C a u 3 : D^it di^n ap xoay chieu u = U o C O s lOOntn-- (V) vao hai dau mpt cupn cam thuan c6 dp tu cam L = —(H). 6 thoi diem dif n ap giiia hai dau cupn cam thuan c6 dp tu cam L = —(H). 6 thoi diem dif n ap giiia hai dau cupn cam la 100 N/2 V thi cuong dp dong di^n qua cupn cam la 2A. Bieu thuc cua cuong dp dong di?n qua cupn cam la
A. U R C = 2 0 0 > / 2 c o s C. U R C = 2 0 0 C O S C. U R C = 2 0 0 C O S l O O T t t - - 6j l O O T t t - - l 3J V B. URC = 200cos D. URC = 200cos lOOTlt - - f 71^ 1007tt + - l 6J L
'Phdn tich vd hu&ng ddn gidi "
Theo gia thiet khi L thay doi Ui dat cue dai thi:
U R C vuong goc voi UAB : U L M A X ^ = ^RC^ + \ J ^ = U^^ + VQ^ +
Mat khac: = UR^ + (ULMAX - Uc)'
Voi U = 100>/2V; Uc = lOOV => UL = 200V
Ta CO U R C ' = U L M A X ' ' ^ ^ ^ URC - IOOV2V va cpRc = | - ^ = -^(rad) Bieu thuc di^n ap hai dau URC = 200 cos(1007it - —) Bieu thuc di^n ap hai dau URC = 200 cos(1007it - —)
6
Chpn dap an B '
m B A I T A P VAN DUNG:
Cau 1: Mpt mach dien xoay chieu RLC khong phan nhanh c6:
R = 50Q; C = -.10-''F;L = - H.
7: 71
Cuong dp dong di^n qua mach c6 dang: u = 2cos 1^ Viet bieu thuc tuc thai di^n ap hai dau m^ch di^n. 1^ Viet bieu thuc tuc thai di^n ap hai dau m^ch di^n.
^ A. u = 200cos(1007tt) V lOOTtt-^ (A). lOOTtt-^ (A). lOOTlt-^ 4 ; C. u=:100cos 1007tt + - 4 ; B. u = 20072cos D. u = 100V2cos(1007tt)V V
<Phdn tich vd hu&ng <Mn gidi
Cam khang: = L.co = -IOOT: = lOOn;
Dung khang: Zc=^ = " lOOT..^:^
Tong tro: Z = . ^ M ^ T ^ = /so^+(100-50)^ = 50V2Q Hieu di?n the cvrc dai: Uo = I0.Z = 2.50V2 V =100 ^ V Hieu di?n the cvrc dai: Uo = I0.Z = 2.50V2 V =100 ^ V Dp l?ch pha: tancp = -Z L ^ Z C ^100-50 , 7t
Z83 . n , . r . ( A ) - + 11^001 V UB dep u6n3 soDQt' = n i q D B u i n e p l e q n o r i q } n a i q Xey\ 01 = !6-(J)= "6<= — = 6<=!:- = = \ <'>ue4 ' ^ 03-01 ^ Z - ^ Z
:i lOA OS qoeui n e p l e q n eriiS e q d qoaj OQ
^ - = ~ 0 =^ - u a u ^ 098 ; o i u i n u o q e q d a j ; 1
q D B u i n e p leq a q ; u a i p n ^ i q eriD n e p u e q e q d q u i ^ E] IBJ UOD a BA 3 UE d B p i p IBOJ XBP I O J ^
(A)Of = Z/^Or^/^Z = Z " ! = °n : q J E U i n g p i B q o i B p o f i D a q j u d i p n a i y UZ^Ol = ;(0Z-0l)+30l/^ = 3(^Z-"^Z)+3a/^ = Z Suol
(V)3A2 = 01 • = Oj : i B p u f t p 8 u o p o p 2uqnj
^01
UOl = —"i^OOl = 1 « = ^z :8uEq>j 0163
uoz = -c-Ol
I I = ^Z :SuBq>f §una
( A ) --moi SOD 3A0^ = n a ( A ) -+4:^001 (adsbygoogle = window.adsbygoogle || []).push({});
