THI LÝ L2-2011( ĐÀO DUY TỪ-HN)

:_ .,* Trua/'ng THPT' Ebo Duy Tl} - FIh NQi Dd thi thfr dai hoc ldn 2 (ngdy z8,lLLl}Arc) Mdn: VAt li, khdi A (Thoi gian tdm bdi: 9A phfi, khing *d tnA gian ph,ir de') Ma dd thi:201 CAu 1. Cho hai dao d6ng didu hol xr = 4cos(20nt + nl?) (cm) vi xz = 8cos(20nt - 5n16) (cm). Bi€n dO vI pha ban ddu cfia dao d6ng tdng hgp cfra hai dao ddng tr€n bdng A.A=+.E(cm); e= 0 B.A =4Jt(cm);q =5x16 C.A=4.5 (cm);,p=r D.A=+J7(cm);9=2rcl3 CAu 2. Chon c6u dring. S6ng si€u im A. lan truydn voi tdc dd l6n hon s6ng h+ arn. B. lan truydn trong chAn khdng vdi tdc dQ ldn nhdt' C fftl lan truydn f,ong nudc Uien aE s6ng kh6ng ddi. D. c6 tdn sd l6n hdn 2ffi2. Cflr-s 3. Trong thi nghi6m I Ang, kho6.ng cdch giita} khe sri.ng lh 0,2mm, Khoing c6ch tt 2 khe ddn min li 1m' Chidu vlo khe S chirm 6nh sdng tring c5 budc s6ng nim trong khoing tit 0,38pm ddn 0,76im- T4i vi tri cdch vin sdng chinh gltra2,5cm, sd brlc x4 cho vAn s6ng trilng nhau t+i d6 id: A.5 8.8 c.6 D'7 Cdu 4. Trong crich mlc m4ng di6n xoay chidu 3 pha, ci mriy phdt vi tii ddu mic kidu hinh sao thi A. dbng di€n tr6n diy trung hoi lu0n bang 0 B. di€n 6p gifta day pha vi dfly trung hoa l6ch pha 2nl3 so v1idbng di€n C. c6.egia tri higu d+ng cta cubng AO aOng diQn trone 3 pha bing nhau D. dien-6p trigu aqng g-ira day phi vd day irung hoi nh6 hon di€n dp hiQu dgng gita 2 d|y pha' Cau 5. nagt dog hinh tru diri 60cm, dua mot'am thia lai gdn migng dng vi cho dao dQng vdi tdn sd f = 1360H2 rdi ad adn ouo" va-o 6ng, kti chidu dhi cQr nudrc thich hqp thi & migng dng nghe thdy.ary le' to nhdt, khi d6 trcng dng c6 s5ng dilng vdi m4t nudc 1l mdt ntit t6og vd miQng dng li arQt bgng s6ng' Bidt loc dQ. tru.ydn ayiyn8 kh6ng tilif^ S:,agn/r. Khieb nudc ddn d3n ddy On! tni c6 bao nhicu leo nghe duoc am & miQng dng li to nhdt? A.4ldn B. 5 ldn C' 6ldq D' T ldn C*nr 6. Bidt hai dao dong didu hoh lu6n nguoc pha, didu nio sau day ld khOng dting? A. Hai dao dOng c6 cing tdn sd. B. Hai dao dOng c6 c[ng bi€n d6. C. Hai dao d6ng c6 pha hon k6m nhau sd 16 ldn n. D. Hai dao d6ng c6 li dd trr4i ddu nhau. CAer T. Cu6n so ctlp cfta*gt n ay bidn 6p ha 6p c6 1200 vdng. DiQn 6p xoay chidu d{t vio cuOn ss cdp c6 gi6 ti hi€u dung u = i00 v. Theo tiah to6n rhi dien di hi€u dung hai ddu cuQn rhrl cttp d€h6 h 60 v, nhung vi c6 mQt sd vbng day'cria cuQn rh*;ap quao ,n.o ciridu'nguoc 14i so vdi da sd vdng cbn lai n€n diQn 6p hi€u duirg cfra cu6n ttrrl cdp"chiia +O V. 86 qua *qiluo phi cira may Uidn 6p. So vdng-lay qudn nguoc bang_ - 4.60 vdng b. lo uong c. 120 vbng D.240 vbng CAu 8. Can crl vlLo cdu tao cfra m5y quang phd, c6 thd ndi A. M6i vach mhu trdn kinh enh lb. Anh don s6c cira thdu kinh' B. M6i vach mdu tr€n kinh 6nh li Anh don sic cria ling kinh' C. M6i vach miru tr€n kinh anh ld Anh don sic cira khe F cira dng chudn truc. D. Ce A, B, C ddu dring. Cau g. rvrEr .oo'16" ld xo c6 chidu ctdi tu nhi€n lb 50cm vd c6 d0 cring k = 100N/m, v8t treo o <idu du6i cfra ld xo c6 kh6i luong m =ZAO1. Gin ddu rr6n cria ld xo vio trdn cfia mOt thang mdy vd cho thang m6y.chuydn.d6ng chAm ddn dd; di ^uOogit * pnuoog thing dr3ng vdi gia tdc 2mls2. LE g = 10m/s2. Khi vat can b5.ng, chidu dhi cira ld xo bdng A. 47,6 cm B. 48 cm C. 52 cm D' 52,4 cm Cdu 10. Chon cAu dring vd s6ng co hoc. S6ng ngang vA s6ng dqc. c6 dac didm chungld A. truydn duoc trong chan khOng. R. truydn dugc trong chdt ran' C. truydn dudc trong chdt l6ng. D. truydn dudc trong chdt khi. CAu lL. Cho m6t mach dao d6ng diQn til gdm mot tu di€n c6 'diOn dung C = 0,2pF vI mOt cuOn thudn cAm c6 dQ rd cim L = 2mtlvd di€n tra thudn R = 0,1f). Dd cluy tri dao dQng didu hob trong mach v6i hi€u dien thd cuc dai ticn tu di6n th 4V thi phii cung cap cho