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I tnuat gtat ttnann m iisi vat L t i^, tap I - Nguyen Quang Lac A? + A^ + A^ => A2 = Vai may FX570-ES ta bam n h u sau : [ M O D E J § t r e n m a n h i n h x u a t h i # n c h u : CMPLX ,y Mat khac: - A ^ = V42 -2^ = 2V3 (cm) A^ = A^ + A^ + 2A^Aj cos(92 - 9]) |SHIFTJ|MOD£| § chuyen doi don vi goc la R (Rad): fi! |4>/3|^HIFTJ § g § ISHIFTJ [SHIFT] § '^^'^ ^^^^ H • '^^t • o j h li jisv'v' :jr 2^ =4^+(2V3)%2.4.2N/3COS Z 7t/2 cos Nghia la bien bang A = 4; pha ban dau cf) = n/2 => Chon A Cau 146 Mot vat thuc hi^n dong thoi hai dao dpng dieu hoa cung phuong c6 phuong trinh dao dong la X j = s i n ( t t + a) (cm), = 4\/3cos7ct (cm) Bien 371 D a = T: C.a = Huong dan gidi: Ta c6: x, = cos Ttt + a — (cm) va X j =4\/2cos(27tt) (cm) Bien dp dao dong tong hop xac djnh: +2AjA2COS a — De bien dao dong dat gia tri nho nha't thi cot-^ 3j cm; X2 = A2cos(o)t + (p2)cni iML.'''i^ \ B Tan so ciia goc dao dpnh tong hpp co = 27t rad/s , ; C Pha ban dau cua dao dong tong hpp = — D Phuong trinh cua dao dpng tong hpp x = 8cos cm Huong dan gidi: Taco: x, = V s i n i t ( c m ) va X j = 4\/2cos27tt (cm) A Bieu dien cac dao dong tren gian vec to, ta c6: OA = A i = 4cm; OB = A2; OC = A = 2cm dap an B d i i n g 2 A - A ^ + A ^ + A J A C O S ( - I ) = (4V2) + ( V ) + ( ) c o s ^ => A = 8cm => Dap an A diing Pha b a n d a u c u a d a o d p n g tong hpp d u p e x a c d i n h : A , sin(p, + A , sin(p, — = -1: (p = — dap an C diing jf' A^ C O S ( p j + A2 COS(p2 C sVScm; Huong dan gidi: BC2 = O C + OB2 A Bien dp cua dao dpng tong hpp la A = 8cm tgcp = — • Cap gia tri nao cua A2 va cp sau day la dung? T u gian vec to suy ra: 0ii_148 M o t vat thuc hien dong thoi dao dong c6 phuung trinh la Bien d p c i i a d a o d p n g tong hpp x a c d j n h : Phuong trinh dao dong tong hop x = 2cos((ot + (p)cm Trong cpj -(p = B 2V3cm; ' VP Vi h a i d a o d p n g t h a n h phan deu co tan so goc co = 27irad/s nen d a o d p n g Cau 147 Mot chat diem tham gia dong thoi hai dao dpng dieu hoa tren cung A sVScm; 2 tong hpp cOng co tan so goc (a = 2n rad/s cos a — = - l = > a - — = 7t=:i>a = — ^ Chpn A 2 xi = 4cos 3; Vay A2 = 2\/3(cm); (p = => Chpn D n A^ = A j + A j + A j A j cos((p2 -(pj) = A j + A j mot true Ox c6 phuong trinh: •cp = 6J I X j = 4^2 sin27it(cm); X2 = 4>/2 cos27it (cm) Ket luan nao sau day la sai? , > dao dong tong hop dat gia tri nho nha't A a = 571 71 n ^T^^-> D 2V3cm;0 V5 / Phuong trinh dao dpng dieu hoa tong hpp co bieu thuc: X = 8cos 27rt-i^ c m d a p a n D s a i -> C h p n D V o i may FX570-ES ta bam n h u sau : 7- P O D E ] ^ tren man hinh xuat hien chu: CMPLX | H I F T ] [ M O D E J § chuyen doi don vi goc la R (Rad): f72 SHIFT (-) -7t/2 SHIFT (-) 161 - SHIFT] y g y M a n h i n h hien t h i ket qua: Z - t / A=(V3B)^-4(52-25)>0 NghTa la bien d o bang A = 8; pha ban dau 4> = - H / A d i i n g ; B d i i n g ; C d i i n g ; D sai ^ C h o n D Bmax = lO(cm) thay vao (1) ta dupe A = S^/Scm => C h p n A C a u 149 M g t vat t h a m gia d o n g t h a i hai dao d o n g c i i n g p h u o n g , cung tan so C O bien d o Ian lug-t la A i = 3cm va A = 4cm Bien dao d g n g t o n g h o p khorig the nhan gia t r i nao sau day: A 5,7cm B 1,0cm C 7,5cm Huong dan M p t lac 16 xo t h a m gia d o n g t h o i dao d p n g d i e u hoa c i i n g phuong, c i i n g tan so' co = 5\f2 rad/s, c6 d p I f ch pha bang ^ Bien d p ciia dao dpng p h a n la A i = c m va A Biet d p I o n van toe ciia v a t tai t h o i d i e m D 5,0cm (Jpng nang bang the nang la 40( cm) Bien dp p h a n A bang gidi: Theo p h u o n g phap gian d o vec to Fre-nen t h i bien d o dao d p n g tong h o p A A2 = cm B A2 = 4V3 l u o n phai thoa m a n : | A j - A j | < A < A j + A j Theo bai ra, ta c : c m < A < 7cm D ±407i cm/s (0 COS(A(P) = 75 => A = V c m a' V = ±4071 ( c m / s) gidi: • A = 8cm X = Bcos c o t - ^ cm (t d o bang giay) Bie't p h u o n g t r i n h dao d p n g tong hop C a u 153 Cho hai dao d p n g d i e u hoa c i m g p h u o n g : X j = c o s ( t + (pj)cm; = c o s ( t + (p2)cm v o i < (P2 -(Pj ^ n Biet p h u o n g t r i n h dao d p n g tong x = 2cos hop la X = 5cos(cot + (p)(cm) Bien dp dao dpng B c6 gia tri cue dai k h i A bSng: B cm , C Syflcm Hwang dan D 2,5V2cm Tir cong thiic tong h o p dao dpng ta c6: 571 c m Gia t r j ciia cpt la: 'ff': B 66 ' Huang dan gidi: Gian d o vecto n h u h i n h ve Ox la tri^c goc: gidi: 5^ = A ^ + B^ - A B C O S — hay A ^ - VSBA + B^ - = De p h u o n g t r i n h (1) c6 n g h i ^ m A v o i B la t h a m so t h i : Al=A^-Al=8^-A^=>A2=4Scm => C h p n B Chpn D CO ^ n C a u 151 Cho h a i dao d p n g dieu hoa c i i n g p h u o n g : X j = A c o s a->t + — cm A 573cm = cm A ^ = A J + A ^ + 2A1A2 C O S ( A = A ^ + A ^ ) ^ CO A2 gidi: A p d y n g cong thuc: v2 D M a t khac ta co: A^ = A^ + A^ + 2A1A2 2v^ A^=2 Ta c6: co = 27:f = 871 (rad/s) ,2 = \/3 c m E = 2W^ = i k A = > - m v = i k A d 2 Van to'c ciia vat k h i no c6 gia toe 32>/2 (cm/s^) la Huong dan A2 K h i d p n g nang bang the nang, ta co: c i m g tan so' i = H z , c i i n g bien d o cm va c6 d o lech pha A(p = — Cho 7t^ = 10 C ± ^ cm/s C Ta C O co nang ciia vat: E = W j + W, = ^ k A ^ C a u 150 M o t vat t h y c hien d o n g t h o i hai dao d o n g d i e u hoa c i i n g phuong, B ± ; : cm/s cm Huang dan Vay A k h o n g the bang 7,5cm => Chpn C A ±307c cm/s B T a m giac O A A can tai O => O A A = O A A O A la p h a n giac A j O A ( V i O A A A la h i n h thoi) Q 2- Thai gian chuyen dpng thling cua v|t m t u liic ban dau den v i tri 16 xo AOA2 = AOAj = OAA2 l^'hong bien dang la: => A O A , = O A A = O A A A A O A deu ^ ', A O A = - =i> AOA, A = - ' Theo bai: AOx = — => A^Ox = — =>(p, = - — ^ ^ kx = fjmg => X = |Limg/k = (cm) giay Biet dp Ian van toe ciia vat tai thoi diem dpng nang bang the nang ij ,^ B 2V3cm C 373cm D 4V3cm Thai gian chuyen' dpng thSng ciia vat m t u liic ban dau den v i tri 16 xo ' ^ ; rSu 157 * Mot lac 16 xo gom mot vat nho kho'i lupng 0,02kg va c6 dp cung Ion nhat vat nho dat dupe qua trinh dao dpng la A 1572cm/s • A = 8cm B 25V2em/s C 40^^ cm/s D 50v^em/s Huang dan gidi: Do hai dao dpng phan vuong pha nen Van toe ciia vat dat gia trj Ion nhat qua trinh dao dpng tat dan ehinl" A = ^A^ - A j = 78^-4^ = 4V3cm => Chpn D v$n toe Ian nhat ma vat dat dupe i chu ki dau tien Gpi x la v i tri l i Cau 155 Mot lac 16 xo dao dpng tat dan Cu sau moi chu ki bien dp ciia no giam 2,5% Phan nang lupng cua lac bj mat d i sau moi dao dpng toan phan la ' '^ •- bj nen 10 cm roi buong nh^ de lac dao dpng tat dan Lay g = lOm/s^ Toe dp 2imv2=ikA2 ^ "^'•> H? so ma sat trupt giiJa gia da va vat nho la 0,1 Ban dau g i u vat v i t r i 16 xo Khi dpng nang bang the nang ta c6: 2Ed = E A 35% T = t J ^ - 0,2n (s) N/m Vat nho dupe dat tren gia c6 dinh nam ngang dpe theo trvic 16 xo Huang dan gidi: k Chu ki dao dpng: khong bien dang la: t = j + - ^ = -^(s) => Chpn C 40cm/s Hay xac djnh bien dao dpng phan Aj ? , D ^- s 30 C.^s 15 Vi tri can bang ciia lac 16 xo each v i tri 16 xo khong bien dang x: Chpn B =4cos^5>/2t-njcm va X = A C O S 5\ll\ — c m , t tinh bang A VScm • Huong dan gidi: 7t Cau 154 Mgt vat tham gia dong thai hai dao dong dieu hoa cung phuang v6, Xj B.