dp ciia nguon sang J D phy thupc vao phan cau t^o va nhi?t dp ciia nguon sang J Cau 29 Tia Ranghen c6 A cimg ban chat vai song am B buac song Ian han buac song ciia tia hong ngo(ii C cimg ban chat vai song v6 tuyen D di$n tich am 86 Cau 30 Ban dau thi nghifm giao thoa anh sang Y - ang khong Hai khe each mm dugrc ehieu bang anh sang dom sic c6 buac song 0,60 |im, man quan sat each hai khe m Sau d$t toan bp thi nghi?m vao nuae c6 ehiet suat ^ , khoang van tren man luc se bang A 0,4 cm B 0,3 cm C 0,4 mm Cau 31 Mpt buc dorn sSc la burc x? A CO v$n toe xac djnh chan khong B chi thupc vung anh sang nhin thay C gom cac photon c6 nang lugng giong D CO t i n so ph\ thupc moi truong suot Cau 32 Dieu nao sau day la sai noi ve tia anpha ? D 0,3 mm A Tia anpha thyc chat la dong cac h^t nhan nguyen tu Heli ^ Hej B Klii di qua di^n truong giCra hai ban ty di?n, tia anpha l^eh ve phia ban am cuaty C Tia anpha c6 cung ban chat vai tia gamma va tia X D Khi di khong khi, tia anpha se lam ion hoa khong n Phan rieng: A Theo chirong trinh chuan: (8 cau, tir cau 33 den cau 40) Cau 33 Con lac 16 xo treo thang dung dao dpng dieu hoa vai tan so Hz Neu gan them vao v^t nSng mpt v^t khac c6 khoi lugng Ian gap Ian khoi lugng cua v§t n§ng thi tan so dao dpng mai se la A 1,5 Hz B V3 Hz C 0,5 Hz Cau 34 Hinh ben bieu dien song ngang truyen tir trai sang phai Hai phan tu P va Q ciia moi truong dang chuyen dpng nhu ^ the nao t^i thai diem dang khao sat? A P va Q dang di chuyen sang phai B P va Q dang dung l ^ i C P di xuong eon Q di len D P di len Q di xu6ng D Hz Cau 35 D$t di^n ap xoay chieu u = 100 N/2 cos OOnt (V) vao hai dau do^n mach RLC noi tiep Biet cam khang Zi = 200 CI, dung khang Zc = 100 Q, eong suat tieu thy ciia do^n m^ch P = 40 W Nhu v^y: A R = 50Q B R = 0 Q C.R=150n D.R = 250n Cau 36 Trong giao thoa anh sang dan sic, khoang each tu van toi.thu (tinh tir van sang trung tam) den van sang b^c (a hai ben van sang trung tarn) tinh theo khoang van i la A 2,5i B.6,5i C 7,5i D 6i 87 Cau 37 M^ch dao dpng a loi vao cua mpt may thu gom cupn cam c6 dp t\ cam va mpt ty di?n c6 di^n dung bien thien Lay c = 3.10* m/s Khi may dupe dieu chinh de thu song c6 buac song 31 m thi di?n dung cua ty di?n la A.63^F B 108MF C 54 pF D 45 pF Cau 38 Mpt mau A khoi lupng 120 g c6 chu ki ban T = 12 dem Thai gian t de khoi lupng mau A l^i 30 g la A 12 dem B 24 dem C 36 dem D 48 dem Cau 39 Mpt tac dyng cua tia hong ngo^i la A gay phan ung quang hoa B lam ion hoa khong C lam phat quang mpt so chat D CO the gay hi?n tupng quang difn Cau 40 Tren mpt spi day c6 chieu dai ( , hai dau c6 djnh, dang c6 song dimg Tren day CO mpt byng song Biet toe dp truyen song tren day la v khong doi Tan so cOa song la 2v V V V A — B — C D — £ It £ 4e B Theo chu-oTig trinh nang cao: (8 cau, tir cau 41 den cau 48) Cau 41 CO hpc gom mpt AB chieu dai i , khoi lupng