mach m6t cdng sudt bing "A. O,A.rO"Vl '-_ " n. i,e.to;w c.3,2.L0-4W D' 6'4'104T/ a t ,r z-'()fi \'<-t I d^,-ct^n CAu.12. MQt mriy phdt di€n xoay ohidu m6J pha thf nhdt, phdn cdm c5 p c4p cuc vi 16ro quay vdi tdc d6 n vdng/s thi tdn sd cfia sudt di€n dQng do mdy phrit ra li f. MOt mdy thrt hai c6 3p cap cuc phdt ra ten set bing 4f thi r6to cria , n6 phii quay vdi i6c d0 ldn hon may nt nfret CAU 13. MOt s6ng co truydn theo m6t phuong truydn s6ng tt M ddn N v6i tdc ttQ 15m/s. Phuong trinh s6ng tai M veNHn-tqOtli:u"=acos(olt-n/3)mmviun=acos(ott-nll)mm.Khoangc6chMN=5cm.Tdnsds6ngbang A. 10 Hz B.25Hz C. 50 Hz D. LZ5Hz cau 14. Didu nio sau day ld sai khi n6i vd dao d6ng didu hoi cria m6t chat didm? 4. Van tdc vi gia tdc cta dao d6ng bidn thi€n theo,qui ludt dang sin hoic cosin theo thdi gian. B. Hudng cira vectd gia tOc phu thuQc vlo vi€c chgn chi€u ducrng cta truc Ox. C. Khi di tlr vi trf bi€n dcn vi rri cAn bing, vAr chuydn d6ng nhanh ddn . D. Khi di tt v.i tri cin bang ddn vi tri bi6n, gratdc c6 d0 l6n tang ddn. CAU 15. M4ch dao d6ng c6 tg C = 8000 pF vi cuQn cim L = lmH, di€.n trdkh6ng ddag kd . Hieu di€n thdcuc dai & hai ddu tu li 1,5 V. Khi hi€u di6n thd cria tu diQn li 0,5V tbi cudng dQ ddng dien qua mqch bing A.2.10tA 8.0,4A C.zmA D-4 mA CAu 16. Chon d6p 6n sai vd s6ng am.: A. DO cao cria em khdngti lQ vdi tdn s6'am. B. D0 to cfra dm khdng ti l0 vdi cudng dQ am. C. Dd to cfia dm kh6ng phu thu6c vlo tdn sO am. D. A; sic c6li€n quai m1t tniet vdi dd thi dao d6ng Am. CAU 17. Mdt con lic lb xo dao d6ng didu hoi vdi bi6n d0 li 6cm vi pha ban ddu ldn/3. Qu6ng dudng vfr di duo.c trong 1/3 chu ki, kd tt rhdi didm ban ddu li A. 8 cm B. 9 cm C. 8,15 cm D.9,26 cm CAu 18. Trong dao dQng didu hoi cfia con lic dcrn, d4r lugnrg nio sau day phg thuQc vio khdi luqng cfia vat? A. Lrlc k6o vd. B. Gia rdc cria vAr. C. Tdn sd g6c. D. Bi€n d6. CAu 19. d,rtrng 6nh sdng ving, chidt sudt tuy€t ddi c&a nudc li 4/3, clndtsudt ti ddi cfia kim cucrng ddi v6i nudc li 1,8. Tdc d0 c&adnh s6ng trong chAn khdng li c = 3.108m/s. Jdc tlQ cria 6nh sdng vang & trcn trong kim cuorg li: A.2,22'108m/s-B.1,56.108m/s-c.2,84.10tm/sD.f2s'tb'd' CAU 20. Chon d6p dn sai khi n6i v€'mdy phrdt di€n xoay chidu m6t pha: A. Phdn tao ra tt trudng gpi ln phdn c6.m. B. Phdn t4o ra sudt di6n dOng xoay chidu goi li phdn r1ng. C. Phdn cim vi phdn rlng c6 thd lh stato hoic r6to. D. Tdc dd g6c cta dbng di0n bing tdc d6 g6c cria rOto. Cdu 21. Trong m4ch dao dQng LC, tu di€n dugc tich di€n ddn di6n tich cryc tl4r ld 6 nC rdi ph6ng diQn qua cuQn cim. Thdi gian dd tu ph6ng h& In luo. ng di€n tich tr€n li 2 ps. Cuirng dQ cgc dai cfta dbng di6n chay qua cu6n dny biing A. 1,59 mA B. 3,14 mA C.6,28 mA D. 12,56 mA C,ilu22. Chon ddp 6n difug vd giao thoa s6ng co vdi hai ngudn s6ng kdt hqrp, cDng pha A. Nh&ng didm tr€n vln cuc dai dao ddng cirng pha vdi hai ngudn. B. Nhdng didm trOn van cu. c tidu dao dOng nguoc pha vdi hai ngudn. C. Nhfrng didm trOn vdn cuc tidu c6 bi€n d0 bing 0. D. NhEng didm tren vAn cgc dai dao d6ng v6i bi€n d0 cuc dai. CAU 23. MOt d6ng co di€n xoay chidu c6 diOn trd day quAn li 40Q, khi mic vlo mach c6 di€n 6p hidu dung lh 200V thi sin ra cdng sudt co hgc la 75W. Bidt hq sd c6ng sudt ctra d6ng co le 0,85. Cudng d0 hiOu dung c&a ddng diOn chay qua d6ng co bing A.0,254 B, O,4A C. O,5A D.0,754 Cku24. Hai khe Yang c6ch nhau 2mm, mln 6nh c6ch mat phing chrla hai khe 2m. Chieu s6ng hai khe bing mdt ngudn sdng ph6t ra ddng thdi hai bfc xa c6 budc s6ng,t, = 0,56 pm vi 1z = 0,64 pm. Bd rong .vlng giao thoa tr€n min id L = 2cm. Sd vdn si{ng trtng nhau cria hai brlc xa tr€n li A 5 8.6 c.7 CAU 25. Mudn tdng tdn sd ri€ng cria mach LC l€n 4ldn thi: A. GiE nguy€n dd u cem