Vật lý 12 tóm tắt lý thuyết và bài tập trắc nghiệm tập 1 (p4)

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Cau 68: (De thi dai hpc nam 2007) D5t hieu di?n the u = Uosincot (Uo
khong doi) vao hai dhu doan mach RLC khong phan nhanh. BiSt dien tro
thuin cua mach khong d6i. Khi c6 hien tucmg cong huong dien trong doan
mach, phat bieu nao sau day sal?
A. Hieu dien the hi?u d\ing a hai dau difn tra R nho hon hieu dien
thk hi?u dung a hai diu doan mach.
B.
Cuomg do hi?u
dvmg
cua dong dien trong mach dat gia tri Ion nhat.
C.
Hieu dien the tiic thai a hai dau doan mach cung pha vdi hieu
dien thg tiic thai a hai dhu dien tra R.
D.
Cam khang va dung khang cua doan mach bing nhau.
Cau 69: Mach dien khong phan nhanh g6m dien tra thuin R = lOOQ, cuon
day thuan cam c6
dp
t\ cam L = -Hva tu
di§n
c6 di?n dung C thay doi
dugc.
Mac mach dien vao ngu6n (220V-50Hz). D6 cucmg do hi?u d\mg qua
mach
CO
gia tri cue dai thi gia tri cua C la

B.1«1F.
C.H21F D.^^J.
" n n n
Cau 70: Trong doan mach RLC n6i tiep dang xay ra cpng huong di$n. Tang
dkn tan s6 dong dien va
giO
nguyen cac thong s6 cua mach, ket luan nao sau
day la dung
A. He so cong suat cua doan mach giam.
B.
Cucmg do hi?u dung cua dong di?n tang.
C.
Hieu dien th6 hi^u dung tren tu dien tang.
D.
Hieu dien the hi?u dyng tren cupn cang giam.
Cau
71:
Trong mach dien xoay chiau g6m di?n tra thuAn R, cuon day thudn
cam L va t\ dien C mic n6i tilp. Liic dau, mach c6 tinh cam khdng, nh
giam thn s6 cua dong di?n mgt lugmg nho (sao cho
tin
so van nho han gia tri
^)thi
27tVLC
A. dung khang giam. B. cam khang tang.
C.
t6ng tra cua mach
tang.
D. t6ng tra cua mach giam.
Cau

72:
Cho mpt doan mach di?n xoay chik AB g6m R, L, C mac noi tiep
CO
R = 200Q. D§t vao hai dhu doan mach nay mot hieu dien thS xoay chigu
CO
gia tri hi?u d\mg 220V va tan s6 thay d6i dugc. Khi thay doi thn s6, cong
suat tieu thv c6 thS d^t gia trj cue dai bang
17?
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A.200W.
B.220V2W.
C.242W. D. 484W.
Cau
73:
Mpt
doan mach khong phan rJianh g6m dien tra R, cugn day thuSn
cam L v^ tu di?n C mac noi tiSp.
Mac

doan mach tren vao dien dp xoay
chik hinh sin thi di?n dp tiic thai a hai dau do^ mach cung pha vai cucmg
d^ dong dien trong mach. Kk luan ndo sau day khong dung?
A. He so cong suat cua mach dat gia tri
cyrc
dai.
B.
Cam khang
bang
dung khang.
C. Dien dp hi?u dyng a hai dau cugn day L va hai dau dien tra R
bang nhau.
fD.
Di?n dp hieu dyng a hai dau^dogn mach va hai
diu
dien tra R
bang nhau.
Cau
74:
Dung khdng cua mgt
m?ich
RLC mic noi tiep dang c6 gia tri nho han
cam khang. Muon xay ra hi?n tugng cgng huong dien trong mach ta phai
A. Tang di?n dung cua tu di?n.
B.
Tang h? s6
tvr
cam cua cugn day.
C. Giam di?n tra cua mach.
D.

Giam tan so d6ng di?n xoay chieu.
Cau 75: Chgn cau dung. Mgt doan mach RLC
mic
noi tilp, cugn day thuan
cam. Biet ring dien dp hi?u dyng a hai dau cugn cam L va hai dau tu dien C
bang nhau. Dien dp tiic thai gifta hai dau doan mach va dong dien trong
mach
A. cvmgpha. B. sampha. C. trepha. D. vuongpha.
au 76: (Be thi dai hpc nam 2007) D$t hi?u di?n thS u =
100>^
sinlOO;rt
(V)
vao hai dau doan mach RLC khong phan nhanh vai C, R c6 do Ion
khong d6i va L = — H, khi do hi?u di^n th6 hi?u d\mg
or
hai dhu moi phin tii
g R, Lva C
CO
dg Ian nhu
nhau.
Cong suat tieu thy cua doan mach la
A.350W.
B.100W.
C.200W. D.250W.
Cau 77: Mgt doan mach gom di?n tra R, cu^n clay thuan cam c6 dg t\ cam
L va
tu
di$n c6 di?n dung C = 15,9 //
F
mdc noi tiep. Mac mach dien vao

nguon (220V-50HZ) thi di?n
dp
hi?u d\mg 6 R
Id
220V.
Gid tri cua L Id
A.0,318H. B.0,636H. C. 0,159H. D. 0,468H.
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Cau
78:
Doan mach noi tiSp c6 difn tra thuan R, cupn day thuan cam c6 do
0,4
10"^
tu cam L = -^H va t\ di?n c6 di?n dung C
= F.
D8 di?n ap hai dhu
doan mach cung pha voi di$n
ap

giiia hai
dhn
dien tra R thi tan
s6
dong dien
CO
gia
tri
A. lOOHz. B. 75Hz. C. 50Hz. D.25Hz.
Cau 79: (De
thi
cao dSng nSm 2008) Dat mpt hi?u di?n thg xoay
chik
c6
tan
so
thay
doi
ducrc vao
hai
dau doan mach RLC khong phan nhanh.
Khi
,
r 1
tan so dong dien trong mach ion hern gia tri
"^^J^^^y^^
A. Hi$u dien the hi?u
d\ing
giura hai dau di?n tra bang hi?u di?n the
hieu dung giiia hai dau do^n mach.

B.
Hieu dien
thi
hi?u dyng giura hai
dau
cupn
day nhd
hom hieu
di?n the hi?u d\mg giiia hai ban t\ di?n.
C.
Dong di?n ch^y trong doan mach cham pha so voi
hi§u
di?n the
giura hai dau doan mach.
D.
Hi?u di?n the hi?u d\mg ^iiia hai dau di?n trd Ian
hom
hi?u difn
the hieu dimg giiia hai dau doan mach?
Cau
80:
Doan mach RLC n6i tiSp voi ampe dugc mac vao di?n ap xoay
chieu
u =
200cos(1007rt)
(V). Cho
biet trong mach
c6
hi?n tugmg cpng
huong di?n va

so
chi cua ampe
kS
la
2A.
Gia tq cua R la
A. lOOfl. B.50Q.
C.50V2Q.
D.
lOOVZQ.
Cau
81:
Mach di?n g6m RLC noi
tiSp
vao mang di?n xoay chiSu c6 di?n ap
u =Uocosa)t(V).
Cho hik khi =
lOnrad/s
va
0)2
=
160nrad/s
thi
cucmg dg hi?u d\mg trong mach nhu
nhau.
Tinh gia trj cua
(o
dl
cucmg
d?

dong di?n qua mach
c\rc
d^i
A.
17071
rad/s.
B.
85
TT
rad/s.
C.
1
SOTT
rad/s. D.407r rad/s.
Cau
82:
Cho mpt doan m^ch g6m di?n tra thuSn R, cupn day thuan cam c6
1
25 , .
do
tu
cam L =—H
va
t\ di?n c6 di?n dung
C
=—}iF n6i tilp. Hi?u di?n
7t
7:
thS
xoay chieu dat vao hai dku mach

6n
djnh va
c6
bieu thuc u =
Uosin(1007rt).
D6
hi?u difn the hai dau doan mach
l$ch
pha
7i/2
so voi hi?u di?n
thS
giua hai dau
bO
t\ thi phai ghep the nao va
gia
trj cua C
bang
bao
nhieu? A. ghep C'song song
C,
C
=
75/71
^iF.
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B.
ghep
C'n6i
tigp
C,
C
= 75/n
^iF.
C.
gh6p C'song song
C,
C
=
25
^F.
D.
ghep
C'noi
tigp
C,
C =

1
GO
^iF.
Cau 83: (De
thi
cao dSng nam 2008)
Mot
doan mach
RLC
khong phan
nhanh
g6m
di?n
tra
thuan lOOQ
,
cuon
day
thuan
cam
c6
he s6 tu
cam
1
L =—H
va t\
dien
c6
di?n dung
C

thay
doi
dugc.
Dat
vao
hai dau
doan
71
mach di?n hi?u dien
the u =
200V2cos(1007rt)
(V).
Thay
doi
dien dung
C
cua
tu
dien cho den khi hi?u di?n
thS
giiJa hai dau cuon day dat gia tri
c\rc
dai.
Gia tri cue d^i do bang
A. 200 V. B. 1OOV2 V. C. 50V2 V. D. 50 V.
Cau 84: Cho hai doan m^ch khong phan nhanh:
i?,i^C,
va/Jj^jC^co tan
s6
rieng

dh\i
bang/o. Khi mac noi tilp hai doan mach nay thi
tin
s6
rieng cua
mach
do
la
A.
2/0.
B.3/0.
C. /o. D.
0,5/0.
•
BIEN THIEN R, L,
C
Cau
85:
(De thi dai
hQC
nam 2008) Doan mach di?n xoay chieu gom bien
tra R, cuon day thuSn cdm
c6
do t\
cam L
ya
t\ di?n
c6
di?n dung
C

mac
n6i tilp. Bilt hieu di?n thg hi?u dun^ hai
diu
doan mach
la
U, cam khang
ZL,
dung khang Zc (voi Zc
ZL)
va tan so dong di?n trong mach khong d6i.
Thay doi R
dSn
gia trj
Ro
thi cong suit tieu th\ cua doan mach dat gia tri cue
.
dai
Pm,
khi
do:
A.Ro=Z,+Zc.
- ~ U
7
C
P
=
—
"
Ro
D.