^s 20 25S B 45% C 55% D.95% Huang dan gidi: 2 Nang lupng chu ki dau la: W = - mco A Nang lupng chu ki tiep theo la: W ^mco^A'^ A/ = (0,975)^ * 0,95 = 95% =^ Chpn D Suy ra: w A Cau 156 * Mot IMc 16 xo c6 dp ciing k = 10 (N/m), khoi lupng vat nan? m = 100 (g), dao dpng tren mat phang ngang, dupe tha nhe tu vi tri 16 xo d^^ 6cm so voi v i t r i can bang H? so ma sat trupt giua lac va mat ban bang H * ma vat c6 toe dp Ion nhat Ap dung dinh luat bao toan nang lupng, nang lupng ban dau ciia h§ gom the nSng cue dai ban dau: ~ k A p , nang lupng ciia h§ tai thoi diem vat c6 van toe c i ; ?i gom dpng nang ^ m v ^ , the nang ^^x^ va dp Ion eong ciia lye ma sat: = ^mg Al = |img(Al + x) kx^ +)img(Al + x) -kAl^ =-mv^ + — ^ J i A l - A x - ^ g ( A l + x) m V / m Dat y = v = — A l ^ - — x - ^ g ( A l + x ) X e t d a o h a m y' = - — x - ^ i g m m m y' = » X = - ^ ^ = -0,02m = -2em ' ,, Ki thuatgilii iiluiiih BI'rN Vat Li 12, t&p - Nguyen Quang Lac Cfy TNHH K h a o sat svt bien thien ciia y ta tha'y v o l x = - c m t h i y dat gia t r j cue {Chi vat d u n g h i n t h i co nang cua vat chuyen het cong ciia l y c m a sat Suy v dat gia t r j eye dai tai v i t r i x = - c m Do do: A ^ ^ = Hmg.s = W => 0,02.0,1.10.5 = 0,5 => S = ( m ) =>ChpnB v ^ ^ = J — A l ^ - — x - n g ( A l + x) = , V m / s = 40N/2cm / s ' ' £^vi 161 M p t lac lo xo n a m ngang d a n g dao d p n g tat dan N g u o i ta d o => C h g n C jju C h p n D Cau 159 M p t tarn v a n bac qua m p t m u o n g c6 tan so' dao d p n g rieng bang 0,5 H z M p t n g u i d i qua t a m v a n v o i bao nhieu buoc t r o n g 12s t h i tarn van bi r u n g len m a n h nhat? A buoc B buoc C buoc K h i b u o c chan vao t a m v a n t h i chan n g u o i da tac d u n g vao t a m van mot luc Muo'n t a m v a n r u n g len m a n h nhat t h i tan so'ciia l y e tac d y n g vao t a m van dao d p n g tren m a t phMng n a m ngang so m a sat g i u a vat va m|it A 22,93em/s B 25,48em/s C 38,22cm/s d u o n g la chieu dan ciia 16 xo K h i vat chuyen d p n g theo chieu am: - k x + famg = ma = m x " -k r _^mg^ - m X \ lOOgphang ngang la fa = 0,02 Cho gia toe t r p n g t r u o n g g = 10 m/s^ Keo vat k h o i v i t r i caf k = 0,02m = 2cm; co = j — = lOrad / s Vm X - = A.cos(tot + (p) =:> V = -(oAsin(a)t + (p) bang m p t d o a n 10 c m r o i tha nh? Q u a n g d u o n g vat d i d u p e cho d e n k h i d i m r Liie to = -> xo = c m => = Aeos cf) vo = han la: => = -lOasincp => cp = 0; a = em A 25 c m B.25m C 250 cm Huang dan gidi: C o nang ciia vat la: W = ^ k A ^ = ^.100.0,1^ = , ( j ) D.250m D 28,66cm/s Chpn Ox = true 16 xo, O = v j t r i ciia vat k h i 16 xo k h o n g bien dang, chieu Huang dan gidi: Cau 160 M p t lac 16 xo c6 d p c i i n g 100 N / m , vat nang c6 k h o i l u p n g tien la: Huang dan gidi: D buoc p h a i bang tan so'dao d p n g rieng ciia t a m v a n N G p i N la so buoc chan: => — = , = > N = b u o c chan => C h p n B tu thoi d i e m tha den t h i d i e m vat qua v j t r i 16 xo k h o n g b i bien dang Ian dau => X - = 4cos(10t) (cm) K h i 16 xo k h o n g bien dang: x = =:> coslOt = -1/2 = cos27i/3 t = n/15 s Vtb = 7t/15 [jjen '^^ 90 a 28,66 cm/s 3,14 ila A 0,05 => Ch(?n D Cau 163 Mot lac 16 xo dao dong tat dan cham Cu sau moi chu ki, bien dao dong cua no giam 0,5% Nang lugng dao dong cua lac bi mat di sau moi dao dong toan phan la A 0,5% vau B 1% ca/.n: Ta c6: ^ A r C 1,5% ;r V Huangddngidi: = 0,5% => - — = 0,005 A ,;,„^_ C 0,005 Huang dan gidi: D 0,0025 Gpi A i , A la bien dp dao dpng tai hai thoi diem each nira dao dpng D 2% £)p giam CO nang cua lac: AW = ^ k ^ A j - A j , , , ,,,, Congcua lire ma sat: AA^^, = F ^ , { A J — = 0,995 A + A2) = nmg(Ai + A2) Do AW = A A ^ , = > A j - A = ^ ,!,v Nang chu k i tie'p theo: W = — mco A W B.0,025 f a tim bieu thue ciia dp giam bien dp sau moi dao dpng toan phan A2 Nang lugng chu k i dau: W = - mco2 A Suy ra: dpng toan phan va h$ so'ma sat giiia qua cau voi day kim Dp giam bien dp moi dao dpng: AA = ( A J - A ) = 4|img )' ^ ' Theo bai ra: 200AA = AQ = 2cm kAA = (0,995^ « , 9 = 99% Tudo: AA = r T r = 0,01cm va n = - ^ = 0,005 200 4mg A Chpn C 1< Vay nang lug-ng bi mat di la 1% => Chon B CSu 166 Mot lac 16 xo dat tren mat phSng nghieng goe ao = 60" so voi mat Cau 164 Mot lac don c6 dp dai lo = 16cm dupe treo toa tau a v i ngang, h^ so' ma sat gii>a vat va mat phang nghieng la | i = 0,1, vat c6 khoi tri phia tren cua true banh xe Con lac dao dpng manh nhat van toe cua lupng m = 400 (g), lay g = 10 m/s^ Cong suat can cung cap cho lac de no doan tau bang 15 m/s Lay g = 10 m M 7t^ = 10, coi tau chuyen dpng thang dao dpng dieu h6a voi bien dp A = 5cm va tan so f = Hz la: deu, chieu dai moi ray bang A 12 m B 16 m A P = 180(mW) C 18 m C.P = 220(mW) D P = 240(mW) Huang dan gidi: D.24m Huang dan gidi: Sau cung cap bu nang lupng cho vat thi vat se dao dpng dieu hoa: Cong cua lire ma sat tieu hao sau moi chu ky: Chu ki cua lye cuong buc tac dung len lac: T = — A^„^| = H.N.4.A = n.m.g.cos(a).4.A = 0,1.0,4.cos60.4.0,05 = 0,04(j) Nang lupng can cung cap sau moi chu ky la: Chu ki dao dpng rieng ciia lac: TQ = 27t J — VS Con lac dao dong manh nhat T = B.P = 200(mW) §iif4 27iJ— = - ==> = 2n,:^.v = 12m IA^, I =0,04 0) Cong suat can cung cap: P = ^ p=> => Chpn A AW = ,1 = AW.f = 0,04.6 = 0,24(w) = 240(mW) Chpn D Cau 165 Mot 16 xo c6 dp cung k = 600N/m, mot dau co'dinh, dau gan qun J67 Mot dao dpng tat dan c6 bien dp giam 2% sau moi chu ki Sau chu cau nho khoi lupng m = 300g, qua cau c6 the trupt tren mot day kim loai cang Vi CO nang dao dpng c6n lai chie'm so'phan tram so voi co nang ban dau la: ngang trung voi true 16 xo va xuyen qua tarn qua cau Keo qua cau khoi vj tri can bang 2cm roi tha cho qua cau dao dpng Do c6 ma sat nho, dao dpng ch^m dan, sau 200 dao dpng thi qua cau dung l ^ i Lay g = 10m / Dp giam l-A 17,3% B 28.9% C 73,2% D 81,5% Huang dan gidi: Theo gia thie't sau moi chu ky bien dp giam 2% tue la: ,1 Huang dan gidi: ' 100 A Ta T CO t = 4s = 2T => S=2.4A=2.4.4=32cm => C h p n D C o nang dao d o n g sau m o i chu k y g i a m d i lai Wi: Q^aJTl: M p t lac d o n c6 chieu dai 121cm, dao d p n g d i e u hoa tai n o i c6 gia toe t r o n g t r u a n g g L a y Tt'^ = 10 C h u k i dao d p n g cua eon lac la: w w 221 = (l-0,02) -1-0,04 A Is B 0,5s C 2,2s , „ , D 2s Huong dan gidi: = ( l - , ) W = 0,96W Chu k i dao d p n g cua eon lac T = 2nJ- Sau hai chu ky, ca nang lai: = 0,96Wi = {0,9ef = 2nP^ Vg W V = 2.1,1 = 2,2s 7t2 => C h p n C , Sau n a m chu k y , ca nang l a i : Cau 172: M p t vat n h o k h o i l u p n g lOOg dao d p n g dieu hoa v o i chu k i 0,2 s va ca W5 = ( , f W = 0,815W = 81,5%W =^ Ch(?n D ' ' Cau 168 M o t lac d o n g o m vat c6 k h o i i u a n g m , day treo c6 chieu doi = I m Keo lie lech k h o i p h u o n g thang d u n g m o t goc ao = 0,1 (rad) mi nang la 0,18 J (moc the nang tai vj t r i can bang); lay A cm, v ti so d p n g nang va the nang la B C D.l r Huang dan gidi: b u o n g k h o n g v a n toe ban d a u Con lac chiu l y c can m o i t r u o n g d g Ian coi nhu k h o n g d o i va c6 gia t r i bang , % t r o n g l u g n g ciia vat Q u a n g d u o n g ma =10 T a i l i d p 372 T a c o (0 = Y = 10n(rad/s) lie dao d p n g ke t u luc b u o n g tay cho den luc d u n g han la A 4m B m C m D m 2 Co nang W = => A = 0,06m = 6cm K h i d ^ = ^ = ^ Huong dan gidi: Ap d u n g d j n h luat bao toan va chuyen hoa nang l u p n g ta c6: Wo = W + = i A«n W, W, x2 => Wo = Anwx = Fcan.Sm.nx => C h p n D ^ Smax = Cau 173: M p t vat n h o dao d p n g dieu hoa theo p h u o n g t r i n h x = A cos47tt (t t i n h mgl"° ^ = 500.1.ao = ( m ) => C h p n B mg u V / 1000 bang s) T i n h t u t=0, k h o a n g t h a i gian ngan nhat de gia toe eua vat c6 d p I a n bang m p t nua d p Ian gia toe cue dai la A 0,083s B 0,125s Cau 169: M o t lac 16 xo c6 k h o i l u a n g vat nho la m j = 300g dao d p n g dieu hoa v o i chu k i I s Ne'u