530.076 PHAN VAN HUAN H561D HlidNG DAN GIAI CHI TIET DE THI TUYEN SINK DAI HOC CAO B&NC VAT LI H Nha xuat ban Dai hoc Quoc gia Ha NOi bJO 01± '-W5t>/< PHANVANHUAN DE THI DAI HQC - CAO DANG M6n VAT LI NHA XUAT BAN DAI HQC QUOC GIA HA NQI N H A X U A T B A N DAI H Q C Q U O C G I A H A NOI 16 HANG CHUOl - HAI BA T R U N G - HA NOI Dien thoai: Bien tap - Che b a n : (04) 39714896 Hanh chi'nh: (04) 39714899 Tonq bien t a p : (04) 39714897 Fax: (04) 39714899 Chiu trach nhi$m xuat ban: Giam doc - Tdng bien tap: tap: PHAM TH! TRAM Nha sach S A O MAI Doi tac lien l Vi Neu chieu dong t h d i h a i bufc xa t r e n v^o qua cau t h i d i $ n the cifc dai cua no chi hang d i e n the I d n hcfn, c h i n h la V2 Vdy chon dap an A Cdu 2: T r o n g t h i n g h i e m ve song dCrn^, t r e n m o t stfi day d a n h i d^i 1,2 m v d i h a i dau co d i n h , ngUdi t a quan sat t h a y ngoai h a i dau day co d i n h co h a i d i e m khac t r e n day k h o n g dao dong B i e t k h o a n g t h d i gian giOfa h a i I a n l i e n tiep sgti day duoi t h i n g l a 0,05 s V a n toe t r u y e n song t r e n day l a : A 16 m/s B m/s C 12 m/s D g m/s Giai Theo de b a i t h i t r e n day tao t h a n h m u i song, m o i m i i i s6ng co chieu dai — T a c o : - = 1,2 = > = 0,8m Khoang t h d i gian giffa h a i I a n l i e n t i e p stfi day a j j t h i n g l a 0,05s nen t a co chu k i T = 0,05.2 = 0,1s V a n toe t r u y e n song t r e n day: ^ 5i, = ^ ~ "QT ~ ^C™'^)' Vdy chon dap an D Cdu 3: Doi v d i SLT Ian t r u y e n song dien tCf t h i A vector ciTdng dien triJdng E va vectcf cam ufng tCr B luon vuong goc v d i phtTcfng t r u y e n song Giai Chi tiSt (3e thi TS DH, CO M6n vat li B vectcf CLfcrng d i e n triTcfng E va vecto cam ufng tiT B luon cung phiiong vdfi phiTctog t r u y e n song C vector cam ufng tif B cung phLfcrng vdri phirorng t r u y e n song vector CLTcfng dien t r i / d n g E vuong goc v d i vector cam ufng ttf B D vectcf cifcfng dien tn/cfng E cung phtfcfng v6i phiromg truyen song c6n vector cam ufng tCf B vuong goc vdri vector ci/orng dien trUdng E Giai D o i v d i suf Ian t r u y e n song dien tCf t h i vecto cifdng dien triicfng E va vector cam ufng tCr B luon vuong goc vdri phiTorng t r u y e n song Vay chgn dap an A Cdu 4: Cof n a n g cua m o t v a t dao dong dieu hoa: A t a n g gap doi k h i bi§n dao dong cua v a t t a n g gap doi B b i e n t h i e n t u a n hoan theo t h d i gian v i chu k y b k n g chu k y dao dong cua v a t C b i e n t h i e n t u a n hoan theo thofi gian v d i chu k y bSng mot nufa chu k y dao dong cua vat D b a n g dong nSng cua v a t k h i v a t id'i v i t r i can bang GiSi Cor n a n g cua m o t vat dao dong dieu hoa bang dong nang cua vat k h i v a t tdri v i t r i can bang Vay chgn dap an D Cdu 5: H a t n h a n '°Be c6 k h o i liTcrng 10,0135u K h o i lifgng cua ncftron ( n a t r o n ) m n = l , 0 u , k h o i Itrcrng cua p r o t o n ( p r o t o n ) mp = l , 0 u , l u = 931 MeV/c^ N a n g liTcfng l i e n k e t r i e n g cua h a t n h a n '"Be D 632,1531 MeV C 6,3215 M e V B 63,2152 MeV A 0,6321 M e V la: Giai N a n g Itfdng l i e n k e t r i e n g cua h a t n h a n '°Be l a : «' AC (6m„+4m -meJ.QBl AJb^V ^ = 6,3215MeV A Vay chgn dap A an C Cdu 6: P h a t bieu nao sau day la s a i k h i n o i ve nang liidng dao dong dien tii t i i (Jo (dao dong rieng) t r o n g mach dao dong dien tCr LC k h o n g CO dien trcf thuan? Giai Chi tiet de thi TS DH, CD M6n Vat li A tl^.ng luang tCr trifcfng cure dai b k n g n a n g Itfong d i e n tCr cua mach dao dong B N a n g Itfcfng dien trtf&ng va n a n