D. di^n ap hieu dung tren tu giam ,\
4.Hai gia tri L,C c6 cung I, P, UR, Ui, Uc.
ạ Khi L thay doi hai gid tri L i va L2 c6 cung I, Uc, UR, P thi
Z, = Z2 ^R^ + (ZL, -Zcf=^R'+ (Z,,2 - Zc f
. : ^ ( Z L , - Z e ) = - ( Z , , - Z e ) ^ Z c = ^ i 4 ^ . ' :. 5
Z] = Z2 — = R R
Z; Z2 COSip, = C0S^P2 9 ] = -^P2
V i dvi 1: Dat dien ap xoay chieu u = UocoslOOTct (V) (Uo khong doi) vao hai ' dau doan mach mac noi tiep g o m d i f n tro thuan R, t u dien c6 dien d u n g
C = 100/7t ()aF) va cuon day thuan cam c6 do t u cam L thay doị N e u L = L i
hoac L = L2 = 3Li thi cuong do hieu d u n g qua mach n h u nhaụ T r i sóLi la
Ạ2/7t(H). B. l / 7 i ( H ) . C. 0,5/71 (H). D . l,5/7r (H). , Huang dan i> i = P 2 = > Z i = Z 2 + ( z , , - Z c f = V R H ( Z L2 - Z c ) ' Ctj' TnaiH MTV D VVH Khang Vl^t =^ ( Z L I - Z c ) = - (ZL2 - Z c ) ^ + = 2Zc = 200 (fi) Z , 1 + 3ZLI = 200 => Z L I = 50(n) => L , = 0,5 ( H ) Chon C. 0) 71
Y i d u 2: Dat dien ap xoay chieu vao hai dau đan mach mac noi tiep g o m dien tro thuan R, tu dien c6 d u n g khang 15 Q va cuon cam thuan c6 do t u cam L thay doị Dieu chinh L de cam khang Ian l u g t la Zị = Z L I va Z L = ZL2 thi cuong do hieu d u n g qua mach n h u nhaụ Dien ap hi^u d u n g a hai dau cuon cam k h i Z L = Z L I gap hai Ian k h i Z L = ZL2. Gia trj Z L I bang
Ạ 50Q. B. 150Q. C. 20 Q. D . l O Q . Huang dan p, = P2 =4. Z , = Z2 => Z L I + Z1.2 = 2Zc = 30(n) U Z L I : U Z L2 U u = 2 U L2 = 2.^ V R' + (Z L I - Z C) ' > ^ + (Z L2 -Z C } Z L I =20 (n) Z L 2=io(n) Chon C. i : => Z L I - 2ZL2
V i d y 3: M a c h dien xoay chieu gom ba dien tro R, L, C mac nói tiep. R va C khong doi; L thuan cam va thay doi duoc. Dat vao hai dau doan mach dien
ap xoay chieu c6 bieu thuc u = 200 V2 coslOOTtt ( V ) . Thay doi L , k h i L = L i =
4/7C (H) va k h i L = L2 = 2/71 (H) thi mach dien c6 cung cong suat P = 200 W. Gia trj R b a n g Ạ 50 Q. B. 150 C. 20 fị D . 100 Q. \ Huang dan Z L I + ZL2 P, = P2 =^ Z, = Z2 => Zc =:i P =• U ^ R • 200 = • • R^ + ( Z L I - Z c ) ' + (400 - 300)^ , , „
Chu y: Khi L thay doi hai gia trj Li va Li c6 ciing I, Uc, UR, P thi
= 300(Q) " 1 . '
R = 100(f^) =>ChonD.
200'R
1) Zc = + ZL2 j^i^- ^.^^ huang (Lmx, Uomx, URmax, Pmax) tkl ZLO = Zc. TU dO SUy
ra: ZLQ = Z L I + Z L2 L, + L 2 h ="—;— 2) Z, = Z 2 R Z l ~ Z R • => COSCPi = C0S<P2 => tPl = -<P2 <^ ( k h i L , > L 2 ) M l = - a < 0 , . ^ ( k h i L i< L 2 ) [(f>2 = +a > 0 w"
BÁ trf> hlSn thdrc V^t If LTt>tl trcn kenh VTV2. t^p 2 - Chu V^n BIcn
V i d u 4: Cho mach dien xoay chieu tan so 50 H z noi tiep g o m cuon day thun'n
cam CO d o t u cam L thay doi duoc, tu dien ccS dien d u n g C va dien trcV R. Cu
hai gia trj khac nhau cua L la V3 / n (H) va 3 SI n ( H ) t h i d o n g dien co cun^^ gia t r i hieu d u n g n h u n g gia trj tuc thoi c6 piia ban d a u l i o n k e m nhau 27i/3 Gia trj cua R va Zc ian l u g t la
' Ạ 1 0 0 Q v a 2 0 0 V 3 Q. , ' B. 100 Q va 1 0 0 ^ 3 Q. C. 200 Q va 200 N/3 Q . . s D. 201; il va 100 V 3 il.