L, giim di6n dung C di 4 ldn. B. Gifr nguydn di€n dung C , giAm dO tu ci.m L di 4 ldn. C. Giem d9 trl cAm L dizldn vi gi6m diOn dung C di I ldn. D. Teng dQ trl cim L l€n 2 ldn vi tdng di6n dung C l€n 8 ldn. na Cfim 26. MOt con l6c lb xo treo thing drlng, dua vAt ddn vi tri ld xo khdng bien dang rdi budng nhe, vAt dao ddng didu hod. Khi vAt di qua vi tri cAn bang thi vat c6 vdn tdc 20n cmls.Ltiy g= 10 m/sz; nz = 10. Chu ki vd bi€n dd i) oao oong oang A. 0,4svh4cm B.0,5svh5cm C.0,8svi8cm C.3cm D.4cm D. 1svdl0cm C,dur 27.Trong so ctd khdi crla mdt mdy phdt s6ng vd tuydn don giin khdng c5 b6 phAn nlo dudi dAy? A. Mach phdt s6ng di€n til cao tdn. B. Mach khudch dai. C. Mach tdch s6ng. D. M+ch bidn diQu. CAu 28. Ddu A cfra diy AB gin vdi mdt Am thoa dao d6ng vdi bi6n dd ld a, ddu B cd dinh, tr€n dAy c6 s5ng dtng. S6ng tr6n dAy c6 bu6c s6ng 12cm, khoAng cdch ngin nhdt gifra hai didm trdn ddy c6 cing bi€n dd lh a vi dao ddng cirng pha bdng A. 1 cm 8.2 cm CAu 29. Cho mQt doan m4ch AB gdm hai doan rnach ndi tidp: doan mach AM c6 di0n tr& R ndi tidp v6i mdt tq dign, doan mach MB ld mot cuon cAm thudn. DAt veo hai ddu doan mach AB m6t diOn rip xoay chidu v = 30 Ji cos 100nt(V); biet he sd cdng sud't cfra doan mach AM le cos{p = 0,6; di€n r{p hiQu dung hai ddu do4n mach AM bang 4l5ldndien 6p hi6u dung hai ddu doan mach MB. C6ng sudt ti€u thu di€n cfia cA mach bdng 48W. Di€n trO R bang A. 12() B. 16Cl c. 18CI CAu 30. Bi€n dd cira dao ddng cudng bric kh6ng phu thuOc vio: D.24 0 A. Bidn dO cria ngoai luc. B. Tdn sd cira ngoai lu. c. C. Pha cria ngoai lrrc. D. Gdc thdi gian. C&u 3tr. Mach vho cfra mOt m6y thu radio li m6t mach dao dQng gdm m6t cudn dAy vi m6t tu di€n bidn ddi. DiQn dung c&a tu diQn niy c6 thd thay ddi tt Co ddn 64C0. Mach dao d6ng niy c6ng hu&ng vdi budc s6ng bang 100 m rlng vdi di€n dung cira tu c6 gi6t4 16C0. Dii budc s6ng mh m6y thu duoc li: C?n32. !d xo dd toa tiu tr€n c6c br{nh xe dao dQng vdi phuong trinh x = Asin2,5rut. Chidu d}i m6i thanh ray ld l= 12mvi gifia 2 thanh c6 khe h&. VAn tdc thu bang bao nhi€u thi toa bi x6c m4nh nhdt? A.54kmlh 8.45 km/h C. 36 km/h D. 30 km/h CAu 33. Didu nlLo sau ddy ll kh6ng chinh xric, khi n6i vd tia hdng ngoai? A. Tia hdng ngoai c5 bin chdt ld s6ng di€n tt. B. Chi c6 cdc vat c5 nhiOt dQ thdp hou 5000C mdi ph6t ra tia hdng ngoai. C. Tia hdng ngoai duo. c dtng dd sdy ho4c su&i. D. Tia hdng ngoai c6 tilc dung 10n loai kfnh inh chup Anh ban ddm. CAu 34. Hai didm M vi N nam 6 cing mOt phia cria ngudn 2m, tr€n cdng mOt phuong truydn 6m c6ch nhau m0t khoing bing a, c6 mric cudng dd 6m le LM- 30dB vd [+r= 10d8. Ndu ngudn am dAt & c]idn M thi mrlc ctrdng d0 Am & didm N bang bao nhi€u? Bidt ngudn am ln ding hudng. A.9dE 8.7 dB c. 12 dB D.t1dB Cau 35. Dat mot dien dp xoay chidu vi.o hai ddu doan mach ndi tidp gdm mOt bidn tr6. R, i:r6t cu6n cdm thudn vlr mor tu dien. Khi bidn tr& R c6 gi6 tri Ro thi cdng sudt ti€u thu dien cira doan mach ld ldn rdiai.t v). bang 100W. FI6i khi thay ddi gi6 tri cria bidn tr3 ddn gi6 tri zRo thi cdng sudt tiOu thu di€n cfra doan mach bang bao nhi0u? A.40W 8.50W c.80w D. i20w CAre 36. I{hi tia s6ng dcrn s6c di qua mdt phdn c6ch gifia hai mOi trudng trong sudt khdc nhau, kdr luAr. nho sau tIAy sai? A. 20 m ddn 160 m C.25 m ddn 200 m 2:. A. ljudc song tnay doi. C. Tdn so khong thay ddi 8.20 m ddn 1280 m D.25 m ddn 1600 m B. Miu cria tia sri.ng bidn ddi D. Tdc d,0 truydn 6nh s6ng thay ddi C.0,48 pm J CAu 37. Hai con l6c don dao dong didu hod 6 ctng mOt noi. Tlong cdng thdi gian, con lac t\tt. nh2.t tttrc irien drro-i; 8 dao dong, con l5c thf hai thuc hi6n duoc 10 dao d0ng. Ndu tdng chidu dAi dAy treo cfra, ccn lac7, ddng thdi giini chi€u dii dAy treo