g Itftfng tCr t n f o n g b i e n t h i e n dieu hoa vdfi t a n so bSng mot nijfa t a n so cua ctfcfng dong dien t r o n g mach C K h i nSng lifcfng dien trtfcrng g i a m t h i n a n g liitfng tCr trifcrng t a n g D Nang Itfofng dien tii cua mach dao dong bkng tong nang liigfng dien tnfcfng tap trung cf t u dien va nang li/cfng tCr tnicfng tap trung cf cugn cam Giai V i n a n g lifcfng dien triicfng va nSng Itfofng tCf triXdfng b i e n t h i e n dieu hoa v6i chu k i bang mot nufa chu k i cifcfng dong dien t r o n g mach nen tan so cua no p h a i gap doi t a n so cua cifdfng dong dien t r o n g mach Vdy chqn dap an B Cdu 7: T i a Rcfnghen c6 A cung b a n chat v i song v6 tuyen B cung ban chat vdfi song a m C dien t i c h a m D btfdfc song Idfn hcfn biTdfc song cua t i a h o n g ngoai Giai T i a Rcfnghen la bufc xa dien tii n e n k h o n g m a n g d i e n , c6 cung b a n chat vdfi song v6 tuyen va c6 bildfc song nho hofn biidfc song cua t i a hong ngoai Vdy chon dap an A Cdu 8: H a t n h a n A dang dufng yen t h i p h a n r a t h a n h h a t n h a n B c6 k h o i lifong ms va h a t a c6 k h o i lucfng m„ T i so giOfa dong n a n g cua h a t n h a n B va dong n a n g cua h a t a sau p h a n r a b k n g : A ^ c B m„ D ^ Giai Ap dung d i n h l u a t bao toan dong liJcfng cho h a t dang dufng y e n , t a c6: mBVB = m„v„ T i so giufa dong n&ng cua h a t n h a n B va dong nSng cua h a t a sau p h a n r a l a : ^ Vdy chqn dap an D Giai Chi tiet de thi T S B H , C D M6n Vat II = - Cdu 9: Cho doan mach di$n xoay chieu gom cuon day c6 dien trd thuan R , m^c nol tiep v6i tu*dien Biet hieu dien the giffa hai dau cuon day lech pha — so v6i hi|u dien the giuTa hai dau doan mach Moi lien h$ giiJa dien tror thuan R vdri cam khang Z L cua cuon day dung khdng Zc cua tu dien la: ' D R=^ = ZC(ZL - C R ' = Zc(Zc - ZL) ' E R2 = ZL(ZC - Z L ) A R ' = ZL(ZL - Zc) Zc) Do lech pha giffa hai dau cuon day: tancp, = —^ R Z Do l$ch pha giffa hai dau doan mach: tan(p = — -Z - R Theo gia thiet 9, +(p = — nen ta c6: cot(p, =tan(p =>^=^^-^R^=z,(z,-zJ Vdy chqn dap an B Cdu 10: Hat nhan ^^X ph6ng xa bien mot hat nhan ^^^Y ben Coi khoi lifcfng cua hat nhan X , Y bang so khoi cua chung tinh theo dcfn v i u Biet chat phong xa X c6 chu k i bdn 1^ T Ban dau c6 mot khoi lifcfng chat ^^X, sau chu Id ban t h i t i so giffa khoi Iffdng cua chat Y A - ^ Aj khoi lUcfng cua chat X la: B ^ A, C ^ A, Sau chu kX, so hat nh^n X c6n lai 1^: D = T i so' kho'i Ifftfng cha't Y • • X la: = 3^ Aj = So hat nhan cua chat Y hinh th^nh la: N„ = N * Vdy chon dap an B N^A, ^ = -N^ = 3^ A, ^ G i i c h i l i S t ( J « t h i T S B H , C D M n V$t« Cdu 11: M o t v a t dao dong dieu hoa c6 chu k i l a T N e u chon goc thcfi gian t = l a luc v a t qua v i t r i can bang, t h i t r o n g nufa chu k i dau t i e n , van toe cua v a t b k n g k h o n g of t h d i diem: T A t = - B.t=I C.t= T - D I Giai Chon goc t h d i gian t = l a luc v a t qua v i t r i can b k n g , t h i — chu k i nufa v a t se tcri b i e n v a v a n toe b k n g k h o n g T r o n g nufa chu k i dau T tien, v a n toe cua v a t b k n g k h o n g d thdi diem t = — Vdy chon dap an B Cdu 12: M o t l a t h e p mong, m o t dau co d i n h , dau l a i diJtfc k i c h t h i c h de dao dong v d i chu I d k h o n g doi va b k n g 0,08 s A m l a t h p phat r a l a : A sieu a m B am C nhac a m D a m m a t a i ngifdi nghe diftfc Giai T a n so a n t h e p p h a t r a : f = - = — ^ = 12,5 < 16Hz T 0,08 T a i ngifori k h o n g t h e nghe di/grc a m co t a n so dtfdi 16Hz n e n a m la thep p h a t r a l a h a a m Vdy