Ro
=
ZL-Ze
Cau
86: Mot
dogn m?ch khong phan nhanh
gom tu
di?n
c6
dien dimg
C
=
——F
va
bien
trd
R. Mac vao
hai dau
doan mach mpt di?n
ap
xoay
chiSu (220V-50Hz). Dieu chinh
hikn
tra
de cong suat tieu th\
Ian
nhat
thi
gia tri hien tra la
A.100Q. B.50Q. C.120Q. D.150Ci.

175
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Cau 87:
(De
thi
cao
dSng nSm 2010)
Dat
difn
dp
u =
f/VZcos (cot)
(V)
vao
hai
dSu doan mach gom cupn cam thuSn mic n6i tiep
voi
mpt bien
tra
R. iTng voi hai gia tri Ri =20
Q
va

R2
=
80
Q
cua biSn tra thi cong suat tieu
thu trong doan mach d8u bang 400 W. Gia tri cua U
la
A. 400 V. B. 200 V. C. 100 V. D.
1
OON/2
V.
Cau 88:
Cho
mach xoay chieu khong phan nhanh
g6m
dien
tra
thuan
R
(thay
doi
dugc)
va
cupn day thuan cam
c6 dp t\
cam
L.
Hieu di?n th6
hai
dau mach

u
= Uyfl cos(l OOTrt) (V).
Bik
rang khi
R =
180ri
va R
=
3200
thi m^ch tieu th\ cung cong suat P
=
45W. Gia tq cua L va U
la
A.L=
-
HvaU= lOOV. B. L =
— H
v^U
=
lOOV.
C.L=-HvaU=150V. D.
L=
— H
vaU= 150V.
n
• n
10"^
Cau 89: Mpt mach di?n xoay chieu noi tilp gom t\ C
= F,
cupn day

2n
thu&i cam
L
=
Hva bien
trd
R. Dat vao
hai
dau doan mach hi?u di?n
thS
u =
200COS
(lOOTTt)
m.Thay
doi
R
de
cong suat mach c\rc d^i. Gid
trj
cua R va cong suat luc nay Ian lugrt la
250
A.
120a
va
—
W. B.nOQ
va
250W.
250
C.280t}vd250W. D.280nva—W.

3
Cau 90: Mpt m^ch di^n xoay chieu khong phan nhanh gom cupn day
(c6
di|n
tr6
thuan Ro
=
lOn
dp ty
cdm
L
=
y^H),
ty
di?n
c6
di?n dung
10-^
C =
—va
di?n tro thuan R thay doi dupe.
D|t
vao hai dau do?in m^ch
hi?u di^n the xoay chieu
u
= 100>/2cos(100;rt) (V). Cong suat tieu th\ tren
doan mach d^t gid tri cvrc dai khi R c6 gid tri:
A.
lion.
B.

78,1«.
C.
50Q.
D.
148,7Q.
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Cau 91: Mot mach dien xoay chiSu khong phan nhanh
gom
cupn
day
(c6
dien
tra
thudn Ro
=
30fi,
dp
tu

cam
^
= y^H),
ty
di?n
c6
di?n dung
C =
F
va
dien
tra
thuan
R
thay d6i dupe. Dat vao hai dau doan mach
71
CO
hieu dien
the
xoay chieu
u
= 100V2cos(1007xt) (V). Cong sudt tieu
thu
tren R dat gid tri cue d^i khi R c6 gid
tri:
A. IIOQ.
B.
78,1Q.
C.
50Q. D.'l48,7fi.

Cau 92: Mot doan mach xoay chiSu khong phan nhanh g6m cupn day (dien
0
2
tra thuan
r
=
15n, dp
tyr
cam L =
—
H)
va
di?n
tra R
thay doi dupe.
Dat
vao hai dau doan mach mpt di?n dp xoay chiSu c6
tan s6
50Hz. DiSu chinh
R dl cong suat toa nhi?t tren R Ion nhat, khi do gia tri cua R la
A. 15Q.
B.
ion.
C.25Q. D.40Q.
f
j:au
93:
(De thi dai
h<}c
nam n5m 2007) DSt hi?u di?n

the
u =
Uosincot (Uo
va
CO
khong d6i) vao hai dau doan m?ich RLC khong phan nhdnh. Biet
dp
t\
cam
va
di?n dung dupe
giii
khong d6i. Dieu chinh trj s6 di?n tra
R
de cong
sudt tieu
thu
cua doan mach
dat
c\rc dai. Khi
do h? so
cong sudt cua doan
mach
bang
V2
A. 0,5. B.0,85.
C.
^
D.
1.

Cau 94: Mach dien xoay chiSu g6m biSn
tra R ya
t\ di?n
C
n6i tiep.
Mac
machi vao mang di?n xoay chik (220V-50Hz). DiSu chinh R ta thay khi
R
c6
hai gid tri
25
Q
va
100 Q thi cong suat nhu
nhau.
Gid tri di?n dung C
•^.lolp.
B.M«1F.
C.1«1F.
D.ifiF.
7t
71 ST: 47t
Zsiu
95: Mach di?n xoay chieu
gom
di?n
tra
thuan
R,
cupn

day
thuan
cam
10""
dp
t\
cam
L
va tu
di?n
c6
di?n dung
C
= F.
Tdn so
d6ng di?n
7t
pOHz.
Qiku
chinh
R
den gid tri 2000
thi
cong suat tieu thu Ion nhdt. Gid
tri
|ung cua
L
la
1
2 3 4

A H.
B H. C H. D H.
7t
71 71 71
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Cau 96: Mach
di|n
xoay chieu khong phan nhanh gom cupn day
thu^
cam
0
2
CO
do ty
camL = -^H va bien
tra
R.

Dat vko hai dau
dogn
m?ich
mpt
di^n
n
ap xoay chieu c6
t^ s6
50Hz. Khi
R =
lOfl, cong
suk
cua mach lOW.
Gia
tri khac ciia bi^n tra ma cong suat van la
lOW
la
A.
15fi.
B.
lOQ.
C.20n.
D.40Q.
Cau 97:
Cho mpt
dogn m?ich di?n xoay chieu g6m mpt bien
tra R
mSc
n6i
tilp

voi
mOt
cupn thuSn
c^ c6 dp
tvr
cam L =—H. Hieu di?n the
hai dku
doan mach
on
djnh
\k c6
hiku thurc
u =
100cos(1007rt) (V). Thay
doi R, ta
thu dupe c6ng suat tod nhi?t c\rc
daii
tren bien tra bSng
A. 12,5W.
B.25W.
C.
SOW.
D.
lOOW.
Cau
98:
MOt
doan mach g6m bien tra R
mSc
n6i tiep voi cupn day c6 dp tu

cam
L =
0,08H
vk
di?n
trd
thuan
r
=
32Q.
D^t
vao hai dliu doan mach mot
hieu di$n
thk dao
dpng dieu
hoa on
djnh
c6 tan s6 goc 300
rad/s.
De
cong
suat
toa
nhi?t tren bien
trd
dat gid tr; 16n nhat thi di^n
tra
cua bien tr6 phai
CO
gia tri bSng bao nhieu?

A.
56Q. B.
24Q.
C.
32Q.
D. 40O.
Cau
99:
Mpt
do?in
mach khong phan nhanh gom bien tra R, cupn day thuSn
cim L =
—
H
vd t\
di?n
fc6
di?n dung C =
.
DSt vao
hai dau
doan
Tt 71
mzich
mpt hi?u di?n
thI
on dinh c6 hiku thiic
u =
U
V2

cos(1007it). Khi thay
doi
R, ta thdy
c6
hai gid
tri
khdc nhau cua bien tra Id Ri va
R2
ung voi cung mpt
cong
sudt tieu thy
P
cua
mach.
Ket luan nao sau day Id khong dung
TT2
A.
R1.R2
-
5000
Q\.
R,
+
R,
=
—.
'
^ P
C.|Ri-R2l
= 50O. D. P<Y^.

Cau 100:
(De
thi
d^i
hpc n5m nSm 2009)
Ddt mpt
di?n dp xoay chieu
c6
gid tri hi?u dyng
U
vdo
hai
ddu doan m^ch AB gom cupn cam thuan c6
dp
tvr
cam L, di?n
tra thu^ R
vd t\ di?n c6 di?n dung
C
mdc noi tilp theo thir
tir tren. Gpi
UL,
UR
vd Ucjan lupt
Id
cdc
di?n
dp
hi?u d\mg giua hai dau moi
phan

tu.
Diet di^n
dp
gifta hai dau doan m^ch AB Ifch pha
^
so
v<5ri
dien dp
no
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CHlgfl
giUa
hai ddu doan mach NB (doan mach NB g6m R va
C).
H?
thurc
nao dual
day la dung?
A. U^=U^+U^c+U^ B.
U^=U^R+U^+U^
C. =
Ul
+
111 +
D.
= Ul+Ul +
Cau 101:
Cho
doan mach xoay chieu khong phan nhdnh theo
thu tu gom:
Cupn day thudn cdm dp t\ cam L =—H. Bien tra R va ty dien
cp
dien dung
JQ-4
C
= F
.
Dat vdo hai ddu
doan mach
mpt

hi?u dien
the
xoay chigu
on
dinh
CO
bilu thiic:
u =
Uocos(1007rt) (V).
D6
URL
(di?n
dp tuc
th6i
6 hai dau
phan
tu R
vd L) l?ch pha
^
so
voi
URC
(di?n dp tuc thai
a
hai dau
R
vd C)
i|hi R bang bao nhieu?
A.R =
300Q.

