C. 100 vong D.400 vong P = 27tf = l60K(rad/s)
h'lB'A J inn gro/' ••
cup g n u b ú:iiH oh
ChonC. - i : : - ' 7'"'':
Chu y:
Khi may phat dien xoay chieu 1 pha mac v&i mack RLC thi cudng do hieu dung:
E „
'"in.
L R C
1 = <(E,fy>
B S trp k l ^ n thiic V^t If LTDii tr£n k€nh VTV2. t^p 2 - Chu VSn BiSn
f = np => CO = 27tf => Z L = coL;Z(;; =
E = 0 f:'r:;'\Ha'V::.r
x/2
Khin' = knthi É= kE;Z'i = kZL;Z'c = — jj f ^ kE
R2 + kZ,
V i du 15: Roto cua may phat dien xoay chieu mot pha c6 100 vong day, dien tro khong dang ke, dien tich moi vong 60 c m l Stato tao ra t u tr'jong deu co cam ling tu 0,20 T. Noi hai cue ciia may vao hai dau doan mach gom: dien
tro thuan R = 10 Q, cuon cam thuan c6 he so tu cam L = 0,2/n H va tu dien
CO dien dung C = 0,3/n mF. Khi roto cua may quay deu voi toe do n = 1500
vong/phut thi cuong do hieu dung qua R la
Ạ 0,3276 Ạ B. 0,7997 Ạ C. 0,2316 Ạ D. 1,5994 Ạ
,,„ui:„:«,,r.,: y .iimi^^u Huong dan A .;,
f = ^ - 25(Hz) m = 27rf = 50n =^Z^=aL = 1 0 ( Q ) ; Z L = — = — ( Q ) 60 ^^NcgSj00.50..0,360.10-^^^3 33^^^ v/2 V2 = s:0,2316(A) =>ChonC, •. . "^^^ > 2 ^ ( Z L - Z C )
Vi du 16: Noi hai cue cua mot may phat dien xoay chieu mot pha vao hai dau doan mach mac noi tiep AB gom dien tro thuan R, cuon cam thuan L va tu dien C. Bo qua dien tro cac cuon day cua may phat. Khi roto cua may quay deu voi toe do n vong/phut thi dung khang cua C bang R va bang bon ian cam khang cua L. Neu roto cua may quay deu voi toe do 2n vong/phiit tlVi cuong do hieu dung qua mach AB se
Ạ tang 2 Ian. B. giam 2 Ian. C. tang 2,5 Ian. D. giam 2,5 Ian.
Huang dan Luc dau: = R, Z L = R -J I ' V R2 + k Z L - = 2,5=>ChonC.
Cty TNHH nrv O VVn Khang Vifl
yji du 17: (DH-2010) Noi hai cue ciia mot may phat dien xoay chieu mot pha vao hai dau doan mach AB gom dien tro thuan R mac noi tiep voi cuon cam thuan. Bo qua dien tro cac cuon day cua may phat. Khi roto cua may quay deu voi toe do n vong/phut thi cuong do dong dien hieu dung trong doan mach la 1 Ạ Khi roto cua may quay deu voi toe do 3n vong/phut thi cuong do dong dien hieu dung trong doan mach la >/3 (A). Neu roto cua may quay deu voi toe do 2n vong/phut thi cam khang cua doan mach AB la Ạ2RV3. B.2R/V3. C . R V S . D.R/-/3. Huong dan .(•.. , Apdung: 7 = 1< ' + ( k Z L f = 3.- V 3 _ JR_
Khi toe do quay tang 2 Ian thi cam khang cung tang 2 Ian: Z ' L = 2ZL =
, J (
2R
V3
=> Chon B.
Vi du 18: Noi hai cue cua mot may phat dien xoay chieu mot pha vao hai dau doan mach AB gom dien tro thuan R mac nói tiep voi tu dien. Bo qua dien tro cac cuon day cua may phat. Khi roto ciia may quay deu »'6i toe do n vong/phiit thi cuong do dong dien hieu dung trong doan mach la 1 Ạ Khi roto ciia may quay deu voi toe do 3n vong/phiit thi cuong do dong dien hieu dung trong doan mach la 3\/2 (A). Neu roto ciia may quay deu voi toe do 2n vong/phiit thi dung khang cua doan mach AB la
Ạ 2 R V 3 . B. 3R. Ap dung: 7 S 2 C . R V S . Huong dan 372 D . 1,5RV7. I R2 + I = 3. V R ^ + Z Z r =
Khi toe do quay tang 2 Ian thi dung khang giam 2 Ian: , Z ' c = - 1,5R 3R 7 7 I Chon D. 2 7 7
Vi du 19: Mot may phat dien xoay chieu mot pha c6 dien tro trong khong dang kẹ Noi hai cue may phat voi cuon day c6 dien tro thuan R, he so tu cam L. Khi roto quay voi toe do n v6ng/s thi dong dien hieu dung qủ. cuon day la 1 Ạ Khi roto quay voi toe do 2n v6ng/s thi cuong do hieu duag qua cuon day la 2 7 M (A). Neu roto quay voi toe do 3n v6ng/s thi cuong do hieu dung qua cuon day la .-: - .
B o t r g hien t h i i c V^t liLTDtl t r c n kdnh VTV2, t a p 2j-Chu V^n B i S n I, =• • = l ; l 2 = 2E, L l +4Z^i Huang dan • = 0,4V2 : Z L I = R El =RN/2 l3 = 3E, 3RN/2
VR^ +9Z^i V R ^ - 9R^ = 3702 (A) => Chon B. . , ; v . /