cfra con l6c i cilng mOt doan 18cm thi chidu dli dAy treo cfra chring bang nhau. DA.li tteo con lic I co ctueu dai la: A.48 cm B. 64 cm C. 84 cm D. 100cn'r CAi-r 38,Trong c6c.dung cu tiOu thu diOn nhu quat, tir lanh, dOng co, ngudi ta phAi n0ng cac he so coag suat nharc A. giAm cdng sudi ti€u thu. B. tdng cong sudt toa nhiet. C. ting cudng dd ddng diOn. D. giem cudng d0 dbng diOn. CAu 39. Hai khe YAng c6ch nhau lmm, miLn 6nh c6ch mdt phing chrla hai khe 2m. Chidu sr6.ng hai khe bang mOt ngudl sdng ph6t ra 6nh s6ng don s5c c6 bu6c s6ng,1. Quan sdt ving giao ihoa tr€n mln thdy 6 r,An giao thoa kd t-idp cdch nhau 3,Bmm. Budc s6ng,t bing A.0,76pn-i 8.0,54 pm D.0,38 pn-r CAu 40. Chon d6p 6n sai? I l.Sog Am truydn til khdng khi vio trong nudc thi budc s6ng ting. l. Fog dnh si{ng truydn rt kh6ng khi vio trong nu6c thi budc s6n g giam. 9. Eng 6nh s6ng v1 s6ng am truydn til kh6ng khi vio trong nudc ttti tan sd s6ng khong ddi. ^ ?-SEg r{nh s6ng vir s6ng am truydn trong nudc thi tdc dg iruydn s6ng kh6ng pfru tn*O:" tdn sd s6ng. -C_e* 41 lrcng thf nghi€m vd giao thoa s6ng tr€n miit nudc c6iai ogridn tgihqp A,B cirng pha. fai hai didm M vi N 0 cing mQt b€n ddi vdi dulng trung truc cfia AB vd 6 trcn*hai van giao thoa cilng loai; til M ddn N cdn c6 3 vfln cuc dai khdc. Cho bidt MA - MB = 15cm vi NA - NB = 33cm. Budc sdng l, vi tr4ng rhdi dao ddng tai M vi N li: A. 8cm; vAn cuc dai B. 6cm; vin cuc tidu 9 9*; vin crgc dai D. gcm; vAn cuc tidu !.f,u fZ, ttl-ot do4n mSch gdm mQt hQp kin c6 2 phdn trl (trong sd 3 phdn tt R, L vi C) m6c noi tidp vfi mQt tu di€n. eiet liar 69 loay chidu hai ddu doan mach l€ch p,hd 900 so vdi di€n ip hai ddu tu di6n. Trong h6.p kin c6 A-RvlC I B, L viC, vdi cim khdng bing dung kh6ng C. R. vd L, vdi R bing t6ng tr6 crja doan mach D. R vi L,vdi R bdt ki CAu 43. MQt con lic ld xo dat thing drlng, vAt treo & ddu dudi cfia ld xo dao d6ng didp hoi vdi chu kt bing 0,5s. nhidu dii tu nhi€n cira ld xo li 60cm, chi€u dii lon nhdt cria lb xo khi vat dao igng le 1ocm. it u=-i6*lrt; n2 = l0- Lfc vit dang & dudi vi tri cin bang vi c6 vAn t6c (L2n)cm/s thi chidu dii ciralO xo n 4.67,25 cm B. 68 cm C. 68,5 cm D.69.,25 cm Cau 44 Mdt doan m4ch gdm mot dicn tr& R mic ndi tidp vdi mot cuon cim thudn. H0 sd c6ng suat cria doan mach bang l/3.Ti sd gita cim khdng vi di€n tr& bing: A. J' B.2J' C. JJ D.2J' Ceu 45. Chgn ddq 6n dring vd dao dQng dt ddn vdi luc cin khdng adittrcdung vio vit. A' Vdi con l6c don, ndu tang khdi luong cfra vit thi dao dQng t6.t ddn nnaon non. B. Vdi con lic lb xo, ndu ting khdi luqtng cira vdt thi dao dgng tit ddn chim hcnr. C. V6i con l6c don, ndu kich thich vdi bi€n d0 cing ldn thi dio ttEng tit ddn cing nhanh. D. Vdi con lic lb xo, ndu kich thich v6i bi€n do cnng ldn thi aao Agig tat ddn cnig ch4m. Cdu 46.lvlQt s6ng dtng tr€n dAy c6 dang: u = 2cos(bx + nl})cos(lOOrct - n\)(cm).Trong d6 u la t dO tai thli dl9q ,:*" mQt phdn trl M tr6n day mi viiri can bing cria n6. cr{ch gdc o *Oi rutoaog x(x io bdng m, t do bang giay). Tdc d6 truydn s6ng doc theo ddy bang g&n/s, [e sd U Uing - A.5n/4(m't) B.3x/4(m-L) C nl7(m4) D.rl4(m4) CAU 47. MOt con l6c lb xo d+t nam ngang, vat c6 khdi luo. ng m = 100 g, lb xo c6 d9 cnlng k = 50 N/m. Dua vit ddn vi.tri li 1o n63 12 cm rdi bu6ng nhe, vat dao ddng tit ddn. He ;d ma s6r gifa vat vi mir ngang le 0,02. Ldy g= 10 m/sz, qu6ng duong ml vft di duoc cho ddn tini atog lai b'ang A. lZm'" B.i8m C.20m D.Z4m CAU 48. Didu ndo sau ddy lh sai khi n6i vd doan mach xoay chidu chi c6 cu6n cAm thudn? A. Cim khdng ti lc thuan vdi di€n 6p hieu dung hai ddu cu6n cim vi ti lc nghich v6i gi6tr! hiQu dung cria ddng di€n qua n6. ! Ddng diOn qua cu6n cim tr6 phanl} so v6i di€n 6p hai