khong dang ke, dau A ciia dupe gan chat diem c6 khoi lupng m va dau B cua dupe gin chat diem c6 khoi lupng 3m Momen quan tinh cua h? doi vai tryc vuong goc vai A B va di qua trung diem cua la c A m^^ B 3m£' 4m^' D 2m^' Cau 42 Momen lye tac dyng len v^t ran c6 tryc quay eo djnh eo gia trj A bang khong thi v^t dung yen ho§c quay deu B duomg thi luon lam v^t quay nhanh dan C am thi luon lam v^t quay ch§m dan D khong doi va khac khong thi luon lam v^t quay deu Cau 43 Mpt v^t rSn quay quanh mpt tryc c6 djnh di qua vgt, c6 phuong trinh chuyen dpng c = -8 - 2t^ (cp tinh bSng rad, t tinh bSng giay) Vat rkn p A khong CO momen lyc tac dyng vao no B CO gia toe goc thay d6i theo thai gian C dang quay nhanh dan deu D CO goc quay dupe sau s bang 26 rad Cau 44 Khi toe dp goc eiia v$t ran quay tang gap doi thi A gia toe goc tang gap doi va dpng nang tang gap bon B momen dpng lupng tang gap doi va dpng nang tang gap b6n C momen quan tinh, momen dpng lupng va dpng nang deu tang D gia toe goe giu nguyen eon dpng nang tang gap bon 88 T Cau 45 Cho do^n m^ch di^n RLC: Biet di?n ap xoay chieu giOa A va B luon c6 gia trj hifu dyng va tan so khong doi ; cupn day thuan cam ; ty di^n c6 d i | n dung C ; R la mpt bien tra Cho R thay doi, R = R^ thi cong suit tieu thy cua m^ch AB Ion nhat Luc hf so cong suat ciia m^ch bang A B.0,5 C 0,707 D 0,866 Cau 46 Chpn phat bieu dung: A Anh sang c6 buac song khac bj moi truong hap thy giong B H? so hap thy ciia moi truong khong phy thupc vao budc song anh sang C Nhung v^t hap thy Ipc lya anh sang nhin thay dupe gpi la v$t suot c6 mau D Nhirng v§t khong hap thy anh sang nhin thay dugrc se c6 mau den Cau 47 Gpi mo la khoi lugng nghi ciia v^t, c la toe dp anh sang chan khong thurc giua nSng lugng E va dpng lupng p ciia v$t la A E = moc^ + p^c^ B E = mo^c^ + ^ p^c^ C E^ = mo^c^ + p^c^ D E^ = moc^ + Cau 48 Hi?u ung Dop-ple la hi^n tupng A nguon song am phat am c6 tan so khac vai tan so am ma nguon phat dung yen B tan so am thay doi song am truyen moi truong vai t6c dp Ion hom toe dp truyen am khong C may thu nh^n dupe tan so song thay doi c6 chuyen dpng tuong doi giua nguon song va may thu D tan so ciia am giam dan song am truyen xa nguon am va tang len song am l^i gan may thu HirOfNG DAN G I A I Cau D Di^n ap giiJa hai ban ty di^n va giua hai dau cupn day luon ngupe pha khong can m^ch c6 cpng huong hay khong c6 epng huong => D sai Cau A Ed = 3E, => E = 4E, c ^ - k A ^ =:4.