B.R=100n.
C.R=100V2Q. D.R = 200n.
Cau 102: Cho m?ich di?n
AB
g6m mpt cupn cdm thuan
L,
mpt tu di?n C
vd
mpt di?n trd boat dpng
R
=
500
(theo thijr ty
d6)
mdc noi tilp voi nhau.
Khi
dat vdo
A, B mpt
dien
dp
xoay chieu
M =
120V2cos(120;rO(V)
thi
dien
dp
giua
hai dau
mach
AM

(m^ich
AM
chiia
L va C)
l$ch
pha — so voi u.
Cuong dp dong di?n qua mach c6 gid tri hi?u dyng bdng
A.
1,2A. B. 1,5A.
C.0,6A.
D. 2,4A-
Cau
103: lin
lupt
dat cdc
di?n
ap
xoay chilu
M,
W2=C/V2cos(120;rf+^2)
vd
MJ
=f/-N/2cos(110;rt+^)
vdo hai dau doan
I
mach
gom
di?n
tra
thuan

R,
cupn
cdm
thuan
c6 dp ty cdm L va ty
di?n
I
CO
di?n dung
C mSc n6i
tiep
thi
cuong
dp
dong di?n trong dogn m?ich
c6
bilu thuc tuang umg
Id:
i, =
/V2cos(100;r0;
i2
=
Iyf2cosi\20;tt+~)
va
is
=/'>/2
cos(l 10;rr. So sdnh I va
r,
ta
c6:

A.I =
r.
B.I=/'>/2.
C.KF.
D.I>F.
179
CHIftfHE
3:
DdNG
OIEN
XOAY
CHlgU
yJT
L»
IZ-TJMTAT
LY
THUYfT
VA
BAI
TAP TBAC
«GHI£M
-
TAP
1
• CAC DVNG CV DIEN
Cau 104: Chon cau diing. Nguyen
tic
hoat dpng cua may phat dien xoay
chieu mot pha, may phat dien xoay chieu ba pha, dong ca khong dong bo ba
pha, may bien ap dya tren:

A. Viec su diang tu tmcmg quay.
B.
Hien tugng cam ling di?n tir va sir dung tir truofng quay
C.
Hien tugng cam ung di?n tu.
D.
Hien tugng tu cam.
Cau 105: Roto cua may phat dien xoay chieu c6 5 cjp cue, quay vai toe do
720 vong/phut. TSn s6 cua
suk
dien dong la
A.50HZ.
B.
lOOHz. C.60Hz. D. 120Hz.
Cau 106: Roto cua may phat dien xoay chi6u c6 5 cap cue, tan so cua dong
dien la 50Hz.
T6C
dg quay cua roto la
A. 12v6ng/s. B.10v6ng/s.
C.
20v6ng/s.
D.
24v6ng/s.
Cau 107: Trong cac cau sau day, cau nao sai?
A. May phat di$n xoay chieu hoat dgng dya tren hi^n tugng cam
ling difn tu.
B.
May phat di?n la thiet bi bien d6i ca nSng thanh dien nSng.
C.
Moi may phat di?n deu

c6
hai
bg
phan chinh
la
phan cam
va
phan tao ra tu truang.
D.
Mgt trong cac each tao
ra
suat di?n dgng cam ung trong may
phat dien la tao ra tir truang quay va cdc vong day dSt c6 dinh.
Cau 108: So v6ng tren cugn
sa
cap va cugn thii cSp Ian lugt
la
300 vong va
2400 vong. Khi may hoat dgng, neu dong
di§n
chay trong cugn sa cSp la 18A
thi dong dien chay trong cugn thii
cSp
la:
(bo qua sy hao phi dif n nSng)
A. 2,25A.
B.
144A. C. 5A.
D.
14,4A.

Cau 109: Mgt may
t§ng
the ly tuong c6 ti s6 vong day giiSa cac cugn sa cap
Ni va thu cap
N2
la
3.
Bik
cuong dg dong dien trong cugn
sa
ckp
vk
hi?u
dien the hi?u dung
giura
hai
dhi
cugn sa c^p \hn lugt la Ii
=
6 A v^ Ui
=
120
V. Cuong dg dong di?n hi?u dyng trong cugn thu
dp
va hifu di?n the hi?u
dung giiia hai dau cugn thu cap ihn lugt la
A.2Ava360V.
B.
18 V va 360 V.
C.2Av^40V.

D.
18Av^40V.
LY
12
-
TdM
TAT
lY
THUYfT
VA
BAI
TAP TBAC
WGHlgM
-
TAP
1
CHlTdNG
3:
DdNG
DllN
XOAY
GHI^U
Cau 110: Dieu nao sau day la khong dung khi noi ve dong di^n xoay chigu
ba pha?
A. Cac dong dien xoay chi^u trong he thong dong dien xoay chieu
ba pha phai dugc tao
ra tir ba
may phat dien xoay chigu mgt
pha.
B.

Dong dien xoay chieu ba pha c6 cac dong di?n xoay chieu mgt
pha lech pha nhau goc
^.
«
C. Moi dong dien xoay chieu trong h? th6ng dong di?n xoay chieu
ba pha dhu c6 cung bien dg, cung tan s6.
D.
Dong dien xoay chi^u
ba
pha
la
h? thdng
ba
dong di?n xoay
chieu mgt pha.
Cau 111: Phat bilu
nao sau day
la
khong dung
khi noi ve
ciu
tao
va
nguyen tic hoat dgng cua may phat di?n xoay chilu ba pha?
A. May phat di?n xoay chieu ba pha hoat dgng dya tren hien tugng
cam ung dien tir.
B.
Stato gom ba cugn day gi6ng nhau, b6 tri l$ch nhau
120°
tren

mgt vong tron.
C. Cac cugn day cua may phat di?n xoay chiSu ba pha c6 the mSc
theo kieu hinh sao hoSc hinh tam giac mgt each tuy y.
D.
May phat di?n xoay chieu
ba
pha
la
dung
cu
biln dien nSng
thanh ca nSng.
Cau 112; Chgn cau sai.
A. Dgng co khong dong bg ba pha bien di?n naiig thanh co nang
B.
Dgng co khong d6ng bg ba pha ho^t dgng dya tren co
so
cua
hien tugng cam ung di?n tir va su dung tir truang quay.
C. V$n toe goc cua khung day luon nho hon van toe goc cua tir
truang quay.
D.
Dgng co khong dong bg ba pha tao ra dong dien xoay chilu ba pha.
au 113: Trong dgng co khong dong bg ba pha, tir truang quay dugc tao ra
ig each:
A. Cho ba dong dien mgt pha vao ba cugn day.
1111
CWlMMS3:Dtll8PlgimYCmgl
W*T
It K -

Tim TAT
LY THDYgT
VA
BAI
TAP
TRAC
leHlgM
-
TAH
B.
Dung dpng
ca
dk
quay
mpt nam cham hinh chu:
U ben
trong
dpng
ca.
C. Cho
ba
dong dien mpt pha vao mot cuon day.
D.
Cho dong di?n
ba
pha vao
ba
cuon day
gi6ng
nhau

dugc
bo
tri
lech nhau
1/3
vong tron.
Cau 114: Ve cau tao,
stato
cua dong
ca
khong d6ng bo
ba
pha gom:
A.
Ba nam cham
vTnh
cuu bo
tri
lech nhau
1/3
vong tron.
B.
Ba
cuon
day
gi6ng
nhau
qu^
tren
ba

loi
sit b6
tri lech nhau
1/3
vong tron.
C. Ba nam cham di?n bo tri lech nhau
1/3
vong tron.
D.
Ba
cuon
day
giong nhau quan tren
ba
loi
sit b6
tri lech nhau
1/3
vong tron va mic n6i ti6p vai nhau.
Cau 115: Trong
cac
cau sau day, cau nao sai khi noi
\h
may bien
ap:
A.
Khi may giam thS
boat
dong thi di?n
ap hai dau

cuon
sa cip
Ion
han dien dp hai dau cupn thu cap.
B.
Ti
s6
giiia
hi?u di?n the hi?u d\mg cua cupn thu cdp
va
cugn
so
cap
Cling
la
ti
so so
vong day cua chung.
C.
Goi
Ui, Ii, U2,
h Ian
lugrt
la
dien
ap va
cuong
do
dong
di?n hieu dving trong cupn

sa cap va thu cip thi ta
luon
c6
U,I,=U2l2
D.
May
biln
ap
la thiSt bi
hoat
dpng dua tren hien tugng cam ung
dien
tir,
dung
de
tang
hoac
giam dien
ap.
Cau 116: Chon
cau
dung. Gpi Ni
la so
vong day
cua
cuon
sa
cap, N2
la s6
vong day cupn thur cip va

Ni
<
N2.
May bien the nay c6
tac
dimg:
A.
Tang cuong dp dong di?n, giam hi?u dien thS.
B.
Giam cuong dp dong di?n, tang hi?u di?n thi
C. Tang cucmg dp dong di?n, tang hi?u di?n the.
D.
Giam cuong dp dong dien, giam hieu dien the.
Cau
117:
Chpn
cau
diing.
Trong
qua
trinh
truy6n tai
di§n
nang, may bien
the
CO
vai tro:
A.
Giam di?n tra cua day dan.
B.

Tang hi?u di?n
the
truyen
tai de
giam
hao phi
trong
qua
trinh
truyen tai.
lY
tt - m TAT Lf
TWYgT
WA lAl
TAP TIAC
tm»
-
TAP
1
CUd»6
8: DtM
Diew
KOAY
CHlgB
C. Gi^ hi?u di?n thS truyen tai
dk
gidm
hao
phi trong
qua

trinh
truyen tai.
D.
Tang cong
suat
truyen tai.
[pau
118: Chpn
cau
sai. Trong mpt may bien the,
neu b6 qua hao
phi di?n
ag cua cac cupn
sa
cap
\h
thur cap thi:
A.
May bien the
1^ ^g
hi?u di?n thi
bao
nhieu
\m
thi cuong
dp
dong di?n giam bay nhieu ISn va
nguoc
lai.
B.