ddu cuon cAm. C. DQ tf cAm ciLng ldn thi cim kh6ng cing ldn. D. Chu ki dbng di6n clng l6n thi c&m khr{ng chng nh6 . CAU 49. Mdt ngudn s6ng co c6 phuong trinh u^ = 2cos50nt(cm), tdc dO truydn s6ng trong moi trudng li 7 'Smls. Van tdc dao dong cria mQt phdn tr? s6ng c6ch ngudn O,Zm tai thdi didm t = 0,05s li: A. 0 B, Z5n (cm/s) C. 50n (cm/s) D. 5AJj n (cm/s) Cau 50. Dogn m4ch xoay chidu ndi tiep 1 gdm di€n tr& R; cuon thudn cim c6 d0 tu cAm Lr; tu di€n c6 dion dung C- "Qle hu&ng v6i tdn sd f, = 3oHz. Doan mach xoay chidu ndi tidp 2 g6m dien tr& R; cuon ihudn cAm c6 dQ ru cirnln; T {ie" c6 di6n dung C cOng hu6ng vdi tdn rd f, = 40H2. Ndu ghZp ndi tidp hai do4n m4ch rr6n rhi n6 cong hrr6ng v6i tdn sd bdng 4.24 Hz 8.2+J2Hz C.25Hz o. zs Ji Hz Gi6m thi coi thi kh6ng gi6i thich gi th€m '4 - ,r1::-:: i-: ii.::i :. .illi ." i - _. 1 : ::__.::: i j I.i;i::.:::::! i 1 j l. i_'1 :i ;-_": i".j: : j_1.,; i-l :ij . . ', :1 j'., : j _.a::-l,j::r4._.,r- ] ".1 :-i,r.r;;i,L:rj :.:1 z TRLTGNG TI.I|"T DAO DUY TU E{{I{yNG naru CrAg pg rrw rntr s.ax E{sc LAN II - zsns - MOru Var r,v' Cfru 1. Dilng c6ng thric tinh bi€n d0: At = A,3 * Oi * 2A1A2cos(gz - g,); thay sd ta duoc A = 4rE cm- Dirng cong thric tinh pha ban dAu tang = (A,sing, + Arsin<pr)/(A'cosg, + A,cosg,) = 0-) I = 0; n.V€ giin dd vectcr ta thay g = n. V4Y chon C. CAu ?. Sring si€u dm c6 tdn sd f > 20kHz, n€n Itfu hon 2kHz- -+ Chon D. CAu 3. Vi tri van s6ng x = k).D/a -+ l. = xaAD. Thay sd ta duo.c l" = 5ik(pm). theo bli ra 0,38(pm) < l" < 0,76 (pm) +0,38(pm)s5&<0,76(pm) -+510,76<k< 5/0,38-+6,5<k< 13,2-+ c61 gi|tricirakthoimfrn-> c6 7 bric xa cho vhn sdng trtng nhau tai d6. CAu 4. Ta c6 Uo = .6Ur+ Up< Uo -+ Chon D. CAu 5. Buoc s6ng cia s6ng Am trong khong khi li )" - vlf = 340/136U = 0,25(m). Khi c6 song cirrrig trong ong thi chidudii ceitkhongkhitrongdngbengl=(2k+1)X/4-(2k+l)0,2514(m)=6,25(2k+l)(cm).Tac60<l< 60cm-+ O<6,25(2k+ l) < 60 (vdi kngny€n duong)-) 0 <k< 4,3 -+ VAy c6 5 gi6tricfia k thoimdn -> c65 ldn nghe dm li to nh{t -+ Chon B. Cau 6.I{aidao d6ng nguo.c pha nhau thi bi€n do cfia hai ciao dOng c6 thd ln bat k) gid tri nho, khdng nhat thiel phii bang nhau + Chon B. CAu 7. Theo c6ng thrlc U1/J2 = NrA{: -+ 100/60 = 12004'{:+ N: = 720 vdng. -> dicn rip hiOu dung tr€n m6i vdng lh IJ = 6Afl20(V) = 1/12(V). Coi so vdng qudn ngud.c li n, theo bii ra ta c6 (720 - n).(lll2) - nll2= 40(V) -+ n = 120(vbng) -+ Chon C. CAu B. Theo SGK Vat ff fop li thi mdi vach nidu tr€n kinh Anh trong budng 6nh cfia nii{y quang phd la Anh don sjic cira khe F cira 6ng chudn truc -+ Chon C. Cdu 9. Khi con lac chuydn dOng di xuong chirn ddn ddu thl xudng dudi , ktri d<l vAt chiLr tdc dung cria 3 luc: luc quzin tinh luc quiin tfnii tr{c ch-rng vlo vai huing thing dring {, ui ttvn8 lqc F }rLrdng rhing dring xuong drt6i, luc din l1,5i f,,, hu6ng thing dfrng l€n tr€n -+ Khi vAt cAn bang Fon = P + lin' -) k'A! = rng + n]a -> z\1= m(g -t-a)/ft = 0,2i10 -r-2)1100 =0,024m=2.,4cm -+ chidu diicita lb xo bang 1= lo + 4l = 50 *2,4 = 52,4cm -+'Chon D (-lAu 1{}. S<ing cloc tlrvrirr ducr.c tlong c6c m,ii trubne rin. l6ntr. khi. cbn s5ng ngang irui'$n ducrc trong clra[rin -+ s6ng ngang v"i s<5ng cloc cidu truydn cluoc trong chat ran -+ Chon B CAu 1i. COnj sr,at cdn cung cap cho mach chlng bang phdn cOng suAl mat miit tlo toA nhi€t. Ta c6 LI6? = CUo:-+ Iot = CUut fi = 0,2.tO6.qtl1.t0"; = 0,0016- Cong suit mdt mdt do toi nhi€t P = ItR= (lorl2)R = 0,0016.0,1 = 0,E.104w -+ Chon C Cf;u J2. Tdrr s0 cira strat c1i0n d6ng do mdy thrl nhAt phdt ra f = np, tdn so c&a sudt diOn d6ng do mdy thf hai phlrt ra lh 4f = 3pn'-+ 4np = lp1l'* n' = 4nl3-+ t6'c dO clLray cira ntriy thfr hai lon hon mriy thfr nhAt li n'- n = n/3 -> Chon C CAu13.DOl€chphagiualr,{viNi}Ag=2ttdl}".Tac6Arp=-xl3-(-xl2)=nl6,thr-ryd=5ctl +}-=60cm-> tdn s0 s6ng f = vll,= 1510,6 =25llz + Chon B Cnu 14. ftu'Otlg ciia vecro gia tdc luon hu6ng vd vi tri can baug nrI khOng phLr tlrr-rOc vho vi€c chon chidu duong cfta truc toa dd + Chon B CAu 15. Ta cr5 LIur = CUo?