(A) --41^001 soDQ^ = n v n§m • (A) fz - + 4"00l so30l7 = n a (A) Bj q3Bui U B o p n g p I B q BriiS d E u a i p D ^ q j 3/^03 = Bj u B n q i UIBO u 6 n 3 n B p l E q em2 de u a i p BA ( j ) — — = 3 9D u S i p r q ' ( H ) = 1 9^ U B n q ; UIBD u 6 n D ' y g i = H 43'9 ' " ^ ^ l ' l o u DBui 3 'q OD q D B u i U B o p n B p I B q OEA n§iqD ABOX d B u a i p ^BQ :s ne3
a UB d B p u6q3
(V) — - I s o D g = I :uaip §uop op Suqno D J i q i naig
V V
— - = — - 0 = * - '*<= ' 6 - "6 = 6 :uaip Suop op SuoriD eriD B q j
Dl ffUyci Ufl luycil !.#»• •
A . i = 2V3cos C. i = 2V2cos lOOTCt- 71 100Kt + - 6) ( A ) ( A ) B. i = 2>/3cos D. i = 2^2 cos 1007tt + - 1 0 0 ; r t - - 6) K 6) ( A ) ( A )
(phdn tick vd hicdng dan giai
Cam khang: Z L = o)L = IOOTT.— = 50Q
Mach chi c6 cuon cam thuan nen i tre pha hon u mot goc ^ :
u 1 ^ y ^ + 22 =2x/3(A)
50^
TC n 71 71
' ^ • = ^ " - 2 ^ 6 - 2 = - 3
Vay bieu thuc cuong do dong dien: i = 2^3 cos lOOTlt —
3 ( A )
Chpn dap an A
Cau 4 : Khi dat hieu dien the khong doi 30V vao hai dau doan mach gom dien tro thuan mac noi tiep voi cuon cam thuan c6 do tu cam — (H) thi dong
471
dien trong doan mach la dong dien mot chieu co cuong dq> l A . Neu dat vao
hai dau doan mach nay dien ap u = 150N/2 cosl207t t (V) thi bieu thuc cua cuong do dong dien trong doan mach la
A. i = 5>y2cos 1207rt--4 C. i = 5x/2cos 1207tt + - 4 ( A ) . ( A ) . B. i = 5cos D. i = 5cos ' 71^ 1207tt + - 1207tt-- 4J ( A ) . ( A ) .
^hdn tick ra hu&ng dan giai
1
Cam khang: Z L = coL = 1207T.— = 25Q
471
Khi dat hi§u dien the khong doi vao hai dau mach thi chi c6 R gay can tro con Zl = 0 R = _ U|c _ 30 = 30Q
lie 1
Khi dat hiC^u dien the xoay chieu vao hai dau mach thi c6 ca R va ZL gay can
tro nen tong tro cua mach: Z = + Zl = 730^+30^ - SOsflQ (adsbygoogle = window.adsbygoogle || []).push({});
Cuong do dong dien cue dai' IQ = = = 5(A)
. . . - - • Z [ 30 , 71 Dp l?ch pha giua u va 1: tancp = ^ S Q ^ T
Co mot each tinh cue nhanh ma cac ban da duoc lam quen trong cuo'n 'ca'm nang luy#n t h i dai H Q C vat ly tap 1' la tinh theo may tfnh casio fx 570 ^u,
hoac casio fx 570 es plus
Hi?u d i ^ n the tuc thoi hai dau mach : u = i.Z = — . Z
Bam may: ^.lOx/2 = 4 0 Z - -
^ 10 4 Vay: u =40 cos 1007rt + -
4 j (V)
Cau 6: M 6 t doan mach dien xoay chieu gom mot dien tro thuan R = 80Q, mot cuon day thuan cam c6 do t u cam L = 64mH va mot tu dien c6 dien dung
C = 40nF mac noi tiep. Biet tan so cua dong dien f = 50Hz. Doan mach duoc
dat vao dien ap xoay chieu co bieu thuc u = 282cos314t (V). Lap bieu thiic cuong do tuc thoi cua dong dien trong doan mach.