-kx2 = ^ x - ± 2 • Co the dp dying cong thicc: Khi Ea = nE, => \ ± Cau C Toe dp truyen song ea phy thupc moi truong truyen song Cau B Xet song CO buoc song A., truyen tu A den diem M each A mpt do^n A M = d Diem M dao dpng ngupe pha yoi A d = ( k + 0,S)X vai k = 0,1,2, 89 Cau C xi = 3cos(nt + ^ ) cm va X2 = 4cos(7rt + a ) cm Bien dp dao dpng tong hgrp A = cm hai dao dpng vuong pha ( A - V A f + A^ ) ^ y - a =± - ^ a = y Cau D Khi song co truyen tCr moi truong sang moi truong khac thi tan so dao dpng sg khong thay doi Cau B T Thoi gian ng4n nhat v^t di tir vj tri can bSng den bien la — - 0,2 => T = 0,8 s Cau A Chiet suat ciia mpt moi truong su6t doi voi anh sang nho hem chiet suat cua moi truong doi voi anh sang tim A sai Cau B Fmin k(A^-A) Nhu v§y a tri can bSng dp dan 16 xo bang Ian bien dp Cau 10 D Ti = s ; T2 = s ; mi Tac6: ^ = = 2m2; aoi = 002 ^ ^ Cau 11 B Dp l^ch pha ciia hai dao dpng cua hai song den M la: ^ k Cau 12 C Khoang each giua gpn song loi kk la X Cau 13 A f = 500 Hz ; V = 250 m/s => 27IX = y = 0,5 m = 50 cm A 7t Tu Acp = — => X = — = 6,25 cm X Cau 14 A Io=10"'^ W / m ^ L = 50dB Tir L = 101g—= 50=> — = ' = > I = ' W / m 90 Cau 15 D Cau A Dong di^n mach som pha hon di?n ap giua hai dau do^n mach m^ch CO tinh dung khang => phai mic noi tiep tliem vac m^ich mpt ty di?n Cau B Tir T = 2n — ^ De T' = 2T thi m' = 4m ho$c k ' = - k Cau 18 C Trong mpt phan ung h^t nhan toa n^ng lirqmg: Tong dp hyt khoi cua cac h^t sau plian umg Ion hom so vai liic tnrac phan ung Cau 19 B C = — ^ F = > Z c = 100fi;L n = - H=>ZL= 0 Q ; R = 100 n u = 200 V2 coslOOTtt (V) => U = 200 V + Z = j R ^ + ( Z L - Z e ) ^ =100V2 Q Z + Di^n ap hi?u dyng hai dau cupn day: U L = I Z L = 200 -Jl V Cau D Song ket hgrp la hai song c6 cung tan so va c6 dp Ifch pha khong doi Cau B + V | t CO nhi?t dp tren 3000°C phat nhieu tia tir ngo^i + Tia tu ngo^i bj thiiy tinh va nuoc hap thy m?inh B sai ' + Tia tu ngo?ii c6 buoc song nho hon buac song ciia anh sang + Tia tur ngo^ii cung c6 tac dyng nhi?t Cau 2 B + Dong di?n xoay chieu ba pha c6 uu diem Ion la c6 the t^o tir trucmg quay m^nh + Ho^t dpng cua dpng co khong dong bp ba pha dya tren hif n tupng cam ijmg di?n tu va sir dyng tu trucmg quay => B sai + Trong dpng ca khong dong bp ba pha: Stato la phan cam, roto la phan umg + Trong dpng ca di|n xoay chieu, d i | n nang dupe bien doi ca nSng Cau C R = 800Q; C = 3,98 => Zc = 800 f2 = > Z = R ^ + Z ^ =800V2n R H? so cong suat cua do^n m^ch: coscp = — = -j= = 0,707 Z v2 91 Cau 24 B Cac h^t nhan dong vj a cung mpt bang tuan hoan nen c6 tinh chat hoa hpc giong Cau 25 D i = 2cos(314t+ - ) ( A ) + — la pha ban dau ciia i nen khong the biet m^ch c6 tinh dung khang hay cam khang + Dong di$n doi chieu 100 Ian giay + Tan so ciia di^n ap hai dau m^ch f = ^ = 50 Hz Cau 26 C M^ch dao dpng di^n tir LC: + Nang lugng di^n tu bang nang lugng di?n truong c\rc d^i + NSng lugng di^n truong bien thien tuan hoan vai tan s6 2f + NSng luqmg di?n tir khong d6i => C sai + NSng lugrng di^n tu hkng n^ng lugng tu truong c\rc d^i Cau 27 A Trong so cua mpt may phat song v6 tuyen di?n, khong c6 m^ch (tang) tach song Con so ciia mpt may thu song v6 tuyen difn, khong c6 m^ch (tang) bien dif u Cau 28 A Quang lien tyc cua mpt nguon sang J khong phy thupc vao phan cau