-+ Int = CUo'/L = 8tJ00.10-rr.1,51li0'r = 1.8.10i. Ta lai cri (Lr/Uct) + (i/int) = 1. Thay Lr = 0,5V,Uo = [,5V vilot = 1,8.10'5taduo.c i= 4.10-3A =4mA -> (}rott D Cau 16. V6i cirng nrOt crrinrg c16 am rhl khi thal,cldi tdn so thl d0 to cira itn thall ddi + D-o to cira Am phu thuoc vi.,-r tdn sd inr + Cirori C CArt l7.liong 1/3 chu ki, didm chuydn d0ng trbn ddu quay duo-c rnot g6c cL - (ot = (ZnlTII'l3 = 2nl3 (tir M rien N tren vdng trbn) -) trcn truc Ox Vat ditirlden N-+ Qulngduhgdiduo.c li s=OI + ON= Al2+ A = 9ctn N l'l -+ Cllr,-:'l B CAu 18. I-r.tc k6o v€ F = - mgx/l -z ndn n5 phLr thuOc vio k[,Oi lrtr:ng -+ Chon A iF':lr'.r :€ii ::r ":,: r :' :r.' +rr.::,ri:qr.;l r,; .r .t:,::;i il, 3ii :t .: r a j :r: .i1, -:i-, _ :;.;_t]-t{i,*" ' ,. .l* , , ,r- .: ji!:r;. ,-,o,*,"-ri*;', o.:;.,-,r-i* : .,_ : 1r I' j -;r:r:.i.,i.r;:.1.i:-:::t- ,st u l*-t Cnu 19. Chidt suit tuyet doi cria kim cudng li n2, cria nudc li nr thi chiet suat ti d6i cria kim cuong d6i vdi nu6c li nr, - nrln,-> n2 = nirnr = 1,8.4/3 = 2,4. Chiel sudt tuy6t doi cfia kim cuong ld n" = c/v -+ toc dQ rinh siing trong kim cucrng lh v = c/nr =3JOBI, = 1,25.1d+ Chon D CAu 28.T6c d6 g5c c&a dbng di€n o - LTf , cdn tdc d6 quay cfia rdto li or' = Zrn =Zttf/p ( v6i n lI sd vdng quay "-e:rcir2 1g1o trong ls, p li so cap cuc tU cira mdy) + G) * c0'-) Chon D. ,.,;.*$eu 21. fhdi gian dd tu ph6ng hdt ll2luong di€n t(ch cuc dai ln l/6 chu ki -+T/6 = 2ps -+ T = 12ps = 12.1O6s 6*;;=; tdn so g6c cira clbng di€n trong rnach li a = Zn/T, = l06x/6 (rad/s) + giri tri cu. c dai cira cubmg d6 ddng di€n =#+;ffiu rn4ch li Io - ogo = (106n/6).6.10-e = 3,14.1or (A) = 3,l4mA -+ Chgn B. ;El::$eiiu 22. Nhrhg didm tr€n van cgc tidu c6 thd c6 bi€n d0 khri.c 0 ndu bi€n dQ dao dQng hai ngudn khdng bang nhau, cdn c6c didm trdn vxn cqc dai thi lu6n dao d6ng voi bi€n dO cuc dai -+ Chgn D. Cau 23.Y6i d6ng co di€n thi cong suAt ti€u thu di6n cria d6ng co rD =LlIcosrp = I2R + ./)co + Thay sd vlo ta ducrcphuongtrinh 8Ir-34I+ 15 =0-+ Phuorg trinh c62nghi€nrI=0,5AvirI= 3,75A. NghiQmi= 3,75Ab! ioai vi khi tiray v}o ia thdy cong su{t toA nhiet rdt ldn so vdi c6ng sudt cc hoc n€n nghi€rn nby kh6ng phit hqtp + I-dy I= 0,5A -+ Chon C. CAu24.Tac6k,l,,=kzL-+0,56kr =0,64k2 +7kt=8kz-)kr=8-+khoingc6chgitahai vitritringnhauk€ tiep c&a hai vAn si{ng tr€n bang xo = krlrD/a = 8.0,56.10''.2nJ0't = 4,48(mm). Bd rQng virng giao thoa ren men lh L= Zcm,cdc vi tri trtrng nhau tr€n min li x = 4,48k(rnm) + -W<x<Lfz -+ -10<4,48k < l0 -+ -2,23< k < 2,23 + c6 5 giri tri ctra k lh nguy€n -+ c6 5 vi tri trirng nhau cia hai vAn s6ng cila hai bric xa tr€n -+ Chon A. CAu 25. Tdn s6 cfra mach LC le f = UQx^l LC )+ khi giAm tich LC di 16 ldn thl tdn sd f tang 4 lAn -+ Chgn C. CAu 26. Kh! dua vdt ddn vi tri ld xo khong bidn dang rdi buOng nhe thi bi€n dO A bang dQ bidn dang cta lb xo khivdtcAnbangAl-)v-*=o)A= AG/N = {g*<-(0,2n)2= l0A-+A=0,04(m) =4cm-)0)=v /A= 20n/4 = 5n(rad/s) + Chu ki T = Zrla = 0,4(s) + Chgn A. Cilu 27 .lvlach td.ch s6ng 6 mriy thu s6ng vo tuyen -+ Chon C. -,,. . CAu 28. Tir c6ng thric bien do s6ng dtmg 4 = l2acos(2ndl\' + n?)l = a, v6i d lh .::. klioirng cdch tir di6m t(nh bien dQ M ddn nrit -+ Zacos(2nd/?' + N/2) = *a-+ C cos(2ncll}" + rcn)= +ll2 ->2ndhl- nlT=2n/3 (Xnl3 khdng chort vl d < 0 + d=)v/li= f:ii:a.Z nrlrt kd ti-ltp le CD =a12 = 6cm -+ Khoing c6ch MN = 4cm + Cnon D. CAu 29. Ta c6 giiin dd vecto nhu