Giai So photon m a nguon p h a t r a t r o n g m o t giay x a p x i bang: N =— = ~ - r « 3,02.10'^ hf 6.625.1(r'-'.5.10'-' Vay chgii dap an C Cdu 9: Theo thuyet luang tijf a n h sang, p h a t bieu nao dvidi day la sai? A P h a n tijf, ngiiyen tuf phat xa h a y h a p t h u a n h sang, cung c6 nghia la chung phat xa hay h a p t h u photon B A n h sang diioc tao t h a n h bdi cac h a t goi l a p h o t o n C N a n g iLfgtng ciia cac photon a n h sang l a nhtf nhau, k h o n g p h u thuoc t a n so' ciia a n h »ang D T r o n g chan k h o n g , cac photon bay doc theo t i a sang v d i toe c = 3.10^m/s Giai N a n g lifcJng cua cAc photon s = h f n e n t a n so a n h sang khac thi nSng li/cfng e khac Vay chgn dap an C Cdu 10: D a t dien ap u - Uocoscot c6 co thay doi dixac vao h a i dau doan mach gom cuon cam t h u a n c6 t\i cam L , di$n t r d t h u a n R va t u dien CO dien dung C mSc n o i tiep K h i co < J — thi: VLC A ciidng dong dien t r o n g doan mach cung pha v d i dien a p giufa hai dau doan mach B dien ap hieu dung giufa h a i dau dien trcf t h u a n R n h o h o n dien ap hieu dung giufa h a i dau doan mach C cUdng dong dien t r o n g doan mach tr§ pha so vdri d i e n ap giufa hai dau doan mach D dien ap hieu dung giffa h a i dau dien t r d t h u a n R b a n g d i e n ap hieu dung giu:a h a i dau doan mach Giai Khi CO < t h i Z , - Zp > Khi Z = ^ R ' + ( Z , - Z , ) ' > R Suy r a U R < U Vay chgn dap an B G\iii Chi ti^t de thi T S D H , C D Mon Vat li 87 Cdu 11: T r o n g scf k h o i cua m o t may phat t h a n h dung song v6 tuyen k h o n g C O bo p h a n nao diTdfi day? D Anten C M a c h khuech d a i B M a c h tach song A M a c h b i e n dieu T r o n g scf k h o i cua m o t m a y phdt t h a n h dung song v6 tuyen, k h o n g can bo p h a n tach song Vdy chon dap an B Cdu 12: Song d i e n tCf A C O t h a n h p h a n dien tnfcfng va t h a n h phan tCf triTdng t a i mot diem dao dong cung phi/cfng B la d i e n tCr trLfomg Ian t r u y e n k h o n g gian C l a song doc hoSc song ngang D k h o n g t r u y e n dtfcfc t r o n g chan khong GiSi Song d i e n tCr l a song ngang, t r u y e n diTcfc t r o n g chan k h o n g va k h i t r u y e n t h l vectcf E va B luon vuong goc vdfi Vdy chgn dap an B, Cdu 13: M a c h dao dong l i t i i d n g gom cuon cam t h u a n c6 i\S cam L va tu d i e n c6 d i e n dung C dang thifc h i e n dao dong dien tCf tiT Goi Uo l a d i e n ap ciic d a i giufa h a i ban t u ; u va i la dien ap giufa h a i ban t u va ciTcfng dp dong d i e n t r o n g mach t a i thofi diein t He thufc d u n g l a : D i ^ = ^ ( U ^ u ^ ) C.i^=LC(U^u^) B i ^ = ^ { U ^ u - \ ) A i ^ = V L C ( u ^ - u = ) Giai A p dung d i n h l u a t bao t o a n n a n g liTong cho mach L C , t a c6: -CU^ =-CU^+lLi^ o i ^ =-(u^-ir) Vdy chgn dap an B Cdu 14: M o t v a t dao dong dieu hoa v(5fi bien cm Moc the nSng d v i t r i can b^ng K h i v a t c6 dong nkng b k n g ^ I a n ccf n a n g t h i v a t each v i t r i can bSng m o t d o a r A 4,5 cm B cm C cm D cm Giai chi tiet cJe thi T S OH, C D M6n VSt 1( 88 Gial K h i dong n a n g bSng — ccf n a n g t h i the n a n g bang: Wt = W - Wd = W - - W = - W 4 K h i t a c6: - k x " = - - k A " x = — x = — = ( c m ) 4 ^ ^ Vay chgn dap an D Cdu 15: Dat dien ap xoay chieu u = CO dien UQCOS cot vao h a i dau doan mach chi t r d thuan Goi U la dien ap hieu dung giOfa h a i dau doan mach; i, lo yk I Ian liJc/t l a gia t r i tilc t h d i , gia t r i cua CLTcfng dai va gia t r i hieu dung dong dien t r o n g doan mach He thufc nao sau day A - ^ - = Uo C L T C sai? B.-^-i.O lo U C — + — = D +— = yjl Giai Tac6: _ ^ Jo_ V2U0 V2I0 ^0 ^^'0 U„ u i _ uV2coscot ij~T~ U Uo V2 l>^coscot u I • 1 lo V2 72 V2 = • + — = —p= + - Vdy chqn dap an C Cdu 16: T r o n g cac loai t i a : Rcfn-ghen, h o n g ngoai, tuf ngoai, dofn sac mau luc; t i a c6 t a n so nho n h a t l a : A t i a h o n g ngoai ' B t i a Rcfn-ghen; C t i a dofn sAc mau luc D t i a tuf ngoai Giai T i a h o n g ngoai c6 bifdc song I d n n h a t nen c6 t a n so nho n h a t Vay chgn dap an A Cdu 17: D ^ t dien ap xoay chieu vao h a i dau doan mach gorh d i e n t r d thuan Q va t u dien mic n o i tiep B i e t dien ap giufa ha^.dau doan Giai Chi tiet tie thi T S B H , C D Mon Vat li 89 ... B.-^-i.O lo U C — + — = D +— = yjl Giai Tac6: _ ^ Jo_ V2U0 V2I0 ^0 ^^'0 U„ u i _ uV2coscot ij~T~ U Uo V2 l>^coscot u I • 1 lo V2 72 V2 = • + — = —p= + - Vdy chqn dap an C Cdu 16: T r o n g... Cdu 17: D ^ t dien ap xoay chieu vao h a i dau doan mach gorh d i e n t r d thuan Q va t u dien mic n o i tiep B i e t dien ap giufa ha^.dau doan Giai Chi tiet tie thi T S B H , C D Mon Vat li... ccf n a n g t h i v a t each v i t r i can bSng m o t d o a r A 4,5 cm B cm C cm D cm Giai chi tiet cJe thi T S OH, C D M6n VSt 1( 88 Gial K h i dong n a n g bSng — ccf n a n g t h i the n a n