.gj•;!;<: Hu&itgdtin
Z i , = c o L , = 1 0 0 x / 3( Q ) < Z | . = 0 ) L 2 = 3 0 0 N / 3 ( n) : ^ r ^ " : •:
I , = I , => Z , = => Z(j- =
Theo bai ra: 2 a = 2n/3 =;
300V3-200V3 ^ ^ i | ^ = 200^/3(n) • a = Tc/3 => tan = Z. . 2- Z c R = tan a R = tan - => R = 100 ( n ) => Chon Ạ ,,. -f.ị h = h = l Ihi Z, (, = Zc =
C/iM y: Khi L thay doi dc so snidi cik gid tri I, P, UR, UC C6 the diing do thi cua chung theo Z;,. Dim vao do thi ta sc thaif. „ (adsbygoogle = window.adsbygoogle || []).push({});
Zị cang gan Z1.0 thi I, P, UR, UC cdng Ion, ccing xa thi cang he (Z^o = Z ^ ); ;
Z u +Z|^2 [ Z i 3 6 ( Z n ; Z | _ ; ) = : > l 3 > I
2 1Z,3 0 [ Z , , ; Z L 2 ] ^ I 3 < I
V i d u 5: D a t dien ap xoay chieu u = 100 -Jl coslOOnt (V) vao hai d a u doan mach mac n o i tiep g o m dien t r a thuan R = 50 Q, t u dien C va cuon cam thuan c6 cam khang Zị thay d o i . Dieu chinh Zi, Ian krgt bang 15 Q, 30 va 45 Q thi c u o n g d o hieu d u n g qua mach Ian l u g t bang I i , I2 va h. Néu I i = I2 = I t h i Ạ I3 = 21. B. I 3 < I . C. b = 2 Ạ D. h =-1.
Huong dan
ZM) - Z|,i + Z,J . = 2 2 , 5 ( Q ) ^ • ' 3 4 Z u ; / L 2 ] < , 2
=>ChonB. ,n" rl ; Chu y: --iv:;"' " r i ; - ,!,; > .'.,xf': • 1) Dt'so sdnh P.i va P4 ta c6 the dung phumig phdp "gidng
day" nhir saii: Tif Pi ke diimig song song v&i true hodnh néu Pi tren day thi P4 > P.? vd néu duai day thi P4 < P.3.
2) Dethn cdng suat Ian nhd't trong sd'cdc cdng suat da cho, ta chi can so sdnh hai g'l^ tri gan dinh nhat bhngphucmg phdp "gidng day". , -fi„^.^^.,^ , ^u^/.
I7n
Cty TNtin MTV DVVH Khang VIft
y f d u 6: D a t dien ap xoay chieu u = UocoslOOnt (V) vao hai dau doan mach mac noi tiep g o m dien tro thuan R, tu dien va cuon cam thuan co cam khang Zị thay d o i . Dieu chinh Zị ian l u g t bang 15 a, 20 Q., 32 Q, 38 Q, 41 Cị va 65 Q thi cuong d o hieu d u n g qua mach Ian l u g t bang I1, I2, h, h. Is va l6. Néu I i = lb thi trong so cac cuong do hieu d u n g tren gia trj Ion nhát la >5.»= - -'-- ,
A J s . , ; B. I2. C.I3?
V i t r i d i n h : Z L O = Z L I
Huong dan
= 40(Q)
Cang gan d i n h I cang Ion. V i ZIA va Zis gan Zio h o n nen chi can so sanh I4 va Is. Gia trj nao Ion h o n se la gia t r i Ion nhat trong so cac gia t r i da chọ T u I4
ke dúong song song v o l true hoanh cat d o thj tai d i e m co hoanh d o Z'1.4 sao
cho: ;. Z L4 + Z ' L4 40 = 38 + Z'L2
2 2
V i Z L 5 e ( Z L 4 ; Z ' L 4) = > l 5 > l 4 =>Chon Ạ
Z ' L4= 4 2 ( Q )