thay vat nho c6 k h o i l u p n g m bang vat n h o c6 khoi l u p n g m ' t h i lac dao d p n g v a i chu k i 0,5s Gia t r i m2 bang A lOOg B 150g C.25g = 0,5Ti => c ^ | ^ = 0,5.27i =^ m ' = ^ Ta CO tai v j t r i l a i = , amax t h i 1x1= 0,5.A K h o a n g t h o i gian ngan nhat tir 'a A i = 8cm, A2 =15em va l^eh pha n h a u ^ Dao d p n g t o n g h p p cua h a i dao = 75gam Chpn D •^Png eo bien d p bang A.7em B 11 em C.17em Huang dan gidi: d u a n g vat d i d u p e t r o n g 4s la: B 16 c m Huong dan gidi: £ | u 174: H a i dao d p n g deu hoa eiing p h u o n g , cung tan so' c6 bien dp Ian l u g t Cau : M o t v a t nho dao d p n g d i e u hoa v o l bien dp 4cm va chu k i 2s Quan;- A cm C 64 c m D 0,167s X = A den X = 0,5.A la t = T/6 = 0,5/6 = 1/12 = 0,083 ^ C h p n A D 75 g Huang dan gidi: Ta c6: C 0,104s D.32 c m H a i dao d p n g v u o n g pha nen bien dp dao d p n g tong h p p : D 23 em end A = A I + A | =17cm =>ChonC Dt - ' ' S O N G C O L Cau 175: H a i lac d o n c6 chieu dai Ian l u g t la 81 cm va 64 cm d u g c tree Q tran m o t can p h o n g K h i cac vat nho ciia hai lac dang v i t r i can bang J H E T H O N G H O A K I E N THL/C d o n g t h o i t r u y e n cho c h i i n g cac van toe cung h u a n g cho hai l i e dao I Song CO hpc va cac dac t r u n g ciia song d o n g dieu hoa v o i c i i n g bien goc, t r o n g hai m a t p h a n g song song v d i ^) Dinh nghta song ca hoc Gpi At la khoang t h o i gian ngan nha't ke t u liic t r u y e n v a n toe den liic hai day treo song song Gia t r i At gan gia t n nao nha't sau day? A 8,12s B 2,36s C 7,20s >.„ D 0,45s Huang dan gidi: PT dao d p n g xi, X : xi = A cos a),t ^ — ; tmin trtfong vat chat theo t h o i gian - 7t A /• = COS (0,t - C em D 12 cm chu k i s Tai t h o i d i e m t = 0, vat d i qua can bSng O theo chieu d u a n g Phuong - X = cos x t + ^ (cm) (p = Tan so f ciia song la tan so dao d p n g chung cua cac p h a n tCr vat chat k h i CO song t r u y e n qua ^ = ~ D X = 5cos diem d o k h i song t r u y e n qua Thong t h u o n g cang xa t a m tao song t h i bien (cm) = n (rad/s) K h i t = vat d i qua can bang O theo chieu d u o n g : x = va v > => eoscp = va sintp < C h u k i T cua song la chu k i dao d p n g ehung eiia cac p h a n t u vat chat k h i B X = 5cos r t - ^ (em) 2j Huang dan gidi: Ta CO A = 5cm; co = 2n/T= lull Song dpc: l a song eo p h u o n g dao dpng ciia cac p h a n t u m o i t r u o n g t r i i n g CO song t r u y e n qua va bang c h u k i dao d p n g ciia n g u o n song - t r i n h dao d o n g eua vat la C Song ngang: la song c6 p h u o n g dao d p n g eua eae p h a n t u m o i t r u o n g voi p h u o n g t r u y e n song Song dpc t r u y e n dupe t r o n g chat ran, chat l o n g va Cau 177 : M o t vat nho dao d o n g dieu hoa doc theo true O x v o i bien d p em, (em) \nrn' C h p n A ;j'.) = v.T = j ; ' T =j; { = ' A v = A f = - - N a n g lu-ong song: Qua t r i n h t r u y e n song la qua t r i n h t r u y e n nang luong N a n g l u o n g cua song tai m p t v i t r i chinh la nang l u g n g cua cac p h a n t u chat dao d p n g tai d o va nang l u o n g cua song ty le t h u a n v o i b i n h p h u o n g hi^^ dp dao d p n g ^ Giao thoa song \ sokhdi ^ Giao thoa song la su t o n g h o p hai hay nhieu song ket h o p t r o n g k h o n g an t r o n g c6 n h u n g cho bien dp song tong h p p dupe tang c u o n g hoac eo D o i v o i song phSng nang l u o n g song g i a m ty le v o i khoAng each D o i voj song cau nang l u o n g giam ty le v o i b i n h p h u o n g ban k i n h Song p h a n g ne'u b6 qua m a t m a t t h i bien d p d u p e xem la k h o n g d o i nen nang l u p n g t r u y e n qug ^hiJnS s P h u o n g t r i n h song la bieu thuc cho phep xac d i n h l i d p u ciia t i m g phan t u X theo t h o i gian t Gia s u p h u o n g t r i n h song tai O c6 dang: U Q = a.cos(a)t) - P h u o n g t r i n h song tai M each O m o t doan d (song t r u y e n t u O den M ) : aeoso) thay doi theo t h a i gian J,) phuong * = acos " i M = aeos = a cos CO = acos a)t + t — + H a i d a o d p n g c i m g p h a : A(]) = k n (voi k e + H a i d a o d p n g n g u p c p h a : A(|) = (2k + 1).TT (voi k € + H a i d a o d p n g v u o n g p h a : Acjj = (2k + 1) ^ COt + CP] - 27rdi' = " i M + " M =2acos = 27t MN Z) Acp d2-di Acp — +—< In X t r u y e n c u a s o n g d e u d a o d p n g t u a n h o a n theo t h a i g i a n v o i c h u k i T V i du, d i e m P CO tpa d p d se c l i d p bien thien theo p h u o n g t r i n h Up =aeos — t - l T X * , Acp k < —+ X 2n Acp , + -X - ^ = -^ 2r 1^2 n + ' < Buoc song dai nhat Amax = 21 k h i k = (chi co bo song) xen ke n h a u Ne'u hai n g u o n dao d p n g cung pha t h i d u o n g t r u n g t r y c eiia 51-^' 17A 177 - D a y d a i /co d i n h rriQt dau, m p t d a u t y do: I = ( k + ) — (Chieu dai ,1 N e u d u n g d o n v j la Ben (B) t h i : L = l o g : ^ day bang m o t so' le Ian m p t p h a n t u b u o c song) + Sobung:k + l + S6'nut:k + d) Do van toe truyeh - N e u d u n g d o n v i la dexiben (dB) t h i : L = l O l o g — f'j^L- IQ song ^) Cac dac trtmg sinh U cua dm D u n g hien t u p n g song d u n g , tit t h i n g h i e m , ta d o dup-c b u o c song > ^ p D p cao: La dac t r u n g sinh l i eua am, p h u thupc vao t a n so' a m A m cao bang each d o d u p e X/2 khoang each giua hai n u t song l i e n tie'p hoac hai byng (tharih) la a m co tan so' am I o n ; a m thap (tram) la am eo tan so' a m n h o D p thap song l i e n tie'p va d o d u p e tan so' f |,ay cao ciia a m d u p e h i e u qua s u t r a m hay b o n g cua am - a) Song + dm Song a m la song co hpc ma tai n g u o i c6 the cam n h a n d u p e Song am CO tan so n a m t r o n g khoang t u 16Hz den 20.000Hz N g u o n a m la ba't k i vat nao phat song a m - Cac a m co tan so tren 20 OOOHz g p i la sieu a m (tai d o i cam t h u dupe) - Cac a m co tan s o d u o i 16 H z gpi la am (tai cho cam t h u dugfc) b) M6i trubng truyen dm vd van toe truyen - dm Song a m t r u y e n d u p e t r o n g cac m o i t r u o n g vat cha't d a n h o i n h u ran, long, k h i Song a m k h o n g t r u y e n d u p e t r o n g ehan k h o n g N h i r n g vat l i ^ u nhu bong, n h u n g , n h i r n g tarn xo'p t r u y e n am kem, ehiing d u p e d u n g de l a m vot l i f u each am ' - D p to: La m p t dac t r u n g sinh l i ciia am, p h y thupc vao m i i c c u o n g d p a m {pxbng d p a m va tan so am) Song am - - D u n g eong t h u c v = Xf ta t i m d u p e v a n toe v Gia t r i c u o n g d p am I be nha't ma tai n g u o i cam n h a n d u p e g p i la nguong nghe Gia t r j cua n g u o n g nghe p h u thupc vao tan so' + thi gpi + Gia t r j I nao d o d i i I o n l a m tai nghe co cam giac nhue n h o i , d a u d o n n g u o n g d a u N g u o n g d a u k h o n g p h u thupc vao tan so' M i e n I n a m t r o n g khoang n g u o n g nghe va n g u o n g d a u g p i la m i e n nghe dupe M i e n r p n g hep p h u thupc tan so' - A m sac: La m p t dac t r u n g sinh l i ciia am, p h u thupc vao tan so' am, bien dp song a m va cac t h a n h p h a n ca'u tao eiia am, t i i c la p h u thupc vao d o t h i dao dpng cua a m + A m CO ban va hoa am: M p t nhac cu phat m p t a m co tan so fo (am co ban hay hoa a m t h u nha't) t h i bao g i o cung phat d o n g t h o i cac hoa am t h i i 2, 3, CO tan s6'2fo, 3fo, Do hien t u p n g do, am phat t u m p t nhac cu la s u tong V a n to'e t r u y e n a m p h u thupc vao t i n h d a n h o i , m a t d p v a nhiet d p cua hpp cua am co ban va cac hoa am, no dupe gpi la nhac am, t u y no co tan so'cua