t^o ciia nguon sang J, ma chi phy thupc vao nhi^t dp cua nguon sang Cau 29 C Tia Ronghen c6 ban chat la song di^n tu nen cung ban chat voi song v6 tuyen Cau 30 D Hai khe each a = mm; X = 0,60 fxm; D = m Khoang van i = — = 0,4 mm a Khi d$t toan bp thi nghi^m vao nuoc c6 n = - , khoang van tren man luc se la i ' = — = 0,3 mm n Cau 31 C Mpt buc X9 dorn sac la burc gom cac photon c6 nang lupng giong Chu y: Cac biecxgdeuco vgn toe xdc dinh chart khong va bSng c = 3.](f m/s Cau 32 C + Tia gamma va tia X la song di^n tu tia anpha la dong chuyen dpng ciia h^t mang difn => C sai 92 Cau 33 A Ban dauf= — j — = 3Hz 27t V m Khi gin them vao v§t n$ng mpt v | t khac c6 m' = 3m thi tan so dao dpng mai se l a r = ± | ^ = 27iVm'+m i J i r : =27t\4m, I = , H z ±JZ 27:V3m + m Cau 34 C S\ truyen song la s\ truyen pha dao dpng nen diem P di xuong diem Q di len Cau 35 A u = 100>/2cosl007rt(V);ZL = 200n;Zc= lOOQ; P = 40 W Giai (•) => R = 50 n Cau 36 B Khoang each tir van toi thur (tinh tir van sang trung tam) den van sang b$c (a hai ben van sang trung tam) tinh theo khoang van i la x = 4,5i + 2i = 6,5i Cau 37 C L = n H ; > = 31m Tir = c.2nVLC => C = 54 pF Cau 38 B mo = 120 g; T = 12 dem; m = 30 g Tir • ^ = 2'' = = 22=>k = = - r : > t = T = 24 dem m T Cau 39 D Mpt tac dyng cua tia h6ng ngo?ii la c6 the gay hi^n tuprng quang difn Cku 40 B Tren mpt spi day c6 chieu dai £, hai dau c6 djnh, dang c6 song dCmg Ta c6: „ ^ V _ 2f , V 2e Tren day c6 mgt byng song (k = 1) => f = — Cau 41 A Cau 42 A Momen lyc tac dyng len v^t rSn c6 tryc quay c6 djnh c6 gia trj bang khong thi v^t dung yen hojc quay deu Cau 43 C TCr (p = -8 - 2t^ => V$t ran dang quay nhanh dan deu ngupc chieu duomg 93 Cau 44 B Tir L = lo) va W j = -^lo)^ => Khi toe dp goc cua v$t rSn quay tang gap doi thi momen dpng lupng ting gip doi va dpng nSng tSng gap bon Cau 45 C P m a x » R = J Z L - Z c | = > Z = R,V2=>eos(p = — = Cau 46 C Nhihig v^t h4p thy Ipe l\ra anh sang nhin thay dupe gpi la v$t suot eo mau Cau 47 C Gpi mo la khoi lupng nghi eiia v$t, c la toe dp anh sang chan khong thuc giua nang lupng E va dpng lupng p cua v$t la = mo^c* + p^c^ Cau 48 C Hi?u umg Dop-ple la hi^n tupng may thu nh^n dupe tan so song thay doi c6 chuyen dpng tuomg doi giua ngu6n song va may thu ON LUYEN TU TAI I Phan chung cho tat ca cac thi sinh: (32 cau, tvr cau den cau 32) Cau V^t dao dpng dieu hoa A qua vj tri can bang toe dp bSng 0, dp Ion gia toe bang B a hai bien toe dp bSng 0, dp Ion gia toe bang C qua vj tri can bang toe dp bang 0, dp lom gia toe c\rc d^i D qua vj tri can bang toe dp eye d^i, gia toe bang Cau May phat di^n xoay ehieu kieu cam ung c6 A phan cam la phan t^o dong di^n B phan cam la phan t^o.ra tu truong C loi thep stato dupe gpi la bp gop D phan ung la phan t^o tu truong Cau Trong m^ch dao dpng di^n tu LC, neu di?n tich tren ty d i | n eye d^i la Qo va