May
ha
thi
c6 tac
dving lam tang cu6mg
dp
dong dien
a
mach
thii
cip.
C.
NSu
s6
von^ day cupn thur cap Ian hem
so
vong day cupn
sa cap
thi
may bien the d6 gpi la may tang thg.
D.
Di?n
ap lay ra
tang
bao
nhieu
Ian so vai
di?n
ap dua vao thi
cong suit

ciing
tang bay nhieu
lin.
Cau
119: Trong qua
trinh
truyk tai di?n nang. Hieu
s6
chi cua cong
ta
di?n
a tram
phat
va
a
nod thu sau m6i
ngay
dem
chenh
l?ch nhau
480KWh.
Cong
suit hao phi dpc ducmg la
?
A.20kW.
B.40kW. C. 83kW.
D.
lOOkW.
Cau
120: Mpt dpng

ca
khong dong bp
3
pha c6 cong suit 3960W
dupe
mic
hinh
sao
vao mang di?n xoay chieu
ba
pha c6 hieu di?n thS
gifta
hai day pha
la
190V,
he s6
cong suit dpng
co
bang
0,8. Cucmg
dp
dong dien hi?u dung
chay
qua tung cupn day cua dpng
ca
la
A.
lOA. B. 12A. C. 15A. D. 20A.
I
183

CHinrNG
8:
DdMG mtn XOAY CHlgP
VAT
11? « - TiU TAT LY
THBYfT
VA BAI TAP TBAC WEHIEM - TAP 1
DAP AN BAI TAP VA CAC CAU HOI TRAC
NGHIEM
CHirONG
III
Bai
tap 1:
Cau
1
2 3 4 5 6 7 8 9 10
Dap
an
D
A A A
D
C
D D
A
D
Cau
11 12
13
14
15

16 17 18 19 20
Dap
an
•A
B
D
A
C C
D
C
A
C
Cau
1: Tir
thong
cue
dai:
(^Q
= NBS = 0,54Wb
Cau3:co =
3000
vong/phiit
=
3000x
—= 100;irad/s;
60
- Eo = NBSco = 40,2V
Cau
4: Suat
dien

dong
eirc
dai:
EQ
=
^QCO
= 2V
Cau
5: Bieu thuc
suit
dien
dong:
e = = 2 sin
(lOO;it
+ ^) (V)
Cau
8: /Q = 3V2.4
=^=3A
Cau
9:u = 100^2 cos f
IOOTT.
— - - ) = 100V2F = L
\0 3 / "
Cau
10: / = ^ = SOHz; T = y =
0,02s;
IQ
= lA ^ I = j=A
Cau
11:/o =/VI = 4/1,6J = ^ = IOOTT rad/s

Cau
12: r = — =
0,02s;
t = -=
0,005s
0)
4
i
= COSCIOOTT.
0,005)
= 0
Cau
13: Su
dung
bai toan
tinh
thai
gian
trong
dao
dong
dieu
hoa:
(Thai
gian
ng^n nhat vat dao
dong
tir vi tri x = +A den vi tri
A
„ ' ' "

x = +-la-)
i
= lA =
lo=>t
= l:i = '-^ = 0,5A
184
VAT lY 12 - TdM TAT LY THUY£T VA BAI TAP TBAC
MEHlgW
- TAP 1
CHIfdNG
3: BANG DIEN XBAY CHI^U
Cau
14:
100V2
= U^f2 cos
(IOOTT.
0 + |) => [/ = 200K
Cau
15:
• u = 0,5f/o => cos(1007rt) = ^
• 0<
t<0,01->t
= -^s; -^s
300 150
1 k
~ 300 150
300 100
Cau
16:
i

= I =
^=1A=^
cos(1007rt) = ^
400 150
1 . k
t = +— +
400 150
t(mm) - — S
_1_
400
Cau
17:
V=^) = 2V2cos(l00rr.^) = V2/l
i' . = -2007rV2sin(l007r.^) < 0
i
= yplA va dang giam (dao ham nho han 0)
Cau
18:
•
Trong
1 chu ki
dong
dien
bang
khong
2 Ian.
. T =
0,02s;
At = Is = 50T -> so Ian (i = 0) la 100 lan
Cau

19: = lOOViK = ^;r = ^ =
0,02s
At = ^ ^
U2
= f/o
I
6
-f/n
0
2
Cau
20:
. Ui =
100V2K=^;T
= —=
0,02s
2 CO
. At = — s = - U2
=-100V2V^
300 6 ^
185
CHi/dH6
3:
DdiiB
mtn
XBAY
mt»
m
ly
n - liu

TAT IY
THOYgj
vA
BAI TAP
TBAC
IIBIUEM
- TAP I
L
—
-200V21/
^—
+200V2K
•
1 • •H •
-IOOV2/
°
-\-lQQ^[2V
Bai tap 2:
Cau 1 2 3 4 5 6 7 8 9 10
Dap an
B
D
B A
D D
A
C C
c
Cau 11 12 13 14 15 16 17 18 19 20
Dap an D D
B B

D
B B A
C
B
Cau 21 22 23 24 25 26 27 28 29 30
Dap an C
B B
C C
B
C
B B B
Cau 31 32 33 34 35 36 37 38 39 40
Dap an
A A B
D
A A A
D D
B
Caul:U
=
IR= IIOV2V
Cau
2:
• Doan mach
chi c6 cac
di?n
tra
thuSn mSc
noi
tiep, tuang

duomg vai doan mach chi c6 mot dien tra
thu§n
duy nhSt vai
dien tra bang tong cac dien tra
thuSn.
R
=
Ri
+
R2
•
/oi = /02 = =
2V2
(A)
-> Cau
D
sai.
Cau 4: Mach chi c6 R u cung pha vai
i
i = Y = V2 cos
(lOOTTt
-1) (A)
Cau
5:
•
—
^
=
4=—|=
= 0->Cau Adung

12
-
TiM
TAT
Lt
TBIYfT
»A
BAl
TAP TBAG
BSHlgH
- TAP
1
CBIDMG
8:BiW6Bl£l«IAYCIIig|
•
—+ —= -4=
+ ^ = >/2->CauBdung
• Mach chi c6 R => u cung pha vai
i
u
=
Uocoscot
i
=
locosoyt
=>
— - -
= -4=
cos(cot)
—7=

cos(a)t) = 0 -> Cau C dung
•
+
4-
=
2cos'
(wt) -> Cau
D
sai
TT2
I2
Cau 8: Mach chi c6 L => u som pha
—
so vai
1
=>
q)i
2
2
Cau 9: Mach chi c6 L u sam pha
-
so vai
1
=>
=
—-
z
z
.
=

-cos(a;t )=-cos(a;t )
Cau 10:
• S6 chi cua ampe ke la cuang do dong dien hieu
dung:
I = 2A
• Uo
=
200V; lo
=
1V2
=
2V2A
• Lo)
= ^
=>
L.
lOOrr
= ^
L
=
0,225//
/o
2V2
Cau 11:
•
Zi,
=
L6J
=
lOOQ; Io= —= 2,2V2A

Mach chi c6
L
=>
u
sam pha
-
so vai i=>(Pi=
i
=
2,2V2 cos (lOOrrt
-1) {A)
Cau 12:
7t
_
•rt
• Doan mach chi
CO
C=>i sam pha
hem
u mot goc —=>
- 2
V
UQCO)
• Cuomg do dong di?n hi?u d\ing:
t =J^
=
~vf~
CHI/dNG
3:
DdNG OICN XOAY CHlf U

VAT LY 12
-
TiM TAT lY THUYfT VA BAI TAP THAC
WeHieilll
-
TAP
1
Cau 13:
• Doan mach
chi
c6
C
==> i
som pha hon u mot goc
^ ~
• Cuong do dong dien cue dai: /Q
=
—
=
UQCO)
• Bieu thuc cuong do dong
dien:
t = t/oCw cos {oit +
Cau 14:
. ZC=^:=100Q;IO=HL = 2,2V2A
Ceo
• Mach dien chi c6 tu C, dong dien i som pha hon dien ap mot
• BiSu
thurc
cucmg do dong

dien:
i = 2,2V2 cos (lOOTit +1) (^4)
Cau 15:
• Zc =
^
= 40fi;[/oc = /o2c = 400V2l'
• Mach dien chi c6 tu C, dien ap u tre pha hon dong dien mot
,
71 71
goc-=*(p„=
• Bieu thuc dien
ap:
u =
400V2
cos (lOOrrt
-1)
(V)
Cau 17:
• Zc =
^=50n;/2
=
i2 +
H!=*/o
=
5/l
• Mach chi c6 tu
C:
-
(p^
= - -

(pi
=
-
2
6
• Bieu thuc cuong
dp
dong
di?n:
i =
5
cos (lOOnt
+
^
(A)
Cau 19:
• Z, =Lco = 20Q; Zc= —= 100Q
Ceo
• Tongtra:
Z
=
^R'+(2^-Z^)'
=100Q
Cau 20: U = ^U^ + {Ui
-
UcY = 40V
Cau 22:
tancp =
^
= -l=>(p = -^=>i

s&m
pha
^
so vai u
lY 1Z
-
TdM TAT l« THBYfT VA BAI TAP TBAC WGHIEM
-
TAP 1 CHlfflHB 8: DflNE D|£N XOAY CHlgU
Cau 24: Cac dap an A, B va D deu sai khi xet vg pha giua dong di$n
va dien dp
Cau 26:
• = Loj = 200aZc = ;^ = 100
->
z
= ^R^
+
(z^
-
Zc)2
= looVIa
Z
V2Z
Cau 27:
U
=
^/W+Ul
=> U„
=
^U^

-
Ul = lOVZK
Cau 28:
• /? = Zi, = Zc = = lOOQ
^
0,05
• vi
Zi.
= Zc
=>
z =
/?
= looa
Cau 29:
/ =
= 2.SA
Cau
30:
UR=^=^UC=>
tancp =
n
= l=>(p = ->0
7t
Suy ra, i tre pha
-
so vai u.
Cau
31: <p
= (^u
-