m o i t r u o n g V a n toe t r u y e n am t r o n g chat ran Ian h o n v a n to'e t r u y e n a m i m CO ban fo n h u n g d u o n g bieu d i e n cua no k h o n g eon d u o n g h i n h sin dieu chat l o n g , v a n toe t r u y e n am t r o n g chat l o n g Ion h o n v a n toe t r u y e n am hoa ma la m p t d u o n g cong tuan hoan phue tap co chu k i , ta g p i n o la d o thj chat k h i - dao d p n g cua am H p a am nao co bien d p I o n nha't se quyet d j n h d p cao cua am Song a m t r u y e n t r o n g chat k h i la song dpc; song a m t r u y e n t r o n g chat phat + ran bao g o m ca song dpc va i o n g ngang c) Cac dac tntng vdt ly cua dm - T a n so am: f t u l H z d e ' n 20.000Hz - C u o n g d p am va m u c c u o n g dp am: + E diem I = — = S-t + ^ khae n h a u phat sac thai am t h a n h ma ta nghe khac la d o so' hpa a m toan khac + C u o n g d p a m I tai m p t d i e m la nang l u p n g t r u y e n t r o n g m p t d o n v! t h o i gian qua m p t d o n v j d i ^ n tich dat v u o n g goe v o i p h u o n g t r u y e n am to' E P — 47tR^t u n g v o i tan so' f = OOOHz) ' ^ o n g t u a n hoan ^guon - 47iR^ g i i i a c u o n g d p a m I tai d i e m d a n g xet va c u o n g d p am chuan lo (lo = 10"^^ W / m A m d u p e phat t u m p t tieng no, tieng go vao t a m k i m loai, g p i la am, chving k h o n g co tan so' xae d j n h , d o t h i cua ehung la d u o n g cong D o n v j : W / m ^ (oat tren met v u o n g ) M u c c u o n g d p am L la dai l u p n g bang loga thap p h a n cua ty s^' Dao d p n g am tong h p p co t i n h tuan hoan, d a n g cang p h u e tap t h i so hpa am cang n h i e u , am sac cang p h o n g p h i i C i m g m p t am sol d o n h i e u d u n g ^ nhac dm vd hgp cong huong N g u o n nhac a m la n h i r n g n g u o n phat nhac a m , tuc la phat n h u n g CO tan so xae d j n h , m o i nhac cu la m p t n g u o n nhac am - H o p cong h u o n g la m p t vat rong co kha nang epng h u o n g d o i v o i nhieu so khac n h a u v tang c u o n g n h i r n g am co cac tan so d o Huong dan D UMN = V ; L = , H C UMN = V ; L = , H M Jh ^^yTNHH B UMN = V ; L = , H A UMN = V ; L = , H gidi: H a i gia t r j cua Z L cho c u n g m o t c u o n g d o hieu d u n g t h i : R L , Ro MTV DWH Khattfj Vi^t N Zc=|(zLi+ZL2)-200i^ Huang dan gidi: D u a vao d p I f c h pha gifi-a cac N D o Z L J < Z L nen Z L J < Z c ^ cpi - (P2 =-| M a t khac, (pi = - 92 Giai he ta co: cpj = - - ; (p^ = ^ 6 dien ap v o i n h a u va v o i d o n g dien ta CO gian d o vecto n h u h i n h ve Theo de U^jvj = Uf^^p nen tarn giac M N P la tarn giac can tai M , Ui M : H ^ - ^ M N I Voi sincpj = — • 6' tan 100-200 R = 10073Q =:> Chon B M H la d u o n g t r u n g tuyen Cau 83 M o t d o a n m a c h d i e n xoay chieu n h u h i n h ben H o p d e n X g o m m o t L P =ULtg30''=15V3V;U MN - u i - - = 30N/3V hoac mQt so l i n h k i ^ n R , L , C mac nol tiep D i e n ap giOa hai d a u h o p X tre pha han c u o n g d o d o n g d i f n t r o n g mach ^ H o p X chua cac p h a n tir „_,o cos 30 MtL A R no'i tiep v o i C UR=UPQ=UMN=30V3V ^BB ^ H C C h i chua p h a n tit L 90V U ^Hp R Huong dan L = 0,0827H => C h o n D d o hi?u d u n g , n h u n g pha ciia hai d o n g d i e n d o khac n h a u m p t goc — R va Zc V3 D Ca A , B, C c u n g sai 364 y, ^ L , r = Oj R B ^ nen d o a n mach t r o n g h o p X p h a i chua phan ti'r C hoac p h a n t u L va C n h u n g (loan mach t r o n g hgp den p h a i co t i n h d u n g khang Suy dap an D la d i i n g Chgn D Biet: UAB = 120 ( V ) ; 200 R - ^ Q gidi: £3u_84 C h o m a c h d i f n n h u h i n h ve: CO gia t r j Ian l u g t bang: B Zc = 200Q; R = 0 V Q ^ H p ) i e n ap hai d a u h o p den tre pha h o n c u a n g d o d o n g d i e n t r o n g mach t r i ciia Z L la Z^^ = lOOQ, Z ^ ^ = 300Q cho ta hai d o n g d i ^ n co c i i n g m p t cuang A Z c = 200Q; R = ~ Q V3 X Z^ Zc C Mach CO R, ZL va Zc voi va ZL < Zc ' B R = 25>/3fi va L = 318mH , Huong dan gidi: vay la tam giac vuong tai N NB 60 tga = AN A R = 25N/3Q vaC = 0,127mF A A RvaR Xi J X? B R va C C L va C r* D L va R Hwang dan gidi: Vi dp l^ch pha ciia di^n ap tren hai dau hai hpp den la = ^ nen chi c6 hai truong hpp sau: Hpp chua R, hpp chua C hoac hop chua R, hpp chua L Ki thuatgiai nhanh BTTN Vat Li 12, t&p - Nguyen Quang Lac cfinh cac p h a n t u mac t r o n g X, Y va gia t r j ciia chiing M a t khac, theo dau bai t h i doan mach k h o n g cho d o n g d i e n mQt chieu chay A X chiia Rx = 30Q, L x = H - H ; Y chiia Rv = C O , Cy = qua nen t r o n g mach phai chua p h a n tit C Suy p h u o n g an B la d i i n g V37t => C h o n B B X chua Rx = 30Q, Cau 88 Cho doan mach A B g o m bien t r o n o i tiep v o i h o p k i n X H o p X chi chua cupn thuan cam L hoac t u C D i e n ap hai dau mach c6 gia t r i hieu durig I U = 200(v), tan so' f = 50Hz K h i bien trcr c6 gia t r i cho cong sua't mach cue C = - ^ F B.XchuaL = - H 2n n 10''* C.Xchua C = - — F , chiia t u C = \/2 D i e n d u n g cua t u : C = = W2 10"^ = 27tfZ^ ; Y chiia RY = 400, Cy = ^ F i /; ' ' , = — H ; Y chua RY = 40Q, Cy = ^ F IOTI 471 gidi: day t h u a n cam Lx V i cupn day thuan cam k h o n g c6 tac d u n g can t r o d o n g D o n g d i ^ n tuc t h a i sam pha h a n dien ap hai dau mach d o d o t r o n g hop D u n g khang ciia mach: ZQ = H bai t h i X chua t r o n g ba p h a n t u nen X phai chua d i ? n t r o t h u a n Rx va cupn d i f n m o t chieu nen: ZQ = = ^ H o p X cho d o n g dien m o t chieu d i qua nen X k h o n g chua t u d i ^ n Theo de gidi: C o n g sua't mach cue dai k h i Zc = R => Z = ^ + C X chua Rx = 30Q, 47371 ,-3 Huong dan n Huong dan 3V3 ^ D.XchuaL = - H 7t 7371 D X chua Rx = 30Q, H o p X chua p h a n t u nao va gia t r j ciia no la bao nhieu? A.Xchiia 30 n "3 = - T ^ H ; Y chua RY = 40Q, Cy = - ^ F IOTI dai t h i I = \/2 ( A ) va d o n g dien tiic t h a i som pha h a n dien ap h a i dau m a c h ~ F 471 42.ZQ j R^ = Hi = ^ = 30Q ^ I, K h i mac A , B vao n g u o n dien xoay chieu: VaihppXtaco: Z A M = ^R^ + ^ =Hi = ^ IT = 100(Q) = Jz^ -'AM v2v2 (F) ^ Chon C ^ TC Cau 89 Cho d o n g dien xoay chieu d i vao m o t hop k i n t h i tha'y mach k h o n g ticu R> thu dien nang va c u a n g d o n g d i ^ n sam pha han d i ^ n ap D i e u khang d i n h ^AM = A H o p k i n chua d i e n t r o - R = ^ - ^ = 30V3D 1071 tg(pAM = nao sau day d i i n g ? ^ = 73 rad Ta ve d u p e gian vec to B H o p k i n chua tu d i ^ n = 60Q A >Au h i n h ben: C H o p k i n chua cuon cam D H o p CO the chua t u dien hoac cuon cam Huong dan gidi: URV =UMB-sin^ = 40V ^ Ucy =UMB-COS^ = 40V3V ^ R Y = - ^ = 40Q UAB B M a c h k h o n g tieu t h u dien nang => mach chua L hoac C M a c u o n g d o n j ' d i e n sam pha h a n d i f n ap => mach chua C => Chon B Cau 90 Cho hai hop k i n X, Y chi chua ba phan t u : R, L (thuan), C m^*^^ noi tiep K h i mac hai d i e m A , M vao hai cue ciia m o t n g u o n dien m o t chieu tin A m p e k e c h i 2(A), V o n ke'Vi chi 60(V) K h i mac hai d i e m A , B vao hai c\fc c u ' CY = 10 ,-3 47371 Zc^ = ^ = 40V3Q F => C h p n C mpt n g u o n d i e n xoay chieu tan so'SOHz t h i A m p e k e c h i 1(A), V o n ke Vi ch' 60(V), V o n ke V2 chi 80(V) va u ^ j ^ lech pha so v o i u ^ g m o t goc lnl3 Xa"^ 369 Cau 91 C h o m^ch di^n xoay chieu n h u hinh ve X la mpt hpp den chua phan A Ux =25%/T4.cos lOOTtt- 41n (V) 180^ L tu R h o § c L holic C biet U ^ B = IO0V2cosl007ct(V); ^ = V ( A ) , P = 0 W , 4171"! B Uy = 25728.cos lOOTlt10-^ - ( F ) , i tre pha hon u^g T i m cau tgo X va gia trj cua phan tu? 37t C Uy=257l4.cos A Hpp