^hdn tich m huang ddn gidi
Tansogoc: co = 2Trf = In.SO = lOOn rad/s Cam khang: Z L = coL = 10071.64.10"^ « 20Q
D u n g khang: ZQ = ^
coC 10071.40.10 - 6 * 8 0 Q
T o n g t r o : Z = ^R^+ ( Z L -Z^f = JsO^ + (20 - 80)^ = lOOQ
Cuong do dong dien cue dai: I^, = U„ 282 = 2,82 A
Z 100
Do lech pha ciia hieu dien the so voi cuong do dong d i ^ n :
Z L - Zc _ 20 - 80 _ 3 R " 80 ~ 4 tancp = •(p*-37° ' 9 i = 9 u - 9 = - 9 = 3 7 " = 3771 Vay i = 2,82 cos 314t + 180 3771 ^ rad; 180 (A)
Cau 7: M o t doan mach gom cuon cam c6 do t u cam L va dien tro thuan r mac noi tiep voi tu dien c6 dien dung C thay doi duoc. Dat vao hai dau mach mot hieu dien the xoay chieu c6 gia trj hieu dung U va tan s o f khong doi. Khi dieu chinh de dien dung cua tu d i ^ n c6 gia trj C = C i thi dien ap hieu dung giOa hai dau tu dien va hai dau cupn cam c6 cung gia trj va bang U,
cuong do dong dien trong mach khi do c6 bieu thuc ij =2V6co6 1007rt+- (A).
Khi dieu chinh de dien dung cua tu dien c6 gia trj C = C 2 thi dien ap hieu dung giua hai ban tu d i f n dat gia tri cvrc dai. Cuong dp dong d i ^ n tuc thoi trong mach khi do c6 bieu thuc la
A. i2=2V2cos(1007rt + 57t/12)(A) B. i2 = 2^cos(1007tt + 7t/3)(A)
C. i2=2V3cos(1007rt + 57r/12)(A) D. i2 = 2^/3cos(1007tt + 7t/2)(A)
<Phdn tich v>d huang ddn gidi
Khi C = Ci => U L = U c = U (cong huong) => U R = U = U L = U c ^ R = Z L
= 9 i i = 7
Cuong do dong dien cue dai: lo, = Y " =
Khi C = C 2 ^ U c n , a x ZC2 = (adsbygoogle = window.adsbygoogle || []).push({});
Z^ + R ^ _ R ^ + R ^ _ R = 2R R = 2R
D Q l?ch pha gii>a u va i luc nay: tancpj = Z , -Zc2 R - 2 R , 7t
R
7t 71 7t 7t
^'2 M^" 4 4 4 2
Ma (p2 =(Pu -cpi2 = - - :
Cuong do cue dai trong truong hop nay la: , Uo Uo _ Uo ^02 - • R R Un 2V6 ^ + ( Z L- Z c 2 f ^
Vay bieu thuc cuong do dong dien trong truong hop C = C 2 :
= 2V3A
h = 2V3COS 1007rt + -
2,
Chpn dap an D
Cau 8: Dat dien ap u = 100 N/2 COS 1 0 0 7 t t - -
2 (V) vao hai dau mot doan mach 25,._2,
gom mot cuon cam c6 dien tro thuan r = 5Q va do t u cam L = —10 H mac noi tiep voi mot d i f n tro thuan R = 20Q. Bieu thuc cuong do dong di?n trong doan mach la
A. i = 2^/2 cos(1007Tt - n/4 ) (A). B. i = 4 cos(1007it + 7i/4) (A).
C. i = 4cos(1007it-37r/4)(A). D. i = 2N/2 cos(1007rt + 7i/4) (A).
^hdn tich vd huang ddn gidi
25.