<Pi
= -f
< 0 t""*? < 0 => Z^. < Zc
Cau 32: (p
=
-5
tancp =
^
Zc = 125^
Cau 33:
. /? =
^
= lOOQ; Z =
^
=
200f^
. Z =
y^^+Zf=>Z,
= 100V3i2-*L =
^
=
f
(//)
Cau 34:
Z =
J
= lOOfi
u tre pha
—
so vai i => mach gom tu di?n va cuon day thuan

2
cam, Zc > Zi
Cau 35:
•
DQ
lech pha:
<p
=
<Pu
-
= +f
189
caiWM a: rtro
mt»
KI»T
cwgy
V>T
tt«
- it»
TAT LT
TBBYgi vA
BAI T*P TBACMHI£H-TAPI
•
tanq) =
=5>
/?
=
lOOQ
Cau
36:

•
=
20aZc
=
lOOQ
-> Z =
80Q,/Q
= v = 2V2/1
•
i = 2V2 cos
(lOOTTt
+1) (i4)
Cau
37:
•
Z =
7^=50V2Q; <p
=
(p„-<^i=J;
/?
coscjo
=
—
-* R =
SOQ
Cau
38:
tan(p = ^
=»
^ > 0

=>
i
tre han u mpt
goc nho
han
R
2
n
3n
Cau 39:
(pu-(Pi
= =^ (Pi = —
Cau
40:

=
^^Z^
= ^
.
Z =
Vft=^
+ (^ ^c)^=7^
Bai
tap 3;
Cau
1
2
3
4
5

6 7 8 9 10
Dap an
B
A
C
C
B
C B
B
C
A
Cau
11
12 13
14
15
Dapdn
D C B D
C
Cau
1: P =
I^R=>R
=
SOQ
Cau
2:
•
Zc = ;^ =
80ft;
Z

= /R2Tzf=100n
C(i>
• cos^
= - = 0,6
z
VAT LY
1Z
-
TJH
TAT it TBBYgf VA
BAl TAP TBAC
BBBIgH
-
TAP 1
CBlfBlIB
8:
BBMS
fliEW
XBAY CHlgB
Cau
3:
•
cos<iP
= ^ =
0,6 =>
Z = —
Cau
4:
Zc
= — =

lOOfi;
Z =
^R^+Zl
=
lOOVfn
/
=^ =
V2>i;P
=
/2i?
=
200V/
Cau
5: Z^
=
Lo)
=
SOQ;
= ^ = 100";
Z
= V/?2 +
(ZL-2C)'
=
50V2ft
/
= ^ =
V2y4;
P = I^R = WOW
z
Cau

6:
•
Zp= —=
100Q;ZL=LO)
= 180Q;
^
c© I;
Z
=
^R'+(ZL-ZJ'=100Q
.
l = R =
2!lA;?
= fR =
30W
Z
2
Cau
7:
• Zi,
=
La)
=
60Q;Zc=7?-=100ft
Cau
8:
•
P =
U/cos(p
=

220.2.
COS
= 220V2M^
Cau
10:
. U^
=
UJ
+
(U,-Ucy
=>
Ul = U^- WL - Uc^ = (2U,y - WL - 2U,y = 3UL
191
CHtfir«e3:DI>«6 0lgl«XDAYCHlgB V<T tY IZ - TIJM
T/JT
LY
THBY£T
VA
BAI
TAP
TBAC
HEHlgM - TAP 1
.
U,=^/3U,;coscp=^
= ^^ = ^
U
2U, 2
Caull:
P = I^R = 'IR = SW
Cau 12: A = Pt =

lOOOWh
=
lA:iy/i
Caul3:
•
L =
CR^
(1)
•
coscpi
=
C0S(P2
Zi = Z2
(^Li
- Zc^y = (Z,2 -
Zc2Y
^LC =
a>^a)2
(2)
Tir(l)va(2)tac6: L = ^ va C= ^
IOOTC
1007I.R
R
2
H? so cong suat: COS9, =
—
= —== =
coscp^
Z,
VI3

Cau 14:
•
Zc.=7;^ = 400Q;Z„=-^ =
200Q
.
P,=P2=^llR = qR^!^ =
!^^Z!=Zi=,
.
z,
=2£ii^=
300/3
=.L =
i//
Cau 15:
•
Dat = (ZL - l^Y
•
Uci =
2Uc2
=> Ii = 2I2
=J>
Z2 = 2Zi
•
t/«2 = 2(/«i /2«2 = 2/i/?i => /?2 = 4/?i (2)
•
Tir(J)va(2)taduac:a2 = 4/?2
cos(px
=-7r =
^1
yfRf+a^

V5
192
IVAT
LY
12
- m TAT It THBYfT VA
BAI TAP
TRAC
HSllltM -
TAP
1
R2 Rz 2
cosq)2
=
Z2 v^l +^
CHIfdNG 3: BANG OI|N XBAY CHlfU
Bai tap 4:
Cau
1
2
3
4
5 6
7
8
9
10
Dap
an B
C D

D
B
A D
B
C
B
Cau
11
12 13 14
15
Dap
an
B
C
D D
B
Cau 2:
Cau 4:
Thay
doi
C de Pmax mach cong
huong
Z,=Zc=^U,
= Uc = 2U
u
cung pha
voi
UR
u
ciing

pha
voi
i mach cong huong.
Tan
so cua
dong
di?n
kjii
mach xay ra
hien
tugng
cpng
huong:
1
f = = 25011/
27t>/LC
Cau 5: Zi =
ZQ
^Mach cong
hugng:
UR
= U.
Cau 6: - 220V = U => mach cong huong
=i,
Zc = =
200Q
=>C
=—KiF
Cau 8: u cung pha voi
UR=»

U cung pha i mach cgng huong
10-3
ZC
= ZL = ion =» c =
Cau 9:
•
i]n = 'Ui =
Uc=>
R = Zi = Zc =
lOOn
->mach cpng huong
•
Pr
max
= ^ = 50iy
Cau 11: Thay
doi
w
dk
Pmax=>
m?ch
cpng
huong:
Pmax
= ^ = 484U^
193
CHlftfHE
8: DiNB
fllgW
XOAY

CHl£u
VAT It
1Z
-
TiM*rAT
LY
THBYfl
tfA
BAI
TAP TRAC
NGHlgM
-
TAP
1
Cau
12:
•
Lcoo
=
lOOQ =i.
L
= —
too
•
=
25Q
i
=
25wo
• Tan so goc cong hurong thoa:

aj^=
—
=
—
=>a>
=
—
LC
4 2
Cau 14:
P =
50M^
=
—
=> mach cpng huong
(o
=
12071
rad/s
Cau
15:
•
u
lech
pha
^
so vai
Uc
=>
u

cung pha vai
i
=>
mach cong
huang
• Ctd la dien dung tuang duong cua bo
tu
C va
C
. Zc^^
=
Z, =
lOOn^ Ct^ =
^HF
<C
=
^^F ^ C nil
tigpC
Cc^
C C' rr ^
Bai tap
5;
Cau 1 2 3 4
5 6
7
8
9 10
Dap
an
B B C

A
B C D D D D
Cau 11 12 13 14 15
Dap
an
B D B B B
Caul:
•
i
lech pha — so vai u => cuon day c6 dien tra trong
r.
•
tan-
=
^=:>r
=
10Q^Z
=
10V2Q
4
r
Cau
2:
•
ZL
=
L(O
=
2SQ;
Z

=
yl(r
+
Ry
+
Zl = IS^a
VAT lY
12
-
TdM TAT
Vt THUYfT
WA BAl TAP TRAC
W6H|£M
-
TAP
1
CHIfflNG
3: DdNG
DIEN
XOAY
CHI^U
• /=^=2V2.1
Cau
3:
271
•
oi
= —
=
10071

rad/s
.
p
=
i2r
=
!^r
=
J^r^Z,
=
S0n^L
=
'^
=
^H
Z2•
r^+Zl
Cau
4:
•
ZL
=
80a
coscp =-=>Z
= -R
Z
3
Cau
5:
coscp =

—
=>
-==4^L==
=
0,8
=>
r = lOQ
Cau
6:
• Dat vao hai dSu cuon day mpt dien ap khong doi, ampe ke chi
3
A
^
cuQn day c6 dien tra thuan ^ -
y
=
= •
•
Vai
dien
ap
xoay chiSu, tong
tra cua
mach
la:
u
60V2
Z
= —=
I

1,5
= 40>/2Q
Vai
Z
=
Vr^Tzf
ta
tinh dugc
Z^.
=
40Q
va L =
—
H
71
Cau
7:
7t
•
Ud
som pha han
UR
mpt goc —, ma
UR
cung pha vai
i
•
suy
ra, Ud som pha han
i

mpt
goc
-^=>
(Pa
=~
tancpj
7t
7t
Cau 10:
(p
=
(Pu -tPj
=
^usamphahanimptgoc —
3
3
Do do, doan mach chi chura cupn day c6 di?n tra thuSn
Cau 11:
/ = ^
=
1^
Zw
=
^
=
15Q
tac
CHI/me
3:
ntws

oigii
XBAY mlt
»<TtYK-TtMTATUTHBYgT VA lAl TAP TRAC HGHIIM - TAP |
Cau 12:
. /=^=l/l-4Zd=^=15aZ =
^=20a
.
Z2
= (r + Ry + Zl
=
(r2
+
Zf)
+
i?^
+ 27?r
Cau 13:
• ZL =Lco = 40Q; I = -^ = 1A; UL=I.ZL=40V
R
• Tathay:
U^T^T
+ UL
cuon day c6 di?n tra thuan r.
• H? so cong suat cua
mach:
cos(p
= —' ^ = -
Cau 15:
• + ->cuon day khong thuan cam
. U2 = (UR + U,)2 + = + 2URUr + + = +

