THI LÝ L3-2011(ĐÀO DUY TỪ-HN)

Trudng
TF{PT
E€'thi
thr} dai
hoc ldn 3
(ngdy
091a112011)
Dbo
Duy
Tri
tr Ha
Mdn: VAt li'
khdi
A
Ngi
(Thdi
gian
ldm
bdi: 90
phitt,
khdng
kd
thdi
gian
phdt
ill)
Ma d6 thi:
301
Ciu
I'
MOt con

ldc
ld xo dao
ddng didu
hoi,
trong
qu6
trinn
aoo
Aong
vAt
ludn chiu
t6c
dupg
cria
1-rc
k6o vd
c6
bidu
thdc
F
=
- 3cos(5rct
- n/3XN),
vAt
ndng c6 khdi
lu'ong
n
=2O0g.liy
g
=

l0m/s2,
n2
=
lo.Bi€n
d0
dao
d6ng
crja
vAt
lh:
A,
6crn
B. 3cm
C.l2cm
D.
Bcm
C0.u
2- Con
ldc
don c6
chidu
dii
I
=
0,64m, vdt
ndng c6 khdi
lu'ong
rn
=
1009,

dao
dong
di€u
hoi
&
'oi
c6 gia
tdc
trong
trudrrg g
=
l0
(rnls2),
rc2
=
I0. Lfc t
=
0,
cou lac qua vi trf
cdn
biing
v)
dang
chuydn
d6ng
theo
chidu
du'ong
cria
quy

dao v6i
vdn
tdc
1On(crn/s).
Sau 0,2s, ddng
ndng
cfra con
lic
bing:
A.5,5.104J
B.2,5.1OrJ
c.
3,5.10
rJ
D.0,15.10'J
CAu
3.
Hai ngudn phdt
s6ng co
tai
hai didrn A vi B cirng. tdn sd,
cing
bi0n
d6,
cilng pha
ndm
sau
rrong
mdr bd
nu'6c.

X6t hai
didm: didm
M nim
ngo)i
du'bng thing
AB
v)
didrn N ndrn
tGn doan
thing
nn c6
hi€u
khoin!'c6ch
r6i
A
vi
B
bang rndt
sd bdn
nguy€n
ldn bu6c
s6ng,
coi bi€n dd s6ng kh6ng
ddi.
Chon
d6p 6ir
dring
A.
Phdn trinu6c ivM
dao dOng,

&N dfing
ydn.
B. Phdn tft
nu6c
&N
dao dong,
oM
dfrrg y6n.
C.
C6c phAntftnudc
6M vi
&N
d€u dfng
y€n.
D. C6c phdn
tri'nu6cdMvn
&N
ddu
daJd'61g.
CAu
4. Doan mach
xoay chidu
AB rnic
ndi tidp theo thri
tu
gdm
rndt di€n
trcy
thuCn
R

=
30O,
mor tu
di€1 c6
di€n
dung
bidn Adi vi
m6t cudn
dAy
khdng thudn cirn
c6 116 tu
ciirn
L.
Di€n np
E
2 dAu
mach c6
'bidu
thric
ld:
u
=
120
J2
cosl00nt
(V).
M li didm
ndi gilfa
di6n tr& vh tu diOn.
Khi

tu di€n
c6
di€n
dung C
=
U03l4n)F
th)
dien
6p
hi0u
dung
hai ddu doan
rnach
MB dat
gi6
tri
nh6 nhdt l)
ljva
=
60 V.
Khi d6
di€n
6p
hi€u dung
hai ddu
cuOn
dAy bf,ng
A.6oJzv
B.9o v
c.

loo v
D. too
"fl
v
CAu
5.
Trong
[?ch
dao d6ng
di€n
td' li tudrg, bidu
thfrc
cria
dbng
di6n
tror-rg
mach
li i
=
Scosot (rnA).
Trong rlibi
gian
ls c6 5.10s
ldn d616lr
cira cudng
dO
dbng di0n dat ctrc dai.
Khi cu'dng
ao
a;ng

di6n rrong
mach bing
4mA
thi
di€n
tich cfra tu
di€n bing:
A. 23,9.10.?C
8.477,5prC
c.0,95.10ec
D.
1,9lnC
CAu
6.
MOt tia
s6ng d6
c6 tAr-r
sd
f
=
4,2.l0toHz chidu
til chdn
kh6ng
v)o
m6r
loai thuy
tinh
c6 chidt
sudt
tt