den chua phan tU R = 40i7 lOOTtt- B Hpp den chiia phan tu C = 3nF D Uy = 25728 cos lOOTlt- C Hpp den chua cupn day khong thuan cam L = — H ; r = 50Q D Hpp den chua cupn day thuan cam L = — H 1 X A H K = ^(5072)^ +(10072)^ rB B 4071 150, (V) 4071 150 (V) -2.50.100.cos| =50V6 = > U L = UC = 2576 ( V ) Y\g dp dong di|n tre pha hon dif n ap nen hpp X phai chua phan tu L => tg(px = va R Mat khac theo dau bai hpp den chua phan tu R hoac L ho^c C nen hpp den phai chua cupn day khong thuan cam Vay hpp den la mpt cupn day co r Taco: P = i^T^t = — = N Ta lai c6: H K = U L + Uc = 2UL = 2Uc Huang dan giai: 100 M J , Huotig dan giai: Theo bai ta ve dupe gian nhu hinh ben: Xet tam giac O H K ta c6: c -i X 180, (pxw =50(n) HE 2576 73 OH 5o7^ 4l7[, 180 (rad) I Ux = N / O H ^ T H E ^ - ^ + 50^2 = (v) Vgy phuang trinh: ,Ux = U x 72coS(ioo;, _ (px) = 25 728 cos (IOOTI - Mgitkhac: r ^ + ( Z L - Z c ) = — ) (V) 180 => Chpn D ZL-ZC Giai ra: Z, = 80(w) =^ L = ^ = — ^ ^ ' (0 lOOTt = — ( H ) => Chpn C 57t^ ' £3iL?2.Cho mach di?n nhu hinh ve Biet X la hpp chua phan tix L'' Ri,Ci mac noi tiep Dat vao hai dau mach di?n ap xoay chieu c6 tan so CO = lOOn (rad) thi di^n ap mgch c6 u^^j = 100.cos(l007tt) (V)' Cau 93 Khi mac Ian lupt mpt difn trd thuan, mpt ty difn va mpt cupn day thuan cam vao mpt di^n ap xoay chieu (c6 di^n ap hifu dung U va tan so'f) thi cuong dp dong di^n hi^u dung chay cac phan tu c6 gia tri Ian lupt la 5A; 1,25A; 2,5A Neu dat vao hai dau doan mach gom difn tro thuan, ty di?n cupn day mac noi tiep vai di^n ap xoay chieu ke tren thi dong di^n chay 3ng mach c6 gia trj hi^u dyng la A 75A B.275A C.375A Huang dan giai: D.47lOA ' "MB =200 cos l O O T t t - - (V) Phuang trinh di^n ap hai dau hpp X la: k 371 P o i v o l mach RLC: U = ^\^m+{^iv => C h o n A ' Cau 94 Cho mach di#n xoay chieu n h u h i n h ve D i ^ n ap hai d a u doan mach la u ^ g = 200sin(l007it)(v), d i ^ n t r o cua cac v o n ke R y * • U h a i d a u doan m^ch s6m pha ^ so v o i i V o n ke Vj va v o n ke V2 Ian l u g t chi R A IO0V2V va IO0V2V B = V^^OO^ + (lOO - lOO)^ = lOOV Va R = Z L = Zc (do h i ^ u dien the tren cac phan t u bang nhau) IL P o i v o i mach RL: P U = ^/u^,, + = =.U2K=-^ = ^ ^ I ^ M +Uicf iP = U2R ^/2 (do Z j = R ) = 50V^V =>ChonB B 150V va 50V Cau 96 P a t d i ^ n ap xoay chieu c6 gia t r j h i ^ u d u n g 200V va tan so k h o n g d o i C lOOV va lOOV vao h a i d a u A va B cua doan mach mac n o i tiep theo t h i i t u g o m bien t r o R, cuon cam t h u a n c6 d o t u cam L va t u dien c6 d i ^ n d u n g C thay d o i G p i N la D 200V va 200V diem n o i g i i i a cupn cam thuan va t u d i f n Cac gia t r i R, L, C h i i u han va khac khong V o i gia t r j C = C i t h i dien ap h i ^ u d u n g giOa h a i d a u bien t r o R c6 gia Huang dan gidi: tri k h o n g d o i va khac k h o n g k h i thay d o i gia t r i R ciia bien t r o V o i gia t r i Q Ta c6: u AB C = =>UAB Voi t h i d i e n ap hieu d u n g g i i i a A va N bang = " A M+ " M B = U A M A 200 V + U M B U A B = U L + U C ; B IO0V2V K h i C = C j t h i d i e n ap hieu d u n g g i i i a hai dau R la: tarn giac v u o n g can nen: U R = I R = 200 A M - '-'MB - 4i ' 1^ , ^ I >^.(z,-Zcf = 100V Pe U p k h o n g p h y thupc vao R t h i Chpn C Cau 95 P a t vao mach d i f n R L C h i ^ u dien the xoay chieu c6 hieu d i ^ n the hieu t C 60V2 V Huang dan gidi: I P 9o72 V t h i Zc^ =2Zc^; \5\^-l'Z\^ = ^/R27Z[ = ^ / R ^ ^ (1) UAB=I'ZkB v o i bang va bang TOO V Ne'u lam ngan mach t u d i ^ n (noi tat hai b a n cue cua no) t h i h i ^ u d i e n the hieu d u n g tren d i ^ n t r a thuan R la K h i C^^C^ = ^ v o i z;,^ d u n g k h o n g d o i Biet h i ^ u d i ^ n the h i ^ u d u n g tren cac p h a n t u R, L, C deu B ^ V = ZQ_^ UAM S o c h i ( V i ) = So chi (V2) =100V A 50V D.200V2V Huang dan gidi: U A M - U R T u gian d o ta c6, tarn giac O A M la U C lOOV ZAB = +(ZL - )' = +(ZL - 2Zcj)' = ^ Z2 ^ (2) \r (1) va (2) ta thay Z;^^ = Z^^B nen U;^^ = ^ A B = U = 200V => C h p n A T a c o : U = ^t i ( U , - U c f ^ 97 M o t m a y bien ap c6 so v o n g cupn so cap la 3000 vong, cupn t h u cap ^OO vong, d u p e mSc vao m a n g d i ^ n xoay chieu tan so 50Hz, k h i d o c u o n g d p '^ong d i ^ n qua c u p n t h i i cap la 12A C u o n g d p d o n g d i ^ n qua cupn so cap la : V l A B.2A C.3A P.4A Chia ve vol ve'ciia (2) va (3) ta dup'c: Huang dan gidi: ' i , , Ap dyng cong thirc may bien ap: ^ DO UT I, N, II N -y^ = -rr- 500 ~ 12 = 2A => Chpn B Ui" ^ N , ^ 3000 Cau 98 Mot may bien the c6 ti so so' vong day ciia cupn so cap va thu cap la B Giam hi$u di^n the va dong di^n 10 Ian , C Tang hi^u di^n the 10 Ian va giam cuang dong dien 10 !an L • D Giam hi?u difn the 10 Ian va tang cuong dO dong di^n 10 Ian l2_U, I1 u N Tac6-A phi) mOt dien ap xoay chieu c6 gia tri h i | u dyng khong doi thi di?n ap hieu dyng giiia hai dau cugn thii cap de ho la 100 V cuon thu cap, neu giam hot n vong day thi di§n ap hifu dung giua hai dau de cua no la U, neu tang them n vong day thi di?n ap la 2U Neu tang them 3n vong day cuQn thu cap thi di?n ap hi^u dyng giua hai dau de ho ciia cupn bang C 220V D 120V Ul_N2 -i'i Ui N I1 N, vai U2=U: _u_ N2 =>•< U2=2U: 2U N2 +n " N, I , = 16(A) N Cong suat m^ch t h i i cap: P2 = U2I2 = 96(W) => Chpn C Cau 101 Di^n nang mpt tram phat di?n dupe truyen d i voi di^n ap 2kV, hi?u suat qua trinh truyen tai la H = 80% Bie't cong suat truyen tai khong doi Muo'n hifu suat truyen tai dat 95% thi ta phai lam gi? A Tang dien ap len k V • C Tang di?n ap len den k V B Giam di?n ap xuo'ng I k V D Tang di?n ap len k V =-=^U2=2U,=4kV =^ Chpn C Cau 102 Diqn nang o mpt tram di?n dupe truyen di duoi di?n ap (6 dau N j - n duong day tai) la 20 kV, hi^u suat ciia qua trinh truyen tai di^n la H = 82% Khi N cong suat di$n truyen di khong doi, neu tang di^n ap (a dau duong day tai) len den 60 kV thi hi?u suat ciia qua trinh truyen tai d i f n se dat gia trj (2) A H = 92% Neu tang n vong day cugn thii cap thi: voi Hi n V D 240V - 96W :6(V) Ni I, C V - W Huang dan gidi: yinN, Tac6:4 =^ =^ U2 Ap2 0,2.p (1) u, Chpn A Huang dan gidi: voi U = 0 V Neu giam n vong day a cupn thii cap thi: = U = 200V B 120V-4,8W Huang dan gidi: Ta c6: (4) " N., ^ 0,8A thi hi^u di^n the hieu dyng va cong suat mach t h u cap la: '1 U, l ^ = i L ^ChpnC U, 10 B.300V Ni rong va 100 vong Hi?u di$n theva cuang dp hi?u dyng a mach sa cap la 120V ^ = 10Ui Cau 99 Pat vao hai dau cupn so cap ciia mpt may bien ap l i tuong (bo qua hao A 200V " :au 100 Mpt may bien the c6 so vong day ciia cupn so cap va t h u cap la 2000 A 6V-4,8W Huong dan giai: N N, _ N2 + N _ 2N2 H i _ -,^2 ^ U'1 ^'1 A Tang hi?u dien theva dong di?n len 10 Ian .U2=U, = =i> N , = 3n T u (4) va (1) ta thay: 1:10 Bo qua hao phi may bien the Dung may bien the c6 the: Ta co: ^ - — i N, U., N j - n Neu tang 3n vong day a cugn thu cap thi: _ N2 +3n N2- do: I , = —-ly U, N2 f n U2 _N2+n U, N (3) A my' B H = 94% •'• C H = 98% D H = 96 % Huong dan gidi: Gpi P la cong sua't truyen di Cong suat hao phi tren duong truyen la: AP = R cos^ cp H i e u suat cua qua t r i n h t r u y e n tai d i # n nang la: C a u 105 M o t m a y bien ap c6 so v o n g cupn so cap va t h i i cap Ian l u p t la 2200 v o n g va 120 v o n g Mac cuon so cap v o i m a n g dien xoay chieu 220V - 50Hz, k h i P • P Khi U = U i - ( k V ) , d i ^ n ap hieu d u n g g i i i a hai dau cuon t h u cap de h o la: :.,;V C h p n C C a " ^06 M p t t r a m phat dien t r u y e n d i m p t cong suat lOOkW tren day d a n c6 dien t r o R = 8Q D i e n ap t u t r a m phat dien la U = lOOOV C o n g suat hao p h i =>ChonC C a u 103 M o t m a y bien ap c6 hi?u suat bang 1, so v o n g day cua cuon so cap va t h u cap Ian l u g t la 1000 v o n g va 50 v o n g D i e n ap hieu d u n g cupn so cap 220V, c u o n g d p d o n g d i e n la 0,18A B.4A C.6A Huong A.80kW dan Huang dan D A A.