cuong dp dong dif n eye d^i m^eh la lo thi ehu ki dao dpng di?n tir m^ch la A.T = i - ^ B T = 27tQoIo C.T = t ^ D T = 27iLC Qo ^0 Cau Sy cpng huong ca xay A bien dp dao dpng v^t tang len eo ngo^ii lye tac dyng B tan so lye cuong buc bang tan so dao dpng rieng eiia hf C lye can moi truong rat nho D bien dp dao dpng cuong buc bang bien dp dao dpng cua h | Cau Chu ki dao dpng be cua lac don phy thupc A bien dp dao dpng B gia toe trpng truong g C nang lupng dao dpng D khoi lupng v$t n^ng 94 Cau Con lie 16 xo dao dpng dieu hoa voi tan so f, the n^ng cua lac se bien thien tuan hoan vai tan so A f = 0,5f B f = f C f = f D f = f Cau Trong cac nha may di?n nguyen tu ho^t dpng binh thuong hi^n nay, phan ung nao xay 16 phan umg h^it nhan cua nha may dl cung cap nSng lugmg cho nha may ho^t dpng? A Phan ung phan h^ch day chuyen dupe khong che a mure vupt h^n B Phan Omg nhi^t h^ch c6 kiem soat " C Phan umg phan h^ch day chuyen dupe khong che a muc tai h^n D Phan ung phan h^ich day chuyen dupe khong che a muc dual h^n Cau Xet mpt nguyen tu hidro nh|n nSng lupng kich thich, electron chuyen len quy d^o M , electron tra ve cac quy d^io ben se phat A mpt buc X9 thupc day Banme B hai buc x? thupc day Banme C ba biic x? thupc day Banme D bon buc thupc day Laiman Cau V^t dao dpng dieu hoa theo phuong trinh x = Acos ^ t , quang duong ngSn nhat v$t di ^ T la A.-A B.A C.AVI D.A — • Cau iO Tia tu ngo^i va tia X deu c6 ban chat la song di^n tu, c6 buac song dai ngan khac nhau, nen A chiing bj l§ch kliac dif n truomg deu B chiing bj l^ch khac tu tru6ng deu C chiing deu dupe su dyng y te de chyp di?n D CO kha nSng dam xuyen khac Cau 11 Trong rtipt thi nghi^m ve giao thoa song tren m$t nuac, hai nguon ket hpp A va B dao dpng vai tan so 15 Hz va ciing pha T^i mpt diem M each nguon A va B Tihiing khoang di = 16 cm va d2 = 20 cm, song c6 bien dp eye tieu Giua M va duong trung tryc ciia AB c6 d3y eye d^i Toe dp truyen song tren m^l nuac la: A 24 cm/s B 48 cm/s C 20 cm/s D 60 cm/s Cau 12 Chpn y sai Moi h^t so cap A CO khoi lupng nghi mo B c6 di^n tich Q C CO so lupng tu spin D luon ben vung, Cau 13 Mpt day dan hoi AB = 60 cm c6 dau B c6 djnh, dAu A dao dpng vai f = 50 Hz Tren day c6 song dung va rung bo Toe dp truyen song tren day bSng A 15m/s B 20m/s C 25 m/s D 28 m/s Cau 14 Khi noi ve song ca hpc, phat bieu nao sau day la sai? A Song ca hpc la s\ Ian truyen dao dpng ca hpc moi truang v^t chat B Song ca hpc truyen dupe tat ca cac moi truang rSn, long, va ehan khong C Song am truyen khong la song dpc D Song ca hpc Ian truyen tren m^t nuac la song ngang 95 Cau 15 Phat bieu nao sau day la khong dung? Trong m^ch di^n xoay chiSu RLC khong phan nhanh, tan so cua di?n ap hai dau m^ch la f : di^n dung ciia ty di^n thay doi va thoa man dieu kifn C = — ^ - r r - thl A cuong dp dong di?n cung pha vai di?n ap hai dau do^n m^ch B di^n