Cam khang: Z L = wL = I O O T I . —1 0 " ^ = 25Q
7t
Do lech pha giua u va i : tancp = 25
R + r 20 + 5 = 1: .cp = -
It 71 3n
Ma (p = cpu - (Pi ^ cPi = (Pu - ^ = ^2 ~4
Cuang do cue dai: IQ = 7(R + rf + Zl 725^+252 Un 100^/2 = 4A Vay bieu thuc cuong do dong di^n trong truong hg-p C = : Vay bieu thuc cuong do dong di^n trong truong hg-p C = :
3TV
i = 4cos 100-Kt--
Chpn dap an C
Cau 9: Dat dien ap xoay chieu u = 100>/2 coscot (V), co thay doi dugc dat (adsbygoogle = window.adsbygoogle || []).push({});
vao hai dau doan mach AB gom hai doan mach AM va MB mac noi tiep. Doan mach AM gom bien tro mac noi tiep vol cupn cam thuan, doan mach Doan mach AM gom bien tro mac noi tiep vol cupn cam thuan, doan mach
MB chi CO mot tu dien. Khi co - 1007i(rad/s) thi dien ap hieu dungU^,^,
khong phu thuoc vao gia tri cua bien tro, dong thai dien ap hi^u dung
UMB =100V. Khi A. u^M =100V2cos A. u^M =100V2cos C. UAM =100^2 COS 1007tt + - 3 3 (V). B. UAM=200COS (V). D. UAM =100V2cos 1007rt + -3 ( V ) . 6 (V).
^hdn tich m huang dan gidi
Hieu dien the hieu dung hai dau AM:
AM - V R 2 + ( Z L - Z c f I Z C ( Z C - 2 Z L )
Theo bai ra: UAM « R O ZC - 2ZL = 0 ZC = 2ZL => UL - ^ = ^
Ta lai c6: UR = ^Ju^ -{\Jj^-Vcf = ^100^ -(50-100)^ = 50V3V
=> U A M = V U R + = ^(soVs)^ + 50^ = lOOV
U L - U C 50-100
= 50V
Dp Ipch pha giiJa u va 1: tancp = Ma (p = (pu - (Pi =^ (Pi = cp^, - (p = 0 - Ma (p = (pu - (Pi =^ (Pi = cp^, - (p = 0 -
I 6
50V3 " V 3 ^ ^ ~ 6
71
6
, . U L 50
tJo lech pha giua UAM va i: tan(pAM = — = U K " 5 0 V 3 ~ V 3 ^ ^ ^ ^ ^ f
Cty TNHH MTV nV\lI Khtmg Viet
Ma <PAM ='PUAM ^
Vay: UAM =100N/2COS
71 TT T:
6 6 1007lt + - V 1007lt + - V
Chpn dap an A « ' >
CaU 10: Doan mach dien xoay chieu AMB cau tao gom doan AM chua R va C mac noi tiep voi doan MB chua cupn cam thuan c6 L thay doi. Dien ap C mac noi tiep voi doan MB chua cupn cam thuan c6 L thay doi. Dien ap xoay chieu hai dau mach AB: u = 7572cos( lOOTit+^] (V). Dieu chinh L den
V 2 J
khi UMB C6 gia tri cue dai bang 125 V. Bieu thuc dien ap giua hai dau AM la A. u,,M= lOOcosflOOTit +^1 (V) A. u,,M= lOOcosflOOTit +^1 (V)
C. UAM^IOO^^'-'OS SoOnt--^ 2,
B. UAM= 100V2cosl00Tit (V) (V) D. U A M = lOOcoslOOnt(V) (V) D. U A M = lOOcoslOOnt(V) (adsbygoogle = window.adsbygoogle || []).push({});
'Phdn tich vd huang dan gidi