^y = R r A ^ = gidi: ,1:, gidi: = 80000 = k W £a» 107 D u o n g day tai dien c6 dien t r o f i d a n dien t u A den B D i e n ap hieu d y n g A la 5000V, cong suat la 500kW H e so cong suat tren d u o n g day tai la U J i coscpi , ^ R = P, => U , ! , coscp, = U J , coscpi => I2 = -rH = ' 0,8 H i e u suat tai d i ^ n la: # A 87,5% =>ChpnB C a u 104 D i ^ n n a n g cua m p t t r a m phat d i ^ n dupe t r u y e n d i d u o i d i ? n ap 2kV va cong suat 200kW H i e u so chi cua cong to t r a m phat va cong to tong noi AP _ P D 40kW;95% gidi: C o n g suat hao p h i tren d u o n g day bang hieu so c h i cac cong t o t r o n g \h, Vixc C 79,5% Huang dan d u o n g day va h i ^ u suat cua qua t r i n h t r u y e n tai di?n Ian l u p t la C 20kW; 90% B.88% A T a c : I = — A P = H Ucosip tieu t h u sau m o i d e m chenh l^ch 480 k W h C o n g suat hao p h i tren Huang dan D.70W > Chpn A H i ? u suat cua m a y bien ap bang nen: B.83kW;85% C.70KW I C o n g suat hao p h i tren day d a n la cong suat toa nhiet tren day dan: Tac6::^ = ^=>U,=U,-^-^ = llV A 0 k W ; % B.80W so cong suat ciia mach so cap va mach t h u cap Ian l u p t la va 0,9 C u o n g dp h i ^ u d y n g mgch t h u cap la: A A ^en day d a n la gidi: Rl2=_5^ RP D 77,5% ^ ^ U^cos^cp "u^cos^cp'S P-AP T u do: H = = 0,875 = 87,5% => C h p n A ^ u J C o n g suat t r u y e n d i cua m p t t r a m phat dien la 200kW H i ^ u so chi cac cong to d i e n a t r a m phat va n o i t h u sau m p t d e m I f c h n h a u la bang: , ^ = 20(kW) C o n g suat den n o i tieu t h u la: 200 - 20 = 180 (kW) H i ^ u suat qua t r i n h t r u y e n tai: H ^ 1^.100 = % => C h p n C 200 ^hem k W h H i ^ u suat tai dien la ,A.70% B.80% C.90% Huang dan D 95% gidi: l?ch cua so chi ciia cong to d i ^ n giCra n o i t h u va t r a m p h a t la cong hao J k h i t r u y e n tai t r o n g m p t d e m la: jCtyTNHH m A = 480kWh ^ A:-y^ = A t = 20000W P — AP AP Hi?u sua't truyen tai di?n nang: H = — - — = - -— 24.3600 V|y hi?u suat truyen tai di?n la: H = ^ — ^ 0 % MTV DWH = 90% w Tu(l)va(2)=:> - H = — = P-!^ P ^ Chpn C Cau 109 Dung rngt hi^u di$n the 6kV de tai di mot cong sua't lOOkW den mot Suy ra: - = noi each xa 7,5km Cong suat ton hao tren duong day bang 3% cong suat car, P-i-; - = Khang Vm (2) ' ) P-V >2 truyen di Tim kho'i lugng dong can thiet de lam day dan biet di?n tro suat cua dong bang 1,7.10 Tim, khoi lugng rieng cua dong D = 8,8 tan//w ? A m = 6,117 tan C m = 4,117 tan D m = 3,117 tan : CMML Mot may phat di^n xoay chieu mpt pha c6 roto quay voi toe dp 300 B m = 5,117 tan ^ * M Huang dan gidi: Cuong dp dong d i f n tren day tai bang: I - I - I - V> -50 ^phat A ^ ••>••'•• Cong sua't hao ton tren duong day la: Pj = 3?/oPphat = 0,03.100 = 3kW p Di?n tra cua day tai: R = -|- = 10,8Q ' l2 The tich cvia day: V = SI = p — ^ R 1^ , Kho'i lugng ciia dong can diing: m = VD - p—D = 3,117 ta'n R => Chpn D Cau 110 Di^n nang a mpt tram phat di^n dupe truyen d i v6i di?n ap dau duang day tai la 5kV, hi|u sua't qua trinh truyen tai la 80% Muo'n hi^u sua't qua trinh truyen tai tang den 95% thi phai A tang di$n - ap len den lOkV j' B tang di^n ap len den 15kV Huang dan gidi: Cong sua't hao phi tren day dan toa nhi?t: ^ " ' l ? y vong/phiit, may c6 10 c^p eye t u thi dong di^n phat c6 tan so: B 10s-i A 50S-' C 20s' D 100s' k Huang dan gidi: P Ta c6: f = np = — 10 = 50(Hz) = 5o(s"^) =i> Chpn A 60 ' ' *' ^ Cau 112 Noi hai cufc cua mpt may phat di?n xoay chieu mpt pha vao hai dau doan mach AB gom di^n tro thuan R mac noi tiep voi cupn cam thuan Bo qua dien tro cac cupn day cua may phat Khi ro to eiia may quay deu n vong/phiit thi cuong dp dong di^n hi^u dyng doan mach la l A Khi roto cua may quay deu vai to'c dp 3n vong/phut thi cuong dp dong di?n hi^u dyng doan m^ch la 3A Ne'u roto cua may quay deu voi to'c dp 2n vong/phiit thi cam khang ciia doan m^ch AB la A 2RV3 B ^ C RN/3 D V3 V3 Huang dan gidi: Tan so' bie'n thien va sua't d i f n dpng eye dai may phat di^n xoay chieu ipt pha tao la: f = —-; EQ = (oNBS = 27tfNBS => Di^n ap hi?u dyng hai dau 60 B>9n mach la: U = E = ^ = V27ifNBS P* Khi roto ciia may quay deu vai toe dp nj = n va n j = 3n thi f2=3fi=>ZLi=3Z^;U2=3Ui C giam di^n ap xuong 2,5kV D giam di$n ap xuong 0,85kV Theo bai ra: Ij = A; I j = N/3A r=> I2 = -Tsii => ^ = N/3 ^-^ •=> Z2 Z2 3> R2 + ( Z , J ' = 3(R2 + ZL J'=:> Z^ = Z, if Cau 116 Cho mach d i # n R, L, C mac no'i tie'p D o n g d i # n qua m^ch d u p e c u n g cap b o i may phat d i e n xoay chieu m p t pha K h i t r o n g mach xay h i ^ n t u p n g cpng h u o n g dien t h i tan so'ciia d i f n ap dat vao hai dau doan mach la 50 H z T i n h so v o n g quay d u p e ciia roto ciia may phat dien t r o n g phiit? Biet rang phan cam ciia may phat d i ^ n xoay chieu m p t pha c6 cap cue? Kt thudt xiai nhanh BTTN Vcit Li 12, tap - Nguyen Quang Lac K h i roto cua m a y quay deu v o i toe d p nj = 2n t h i f3=2fi=>ZL3=2Zn=^^ChonB A 1200 v o n g Cau 113 M o t m a y phat d i ^ n xoay chieu m p t pha c6 cap eye, roto quay v o j B 1500 v o n g Huong dan toe d p 900 vong/phiit M a y phat dien t h u hai c6 cap cue De hai d o n g d i ^ n d o cac may phat hoa d u p e vao eiing m p t mang d i ^ n t h i m a y phat d i ^ n t h u hai B 1100 vong/phiit C 600 vong/phiit D 800 vong/phiit '" Huang dan gidi: ^au 117 Ilia m o i cupn day ciia p h a n l i n g xa'p xi bang 60 A 50 v o n g B 100 v o n g i n, = P2 = 600 vong/phiit ^ C h p n C Cau 114 Phan u n g ciia m p t may phat d i ^ n xoay chieu c6 100 v o n g day giong n h a u T u t h o n g qua m p t v o n g day c6 gia t r j eye dai la m W b va bien thien dieu hoa v o i tan so 50Hz Suat di?n d p n g ciia may c6 gia t r i h i ^ u d y n g la : A 111,25V B 133,28V Huang dan C 145,11V D 157,21V T u tinh duoc: E = V2 D 140 v o n g gidi: T u t h o n g qua k h u n g c6 N v o n g day: ^ft ())^ N.B.S.cos((ot + (p) = (pQ,.cos(o)t + (p) V o i (J)Q^ la t u thong cue dai qua mpt v o n g day Suat dien d p n g cam l i n g tiic thai bang dao ham bac nha't ciia t u thong theo thoi gian n h u n g trai dau: e = -(()' = NBSa)sin(cot + cp) = EQ sin(a)t + (p) Eo = NBSco = NcDo27tf Oo = m W b = ->'•- C 120 v o n g Huong dan gidi: Suat d i ^ n d p n g cue d a i giCra hai d a u cupn day p h a n l i n g la: voi M p t m a y phat dien ma phan cam g o m hai cap cue t u quay v o i toe dp p n g hi^u d u n g 220V, t u t h o n g cue d a i qua m o i v o n g day la m W B So' v o n g fi = b ^^^^ 60 :r 500 vong/phiit va phan l i n g g o m hai cap cupn day mac n o i tie'p, c6 suat d i ^ n De hai d o n g d i ? n cac m a y phat hoa dupe vao eiing m p t m ^ n g di^ n thi Do d o : = 60 gidi: Vay so v o n g quay dupe t r o n g m p t p h i i t la: 25.60 = 1500 v o n g =>ChpnB Tan so' f ciia d o n g d i ^ n may phat d i ^ n xoay chieu m p t pha c6 p cap cue va roto quay v o i toe d p n vong/phiit: f = D 2100 v o n g Ta CO f = np, suy n = — = 25 vong/giay p phai CO toe d p quay ciia roto la A 550 vong/phiit C 1800 v o n g 6.10-m ' Voi E , , - E V = NBSco = " NBS^^ 60 So v o n g day ciia m o i cupn day ciia phan u n g (c6 cupn day) la: = 133,28V Ev'^ = NBSco = N B S ^ 60 =:> C h p n A => C h p n B Cau 115 Phan l i n g ciia m p t may phat d i | n xoay chieu c6 200 v o n g day giong = 4.