CHlfflHBSlDdHSnigHllBAYCmgO VAl
H
12
- TJM TAT LY THUYgt VA BAI T^P TRAC HmitU - TAP
1
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

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?
VAT
LY
12
- IIJM
TAI
li IHUYgT WA
BAI TAP
TRAC
WSHlgM -
TAP 1
CHItlfHB
3:
OdHB fllgH XOAY CHlgO
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

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

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.

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?

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.
IT/I
If
AT
lY W - m
TAT

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

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

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.

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

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.

78,1«.
C.
50Q.
D.
148,7Q.
178
DitT
lY
1Z - TOM TAT LY
THUYgl
VA
BAl
TAP
TBAC WGHIEM - TAP 1
CHlfltHB
3:
BflHS
DlEll XjmHjgB
Cau 91: Mot mach dien xoay chiSu khong phan nhanh
gom
cupn
day
(c6
dien
tra
thudn Ro
=
30fi,
dp
tu

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

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

A H.
B H. C H. D H.
7t
71 71 71
177
CHlfmiG3:Bi>H8DlC»HAYCHig|
><T
t»
« -
TtM TAT TWYfT
Mk
lAl
TAP
TBAC
WaneB
-
Iht
1
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.

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

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

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

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

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

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. 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

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.

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

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

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

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

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

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

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

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

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
„ ' ' "

= 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

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

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

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
.
=

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

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^
= - -

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^

<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

•
=
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

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

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

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 =

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^

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

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

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

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

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 =

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

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 + + = +

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
^

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

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

-
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

=
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

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

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
—

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

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
=

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

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 ^ =

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 =

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

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

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-

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
-

'
+ =
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
^
_

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

=
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

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;
^
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)

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

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

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

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

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

=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

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
=

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

-
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^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

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:

; /? = + 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 ;

/?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

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

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:

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

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