hinh v6, trong d6 UAM - 4UJ5, coso = singonn = 0,8 Dinh li hdnt cos lJort = Uor,' + UL2 - 2UorUrcoscr -> I ur? + l6uL1p5- 2.4u1u1.0,8 - 302uAp1 = 4.50/5 = 40(v) -) ur, = 50(v) Un = U^n, cosqAM = 40.0,6 Z4(V). Tir cOng th'lc rD = U*3/R -> R = Un? rJt=242148 = l2(O) -+ Chon A Ctiu 30. Bi€n do cfia dao clong cudng bfc phu thu6c vho bi€n do vti tdn so cria ngoai luc tfic li phti thuOc viro pha cuii dao d6ng mi kh6ng phu thudc vio vi0c chon goc thoi gian -+ Chon D. Carr 31. Budc s6ng )" = c.2nJTC . Theo bdi ra ra c6 ".2"r[nOq = 100(m)-+ a( c.zn$C., ) = l00m -> ^ r;;- c.?n,JLL'o - 25rn; + c.Zn 8(c.2n $.C" ) = 8.25 = 200m. Vay dii budc s6ng mh m6y thu cluo.c tit 25m den 200m-+ Chon C. (.nu 32- Toa xe bi x6c manlr nhit khi c6 c6ng hudng co, khi d6 chu ki dao dOlg cria ngoai lu. c ti{c dung vdo ld xo l-ring cliu l<i clao d0ng ri€ng cira lb xo. Chu ki riing cira ld xo lh I = 2nl(2,5n\ = 0,8(s) -+ vin toc cira thu v =llt= 1210,8 = 15(m/s) = 54kmlh-> Chon A. CArr 33. 'fdt c|cic vat d€u phr{t tia hdng ngoai -> C}ron B. {-li.u3,$.GoikhoingcrichtirngudnAmddnMlhcl+ti sdcuongcJ,SAnrtaiMviNleIM/I^,=10?=(d+a)?d2-> (cl+a)/d=10->a=9cl.Khid6 l*=rp/(4ndz1 =8lr12714za1.Khi ngudndattai MthicudngdoArntai Nlh ' :';': rr:iiri:::l:1 'r'lr'- : '::' ::';t; i 1:' 'rr,,=r/)/4na2)Ir,/Bl-+LM-Lu'=101g(Ir,[")=l01g8l*:19(dB)+L*'-LNi-19=30-i9=11(clB)+Chqn D CAu 35. Thay ddi bien trdR dd cong suar tieu thu cli6n clat cuc dai th'i R6 = lZ, -Zrlvi' c6ng suAt crc dai bang q),,,.=Utl(2RJ = 1000il). I(hiR - 2Ro thi tdng trb-t =4Ro?+ Ro'= 5Rot -+ I = rJlz= ul(R."'6)+ Cong sudt tidu thu diOn bangrp = I?(2Ro) = 2Ro U2(sRo)?= 2u75Ro) = 80@) + chon c' Cau 36. Khi di tt m6iiro*gi.ong suat nay vao hoi truinrg rrong suat khdc th} budc s6ng thay ddi nhung tdn s6 khdng thay ddi n6n mhu s6c tia s6ng don sfc khdng thay ddi -> Chon B' CAu 37. Trong cing khoing thbi gian lir t, con t6c iir* nhat thuc hi€n duoc 8 dao dong -+ citu ki T, = t/8' con lac 2 thu. c hi€n duo. c l0 dao dong -+ chu ki T2 = t/10 s T,ff, = J/4. Chidu ddi cdc con lac ii l, vh l, th) the': b2Li ra 1' lgcm=l:* lgcm-+lr-lz=36cm-+lr=1,-_36cm. T{r2= {Jh=514-+l,A'=25116-+ Iri(lr -36) =25/16 -) 11= 100(cm) + Chon D. Ciru 3tt. C6ng suat hao phi trong ciic clung cu dicn ld cdng sudt toA nhiOt (Orr=12r = {F/N2cottq) -+ khi tang h€ so c6ng sudt cosg rhi cutrng d9 hieu dung cria ddng di€n giim -+ c6ng sudt hao phi gilm -> Chon D' cdu 39. 6 van giao thoa kdliep cdch nhau 3,8mm -+ 5if2= 3,8 -> khoing van i = l,52mm. Ta c6 c6ng thrlc tinh bu6c s6ng 6nh sring I = ia/D = 1,52.1O'3- 10'3/2= 0,76(pm) -+ Chon A' Cnu 40. iO. a9 t*lyen s6ng Am trong nudc lh kh6ng ddi khong phu thLr6c vlo tdn so s6ng, cdn s6ng r{nh sdng c5 tdn so khr{c nhau thi t6c oJtruydn sZng Ih kh6c nhau. Li do: khi di tir khong khi vro.trong nu6c thi tdn-sd rinh ra"g tt'6;g adi, .ttid, sudr cria nudc n = c/v, rinh sd.ng c6 tdn sd kh6c nhau thl chiel sudt n cria nu6c lh kh6c nhau + tdc d0 truyiin s6ng v li khdc nhau. VAy D sai -+ Chon D' CAu4l.GilsfrMvlNdtiundmtrdnvAncu.cdai:MnamtrdnvAnthfkthlNnamtrdnvAnthfk+4-+MA- MB = kl, = I5cm; NA -NB = (k + 4)tr = 33cm -+ (k +4)/k =33/15 +k = l0/3 4Z -+ khdng thoA mdn. V4y M v) N cing ndnr tren van cu.c tidu -+ M nam trOn vdn thfr k, N ndm tr€n vfln thrl k + 3 + MA - MB = (2k + l)hlT = iicm; NA - NB = [2(k -F 3) + 17?t12 = 33crn -> 6LE = lScm -> ]. = 6cm' V4y M vi N cr)ng nam tr€n vin cuc ti,iu vl buoc s6ng l" = 6cm + Chon B. Cau 12. Didn 6p hai dAu doan mach l€ch pha 900 so v6i di€n 6p hai ddu tu di€n -+ dien dp hai ddu doan rnach cilag pha v6i cuirng d6 dbng di€n + nrqch c6 cong hu6ng -+ hQp kin phAi cd di€n tr& thudn vi cuOn cAm thudn' i hi ti5 idng irtr Z=1i. + Chon C. ija,* 43. '1'a cd T = 0,5s -+ trin