chon dap an B Cdu 13: P h a t bieu nao sau day l a s a i k h i n i ve p h o n g x a (hoat d6 phong xa)? A Dcfn v i do phong xa l a beccfren B Do phong xa l a d a i luang dac trifng eho t i n h p h o n g xa m a n h hay yeu cua m o t li/cfng chat phong xa C Vdri m o i iLfotng chat phong x a xAc d i n h t h i dp p h o n g x a t i le vdri so nguyen tuf cua liTcfng chat D E)o phong xa cua m o t lacfng chat ph6ng xa p h y thuoc n h i $ t dp cua lUtfng chat Giai Do phong x a cua m o t li/tfng chat phong x a k h o n g p h u thuoc v k o cdc tac dong b e n ngoai nhtf n h i e t do, ap suat, a n h sang, Vdy chon dap an D GIJichitiStdlthiTSDH, CDMdn V l L t l f Cdu 14: Doan mach dien xoay chieu khong phan nhanh gom a/^n day C O tir cam L , dien t r d thuan R va tu dien c6 dien dung C K h i dong dien c6 tan so' goc chay qua doan mach t h i he so cong suat cua doan mach A bang B phu thuoc dien trof thuan cua doan mach C b k n g l D phu thuoc tong irb cua doan mach GiSi K h i dong dien c6 tan so goc chay qua doan mach t h i xay hi^n tiTtfng cong hLfomg K h i u, i cung pha va he so cong suat cua doan mach bang Vdy chgn dap an C Cdu 15: Cho hai dao dong dieu hoa cung phiTcfng, cung tan so, cung bien va c6 cac pha ban dau la — va - — Pha ban dau cua dao dong tong hcfp hai dao dong tren bkng: A ^ 12 B ^ C D ^ Giai Pha ban dau cua dao d6ng tong hap hai dao dong tren bang 7t 12 Vdy chgn dap an A Cdu 16: Trong mot mach dao dong LC khon^ c6 dien t r d thuan, c6 dao dpng dien tii ttf (dao dong rieng) Hieu dien the CLTC dai gifla hai ban tu va ctr&ng dong dien ciJc dai qua mach Ian Itfcft la Uo va I Q T Tai thdi diem ctfofng dong dien mach c6 gia t r i y t h i 16n hieu dien the giiJa hai ban tu dien la: A ^ U o C.iu, B |Uo D ^ U , Gi^i Chi ti^t de thi T S B H , C D IVIon Vat If Giai cu nen W = Wd + Wt O Wt = W - Wa cu' LI' LI' 8 Vay chgn dap an D Cdu 17: Trong quang cua nguyen tuf hidro, neu biet h\idc song dai nhat cua vach quang day Laiman la X, i va h\i6c song cua vach ke vdfi no day la ^2 thi h\idc song cua vach quang day Banme l a : A (X,-^,)- c B + D Giai Difa vac scf chuyen mufc nSng Iifpng, ta c6: hfi = E i - E o (1) hf2 = E2 - Ee (2) hf„ = E2 - E l (3) E3- E2- K Ei- TrCf ve vdi ve (2) va (1) ta difpc: Eo- hf„ = hf2 - hfi 1-v he ^ he he V i hf = — nen — = he =>^„ = Vay chgn dap an B Cdu 18: Phat bieu nao sau day l a s a i k h i noi ve dao dong cua iSc dcfn (bo qua liic can cua moi triTdng)? A Vdri dao dong nho thi dao dong cua lac l a dao dong dieu h6a B K h i vat nang d vi tri bien, cd nang cua lac bang the nang cua n6 C Chuyen dong cua iSc tCf vi tri bien ve vi tri can bang la nhanh dan D K h i vat nang di qua vi tri can bang, thi ILTC tac dung len no can Vlng vdi life cSng cua day Giai Chi l e t d6 thi TS DH, CD Mdn V$t If Cdu 29: Dieu k i e n de h a i song ccf k h i g^p nhau, giao thoa dxiac wdi la hai song p h a i xuat p h a t tii h a i nguon dao dong: A cung b i e n va c6 hieu so pha k h o n g doi theo thcfi gian B cung t a n so, cung phi/cfng C CO cung pha ban dau va cung b i e n D cung tan so, cung phutfng va c6 hieu so pha khong doi theo thcri gian Giai Dieu k i e n de h a i song ccf k h i gap nhau, giao thoa diiOc vdfi la hai song p h a i xuat p h a t tii hai nguon dao dong k e t h g p , nghla la chiing phai c6 cung t a n so, cung phiicfng va c6 h i e u so pj^a k h o n g doi theo t h d i gian Vdy chgn dap an D v Cdu 30: N o i h a i c\ic ciia m o t m a y p h a t d i e n xoay chieu m o t pha vao hai dau doan mach A B gom d i e n tror t h u a n R mac no'i t i e p v d i cuon cam t h u a n Bo qua d i e n