=
1,52 ddi vdi
tia s6ng
d6.
Van
tdc cria hrrh
sdug ttong chAn
khOng
li
3.108m/s.
Budc
s6ng
cria 6ph
szing
d6
& tr€ir
trorrg
thuy tinh
li:
4.0,47 ptn
B.
0,54pun
C. 0,66pm
D.
l,O9prn
Clu
7. Mdt
nguyOn
tft hay phAn
tri'c5 thd ph6t

ra bao
nhi6u loai luong
trt
ning
luong?
A.
Mdt loai .
B. Hai
lo.i.
c. Ba lozri.
D.
Nhidu loai.
C1u 8,
M6t dng
Rorighen
ph6t
ra tia^X
c5 budc
s6ng nh6
rrhdt li 0,5
nm.
L.{y
hang
sd Pling
h
=
6,625.10-3aJs:
viip
rdc
ilrrth

siing
trong chAn
khOng
c
=
3.108rn/s.
Ndu ting
hi€u di€n th€ giira
andt
vi
cat6t
th6m
SkV thi
tia X phdt
ra c6
tdn
sd
l6n nh0t
bang:
A. 8,15.Ia1'Hz
B. 2,53.10rsH2
C. 5,24.10r8H2
D. 0,95.
lTteHz
Cliu
9. Chon ddp hn
dfng vd
s6ng
dr)rrg tr6r-r
m6t dAy din

h6i:
A.
Nhfrrrg didm
tr6n dAy
dao
ddng cing pha v6i
nhau
thi
c6ch
nhau
nrdt
sd nguy€n
ldn
btr6c s6ng.
B.
Nhirng.didm
tr0n dity
rrfun trong
khoing
giua
hai bung kd tidp
thi
dao
ddng cing pna.
C.
Hai didm
pung c6ch
uhau
mOt
sd 16 lAn nfr:r bu6c s6ng

thi clio
dong
ngug" phal
^
D.
Nhfrrrg didrn
tr€n d{iy
chch
uhau
m6t rndt phdn tu
bu'6c s6ng
th) aao
aOng
nguo.
"
pha v6i
nhau.
CAu 10,
MOt
vat
thuc
hi€n ddng
thdi
hai dao ddng didu
hoi.
cing
phuong,
ciurg
tdn
sd t'

=
5
Hz, c6 gia
tdc cuc
dai
bing
10^6
Inls2.
Bien d0
dao
ddng
thrl nhdt l) I crn, dO
l6ch
pha
cia
hai dao
ddng
li nl3. L{y
nz
=
10. Biel
cl6 cira
dao
dOng
thf hai
bing
A. I cur
CALI
ll.
M6t ngudn

s6ng
co
O c6 phuotrg
tr-inh: u
=
4cos(100rut)(rnm)
truydu
doc theo
tluc
Ox
v6i
tdc
d6 2Ornls
;
trong d6 t
lA thdi gian
du-o.
c
tinh biurg giay(s).
Li dd
cfra didm
c6
toa d0
x
=
25 rn
sau 0,2s kd til
khi
ngudp bit ddu
dao dOng

bfurg:
A.2Jimn
8.0
C ZJimm
D 4mm
Ciu 12.
Didu
niio sau
dAy
l)
sai khi n6i vd ddng co
kh6ng ddng
b6
ba
pha?
A. DOng
co
kh6ng
ddng
bd ba
pha
bidn
diOn
niurg
thinh co
ning.
B.
Ddng co
khdng
ddng

b0
ba
pha
hoat
dOng
dua
tr€n
nguy6n
tic hoat ddng
cria ddng
co
kh6ng ddng
b6.
C. Ddng
co
khdng
ddng
bd ba
pha
sri'dung til tru'bng
quay
cfra
narn cham vinh
ciru.
D.
Trong ddng
co
khdng
ddng b6 ba
pha

tdc dO quay
cfra
rOto
lu6n rrh6
hon t&
clQ
quay
cfia tD'trubng.
B.
2
crn
C. 3 crn
D.
4 crn
\ /
Mr,1
t> ,-'
l,
,tzv,
/l'-r^-r'c4,-_
I
CAu 13. Mach
dao d6ng
c6 thd bidr]
ddi trong
giii
tdn sd
ti' l0
MHz
ddn 160 MHz