2URUr
+ -> Ur = 40V
• P = (UR +
Ur)I
=> I = 0,5A
B^i tap 6:
Cau 1 2 3 4 5
6 7
8
9
10
Dap an A A D B
C C C C
A B
Cau 11 12 13 14 15
Dap an A D
C
A D
Cau
2:
Zc = =
lOOQ;
/?
=
IZ^,
- Zd = lOOfi
Cau 3: P == 200M^
R1+R2
Cau 4: P =
=>

f/
= 2001^
Cau
5: R =
ZL
= 50fl
->
P =
—
= SOW
2R
Cau 6: +
i?o
= iZf, - Zcl
=>
P
= lOfi
inn
VAT lY 12 -
TiM
TAT L* THBYgT WA BAI TAP TBAC •BHigM - TAP
1
CHlftfHB 3:BftHe BIgM XBAY CHlgU
•
C«u
1:R = -jRl +
(Zt
- ZcV = 50n
2
^

Cau 8: 0^16)2 = ^cpnghutag =
7^
Cau 9:
CO
= = lOOu
rad/s
Cau 10: ZL =La) = 30Q ;Zc = —= 60Q
Ceo
p=rR =
u
R=-
RU(ZL-ZC)^
-Ri:^R
= 10Q V R = 9()Q
Cau 11: Thay d6i C dh
UL(max)=>mach
cong huomg
ULimax) = lmaxZL=jZ, = 200V
Cau 12:
71
•
tanw
= ^'•"^^ = 4=
=>
<p = - =^u som pha hom i mot goc -j
• Vi
UR
cung pha
i
=>

u som pha
hom
UR
mot goc ^
6
Cau 13:
•
P1P2
= Z^ =
100^
(1)
. Uci = 2yc2 =>
/i
=
2/2
=>
Z2
=
2Zi P2
=
4Pi (2)
Giai he hai phuomg trinh (1) va
(2),
ta c6:
Pi
= 5on,P2 =
200a
Cau 14:
.
(ZL-ZC)2

=
RIR2
• I1 = =
= 4A;
l2=f
=
= 3^
Cau 15:
PjPz
= (Z^, - Zc)^
P2
= 40Q
Bai tap 7:
Cau
1
2 3
4
5
6
Dap an C D C C B ' A
CHlftfHS 3: DdHEDlEHXOAY CHlf 0
Hni
12
-
TiM
TAT
it IHUYfl VA
BAI TAP TRAC
HEHlgM
-

TAP 1
Cau
1:
AAOB
vuong tai
O,
duomg
cao
OH.
Ap
dung
he
thuc
luomg trong tarn
giac
vuong
0H2
=
HA.HB
=
HA(AB-HA)
Ui
=
UL(Uc-Uj=.R2
=
ZL(Zc-ZL)
Cau
2: Do
lech
pha cua

Uj
so vai u la
f
^)
(p=
a +
—
•
AOHA vu6ngtaiH:
OA=-^=20H;
n
cos
—
3
AH
= 0H.tan| = 0HV3
•
AB
=
Uc
=
V3Ud
=
V30A
=
2V30H
•
HB
=
AB

-
AH
=
V30H
HB
V30H
tana
=
OH
OH
3 ^ 3
Cau
3:
•
AAHO vuong
tai H:
tanAOH
=
OH
r 4
•
mR
=
mi
=
-
2
4
O
U

i
/
/
\
/-V
u
V
1'
IQA
VAT
lY
12
-
TIJM TAT lY THUYgT VA
BAI TAP TRAC
HEHIgM
-
TAP
1
CHIfflwe3:
DdNGOl|NXDAYCHl£u
•
ABKO vuong tai K:
BK
Zc
tanBOK
= - = -^
=^R
=
Zc

=
20on
Cau 4:
^AOB
vuong tai
O va c6
duomg
cao
OH.
OH^=HA.HB
Cau
5:
AAOB
vuong tai
O va c6
duomg
cao
OH
OH^
OA^ OB^
u u
'AN
u
'MB
R
CHl/tfWE
3:
ndWB
BieilXBAYCmgll
WATLtlt-TtllTATtf

THBYgT
VA
BAI TAP
TRAC
MGHlf
M
-
TAP
1
Bai
tap 8;
Cau
1
2
3
4
5
6
7
8
9
10
Dap an
C
A
B
C
A
B
A

C
A
C
Cau
11
12
13
14
15 16 17 18 19
20
Dap
an
c
D B
A
C C
B
A
B
C
Cau
,
21
22 23
24 25 26 27 28 29
30
Dap an
C
D B B B B
B B D

A
Cau
3:
/ = — =
SOHz
'
60
Cau
4:
/ =
60
np
60
n
= ^ =
750i76n^/p/iut
Cau
5: /i
= /2
=>
n^Vx
=
niP2 =» n2
=
450 vbng/phut
Cau
10: Ua
=
^fSUp
= 381V

Caull:/d
=
V3/p
=
17,3i4
Cau
12: Ta
thdy
220 =
127V3 nen
dien
ap
a
hai dhu mot pha
ciia dong
ca
bang
VS
Ian
dien
ap
gifta
hai day pha
trong
mang dien chon
dap an D.
Cau
17: Vi cac
dong dien lech pha nhau
—

hay \h thai gian
la —
Cau
18:
•
Bi
=
BoCOSa)t
B^^rnax)
'
2n^
•
Bj =
BQCOS
•
B3 =
BQCOS
(Ot +
-
cot
2n
=
BQCOS
=
BOCOS
k27i +
-
k2n
(x)t
=

k2n
27t^
Bo
_ B,
3
>
2
2
BQ
_ B,
3
J
2
2
Vay, 1^21 =
IB3I
=
B,
zoo
yAT
LY
12
-
TBM
TAT
IJ
THUY£T
VA
BAI TAP TBAC
NEHIgM

-
TAP
1
CHlfdNG
3:
DdNG
OllH
XOAY
CHlEO
Cau
19:
• Xet thai diem cam ling
tir
Bi(max)
=
BQ
Khido
• Vecta
cam umg tir
t6ng
hop tai
O:
B
= Bi
-\-
B2
+
B^
•
Do Ian cam ung tir

t6ng
hop tai
O:
B
=
B, + IB21
cos
60° +
IB31
cos 60° =
^
Cau25:^
=
^=>^
=
i^=.f/2
=
20K
N2
U2 100 Uz ^
Cau
26:
^ = ^ =
2200 vbng
N2
U2
Cau
21:H =
^=^P2=Pr.H
=

UOW
Pi
Cau
28: ^.
100%
=
^^£2^.
100%
= 2.5%
Cau
29: Phj,
= (-^) R =
16S3W
\Ucos<p/
Cau
30: Hi
= 1 - ^ ^ = 1 -
Hi
= 0,2 (1)
//^
=
l_^^^=l_//2
= 0,05 (2)
Lay^tadugc^
=
4=.(^f
= 4
(2)
Php(2)
=^U2=

2(/i
=
AkV
^au hoi
trkc
nghiem tong hou
Cau
1
2
3
4
5
6
7
8
9
10
Dap an
D
D
D
A
B B B
B
D
D
Cau
11
12
13

14
15
16
17 18
19
20
Dap an
B
A
B
C
B
B
A
D
C
C
CHtfltwe
8:
Dime DIEN XOAY mtV VAT 1Y
1Z
- TJM TAT it THUVfT
\lk
BAI TAP TBAC MHlgM - T<P
Cau 21 22 23 24 25 26 27 28 29 30
Dap an A C A D C D B B C A
Cau 2: 0o = ^^-^ = 0-01
Cau 3:
• 0) = 3000 vong/phut = lOOn —
• Eo = N(t)max^ = 31,4 V

Cau 4:
FQ
= NBSco
=>
EVI =
WBS^
=>
T = 0,02s
Cau 5:
a>
= 150^ =
STT^;
£ = § = ^ = 25V2K
phut s V2 V2
Cau 6:
• Bilu thuc tu
thong:
0 = 0o cos(a)t + ^)
• (p = NBScos (a)t + ^)
• Sudt dien dong tuc thai: e =
4>'
= NBSo)sin(oit + ^
NBS(i)cos
(o)t -1)
Cau 7:
• Bieu thuc tir thong c6 dang: 0 = 0o cos(a;t + ^)
•
(t)o
= NBS= 1,2 lyfo
• ^ = 120 ^ =

47r
rad/s;
,p
=
(n,
B)^^^
=
TT
• Suy
ra,
0 = 1,2
cos(47rt
+
TT)
(Wb)
• Bieu thiic sudt dien dong cam ung:
e = -0' = 4,87r sin(47rt +
TT)
K
Cau 8:
• Bieu thuc cuong do dong dien c6 dang: i =
IQ
cos(a)t +
<p)
• Vai, /o = /V2 =
3,53/1,
co
= 2nf = lOO/r rad/s
• t = 0,i = Oi7ai'>0 =>(p =
• i = 3,53 cos (lOOTTt -1)

iT
lY
1Z
-
TAM
TAT
LY
THUYfT tfA
BAI
TAP
TRAC
NBHltM -
TAP
1
CHtffllie
3:
DftUB BltW XOAY CHlgU
Cau 9: i = 0,5Io
=>
sinlOQ-rrt = 0,5
600
300
t = -^ + ^
\0 300
0<t<0,01s-t = ^shoact = J^s
Cau 10:
• Doan mach chi chua dien tra thuSn R =» u cung pha i
Cau
11:
U =