trof cac cuon day cua m a y p h a t K h i roto cua may quay deu vdfi toe n v o n g / p h i i t t h i ciicfng d o n g d i e n h i e u dung t r o n g doan mach la A K h i roto cua m a y quay deu vdri toe 3nv6ng/phut t h i CLfdng d o n g d i e n h i e u d u n g t r o n g d o a n mach l a V S A Neu roto cua may quay deu v d i toe dp 2nv6ng/p}iut t h i cam khang cua doan mach A B la: A.i B R V C V3 D 2RV3 V3- Giai Suat dien dong ciia nguon va cam k h a n g deu t i le v d i toe quay n nen ta c6: - K h i quay v d i n t h i suat d i e n dong la E, cam k h a n g la Z L : == = I , = ( A ) « =1 (1) - K h i quay v d i 3n t h i suat dien dong la 3E, cam k h a n g la Z L : 3E , rz 9ER'+9Z^ = (2) Tii (1) va (2) suy r a : ^'t^^l^ = « 3R^ + 3Z[ = R^ + 9Zl Z , = Giai Chi tig't de thi TS DH, CD M6n Vat!( R ^ 69 K h i quay v d i toe n t h i cam k h a n g cua cuon day l a : Z -2Z Z,, 2Z, ^ Vgy chgn dap an C Cdu 31: O m a t t h o a n g cua mot chat l o n g c6 h a i nguon song k e t hop A va B each 20 cm, dao dong theo phiTcfng thSng dufng vdri phiTcfng t r i n h U A = 2eos40 7rt va U B = 2eos(407tt + T I ) ( U A va U B t i n h bSng m m , t t i n h bang s) B i e t toe t r u y e n song t r e n m a t chat long la 30 cm/s Xet h i n h vuong A M N B thuoc m a t thoang chat long So diem dao dong vdri b i e n ciic d a i t r e n doan B M l a : A 19 B 18 C 17 D 20 Giai Theo de b a i t a c6: - T a n so f = — = = 20Hz 2n 2% v 30 - Birdrc song K = — = — = 1,5cm f 20 X e t t r e n doan A B , dao dong cua B n h a n h pha h o n A la TI nen v a n t r u n g tarn O l a m o t ciic tieu 10 So d i e m CLfc d a i t r e n doan OB eo t a t ca N , = = 13,33 0,75 Ta chi chon p h a n nguyen n e n N i = 13, ufng vdri 13 v a n giao thoa se cat M B , tao t h a a h t r e n M B ciic d a i Cac v a n t r e n doan O A chi c6 N2 cSt M B , t a t i m so N2 - H i e u difdrng d i tCf M den A , B l a : Ad = M B - M A = 20V2 - 20 « 8,28 cm - H a i nguon dao dong ngu:oc pha nen dieu k i e n M la mot Ad = Nhir vay, N2 = CLTC dai: X = 8,28 « k + - = - ^ = 5,5 1,5 CLTC dai T o n g so circ d a i t r e n M B la: N = N i + Ng = 13 + = 19 Vay chgn dap an A 70 Giii chi tiSt de thi TS DH, CD Mon VSt I Cdu 32: Dat dien ap xoay chieu c6 gia t r i hieu dung khong doi, tan so 50 Hz vao hai dau doan mach mac noi tiep gom dien trof thuan R, cuon cam thuan c6 t i i cam L va tu dien c6 dien dung C thay ddi difcJc 10"^ Dieu chinh dien dung C den gia t r i 10"^ F hoac 471 F t h i cong suat 2K tieu thu tren doan mach deu c6 gia t r i bang Gia t r i cua L bang: A — H B — H 2n 371 C - H D - H n 71 Giai Cong suat tieu thu P = I^R bang nghia la ctfcfng dong dien bang K h i tong trd bang nhau, ta c6: Z i = Z2 ( Z L - Hay coL Zc\f — =— C0C2 coC, 2aiL=—^ = (Zc2 - Z L ) ^ coL «> 2(oL = L = — a)C,C , + ^ coC, C0C2 =- = - ( H ) 2arC,C2 7r^ ^ Vdy chon dap an C Cdu 33: Mot lac 16 xo gom vat nho kho'l hiqng 0,02 kg va 16 xo c6 cufng N/m Vat nho dtfcfc dat tren gia d6 co' dinh nkm ngang doc theo true 16 xo He so ma sat tru'Ot giufa gia dof va vat nho la 0,1 Ban dau giOf vat 6' vi t r i 16 xo bi nen 10 cm roi buong nhe de ISc dao dgng tat dan Lay g = 10 m/s^ Toe 16'n nhat vat nho dat difgrc qua trinh dao dong la: A 40N/3 cm/s B 2oV6 cm/s C I0V3O cm/s D 40 V2 cm/s Giai Vat dat diTo'c van to'c 16n nhat k h i ve den vi t r i l i x c6 hop life bang khong: Fjns Khi X = - kx = \img 0.1.0,02.10 ^ ^ ^= — = 0,02m = 2cm k Theo dinh luat bao toan nang lifcfng ta c6: -kA =A,„,+-mv,„,,+-kx- Giai Chi tjgt as thi TS DH, CD Won Vat li 71 Cdu Thay A^^ = |amgs = ^ m g ( A - x ) ; k = co^m, t a difdc: — mco^A^ = L i m g ( A - x ) + — m v ^ + —mco^x^ o - c o ^ A ^ = u g ( A - x ) + - v ^ +-co^x^ « v _ ^ 7o)W-2^g(A-x)-co^x^ Thay so vdri co = J — = , 1—^ = V S O ta c6: v,^^ = , - , , - ^ = 0,4V2m/s = 40V2cm/s Vay c/ipn dap an D 34: Dao dong tong hcfp cua h a i dao dong dieu hoa cung phtfcfng, ' 571^ (cm) d o n g thuf n h a t c6 phiTofng t r i n h l i d o x, = c o s (cm) cung t a n so c6 phifcfng t r i n h l i x = 3cos ut Biet dao Dao dong thuf h a i CO phi/cfng t r i n h l i l a : A x , = c o s C X2 =2 cos 7rt + — 5n Trt (cm) J (cm) B X , =2cos D X2 = cos 6, ^ Trt V (cm) 571 (cm) Giai TCr g i a n vectcf, bieu d i e n cac dao dong bSng cac vector A , , A , v a A T a t h a y dao d o n g t o n g h o p A ngiroc p h a v d i dao d o n g A, V i v a y dao d o n g A j p h a i ngifgrc p h a vdi A, va cung p h a vdi A Tir d6 t a c6: A2 = A i + A = c m 72 Giai Chi ti^t 06 thi T S DH, CD M6n V$t II M a t k h a c A , c u n g p h a vdri A n e n p h a b a n d a u l a cp = Dao d o n g t o n g h o p l a =8cos Tit 571 571 Vdy chgn dap an D Cdu 35: Life keo ve tac dung l e n mot chat d i e m dao dong dieu hoa c6 I d n : A va htfdfng k h o n g ddi • B t i le v d i lorn cua l i v a luon hudng ve v i t r i c a n bSng C t i le vo'i b i n h phiidng bien D k h o n g doi nhtfng hudfng thay d o i Giai Life keo ve F = - k x , suy r a life keo ve t i le vdfi x v a Yuidng ve v i t r i can bSng Vdy chgn dap an B Cdu 36: Quang vach phat x a : A ciia cac nguyen to khac nhau, d cung m o t n h i e t t h i nhtf ve sang t i doi cua cac vach B la m o t he t h o n g nhu'ng vach sang (vach mau) r i e n g l e , ngan each bo'i nhufng khoang t o i C cac chat rin, chat l o n g hoac chat k h i c6 ap suat lorn p h a t r a k h i b i nung nong D la mot dai c6 mau tCr den t i m n o i l i e n mot each l i e n tuc Giai Quang vach phat xa la mot he thong nhCfng vach sang (vach mau) rieng le, ngan each, bo'i nhCfng khoang t o i Vdy chgn dap an B Cdu 37: D a t dien ap u = Uocoscot vao hai dau doan m a c h gom d i e n trof thuan R, cuon cam t h u a n c6 i\i cam L va t u d i e n c6 d i e n dung C mac n o i t i e p Goi i l a ctfdng dong dien tufc thcfi t r o n g doan mach; u i , U2 va Us Ian liicft la dien ap tufc t h o i giCfa h a i dau d i e n t r d , giufa h a i dau cuon cam va giufa h a i dau t u dien He thufc dung l a : A i = B C i = U j C o C D i = R coL- Giai Chi tiCt de thi T S D H C D IMon V a t li wC 73 Gi^i V i i va ui dong pha n e n i = — R Vay chgn dap an B Cdu 38: M o t v a t dao dong tht dan c6 cac d a i li/dng giam l i e n tuc theo t h d i gian la D bien va gia toe C b i e n va toe B l i va toe A b i e n va n a n g lUc/ng Giai V a t dao dong t a t d a n t h i c6 bien va n a n g l U d n g g i a m l i e n tuc, c o n cac d a i lucfng khac nhxi l i do, gia toe, v a n toe c6 luc tang, luc giam Vay chgn dap an A Cdu 39: M o t k i m loai c6 cong t h o a t electron la 7,2.10"^^J Chieu Ian lifcft vao k i m loai cac bijfc xa c6 btrcfc song X^= , j i m va = 0,18 |am, = 0,21 |j,m, 0,35|im Nhufng bufc xa eo the gay h i e n tUgfng quang dien d k i m loai c6 h\idc song la: va X C A.,, va X, A X,, kj B va D A., va X^ Giai Gidti h a n quang dien cua k i m loai la: he _ 6.625.10-'\3.i0'' X,= — = ^ = 0,276.10"" m = 0,276|am A ~ 7,2.10"" Nhu' vay, cac bufc xa eo bi/drc song X^ va X, c6 the gay quang dien Vay chgn dap an B Cdu 40: M o t \kc 16 xo dao dong dieu hoa v d i chu k i T va b i e n cm B i e t t r o n g m o t chu k i , k h o a n g thofi gian de v a t nho cua Mc T CO Idfn gia toe k h o n g vUdt qua 100 em/s^ la — Lay it' = 10 T a n so dao dong cua v a t l a : A Hz B Hz C Hz 74 D Hz Giai Chi tiSt t = — 12 (2n ) 2K T 47i"f "Asia = 100 Ta c6: a — co'Asm — t = 100 T 12 «47r'f'Asin- = 100 f= 100^r' =-^.5.0.5 = « l(Hz).