ap hi^u dyng hai dau di?n tro R d^t gia trj cvrc dai C cong suat tieu thy trung binh m^ich d^t gia trj eye dai D di^n ap hi?u dyng giira hai dau ty di^n d^t gia trj eye dai Cau 16 Khi truyen tai di^n nSng di xa, de giam cong suat hao phi tren duong day tai di|n, nguai ta sg A giamiiet dif n ciia day dan B tang di$n ap a nai truyen di C giam h? so cong suit eac m^ch tieu thy D tang cuong dp dong di^n tren day dan Cau 17 d hai dau cupn day thuan cam L = 0,159 H c6 di?n ap xoay chieu : u = 180cos(1007rt +— ) (V) Bieu thuc cuong dp dong di?n qua cupn day la D i = 4,8cos(1007tt + - ) A C i = 3,6cos(1007tt - - ) A B i = 3,6cos(1007tt - — ) A A i = 4,8cos(1007it - — ) A 2 Cau 18 Cho m?ich xoay chieu gom cupn day c6 di^n tra ho^t dpng R = Q va dp ty cam L = noi tiep vai ty difn c6 di?n dung C Difn ap hi?u dyng hai 71 dau m?ich bang 10 V, tan so f = 50 Hz Cuong dp hi^u dyng qua m^ch bang A Ty C CO gia trj A 398|iF B 31,8^F C jiF D 39,8 ^F Cau 19 Khi cuong dp am tang gkp 100 Ian thi mire cuong dp am s6 tang them A 20dB B 100 dB C dB D 10 dB Cau 20 Cho do^n m^ich di?n gom di$n tra R = 40 Q mac noi tiep vai cupn day c6 di?n tra ho^t dpng bang 10 Q va ty c6 difn dung C DJt vao hai dau do^n m^ch mpt di?n ap u = lOcos cot (V) thi di^n ap giOa hai ban ty di?n l^ch pha 90° so vai u Cong suat tieu thy ciia cupn day bang A 12,1 W B 121 W C 24,2 W D 96,8 W C a u 21 ^iNa la chat phong x? P" va t^o Magie T?ii t = c6 4,8 g n ^ a , khoi lupng Magie t^o sau thai gian 15 h la 2,4 g Sau 60 h (tinh tu t = 0) khoi lupng Mg t^o bang A.0,3g B.3,6g C.4,5g D 4,2 g Cau 22 Trong mpt m^ich dao dpng LC (khong c6 dif n tra thuan R), c6 dao dpng difn tir ty (dao dpng rieng) Cu^fng dp dong di?n eye d^i qua m^ch la IQ T^ii thai diem cuong dp dong di?n m^ch c6 gia t r } ^ ^ ^ thi nang lupng 96 A di$n truong bang nua nang luqmg tir truong B di?n truong gap ba Ian nang lugrng tir truong C tir truong bang nang lugrng dif n truong D tir truong gap ba Ian nang lugmg di?n truong Cau 23 Xet cac hanh tinh Mpc tinh, Thuy tinh ; Hoa tinh ; Thien Vuong tinh Hanh tinh xa M$t Troi nhat la: A Mpc tinh B Thien Vuong tinh C Hoa tinh D Thuy tinh Cau 24 Buc c6 buoc song X, = 0,21 |j,m A thupc vung anh sang nhin thay B la tia hong ngo^ii C la tia tu ngo^i D la tia Ronghen Cau 25 Th\rc hi?n giao thoa anh sang don sac doi voi khe Y - ang Tren man anh, be rpng cua 10 khoang van dugrc la 1,6 cm T?ii diem A tren man each van chinh giua mpt khoang x = mm ta thu dugrc van A sang b^c B toi thu ke tir van sang chinh giua C sangb$c3 D toi thu ke tir van sang chinh giua Cau 26 ^'hat bieu nao sau day la sai noi ve anh sang trang va anh sang don sic? A Doi v6i anh sang trdng thi chiet suat cua moi truong doi voi anh sang tim la Ion nhat B Anh sang trang la hon hgrp cua v6 so anh sang don sac khac c6 mau bien thien lien tyc tir den tim , C Anh sang don sac la