UR
= IR = 200V
Cau 12:
7 1 1
^ CM C2Ttf
, I = Ji.
=
-^^ =
I^«^i^=>ItilethuanvaiC.
^/2 V2Zc V2
Cau 13:
1 1
Ceo C27:f
. i =
Jo
=-^
=
Ho^2^^tangflen4ianthiItang4mn
^/2 V2Zc V2
Cau 15:
• Doan mach chi c6 R u cung pha i u = UQCOSCOI =
lQRcos{cot)
U I R
• Khi thay R bSng ty C: lo = = -rV- = IQRCCO
/Co
• Doan mach chi c6 tu C: i sam pha ^ so vai u i =
RlQ(ji)Ccos(a)t
+ ^^
Cau 16:
• Doan mach chi c6 R => u cung pha

i
=» u = /oi/?cos(wt)
203
CHIMBS
3:
DftHB
m^K
XBAYCHlgB
VAT
LY
n - TiM
TAT LY
THOYfl
VA BAI TAP TBAC
MeHlgM - TAp i
R
I
•
Dat
dien
ap nay vao hai dhu
R2:
i2 = ' °' cos(Qt)
R2
Caul7:
•
IR =
loCOSCOt
=> U =
RIQCOS

(tot)
•
Dat dien ap u vao hai
dfiu
cuon day thuan cam L-
ZL
COL
Doan mach chi c6 L i tre pha ^ so voi u
li
—
Cau
18:
coL
cos
^cot-^^
2/
.
Io=-^ = UoCco
7t
Doan mach chi c6 tu C => i som pha — so vai u
i
=
UQCCOCOS
cat +
Cau
19:
Z=
L(o = 200n,
Io=^
=

V2A
71
Doan mach chi c6 L => i tre pha
—
so vol u.
2
i
= V2<
cos
6 2J
=V2.
cos
^OOTit ^
(A)
Cau
21:
UL
som pha -so voi
i;
UR
ciing pha i =>
UL
som pha hon
UR
mot goc
—
9n»
lY
12
- TiM

TAT
It THBYfT
»A BAI TAP TBAC
IIBHigM
-
TAP
1
CHIWII6
3:
BtllB BitII
HAY
CHI^B
71
Cau
22: uc tre pha 2 so vdi
i;
UR
cimg pha i =^ uc tre pha hon
UR
mot
goc -
Cau
23:
u
tre pha ^ so voi i =>
(p
= -•mach c6
tinh
dung khang
tan

3j
R
•Cau B sai.
Cau
24:
Z.=
C27if
; ZL=L27rf;
Z =
R^
+
\
L27tf-
C27rf
J
Tang tan s6 f: Dung khang Zc giam, cam
kMng
ZL
t3ng, di?n
tra
R
khong doi, tong tra Z thay d6i.
Cau
25:
C27tf
>ZL=L27xf
; Z =
R^
+
L2nf-

1
C27if
Giam
t&n
so f: Dung khang Zc tSng, cdm khdng
ZL
giam, t6ng
1
tr6
Z tang vi dp 16n
L27if-
C27rf
tang.
Cau
26:
71
<P
=
(Pu-(Pi
= -2
7t
u tre pha
—
so
voi
i => m?ich
chi
c6 L va C nhimg (Z^ < Zc)-
Cau
27:

U =
I/QCOS
(cot)
COS
(wt) = —
i
=
/Q
cos (wt + f) =
-^0
sin(a)t) =>
sinayt
=
sin^ (Dt + cos^ 6)t =
l=>7:T
+
7T=l
'/o
1/2 ;2
HIS
EHIftfHS
3:
DflHB
PrEll
XOAT
EHlgy
VAT
lY
12
-

m
TAT
n
im€l
VA
BAI
TAP TRAC
WGHlgM
- TAP 1
Cau 28:
•
u = Uo
cos(ajt)
t =
/o cos
(cot - f) =
/Q
sin(a>t)
U
I 1 1
= 0=>CauAdiing.
—
-
-
J =
cos^ (cot)
-
sin^ (cot)
?i
0 => Cau B sai

'
+ =
2cos^
(cot)
+
2
sin^ (cot) =
2
Cau C dung
U
U
Cau 29:
+ -p = -U+4=
=
V2=>CauDdung.
0
^0
lo
V2 ' V2
u = (/QCOS (cut) =» t = /QCOS (cut)
U
I 11
T"
=—?r = 0 Cau A dung.
Uo
lo 72 V2
u
i
^
_

i
=
V2cos(cot)
-
V2cos(cot)
= 0 => Cau B dung.
u2
Tl2
T2
'-'0
^0
+ —= cos (cot) + cos^(cot) =
2cos^(cot)
=>CauCsai.
•
-;7-
+ -;^ =
4-+4= =
V2=>CauDdung.
UQ
IQ V2 V2
Cau
31
32
33
34
35
36
37
38

39
40
Ddpan A A
C
A A
D
A
D A
C
Cau 41 42 43 44 45
46
47
48
49
50
Dap an B D
C
B A D
A
B
B
C
Cau 51 52 53 54 55 56 57 58
59
60
Dap an
C
A A D A
C C
B

C
C
71
Cau
31:
Mach di?n chi c6 L va C i som pha
-
nSu
ZL
< Zc
2
IAT lY
12
-
Tl>M
TAT LY THUY^T
tfA
BAI
TAP TRAC
HGHlgM
- TAP
1
CHtfJHB
8: BflNS
fllgK
XBAY
CHlgli
Cau 33:
•
Zi,

=
L(o.
=
icon;
Zc
= ^ =
200n; Z
=
^{Zi-ZcY
=
100ft
•
Cucmg
do
d6ng di?n hi^u
dving:
I
= - =
lA
ZA
Cau 34: U^
=
Ul
+
=>
Ul
=
U^-Ul=^Ui
= 80K
Cau

35:
y
=
Vf^JT(yr^yj2
=
130K
Cau 36:
•
Zt
=
Leu
=
icon;
Zc
=;?-=
son; Z
= + -
^cY
7
50V2fl
Cucmg d? dong di?n hi?u d\mg I
= ^ =
V2
A
Cau 37:
Lit)
z =
VR' + (ZL -
Zc)2
=

son
•
/
=
^
=
2^=>f/
=
/.z = iooy
Cau 38:
•
1 tre pha
—
so voi
u =» 9
=
T
4
4
tan
(p
=-^t—^
=> Z, = 300Q => L =
-
H
Cau 39:
•
Zi
=
Leu

=
son;
Zc=^=100n;
z =
^JR^
+
iZi^-ZcY
=
loon
.
/„=^=2^;tan^=^=-^ ^
= -f
•
<Pu-<Pi
=
-1^<Pi
= I i =
2
COS
(lOOTTt
+ J) (^)
Cau 40:
.
Z„
=
J-
=
150n; Zi,
=
Leu

=
SOn;
^
CO)
z = VFT(z7^r^ = looVIn
CHtflfIS
8:
DftMG
mtH
KflAT
mJU Hkl n - TJM
TAT
LY THUYfT VA
BAI TAP TBAC
HmtU -
TAP
1
n n
• u =
2OOV2
cos (lOOrrt - (V)
Cau41:
'0
•
<P
= <Pu-<Pi=7; coscp = ^=>R=Z.cos(p = 2on
• Z = JR'+ZJ =>Zi=VZ2-/?2 = 20n=>L = —H
Cau 42:
• Zi =
Lo)

= 50n;Z = + 2f =
loon
-
• i = cos (lOOnt -1) (A)
•
UoL
= IoZi = 50V
• UL som pha so v6i i
=>UL = 50
COS
(lOOTTt - f + f) = 50 cos (lOOrrt + -)
(V) '
Cau 43: UR cung pha i => i = IQCOSCJI =
—
coswt = -
R
R
Cau
45:
^ = -
ip,.
= J tan<p > 0 =» Z^ > Zc
Cau 46: q) = (pu- (Pi=^=> taivp > 0 => doan mach gom cugn day
thuSn L \k di?n trd thuin,
Cau 47:
• Zi =
La)
=
100n;Zc
=

7-
= SOU
• ucl?chpha ^ sov6ium^uclu6ntrepha-sovoii
4 2
VAT LY
12-TOM
TAT LY THUYET VA BAI TAP TBAC
WEHIgM -
TAP
1
CHIIdNe
3:
DANG DlEN
XOAY
CHI^D
, 7t . n
u som pha
—
so
vai i
==><p
=
—
4 4
Cau 50
Cau 51
tan2 =
^^=*/?
= 50n
4

R
1
6J
< -;i=
=>
a)L < — =» Zi < Zc => i sam pha han u
=Lo) = 100Q
71
u tre pha
—
so voi i
4
Cau 52;
Cau 53;
,p = -2
=>
= -1
=>
Zc =
125fl
^ 6 « V3 V3 1071
Ul = UQI cos (a)t +1) => i = /o cos (wt - (vi UL sam
71
Cau 54
pha
—
so voi i)
(/J =
<Pu
- = I > 0: mach

c6
tinh cam khang.
: Dap an D.
Zi = Lo) =
lOO;
Zc = -^= 20n; Z =
lOVIn
/Q
= H2L = 2V2^ ; UL sam pha ^so voi i
=» i =
2V2cos(1007rt)(i4)
Uo = hZ =
AQV
Cau 55:
u = 40 cos (lOOTTt - J) (V^)
= ^ = 8oaz = JWTz^
=
loon
• cos(p = - = 0,6
Cau
56:
F = i//cos<p
=>
/ = = 0,5^
=>
« = ^ = 120n
mm 3: DANG OIEK XOAY mto
VATIY
IZ-TJMTATLY
THBYfiyA

BAl
TAPTRACNGHIEM-TAP
API
Cau
57:
T
s
Z,
=
50fl
-»
Z,
=
0,5
H
Cau
58:
UR
=
U^yfS
. COS(p=^ = ^ = ^
^ U 2UL 2
Cau
60:
1
•
ZL=LCO
=
180Q;ZC=
—= 100Q;

Co)
Z=7R^+(ZL-ZC)^
=
1OOQ
. .
i=I^=-yi-=:/2^_>P=i^R=3ow
Z V2Z 2
Cau
61
62
63
64
65
66 67
68
69
70
Dap an
A
C
B
B
D B
C A
A
A
Cau
71
72
73

74
75
76
77
78
79
80
Dap an
D
C
C
D
A
B
B
D
C
C
Cau
81
82
83 84
85
86
87
88
89
90
Dap an
D