sd g6c a = Znlat= zln(ntd/s) -+ clo bi€n ciang cira ld xo khi vat can bang Al = glaz = l0l(4n)2 = 6,25(cm).Chidudnicuc ciai cila ldxol-". = lo+AI+A -+ 70=60 +6,25 + A -+ A= 3,75cm' Tri ,ong ifruc A. = xj + iui<ot. + 3,:51= xt + (l1nl4ril i;ii = 7,25cia, '"'l i'at c Cufr'.'r tli ci-n br.ng n€n khi d{i cliiOn ci2ri cua lo xo bdng l= lo + Al+ lxl= 60 + 6'25 +2'25 = 68'25cm -+ chgn c' ciru 44.Tac6cosrp =ll3 -_>R[z= tl3_>RlF +4 =113 -+(R: +Zr2)/R==g -> t +ZJlR'1 =9-> ZrtlR' = 8 -+ ZL|R=zJ| >Chon B. CAu 45. A. Vdi con l6c don, leu rang khoi luong th) co ning con lic tang (W = nrgH) + tat ddn chAm horr -+ A sai. B. V6i con lac lb xo, ndu tang khoi iuorrg thi co ning con l6c kh6ng ddi -+ kh6ng inh huong t5'i dao d0ng + B sai. C. V6i con l6c don, ndu kich thich v6i bi€n dO cirng lolr thi co ndng cort litc tdng -> C sai D. V6i con lic lb xo, neu kich rhich v6i bign do cdng ldn thi co nf,ng con lac tang -+ dao dOng tit dAn cirng cham + D dfrng -+ Chon D. Cnrr 46. Mot s6ng dirng rr.en diy c6 dang: u = Zcos(bx "r n/2 )cos( 100nt - nlT)(cn1-> I = vlf = 80150 = 1,6rn/s, he sd b =2n17.=2x17,6 =5x14 (tn-') + Chon A. {)iut 4'/. Khi vtir chir-r tiic dLrng cua lr.rc ma sdr th) co nang bierr ddi tiriLrrh c08g cArt cia lrLc ma siit -+ kA2l? pmgs -> quing ciunng s = kA'/(2FrnB) = 50.0, L22l(2.A,02-0, l. l0) = i 8(nr) + Chqn B' bau as. ianr [l,ang ir,u ttruo.'oio t"ar, sd f ci,a dbng c1i€n v)L cld tu cirn cua cuon cim mii khong phu thu6c vho cli€n ip hi€u clrrng hai ddu cuon cftm vi cLr&ig dO hi€u dung cla dbng diOn qua no + A sai -> Chon A CAu 49. phuong trinh s5ng tai didm M c6ch ngudn li x c6 dang u", = 2cos(50nt - Znx/L) (cm)' Vin tdc dao d6ng cira phdn t& s6ng M lir voo= du/dt = - 100*sin(5ont -2nx/7u) (cm/s). Budc s6ng X=vlf ='7,5f25 =0,3m; thay x = o,Zm ve t = 0,05s ta duoc vaa = 5On(cm/s) +-chon c' -CAu 50. Ta c6 t, = l/(Zx^[L,C ); fz = tlQnr[I.C ). Khi ghdp ndi tidp hai doan mach v6i nhau th\Zv= 'i;,*Zr, -) L = Lt + I-2, <li€n dung cria b6 tu ll Cu = CIZ-+ n6 cQng huong vdi tdn sd f = "",j!(r"J(2, * L,)c t2)-+ ": tlf = (41fL.C + 4nztnc)fz = (l/f ,2 + 2'+,!2 (FIz) -+ Chon B. \ffhn= o3o'z + 1140112 = 50'/(2-302.402) -+ f = ',12 '30'40/50 = Me dd 201 Me dd 202 Me dd 203 Ma dd204 I C 26 A I C 26 D I A 26 A I B 26 A 2 D 27 C 2 C 27 D 2 B 27 D 2 A 27 D 3 D 28 D 3 D 28 B 3 c 28 C - J D 28 D 4 D 29 A 4 D 29 C 4 C 29 C 4 C 29 A R -?0 D 5 A 30 A 5 D 30 D 5 D 30 D 6 B 3l C 6 D 31 B 6 A 3l C 6 B 3l D 7 C 32 A I D 32 C 7 B 3L B 7 A 32 c 8 C 33 B 8 A 33 C 8 A 33 C 8 C 33 D 9 D 34 D 9 C 34 B 9 C 34 B 9 C 34 A 10 B 35 C 10 A 35 D 10 B 35 D 10 A 35 C 1l A 36 B ll A 36 C l1 A 36 A 1l D 36 B t2 C 37 D 12 C 37 B l2 D 37 C t2 C 3't B t3 B 38 D t3 D 38 B 13 C 38 C I3 B 3B C 1A LA D 39 /\ l4 D 39 IJ l4 A 39 D t4 B 39 iJ 15 D 40 D 15 B ,i0 D IJ (l 40 B l5 A 4U IJ r6 C 4l R t6 D 4l B t6 B 4t D r6 C 4l B l7 B 42 C l7 B 42 B 11 lt D Ar) C l7 A 42 B 18 A 43 C 18 B 43 C l8 D 43 D l8 D 43 B 19 D 44 B 19 D 44 B 19 D 44 C r9 D 44 D 20 D 45 D 20 A 45 A 20 B 45 B ?0 C 45 C 2l B 46 A 2l C 46 2l B 46 A 2l D 46 C 22 D 47 B 22 tl1 C 22 B 47 B 22 B 47 D ZJ C 4B A ZJ C 48 D 23 D AO +o D D 23 D Aa TU L 24 A 4\) 24 D 49 D 24 D 49 D 24 C 49 B 25 s0 B 25 B s0 25 D 50 A 25 50 D { . THPT' Ebo Duy Tl} - FIh NQi Dd thi thfr dai hoc ldn 2 (ngdy z8,lLLl}Arc) Mdn: VAt li, khdi A (Thoi gian tdm bdi: 9A phfi, khing *d tnA gian ph,ir de') Ma dd thi: 201 CAu. 60cm, dua mot'am thia lai gdn migng dng vi cho dao dQng vdi tdn sd f = 1360H2 rdi ad adn ouo" va-o 6ng, kti chidu dhi cQr nudrc thich hqp thi & migng dng nghe. cfra vit thi dao dQng t6.t ddn nnaon non. B. Vdi con lic lb xo, ndu ting khdi luqtng cira vdt thi dao dgng tit ddn chim hcnr. C. V6i con l6c don, ndu kich thich vdi