bdng
c6ch thay ddi khoing
ct'rch
gifa
hai bin
tu didi
pli&ng. V6i giAi
tdn n)y
thi
khoing
c6ch gifia c6c bin tu thay
ddi
A. 4 ldn
B.
l6ldn
C. 160 ldn
D. 256lArr
CAu
14. Trong
thi nghi€m
giao
thoa 6nh
si{ng
cfra YAng,
khoAng
c6ch giiizr
2 khe
sdng l) 2mm,
khoAng cich
ti'2 khe

ddl
rnin Ii
lrn. Khi
chiOu
s6ng khe
F
6nh s6ng
dotr
sic
dorr sic
c6
bu6c s6ng
l"' thi khoing
vdn do duo.c bdng
0,2rnm,
khi
chi€u
sdng khe
F
6nh
s6ng
dorr s6c
c6
bu6c
s6ng L,
> X, thi tai
vAn s6ng bAc ba
cua {r"rh siing c6
bu6c
s6ng ),, c6

vAn
sSng
cfra
6nh sdng
c6 budc s6ng
l-r. Bu6c
s6ng
1", bang:
A.0,45pm
8.
O,Strun
C.0,6pm
D.0,64prt
Cdu 15.
Tropg
dao
d6ng
didu
hoi
cfia con l6c
don, s6
dao
ddng
tl-ruc hiOn drrqc
trong 1
giiry s6
A. tang,-khi
con16!
chuydn
dOng

nhanh
ddn
dt)u di
l€n
theo
phu'ong thing dfnrg.
B.
gi6rn,
khi
con lic
chuydn
d0ng
chflm
ddn
ddu theo
phuorrg ngang.
C.
g-iim,
k|i
cor-r lic
ctruydn
dQng
cham
ddn dtju
di xuong
theo
phuong
thing dfurg.
D. talng, khi
con lhc

chuydn
ddng
ddu
theo phuong
ngang.
CAu i6. Mdt
doan mach
gdm m6t
dien
tr& R,
indt
cu6n
cAm
thudn v) mot
tu di€n mic
ndi tidp.
Di€n 6p
dAt
vho
hai
diiu
doan
mach
c6
bidu
thuc:
u
=
U
Jicos2nft(V),

tiin sO
f
thay ddi clu-o.
c.
Khi
tdn so f
=
fr thi
dung
khdng
blng
500,
cArn kh6lg
bang 200O.
Khi f
=
fz=
4oHzthi
di€n
rip hi€u
dung hai ddu
di0n tro R
dat
gi6
tri
cuc dai. tdn
sd f, bang
A.\OHI
B.40Hz
C'

60Hz
D- 80Hz
Ciu 17. Khi
s6ng Arn
truydn trong
m6t mdi
trudr-rg
thi:
A. Bi6n
d0 s6ng
tai rnOt
didrn
phu thu0c
vio
tdn sd
s6rrg.
B. T6c
dd s6ng
truydn s6rlg
phu thu0c
vio tdn
sd s6ng.
C. Bu6c
s6ng khdng
phu thuOc
vlo tdn
sd s6ng.
D. Chu
ki s6r-rg
v) tdc

dO truydn s6ng
ti l€
nghich
v6i nhau-
CAu
18. Mdt
con lic
ld xo
dao ddng
didu l-ro)
c6
khdi
lu'ong m
Ldy n2
=
10. Tdc
dd trung
binh
cfra vAt trong
mOt
chu
ki
bing:
A. 40
cm/s
8.45
crn/s
C.
50
cm/s

-
2009,
co nf,ng
cira cor-r iac
W
=
0,04J.
D.
60 cm/s
CAu 19. Mdt
duong
day
tii dien c6
di6n tr6
tdng
c6ng
lh
100, cdng
sudt ndi truyen
di l)
40 kW,
cOng sudt hao
phi
rr€ndAyld2560W,he-sdcongsudtcriamachbing
1.DdgiimcdngsuAthaophitrendaychicbn257ohao
phiban
diu thi
cliOn 6p hi€u
dung noi
truydn

diphii
ting
thOrn
bao nhi6u?
Ctu
25. Su
ph6t s6ng
cfrar
vAt
niro du6i
dfly
khdng
phii l) su
plr6t quang?
A,
Con
dorn d6m. B. Ddn
LED.
C. B6ng
dbn
dng.
D. Hd
quang'
A. 4000 v
B, 2500 V
c. 2000
v D.
1500
V
Cdu 20.