- Vdy chgn dap an C Can 41: T r o n g giof hoc thiTc h a n h , hoc sinh mac n o i t i e p m o t quat dien xoay chieu vdfi d i e n trof R r o i mAc hai dau doan mach vao dien ap xoay chieu c6 gia t r i hieu dung 380 V B i e t quat d i e n c6 cac gia t r i dinh mufc: 220 V - 88 W va k h i boat dong diing cong suat d i n h mufc t h i lech pha giOfa dien ap or hai dau quat va cUorng dong dien qua no la , vdfi coscp = 0,8 De quat dien chay dung cong suat d i n h mufc thi R bang: A Q B Q C Q D 180Q Giai CcTcfng dong dien dinh mufc qua quat: = P 88 U coscp 220.0,8 = 0,5(A) U Ta CO coscp = —'-^ => U , ^ = 0,8 220 = ( V ) U Vi U A.2k CSX D 2,5X Giai V i v a n to'i thuf ba n e n t a c6 k = K h i Ad = + ^ \X = 2,5l 2) Vdy chqn dap an D Cdu 44: B a n dau c6 No h a t n h a n cua m o t mau chat ph6ng xa nguyen chat CO chu k i ban r a T Sau khoang thori gian t = 0,5T, ke iii thcfi diem ban dau, so h a t n h a n chiia b i p h a n r a cua mau chat phong xa la: A ^ B.-^o V2- D 76 N,V2 GiSl Chi ti^t de thi T S DH, C D Mon Vat II Giai So h a t chira p h a n r a sau t h d i gian t = 0,5T l a : N„ N 0.5T 2^ N„ V2 T Vdy chgn dap an B Cdu 45: T a i m o t d i e m t r e n m a t chat l o n g c6 m o t nguon dao dong vdfi tan so 120 Hz, tao r a song o n d i n h t r e n m a t chat long X e t ggtn l o i lien tiep t r e n m o t phiiong t r u y e n song, of ve m o t p h i a so vdri nguon, gcfn thuf n h a t each gcfn thuf n a m 0,5 m Toe t r u y e n song l a : A 30 m/s B 15 mis C 12 m/s D 25 m/s Giai Giufa h a i gcfn song l a m o t btfoc song n e n giufa ggrn song thuf n h a t va gtfn song thuf n a m c6 b o n hxSdc song K h i h\i6c song l a : X =M = o,125m * Toe t r u y e n song l a : v = XS = 15m/s Vdy chgn dap an B Cdu 46: D a t dien ap u = UQ COS tot vao h a i dau cuon cam t h u a n c6 t\i cam L t h i cUbng dong dien qua cuon cam l a : A i = G i = coL B i = cos cot + — -cos cot coL 7t D i = (OLV2 (0 L V cos 0)1 + — cos cot 71 Giai Cuo'ng dong dien cham pha so vdfi d i e n ap giufa h a i dau cuon cam n e n bieu thufc cua i l a : i = - ^ c o s cot coL V — Vdy chgn dap an C Cdu 47: K h i chieu chum t i a tuf ngoai vao m o t o n g n g h i e m dUng dung dich fluorexein t h i t h a y dung dich p h a t r a a n h sang m a u luc Do la h i e n tiftfng A p h a n xa a n h sang B quang - p h a t quang C hoa - p h a t quang D t a n sac a n h sang GiaichitietdethlTSDH.CDMonVStll 77 Giai K h i c h i e u c h u m t i a tuf n g o a i v a o m o t o n g n g h i e m diTng d u n g d i c h fluorexein t h i t h a y d u n g d i c h n a y p h a t r a a n h s a n g m a u luc D o l a h i e n tifcrng q u a n g - p h a t q u a n g Vay chgn Cdu dap an B 48: V a t n h o c u a m o t c o n l a c 16 xo dao d o n g d i e u h o a t h e o phiTcfng n g a n g , m o c t h e n a n g t a i v i t r i c a n b S n g K h i g i a toe cua v a t c6 \6n b a n g m o t nufa Idfn g i a toe CLTC d a i t h i t i so giOfa d o n g n a n g v a t h e n a n g cua v a t l a : A.i B C 2 D.i Giai L i dao d o n g eo d a n g x = A c o s ( ( o t + (p) t h i v a n toe l a : V = - c o A s i n ( c o t + (p) v a g i a toe l a : a = - c o ^ A c o s ( c o t + (p) K h i g i a toe b a n g nijfa g i a toe CLTC dai t h i : a = co^Acos(a)t + (p) = ^ c o - A => c o s ( c o t + (p) = ^ sin((ot + (p) = ^ - C O S ' (cot + cp) = — D o n g n S n g c u a dao d o n g : Wd = -^mv^ = - ^ k A " sin^ ( c o t + (p) T h e n a n g cua dao d o n g : W t = ^ kx^ = i k A ~ cos" (cot + cp) T i so _ sin^ (cot + cp) Wj Vdy chgn Cdu ^ = cos'(cot + (p) dap an B 49: M o t c o n l a c d o n c6 c h i e u d a i d a y t r e o c m v a v a t n h o c6 k h o i lifgrng , k g m a n g d i e n t i c h q = +5.10"^C, dcTcfc coi l a d i e n t i c h d i e m C o n l a c dao d o n g d i e u h o a t r o n g d i e n trUorng d e u m a vector eiTdng Giai Chi tidt de thi TS D H , C D M6n Vat li 78 dp dien triTcfng c6 dp Idfn E = lO^V/m va hi/dng t h a n g dufng xuong dudti Lay g = 10 m/s^, n = 3,14 Chu k i dao dpng dieu hoa cua lac l a : A 0,58 s B 1,99 s ' C 1,40 s D 1,15 s Giai Con lac ngoai chiu tac dung cua t r p n g lyc P = m g chiu tac dung cua life dien F = qE , mg + qE qE ,^ S I O ' I O ' , ^ K h i g = — ^ — — = g + — = 10 + — — = 15(m/s-j IQm m Chu k i T = Vdy chgn dap an D Cdu 50: Trong t h o n g t i n l i e n lac bang song v6 t u y e n , ngifdi t a sijf dung each bien dieu bien dp, tufc la l a m cho bien dp cua song dien tii cao t a n (gpi la song mang) b i e n t h i e n theo thori gian vdfi t a n so b k n g t a n so cua dao dpng a m t a n Cho t a n so song mang la 800 k H z K h i dao dpng am t a n c6 t a n so 1000 Hz thifc h i e n m o t dao dpng toan p h a n t h i dao dpng cao t a n thiic h i e n difpc so' dao dpng toan p h a n l a : A 800 B 1000 C 625 D 1600 Giai So dao dong cao t a n thiTc h i e n : N = • • = goO 1000 Vdy chgn dap an A Cdu 51: M o t b a n h da c6 momen quan t i n h doi vdfi true quay co d i n h cua no la 0,4 kg.m^ De b a n h da t a n g toe tii t r a n g t h a i dufng y e n den toe dp goc (0 p h a i t o n cong 2000 J Bo qua ma sat Gia t f i cua co l a : A 10 rad/s B 200 rad/s C 100 rad/s D 50 rad/s Giai Dpng n a n g cua b a n h da: Wd = ^/co^ Dpng n a n g cua b a n h da bang c h i n h cong da cung cap: Wd = A Suy r a M = , 2A 2.2000 = 100 rad/s Vdy chgn dap an C Giai chl tiet de thi TS BH, CD Mon Vat li 79 Cdu 52: De k i e m chuTng hieu ufng Dop-ple, ngu&i t a bo t r i t r e n m o t difdng r a y t h S n g m o t nguon a m chuyen dpng deu v d i toe 30 m/s, phat a m vdfi t a n so xac d i n h va m o t m a y t h u a m dufng yen B i e t a m t r u y e n t r o n g k h o n g k h i v6i toe 340 m/s K h i nguon a m l a i gan t h i m a y t h u diTpc t a n so a m l a 740 H z K h i nguon a m r a xa t h i may t h u diXpc t a n so a m l a : A 620 H z B 820 H z C 780 H z D 560 Hz Giai Khi nguon a m l a i g a n m a y t h u , t a c6: f, - ^ f =>f = f , v - v ^ V = M z ^674,7Hz 340 K h i nguon a m r a xa m a y t h u , t a c6: 340 = — 674,7 = 620Hz 370 V f, = f v + v^ Vay chgn dap an A Cdu 53: C h u m t i a X p h a t r a tCf m o t ong t i a X (ong Cu-lit-gicf) c6 t a n so Idrn n h a t l a 6,4.10^^Hz Bo qua dong nang cac electron k h i buft r a k h o i catot H i e u d i e n t h e giuTa anot va catot cua ong t i a X l a : A 13,25 k V B 5,30 k V C 2,65 k V D 26,50 k V G\k\ Theo d i n h l u a t bao toan nSng lupng, chiing t a coi nang lifpng electron dap vao tarn k i m loai b k n g nang li/png cua photon t i a X phat ra: eU = h f hf 6,625.10-".6,4.10'' ^mH/ [...]... la chuin; a m t a i M va N I a n cUcfng d6 a m t a i M v a N lUcft l a : = 1 0 / i - = 40dB;L2 = 1 0 / g ^ = 80dB 32 ' Giai Chi fiSt 34 thi TS DH, CD M6n V$t 11 k Ta c6: U -U = 40dB = 1 0 / g ^ - 1 0 / g i - = 1 0 / g ^ = 1 0 / g ^ = 40 lo 3 ^ 1 g ^ = 4 ^ ^ - 1 0 * =10 000 1 1 Vgy c/iort cfdp an A Cdu 13 : T r o n g chan k h o n g , cac bufc x a diforc s^p xep theo thuf tU bu6c song g i a m dan l a... i Z c = 2I2ZC => I i = 2I2 Giic Chi ti6t d6 thi T S D H , C D M6n VSt 1( (2) 33 Thay (1) vao (2) ta c6: 4I^R, = I^R^ ^ 4R, = R^ Ta l a i c6: P = UI cos 9 => UI, cos (p, = UIj cos => I , C0S(p| = I2 cos(p2 => 2cos(p, = C0S(P2- »4 VR?