A
A
C D
A
B
D
A
C
Cau
61:
• ZL =
LO)
= son; Zc = ^ =
lOOH;
Z = SOVZfl
• P = I2R = R = iQOW
Cau
62: (p =
(p^
- (pi =- P = UIcos(p = SQy/SW
6
Cau
63:
• Zi, = Lw = 40a
Zc=-^=
lOOfl;
lY
12
- TdM
TAT

lY THUYgT VA
BAI
TAP
TBAC
MHltM - TAP 1
ClltfdNG
3:
BdNG
flIEW
XBAY CHlgU
z = V(/? + ry +
(Zt
-
ZcY
= loon
Cau
64:
vi
(/2 =
(75V2)'
y| +1/2 = 352 + 852
khong thuan cam
cuon day
u^+uj-u^
2UR
P
= WR +
UrV=>I
=
= 401^

p
= 0,5/1
Cau
65:
Z, = L(o =
20il,Zc=
—
=100a
=^R = 160n;
40fl
/? = 160
=>
Z =
SOVSfi
=*
cos(p
= ^ = ^
R
= 40n
=>
Z =
40V5fi
=>
cos(p
=^ = ^
Cau
66:
Cau
67:
Cau

68;
Cau
69
Cau
70
Q = I^Rt = UOkJ
<PRL=f
=*7 = V3=>Z, = /?V3
Zc=Z, = /?V3
Khi
mach dien xay ra cong huong:
UR
= U
Mach cong huong: Zc=Zi = L(o =
200n
^ 50 p
Khi
mach xay ra cong huong:
1
U
Tang tan so: I giam (cau B sai),
UL C6
the tang
hoac
giam (cau C
sai), Uc giam (cau B sai) va h? so cong suit giam (cau A dung).
Cau
71:
C2Kf
>Z,

=L27if ; Z =
^ 1
L27tf-
C27tf
Z11
CHITDHG
3:
Dftme
DIEM
XOAY
CH|£B
VAT
tt
12
-
TiM
TAT
lY
THIlYfT
VA
BAI
TAP
TBAC
HGHlfM
-
TAP 1
Giam
tan s6 f: Dung khdng Zc tSng, cam khang giam, t6ng
tra
Z giam vi dp Ion

|L27tf
-
-
^
C2nf
giam.
Cau
72: Thay
d6i
f
dS
P„^
=> mach cgng
hucmg:
P^^x
=
f
=
2421^
Cau
74:
1
C2nf
>
ZL
= L2n{
=>
de c6
hi?n tugng cong hucmg
=

L27cf
=>
giamtansof.
C27rf
Cau
75:
= =>
=
Z^
-> mach cong huong =>
u
cung pha
i.
Cau
76:
•
Uji
=
Ui
=
Uc'=^
R
=
Zi
=
ZQ'.
mach cong hucmg
•
Pma.=y
=

|;=100H^
Cau
77:
UR
=
U
^Zi=Zc
=
200n
=> L
=
0,636//
Cau
78:
•
UR
cung pha
i
ma
u
cung pha
UR
=>
u
cung pha
i
mach
cong hucmg
•
Tan so

dong
di^n khi
mach
xay ra
cong hucmg:
f
= \
=
25}\z
27tVLC
Cau
79:
/ >
=>
Llnf
>
^
=>
Z^.
>
Zc:
i
cham phahon u
Cau
80:
/?
= y =
SOVIn
Cau
81: w

=
V^i<^2
=
407r
rad/s
Cau
82:
•
u
l?ch pha
^
so
vai uc
u
cung pha vai
i
mach cong
huong.
Z1Z
VAT lY
12
-
TflM
TAT lY
THUY^T
«A
BAI
TAP
TRAC
WGHIEM

-
TAP
1
CHlfflWS
3: DdNG
DIEN
XOAY
CHlf
D
•
Goi Ctd
la
di?n dung tuong ducmg cua bp
tu C va C.
Khi
mach xay ra cong huong:
100
Zc^^
=Zi
=
Lio
=
lOOn
=>
Qa
= —I^P
•
Ct&>
C = —nF =>C' song song C
Ct&

=
C + C'
=>C'
=
-^F
Cau
83: Thay d6i C dk
UL(max):
mach cong huong
Imax
=^=2A^
U^^rnax)
=
ImaxZi
=
200V
1
Cau
84: Tan so cua rieng cua mach
RLC:
f
=
27tVLC
C
L
Theo de bai ta c6: fo, =
f^^
=>
C,L,
=

C^L^
=>
= -^(1)
Khi
mac noi
tiep
hai
doan mach
vai
nhau:
L=
L1+L2;
C,C,
Xet:
LC =
_C,C,(Li+L,)
c,+c.
(2)
Cau
86:
Cau
87:
Cau
88:
Thay
(1) vao (2) ta dugc: LC
=
LiQ =>
/
= /o

R
=
Zc=-^
=
loon
p
=
R1+R2
U
=
200K!
2,4
Zf
=
R^R2
=>
Z|,
=
240n
=>L
=
=^H
•
P
=
R1+R2
=^U
=
ISOV
Cau

89:
z^
=
Lw
=
son;
Zc
=
-^
=
2oon
R
=
\Z,-Zc\
i2on
,p
= !^ = ^w
CHirifKG
3: DdNG
OIEM XOAY
CHlfU
VATLY IZ-TOMTATLY
THUYf
I
UA
BAI TAP TBAC NGHI£M
-
TAP 1
Cau
90:

•
Zi
=
L(x)
= 40n;
Zc=^ =
loon
•
R +
Ro
=
\Z,-Zc\-^R
= Sm
Cau 91: Zi
=
Lw
=
600; Zr
= — =
lOOH
Cui
R
=
R^o
+
iZL-Zcy
= son
Cau 92: Z^.
= =
20fi

; /? = + Zf = 250
Cau 93:
/? =
|Z,
-
ZcI
Z =
/?V2
C05(p
= j = f
Cau 94: Z^
=
/?i/?2
Zc = 50Q
=^
C = —F
10
1-3
5n
Cau 95:
Zr = — =
lOOH
R
= \Z,-
Zr\ = 300a =^L = -H
n
Cau 96: Z^,
=
Loj
= 20n ;

/?i/?2
= Zl
/?2
= 40n
Cau 97:
/? = ZL
=>
P = = ^ =
25M^
Cau 98: Zf,
=
La>
=
240 ;
/? =
Vr^Tzf
= 400
Cau 99:
/?iP2
= -
•^c)^
=
50000^
-> Cau
A
dung
P
=
=>
/?i +

/?2
= ^
-> Cau
B
dung
Rl+R2>
2yfR^
=
1000
=>
p=i
U2
(;2
R1+R2
~
100
Cau
D
diing
Cau
i 91
1
92
93
94
95
96
97
98
1

99
100
Dap
an
C
C
C
C
C A
B
D
1
C
C
Cau
101
102
103
104
105
106
107
108
109
110
Dap
an
D
A
C

C
C
B
C
A
A
B
Cau
111
112
113
114
115
116
117
118
119
120
Dap
an
D
D
D
B
C
B
B
D
A
C

VAT
lY
1Z
-
TDM TAT
lY
THUYET
VA
BAI TAP THAC HGHIEM
-
TAP
1
CHIiaNG
3: DdNG
DIEN XOAY
CHlEu
Cau
100:
Cach
1:
ui
vuong
pha
U2 =>
Ctancpi).
(tan^z)
=
— 1
•
UAB

lech
pha
—
so
voi
UNB
==>
(tan^^e).
(tancpf^B)
= ~1
2
=
Ul + Ul
-2U,Uc
+ Ul
=
Ui + ul - 2(U^ + Ul) + Ul
.
Ul = ul + ul +
u^
Cach
2:
Dung
gian
do
vecta
• UAS
=
OA:UI^
= AB:

URC
= OB;
Uc
= HE
• AO//B
vuong
tai H:
08^
=
OH^
+ HB^
=>
Ulc = Ul + Ul
•
AAOB
vuong
tai
O:
AB^
=
OA^
+
OB^
Ul
=
U^
+ Ul + Ul
Cau 101:
• Zi,
=

La)
=
400O;Zc=
—=1000
• URL
l?ch
pha
^ so
voi URC
=^
itan^Ri)-
(ta"<PRc)
-
.
£ix^ =
-l=>/?2=Z:,.Zc=»/?
=
200O
R
R
-1
Cau
102:
•
ULC
luon
lech
pha
^ so
voi

i
•
ULC
lech
pha —
so
vdri
u
(theo
de
bai)
6
•
ta
suy ra:
u
l?ch
pha
^ so
voi
i 9 = ^
CHtftfme
3:
DftwG
mtn
XBAY
cmgo
VAT LY
12
- TOM TAT LY

THuygT
vA BAI TAP
TRAC
HEHIEM
- TAP
1
•
cos(p
= —=:>Z = -^ =
100fi^I= —-1,2A
Z coscp Z
Cau 103:
• Ta thdy: o) =
co^
= lOO/r rad/s va o) = = 120n rad/s
thi cuong do dong dien hieu dvmg
Ii
=
I2
=
I
=^
tan so goc
khi xay ra hien tugng cong hixong la (OQ =
yfco^Oil
=
109,Sn rad/s.
• =
IIOTT
rad/s c6 gia tri ghn voi nhdt so vai Wjva

=>/'>/
• Luru y: Bien do dao dpng tang dan khi tan so tien ve gia tri
xay ra cong hucmg.
Cau 105: / = ^ = 60Hz
60
Cau 106: / = ^
=>
n = 600 ^ = 10 vbng/s
' 60 p/liit
Cau 108: ^ = =» /, = 2,25/1
JV2
'1
Cau 109: ^ = i^ = ^=>[/2 = 3601^ = 2A
Ni
U2 h
Cau 119: P = -= lOkW
t
P =
3UpIpC0S(p
=^ Ip = ISA