anh sang khong bj tan sac di qua lang kinh D Chiet suat cua chat lam lang kinh la giong doi voi cac anh sang don sac khac Cau 27 Theo thuyet lugmg tu, ta c6 cam giac chiim sang lien tyc la A anh sang la mpt moi truong d^c bi^t lap day toan bp khong B mat ta luon Iiru l^ii cam giac sang tren v6ng m^c thoi gian 0,1s C mpt chum sang dii yeu cung chua mgt so rat Ion lugmg tu aifh sang D anh sang c6 tinh chat song va ca tinh chat h^it Cau 28 Thi nghi^m giao thoa khe Y - ang voi anh sang don sic c6 buoc song X = 0,5 }im Khoang each giua hai nguon ket hgrp la a = mm, khoang each tu hai nguon den man la D = m Biet giao thoa truong c6 be rpng L = 7,8 mm, so van sang va so van toi thay dupe tren man la A van sang, van toi B van sang, van toi C 15 van sang, 16 van toi D 15 van sang, 14 van toi Cau 29 H^t nhan cang ben viing c6 A nang lupng lien ket h^t nhan cang lorn B nang lupng lien ket rieng cang lorn C so khoi cang Ion D so khoi cang nho * 97 Cku 30 Quang phd lien tyc cua anh sang tr4ng A gom mpt dai sang bien thien lien tyc tir den tim B cac chat dupe chieu bSng tia tu ngo?ii phat C cua m3i nguyen to d$c trung cho moi nguyen to D dupe phat tu cac den c6 nhi?t dp va ap suat thap Cau 31 Phan ung h^t nhan nao sau day Ta phan ung thu n ^ g lupng? A ^ H + ^ H ^ ^ H e + {,n B ^He +'^N -)• ^^O + }p C '^C -» ' ^ N + > D } H ^ ^ H e + 2+^e* Cau 32 Tia hong ngo?ii A la mpt bufc don sic c6 mau hong B la s6ng di^n tu c6 bu6c song nho hon 0,4 (xm C gay mpt so phan ung hod hpc D bi l§ch di^n truong va tu trufirng II Phan rieng: A Theo chirong trinh chuan: (8 cau, tir cau 33 den cau 40) Cau 33 Mpt lie don gom mpt hon bi nho khoi lupng m, treo vao mpt spi day khong gian, khoi lupng sgi day khong dang ke Khi lie don dao dpng dieu hoa v6i chu ki s thi hon bi chuyen dpng tren mpt cung tron dki cm Th6ri gian de hon bi di dupe cm ke tir vj tri can bSng la A 1,5 s B 0,25 s C.0,5s D 0,75 s Cau 34, Mpt day cao su dai m hai dau c6 djnh, thyrc hi^n song dimg tren day thi khoang each giO-a byng va nut s6ng ke c6 gia trj Ion nhat bSng A m B m C 0,5 m D 0,25 m Cau 35 Mpt m^ich di?n xoay chieu khong phan nhanh gom : di^n tra thuan R, cupn day thuan cam L vd ty difn C D§t \ko hai dau d o ^ m^ch di?n dp xoay chieu c6 tan so va di^n dp hi?u dyng khong doi Diing von ke (von ke nhi^t) c6 di^n tra rat Idn, Ian lupt difn dp hai dau do^n m?ich, hai dau ty di^n va hai dau cupn day thi so chi cua von ke tuomg ung la U, Uc vd UL Biet U = Uc = 2UL H? so cong suat ciaa m^ch di^n la A cosq) = ^ B cos(p = ^ C cos(p = ^ D cos(p = l Cau 36 Tia X A Id s6ng di$n tijr c6 tan so nhd hon tan so cua tia tur ngo^i B cdc v§t bj nung n6ng d nhi^t dp cao phdt C c6 the dupe phdt tir cac d^n di§n D c6 bdn chat giong v6i bdn chat tia hong ngo^i Cfiu 37 Khi mdc ty Ci vdi L thi m?ich thu dupe s6ng c6 bu6c s6ng X,, = 60 m; Khi mdc ty C2 v6i cupn L thi m?ich