+IOO' ^R^+ioo' 1 16 R? +10 0' ~16 R? +10 0-" '7 ^1+ 100' Vi6Rf +10 0' Giai ra ta dUtfc R, = 50Q, Rj = 200Q Vdy chgn dap an C Cdu 15 : Mot con lac 16 xo c6 khoi Itfcfng vat nho la... khong can bkng vdri lire cang cua day Vay chon dap an D Cdu 19 : Trong nguyen tuf hidro, Mn kinh Bo la ro = 5,3 .10 ""m Ban kinh quy dao dCifng N la: D i32,5 .10 -"m C 21, 2 .10 -"m B 84,8 .10 -"m A 47,7 .10 -" m Giai Ban kinh quy dao dCtog N la: r„ = n\ 16 ro = 84,8 .10 -"m Vay chon dap an B Cdu 20: Mot chat phong xa c6 chu ky ban ra la 3,8 ngay Sau thcfi gian 11 ,4 ngay t h i do phong xa (boat do phong xa) cua liTong... lO"* rad/s Dien tich dai tren tu dien la lO'^C CLTC Khi cUofng do dong dien trong mach bkng 6 .10 "^ A t h i dien tich tren tu dien la: A 4 .10 "^°C B 6 .10 "^°C C 2 .10 -^°C 16 - D 8 .10 -^°C QiaichitigtdethiTSDH, CBMSn vatli Theo d i n h luat bao toan nSng lucfng, t a c6: 2 - +2C— cu^ =- q = ^ C ' U ^ - C L i ' =8 .10 -'° (C) Vdy chgn dap an D Cdu 35: H a t n h a n ^^gRa bien ddi t h a n h h a t n h a n ^g^R"... ItfPt la 0,00 910 6u; 0,002491u; 0,030382u va l u = 9 31, 5 MeV/cl N a n g liTong toa ra cua phan ufng xap x i bang: A 21, 076 MeV B 200,025 M e V C 17 ,498 M e V D 15 , 017 M e V Giai T'lr p h a n ufng + ^D ^He + X t a suy r a ^X V i QX la m o t n d t r o n n e n k h o n g c6 n a n g lUdng l i e n k e t Do h u t k h o i cua p h a n ufng: A M = Am^^ - Am^ + Am^ = 0,0303 82u - 0,00 910 6u + 0,0024 91 u N a n... e n day 1^ : A 20 m/s B 600 m/s C 60 m/s D 10 m/s GiSi Scfi day difcfc co d i n h h a i dau, dang co song difng v d i 6 b u n g song t h i CO 6 m u i s6ng M o t m i i i song l a khoang cdch giffa 2 n u t co chieu dai — 2 Ta co: L = 6 - = 3?i = 1, 8m :ii> 2 = 0,6m V a n toe t r u y e n song: v = >uf = 0,6 .10 0 = 60m/s Vay chon Giai Chi tiSt dap an C thi T S D H , C D M 6 n V $ t li ' 29 Cdu 5: Chieu x... h o n g neu chieu t i a sang theo chieu tii m o i trifcfng (2) sang moi trifcfng (1) ? A K h o n g t h e , v i m o i triX&ng (2) ehiet quang hcfn naoi triTcfng (1) B C o t h e , v i m o i trifofng (2) chie't quang k e m m o i triTcfng (1) C C o t h e , v i m o i trifcfng (2) ehiet quang hcfn m o i triTcfng (1) D K h o n g t h e , v i m o i trUcfng (2) ehiet quang k e m m o i tri/orng (1) Giai K h o... bSng nhau ufng v6i h a i t a n so coi, CO2 t h i : Z, = Z2 R ' + Lo), - - 1 Leo, - Ceo Loo, Ceo 1 Leo, y 1 Ceo 1 Ceo 2J \2 2J X e t h a i trUcfng hcrp: 1 Leo, - - r — - = Leo, — < » Ceo, Ceo, eO|eo2 = 1 Leo, - • Ceo, eo,eD2 = • Vdy chgn dap an CcOj -Leo, LC (loai v i eo > 0) LC C Cdu 4: T r e n m o t sgri day dan h o i d a i 1, 8 m , h a i dau co d i n h , dang co s6ng ditog vdi 6 bung song B i e t... ai thi O H , C O M6n V $ t If 11 Cdu 25: H i e u d i e n t h e giffa ano't v a cato't cua m o t o'ng Rornghen l a U = 2 5 k V Coi v a n toe ban d a u cua chum electron (electron) p h a t r a ttf catot b k n g k h o n g B i e t h a n g so P l a n g h = 6,625 .10 ~^^J.s, d i e n t i c h nguyen to b a n g 1, 6 .10 '^^C T a n so Idm n h a t cua t i a Rornghen do ong nay c6 the p h a t r a l a : D 60,380 .10 '^Hz... h i e u difdng L a y g i a to'c r o i tii do g = 10 m/s^ v ^ 7t^ = 10 Thori gian ng^n n h a t ke tijf k h i t = 0 den k h i ILTC d a n h o i cua 16 xo c6 do I6n ale t i e u l a : A ^ s 30 B ±s 15 C Is D 10 -s 30 GiSi Chu k i : T = 2% CO = STC CO K h i treo v a t vko, 16 xo g i a n m o t doan: A / = — g = = 0,04m < A = 0,08m k CO LLTC d^n h o i cua 16 xo c6 do l