(t)oj.27inp = 49,5 50 v o n g * Cau 118 Phan c i i n g ciia m p t may phat d i ^ n xoay chieu c6 200 v o n g day g i o n g n h a u T u t h o n g qua m p t v o n g day c6 gia t r j cue d a i la , m W b va b ie n thien T u t h o n g qua m p t v o n g day c6 gia t r i eye dai la m W b va bien thien d i e u hoa voi tan so 50 H z Suat d i ? n d p n g m a y p h a t c6 gia t r j hi?^ dieu hoa v o i tan s6'50Hz Suat dien d p n g ciia may c6 gia t r j cue dai la: d u n g la A 8,88 V B 11,54 V Huang dan Taco: ^ = ^ ^ C 14,36 V D 18,66 V gidi: A 120V B 125,7V C 120N/2V D 220V Huong dan gidi: Tu" thong cue dai qua vong day ciia cupn day phan l i n g : ^ ^ ^ ^ ^ - ^ " - ^ =8,88(v) 381 cpo = m W b = 2.10-3 wb C&u 121 M p t m a y p h a t d i ? n ma phan cam g o m hai cSp eye t u quay v o i toe d p 1500 v o n g / p h i i t va p h a n l i n g g o m hai cupn day mac no'i tiep, eo suat d i ^ n d p n g Suat d i ? n d p n g c\tc d g i giua hai dau cupn day p h a n u n g : hi$u d y n g 220V, t u t h o n g cue dai qua m o i v o n g day la m W b M o i cupn day Eo = N Chpn B Cau 119 M p t m a y phat di?n xoay chieu c6 p h a n cam g o m hai cap eye va quay v a i v a n toe 1500 v o n g / p h i i t Phan u n g g o m cupn day g i o n g n h a u mac noi g o m CO bao n h i e u vong? A 74 v o n g B 97 v o n g A 21 v o n g B 27 v o n g Ta c6: f = C 44 v o n g D 78 v o n g Huong dan gi&i: " " i ; v.-?.- : : ' - 60 = 50Hz 220V2 CO 9o« A • N =j^^^^^ = 60 , g EQ = (oN(po = 27tfN(Po = 27tfpnN(po n p _ 1500.2 Eo = N (PQ Taco: vong D 198 v o n g Huang dan gidi: tiep T i r t h o n g eye dai qua m o i v o n g day la m W b Suat d i ? n d p n g h i § u d y n g may tao la 120 V So v o n g day cua m o i cupn day la C 156 v o n g = 198 v o n g 5.10-^271.50 •ChpnD Cau 122 M p t m a y phat d i f n ba pha mac h i n h c6 diC^n ap pha 127V N g u o i d u a d o n g ba pha vao ba d i f n t r o giong m5c h i n h t a m giac, m o i tai c6 N :i?n t r o lOOfi C o n g suat tieu t h y ciia cac tai la Suy so v o n g day tren m o i cupn la: N ' = — = 27 v o n g A 1452 W B 1600W C.3210W D.4800W Huang dan giai: => C h p n B Cau 120 M o t m a y phat d i ^ n ba pha mac h m h c6 dien ap h i f u d u n g p h a Cac di?n trcic g i o n g nen c u o n g dp d o n g dien qua c h i i n g la n h u bang 127V, tan so 50Hz N g u o i ta d u a d o n g ba pha vao ba tai n h u mac V i cac d i ^ n t r o d u p e mac h i n h t a m giac nen d i ^ n ap dat vao m o i tai bang dien h i n h tarn giac, m o i tai c6 dien t r o a va cam khang 32Q T o n g cong suat cac ap day C o n g suat tieu thy bang cong suat tieu thy tren tai tai tieu t h y la P = 3UIcoscp = U I = - ^ = 1452W A.3121W B.2178W ^ C 4242W D 1116W =>Chpn A Huang dan giai: Cau 123 M p t m a y p h a t dien xoay chieu tren stato c6 b o n c^p eye quay v a i toe H i ^ u di?n the dat vao m o i tai la: dp 750 v o n g / p h i i t tao d o n g d i ^ n eo tan so f De dat d u p e tan so' tren v a i may Ud=UpN/3= 127V3«220(V) phat d i ^ n c6 sau cap cue phai quay v o i toe dp bao nhieu ? T o n g t r o cua m o i tai la: Z = ^R^+Zl A 200 v o n g / p h u t = ^24^ + 32^ = 40(fi) D o n g dien tren m o i tai la: Z , 40 ^ B 300 v o n g / p h u t C 500 v o n g / p h i i t ' :;; C o n g suat tieu t h y tren m o i tai la: Pi=Rl2=24.(5,5f =726(W) T o n g cong suat cac tai tieu t h y la: t n i ;jr! Huong dan giai: t*^ ' D 600 v o n g / p h i i t v; , j, 750 Ta eo: f = n i p i = = 50Hz • •}• ^ V o i m a y phat d i ? n eo e | p eye, ta eo: f = n2p2 = 6n2 T u do: n2 = f 50 vong/giay P2 P = 3Pi=2178(w) Toe d() quay cua may bang: —.60 = 500 v o n g / p h i i t => C h p n C => C h p n B 383 Can 124 lA)n;; dK.-a d o M u i t n i i } p l M i d u i i xoay chieu phat sau tang ap du(?c truyen di xa bSng mpt duong day c6 di#n tra lOO Coi h$ so cong sua't bang 1, dien ap dua len duong day la 35kV, cong suat cua may phat la HOOkW.Cong sua't hao phi tren duong day la A IIOOOW B 14000W I ' C 15000W D 16000W Huong dan gidi: ' Ta c6: R = lOfi; costp = ', ^ ' Dien ap dua len duong day: U = 35kV = 35.10^ V Cau 127 Mpt dong ca khong dong bp ba pha c6 cac cuon day mac theo kieu hinh vao mang di?n xoay chieu ba pha c6 difn ap day 380V Dpng co c6 cong sua't 5kW va h? so cong sua't 0,8 Cucmg dp dong difn chay qua dpng cola t Cau 125 Dien ap hieu dung giira hai dau mot pha ciia mpt may phat dien xoay chieu ba pha la 220V Trong each mac hinh sao, dien ap hieu dung giua hai day pha la: C.381V D 513V B Ba cuon day ciia may phat m5c theo hinh tam giac, ba cupn day ciia dpng C O theo hinh tam giac C Ba cupn day ciia may phat mac theo hinh sao, ba cupn day ciia dpng co theo hinh llOV Tai ciia cac pha giong nhau, mac hinh tam giac, moi tai c6 di^n tra thuan va dung khang 12Q (mac noi tiep) Cong sua't tieu thu cua D Ba cupn day ciia may phat mac theo hinh sao, ba cupn day ciia dpng co theo hinh tam giac dong ba pha la: C 1831W D 2904W Huang dan gidi: : Tong tro cua m6i tai: Z = + [Z^ - Z^f A Ba cuon day ciia may phat mac theo hinh tam giac, ba cuon day ciia dpng C O theo hinh => Chon C Cau 126 Mot may phat dien xoay chieu ba pha mac hinh c6 dien ap pha in B 1567W = 220V Cau 128 Mpt dpng co khong dong bp ba pha hoat dpng binh thuong dien ap hieu dung gii>a hai dau moi cuon day la 220V Trong chi co mpt mang dien xoay chieu ba pha mpt may phat ba pha tao sua't di?n dpng hieu dung a m6i pha la 127V De dpng co hoat dpng binh thuong ta phai m^c iheo each nao sau day? ' Trong each mic hinh c6: U j = VsUp = 220N/3 = 381V A 1231W Huang dan gidi: Cong suat ciia dpng co bang tong cong sua't tren ba pha ciia dpng co: P = 3UpI.cos(p^ I = « 9,5A => Chpn C >^ ' ' ' ' 3UpCos(p Huong dan gidi: 24Q, cam khang D 5,9 A V3 Chon D B 142V C 9,5 A dpng C O bang dien ap pha ciia mang dien ba pha: U = ^ Cong sua't dien hao phi tren duong day: AP = RI^ = 16.10^ W = 16kW A 120V B 6,5A Cac cuon day dupe mac theo kieu hinh nen dien ap dat vao moi pha cua ^ ^ ; " Cong sua't dong dien tren day phat: P = 1400kW = 1,4.10^ W p Cuone done dien tren day: I = = 40A " • Ucoscp A 5,6 A A Huang dan gidi: • B a cupn day cua may phat theo hinh thi dien ap hieu dung giua hai day - ^jlA^+{30 - uf = 30Q Do cac tai mac hinh nen dien ap hieu dung tren moi tai: Wiala: - VsUp = 12/73 = 220V Ba cupn day ciia dpng co theo hinh tam giac thi di?n ap hieu dung dat vao i6i cupn day ciia dpng co la 220V, dpng co hoat dpng binh thuong Ud = V U p = i i o V v => Chpn D _Ud_110V3 11 Cuong dp dong dien qua moi tai: I = -— = — = Cong suat tieu thu cac tai: P = 3Pi = RI^ = 3.24 => Chpn D 384 riio^' = 2904VV 129 Mpt dpng C O xoay chieu hoat dpng binh thuong voi di^n ap hieu g 220V thi sinh cong sua't co hpc la 170W Bie't dpng co co he so cong i't 0,85 va cong sua't toa nhiet tren day qua'n dpng co la 17W.B6 qua cac hao i khaccuong dp dong dien cue dai qua dpng co la A 72 A B 2A C 3A D 373 Huang dan gidi: Cong sua't toan phan bSng tong cong suat co ich va cong suat hao phi: va di?n ap hi^u dyng hai dau cupn day la 135V Gia trj cua Uo gan gia trj nao nhat sau day? A 95V Ptp=Pci+Php=187W B.75V C 64V.; D 130V Huang dan gidi: Cong suat tieu thu dien nang ciia dpng co: P(p = UIcoscp Taco => = 187 Ucos(p = lA=>Io = =>l2 = 3Ii =^Z,=3Z2 =45(V); U^^ = ( V ) ^ ^ =IV2-V2(A) 220.0,85 => Zl= 9Zl => Chon A Cau 130 Stato cua mot dong co khong dong bo ba pha gom cuon day, cho Hay dong di^n xoay chieu ba pha tan so 50Hz vao dong co Tit truong tai tam cua R2 + ( z ^ - Z^^ f = 9R2 + z, — ^ stato quay voi van toe bang bao nhieu? A 1000 vong/phiit B 1500 vong/phiit C 2000 vong/phvit D 2500 vong/phiit = > ( R + z ) = ZLZe^ Vi Huang dan gidi: = —- n (Pi nen tan cp, tan ^2 = - (vi (pj < 0) Trong stato co cuon day tuong ung p = cap cue, t u truong t^i tam ciia stato quay voi toe do: n = Zc = 1500 vong/phiit => Chon B Ma tancpj = P R —i-;tan(pj=- R R Cau 131 Mot dong co dien xoay chieu mot pha tao mot cong sua't co hoc Zr 630W va CO hieu suat 90% Dien ap hieu dung hai dau dpng co la U = 200V, Suy R hf so'cong sua't ciia dong co la 0,7 Cuong dong di?n qua dong co la A 2,5 A B.5A C 7,5 A ZL-ZC R ^ ^ J D l O A Hay 3R2 + SZL^ - 4ZLZCI + Z^^ = Huang dan gidi: =^ 3(R2 + ZL2 ) - 8(R2 + Zi,2) + Z^^ = Dua vao dinh nghla hif u sua't ciia dong co va cong thiic tinh cong sua't ta dugc: =^z2^ = 5(R2 + ZL^)r) H =i = 90% P(p = U.I cos (p P H.Ucoscp 630 90%.200.0,7 = 5A T u (*) va ta suy Z^^ = 2,5ZLZCI => Zci = 2,5ZL 2(R2 + Z ^ ) = ZLZCI = 2,5 Z^ : ^ Z L = 2R va Z o = 5R (***) Ch(?n A \ Suy ra:Zi2 = R + ( Z L - Z c J Cau 132*: Dat dif n ap u = UQ COS cot ( V ) (voi UQ va co khong doi) vao hai dau doan mach gom cuon day khong thuan cam mac noi tie'p voi tu dien co dien =>ZI = R V I O =10R2 va Zj^ = ^ R + Z ^ -RVS dung C (thay doi duQ'c) Khi C = CQ thi cuong dp dong di^n mach som pha hon u la (p < (Pi < - '1 _ U va di^n ap hi^u dung hai dau cupn day la 45V ^ J Khi C = 3Co thi cuong dp dong dien mach tre pha han u la 92 ~ ^ ' il Zdj Zjj U =U,,—L '1 z = UH,V2 Do Uo = U N/2 = 2Udi = 90V => Chpn A 38^ Cau 133*: Dat di#n ap u = 120A/2 cosZnft (V) (f thay doi dugc) vao hai dau Cau 135: Dat dien ap u = 220^2 cosl007tt(v) vao hai dau doan mach mac noi doan mach mic noi tie'p gom cuon cam thu an c6 dp t u cam L, dien tro R va tu dien C O di^n dung C, voi CR^ < L Khi f = fi thi dien ap hieu dung giua hai dau tie'p gom di^n tro O , cupn cam thuan c6 dp t u cam tu dien dat cue dai Khi f = f2 = fiV2 thi di^n ap hieu dung giua hai dau dien tro dat cue dai Khi f = b thi dien ap hieu dung gii>a hai dau cupn cam dat cue dai ULmax 10"^ Gia tri cua Ui max gan gia trj nao nhat sau day? ' A 173 V B.57V C 145 V dung - g ^ F - Khi cp = Cuong dp dong di?n cue dai IQ = = TooTT ^'^^ i = 2,2cos 1007tt + -4 j v( A ) r ^ C h p n C • A = 4 V => Chpn B Huang dan gidi: ZL , - (V) => Chpn C Cam khang = 207^Q; l , = ^ = ^ = 11(A) Z 20V2 ^{Z^-Z^f U Q R = I Q R = 11.20 = 220V; U Q L = I Q • Z ^ = n = 8 V = 80N/3V = , V * 145 C i = 2,2cos 1007tt + - ( A ) H va t\ di^n c6 di^n Theo gia thie't U , = 0 V => Hi =^ (i) Ki hi^u may bie'n ap M c6 so' vong day moi cupn tuong ung la N j , Di?n ap hieu dung giira hai dau so cap va thu cap la U j / U j t Khi noi hai dau so ca'p may => — L = _ J L 12,5 M2 vao hai dau thu cap may M i : (2) ^ ' Khi noi hai dau ciia cugn thii- cap cua M2 voi hai dau cupn thii cap cua M i thl di%n ap hi^u dyng hai dau cupn so cap cua M de ho bang 50V 50 =^ (3) N; MUC L U C Chii de 1: Dpng luc hpc vat ran Tir (2) va (3) CO =^ U i = N / I A = V H? thong hoa kien thuc Thayvao(l)c6Hl = ^ Cae dang bai tap va v i du minh hpa =8 Bai tap t u luy^n c6 huong dan each giai => ChQn C Cau 137: Mpt khung day dan phSng, d?t, hinh chu nhat c6 di?n h'ch cm^, quay deu quanh mpt tryc dol xung (thupc mat ph^ng cua khung) t u truang deu c6 vecto cam ung t u vuong goc vai true quay va c6 dp Ion 0,4 T Tu thong cue dai qua khung day la A 2,4.10-3 Wb B l,2.10-3Wb C 4,8.10-3Wb Huang dan gidi: Ta CO t u thong cue dai OQ = BS = 0,4.60.10"'' = , - ^ W b => Chpn A D 0,6.10'^Wb 19 Chii de 2: Dao dpng ca 68 thong hoa kien thuc 68 Cac dang bai tap va v i dy minh hpa Bai tap t u luy|n eo huong dan each giai Chu de3: Song ca 73 » 99 173 He thong hoa kien thiic 173 Cac dang bai tap va v i dy minh hpa 180 Bai tap t u luyen eo huong dan each giai 194 Chu de 4: Dao dpng va song di$n tir 231 He thong hoa kien thuc 231 Cac dang bai tap va vi du minh hpa 235 Bai tap t u luyen c6 huong dan each giai 247 Chu de 5: Dong dif n xoay chieu H ^ thong hoa kien thuc 291 291 Cac dang bai tap va vi du minh hpa 295 Bai tap t u luy^n c6 huong dan each giai 324 www.nhasachkhangviet.vn L w S% H ® •••••• CONG TY TNHH MOT THANH VIEN DWH KHANG VIET • Nha Sach • KHANG VIET • Oia chi:71 OinhTien Hoang - P.Oakao-Quan -Tp HoChf Minh oien thoai: (08) 39115694 - 39105797 - 39111969 - 39111968 Fax: (08) 39110880 Email: khangvietbookstore@yahoo.com.vn Website: www.nhasachkhangviet.vn 935092 Gia: 89.000 525594 [...]... dpng tai M : A|y^ = 2a COS A(p = ^ ^ = ^ ^ f ( r a d ) X V ^ ' Tren doan thang noi tu Si den S2 (S1S2 = 1) so'cue dai, cue tieu giao thoa di Theo gia thiet n , 27 id, n / ^ { k + 0,5).y (k + 0,5).400 (k + 0,5).50 Acp = - + krc => f = - + k7i => f = — = =^ -^ — ^ 2 V 2 2d 2. 28 7 M a 2 2 H z < f 22 H z < V i k nguyen nen k = 3 (k + 0,5).50 ' - — < 26 H z 7 2, 58 < k < 3,14; f = 25 Hz V Vay buoc song... la A 2m/s B 4m/s C I m / s , D l,2m/s Huong dan gidi: - (i Dao d p n g tai M l u o n n g u p e pha v o i dao d p n g tai O nen A(p = 7t + 2k7r = 27 td => V = 2df _ 6 fm^ 2k + l ~ 2k + l l s Theo bai ra 1,6 m/s < v < 2, 9 m/s => 1,6 < — ^ — < 2, 9 2k+ 1 Huang dan => k = 1 gidi: pao dpng tai M luon ciing pha voi dao dpng tai N 27 td nen ^ 9 - 2 k T : = — V a y v a n toe la v = 2m/s =i> C h o n A 2df =^... gidi: V = — = (0 = 20 £la^: ^ (2k + l ) v (2k + l).80 , , f = ^ — / - = ^ - — / - = 8(2k.l)(Hz) 2d C.40 cm/s X = 0,5n 27 1X Acp = —;— = — - — Theo gia thiet A(p = TT + 2k7i nen ^ ^ f = 71 + 2k7i v •" B.50cm/s Huang dan V a n toe t r u y e n song v = Xf = X — = l , 5 m / s =i> ChQn A 2n A 64Hz J- D.72em/s Ta co: < B 150 cm/s Huang dan 2n\ 0, 027 tx = X CO = 47t ? = 100(cm) T = 0,5(s) C 20 0 em/s D.50 cm/s... 5cos(a)t - 120 7T) ( m m ) D u ^ = 5cos(ajt - l,2n) ( m m ) I ^; = 5 cos cot V 27 1.6^ J 10 => C h o n D => 2 = acos ( r t - — ) = — = > a = 4 c m => C h p n B 3 2 A A = Tia B X = 27 ia C A = 2na/3 D A, = 37ia /2 Huong dan gidi: In j^^y 6 d a y hpc sinh c6 the n h a m n h u sau: + 3.x d i i n g la: = 5cos(cot - l , 2 7 t ) ( m m ) Ltfu y: - 2 eye d a i eiia p h a n ttr m o i t r u o n g bang 2 Ian toe... 0,57i) (cm) Huang dan 2nd gian ngan nha't sau d d d i e m M ha x u o n g tha'p nha't la A.11 / 120 S B l/60s C.1 / 120 S Huang dan gidi: X = j= 12cm K h o a n g each M N = 26 em = D.l/12s 2X+^X gidi: P h u o n g t r i n h song tai M : U M =4cos lOOnt- nguon sdng hon) Tai thai d i e m t, d i e m N ha x u o n g tha'p nha't K h o a n g t h a i K h o a n g t h d i gian ngan nha't At = ^ T = ^ s 27 t = 4 cos l O O... k.A 2 21 2 40 So bung song: k = — = —— = 10 => so byngsong la 10, so niit song la 11 X 8 ^ Chon A Huang dan gidi: Day AB hai dau co'djnh nen chieu dai cua day la • i l = k ^ = k ^ = ^ f = k.- ^2 2f 21 - Khi day rung voi tan so f thi tren day co 4 bo song: f = 4 ^ (1) - Khi tan so tang them 10 Hz thi tren day co 5 bo song: f +10 = 5.-^ (2) Tu (1) va (2) suy ra ^ = 10 ^ 1 = 0,5m - 50cm JThay vao (1). .. tan so' song thay doi tu 2 2 pha voi nguon Buoc song truyen tren day la: B 1,6 cm C 16em 1 27 1 1 Acp +— 2 /, (keZ) 27 t ^ If " i t / ! 0 « ' Truang hop hai nguon cung pha: H z den 26 H z Diem M each nguon mpt doan 28 cm luon dao dpng vuong A 160 em Acp , +—f = — => Chpn B 2 2 2f 21 Cau 78; Mpt sgi day cang ngang 2 dau co dinh dai 1 = 2m Nguoi... nhau 20 dB T i so c u o n g d p am coi B.80 C 100 Huang dan D.50 gidi: Lj-lOlog^I Ta CO < 0 L2 = 1 0 1 g ^ = 20 + L , => C h p n C Chpn C ' A K h o n g thay d o i B G i a m d i 4,56 Ian C Tang len 4,56 Ian D Tang len 121 0 m Huang dan gidi: Ta c6X' = X.~ = 4,56X => C h p n C n C a u l 2 2 : H a i a m h o n k e m nhau I d B ve dp to T l so c u o n g d p a m cua hai am do la A l,2VV/m2 B.l ,26 W/m2 C