thu dupe s6ng c6 bu6c song 80 m Khi mdc noi tiep Ci vd C2 v6i cupn L thi m?ich thu dupe s6ng c6 budc s6ng X bdng A 140 m B.48m C.20m D 100 m 98 Cau 38 K i m l o ^ i lam catot cua te bao quang di^n c6 gioi quang di?n la Xo = 0,5 j j m Chieu anh sang vao catot, chum anh sang khong gay hi?n tugmg quang d i f n k h i la A anh sang t u ngo?ii B tia Ronghen C tia gamma D tia hong ngo^i Cau 39 K h i noi ve thuyet lugmg t u anh sang, phat bieu nao d u a l day la sai? A K h i anh sang truyen d i , lugmg t u anh sang khong bj thay doi va khong phy thuQC khoang each t a i nguon sang B Nguyen t u hay phan t u v$t chat khong hap thy hay biic x?i anh sang mpt each lien tyc ma tCmg phan rieng bi^t, dut quSng C NSng lupng cua lugrng t u anh sang Ion hon nSng lugrng ciia lupng t u anh sang t i m D M i chum sang d i i rat yeu ciing chua mpt so rat I6n lugmg t u anh sang Cau 40 Qua trinh phong h^t nhan la qua trinh A thu nSng lugmg B toa nSng lugmg C khong thu, khong toa nSng lugmg D vua thu, vua toa nSng lugmg B Theo chirong trinh nang cao: (8 cau, tir cau 41 den cau 48) Cau 41 K h i mpt v$t rdn quay bien doi deu thi A toe dp goc cua v$t rSn khong thay doi theo thai gian B gia toe goc cua v^t r i n khong thay doi theo thai gian C momen dpng lugmg cua v^t r i n khong thay doi theo t h a i gian D momen l\rc tac dyng len v^it r i n thay doi theo thai gian Cau 42 M p t v$t r4n dang quay nhanh dan deu quanh mpt tryc c6 djnh xuyen qua v$t v o i gia toe goc y K h i toe dp goc cua v$t la co, diem M tren v$t ran each tryc quay mpt do^n R ^ c6 gia toe A a = R>//7©^ B a = C.a = R > / / + © ^ R>/Y^T©^ D a = R^V7 Cau 43 Tac dyng vao mpt + «^ rSn dang dung yen, c6 tryc quay c6 djnh xuyen qua v$t, mpt lye F B o qua m p i lyc can V(it r i n A sg quay nhanh dan k h i lyc F c6 gia d i qua tryc quay B se dung yen k h i lyc F co gia song song tryc quay C luon khong quay k h i tryc quay khong d i qua trpng tam cua v$t rSn D sg quay nhanh dan k h i lyc F co dp lorn Ion horn trpng lygmg ciia v^t Cau 44 M p t dia dang quay v o i toe dp 30 rad/s t h i hit dau quay ch|im dan deu va sau 10 s ke tir liic bit dau quay ch$m dan t h i dimg l ^ i So vong dTa quay dupe then gian quay e h ^ dan la A 32,78 vong B 38,27 vong C 23,88 vong D 27,83 vong 99 ... luat bien doi theo thai gian VII Di^n tir trirong: * Hai gia thuyet cua Macxoen (Maxwell): + Trong vung khong gian c6 tir truong bien thien theo thoi gian se xuat hifn khong gian mpt dif n truong... : Theo Macxoen: Trong vung khong gian c6 tir truong bien thien theo thoi gian se xuat hifn mpt difn trirong xoay, va c6 difn truong bien thien theo thai gian thi xuat hif n mpt tir truong vung... quang + Sau ngung kich thich thi mpt so chat v i n tiep tyc phat quang mpt khoang thai gian nao Khoang thai gian tijr luc ngimg kich thich den liic ngimg phat quang ggi la thai gian phat quang * Lan