Chon
ddp 5n sai
vd s6ng
dien til:
A.
Mot di€n tich
didm dao
ddng didu
hoh
bLic xa
ra
s6ug diOn tit.
B.
Tai m6r
didrn bAt ki
tr€n
phuong truydn
s6ng,
vectd
cu'bng dd diOn
tru'brrg
E
vh
vecto ciirn ri'ng tl'
F
adu Uidn
thiOn
tudn
hohn
vi vudng

pha vdi nhau.
C. S6ng
di€n
tit c6 mang
theo niurg lucrrtg.
D. Khi
s6ng di€n
til truydn
tir chAn kh6ng
viro mdi
tru'dng
thi buoc s6ng
giim.
C1u
21. Trong
nguyen
ti'hidr6,
c6c
qui dao
ding
K, L,
M, N c6 ndng
luong
tuong
ri'ng 1I Er
=
-13,6eV,
Er=
-3,4eV, n,
=

-i,S"V, EN
=
-0,84eV.
Lt'y
hirng
sd Plang
h
=
6,625.10-3'Js;
vAu tdc
6nh sdug
trong
chAn khdng
"
"=
g.
ib*,r/r.
Kiii nguycn
ttr'
ciiuydn
til trang
ifrai
aU-tg
c6
ndng luong E*
vd
trang
thdi
co
brin

thi
vach
quaug phd
c6
tdn
sd l6n nhdt
thuOi
ving nh)n
thdy
do nguyOn
ttr c6
thd
phdt ra bang:
A.3,08.10rsH2
-
B 2,9.10r'Az
c.6,l8.l0r4Hz
D.2,tl8.10r4Hz
Ci1u 22.
M6t
con 16c lb xo
c6 d0
cfng k,
vat
niurg
c6 khdi
luo. ng m
thi chu kl
dao
d6ng didu ho)r

li T.
Cit ld xo k\rn
hai
phdl bipg
phau
rdi
gh6p
song
song
v6i
nhau
vir treo
v0t
c6
khdi luong
m'
tl-ri chu ki
dao ddng
vAn
li T.
Kdt luAn
nlo
sau
day li dring?
A. tni
=
2m.
B.
n'
=m12.

C.
m'= 4m.
D'
rn'
=
tn/4
C.lu 23.
Khi chieu
tia si'urg
phric t4p
gdrn hai
thinh
phAn
vdng
vi
chim
ti'troug urr6c
chdch rn6t
g6c t6i mIt
phiin cfch
gifra
nu6c
vi
khOng
khi thi
A.
goc
hqp b&i
tia khfrc xa
rnhu

vhng v)r rnf,t
phAn
cdch l6n
horr
g&
hSp b&i
tia khfrc xa
rniu
chi\m
vI
miit
phAn
c{ch-
B.
g6c
khfrc
xit cira
tia mi\g chl6
nh6
hol
g6c
khric
xa
crta tia miu
vhng.
C. cfuc
g6c
khric
x4
cria tia rniu chi\m

v)
cila
tia tnhu
ving nh6 horr
g6c t6i.
D.
tia khr.ic xa
li tia sfirg
cilng rniu
vdi tia
tdi.
CM 24. M6t
cor-r
l6c lb
^otit
tign m6t
n-r[t
s]ur
nilm
ngarg.
Ld
xo
c6 d0
citrg k
=
25 NAn,
khdi
luong
cria
vdt

m
=
50
gou.,, trg sd ma
s6t
gifia vdt
vi
rrdt
sln
li
0,02.
Ldy
g= 10 rnls2. Dua
vit
ddn vi tri ld
xo n6n B
crn r-di budng
nhe,
vdt
dao iOng
tiiddn chtrn
Joc theo
truc lE xo.
Sd
chu ki mh
vat thue
hiOn
du'oc
cldn khi dirng
hin bnng

A.40
8.50
c.80
D. 100
Cttt
26'
Diy
dln
hdi AB c6
ddu
B cd
dinh, ddu
A
clao
ddng
didu
hoi
v6i
bi€n
d6
6rnrn,
rr€n
diy
c6
s6'g
dii:rg.
Tai
didm
tr€n
dAy

c6ch
rndr bung
bane
llt2lbn
bu6c s6ng thi aai
aong
"Jl
frie,,
AOll*g,'""'
A.3.,6rnni
B.6{imm
C.6JJmm
D.6mm
Cdu
27
-
Didu
nio sau
day
li sai
khi
n6i vd
nguyOn
tic hoat.ddng
cria
c6c
loai
m6y phdt
di€n
xoay

chidu?
A.
Nguy€n
tic
hoat dOng
cfra
m6y phrit
dien.xoay
chidu
ldlua
tr€n
hier-r
tuoni
c{rn
tnrg
dien
tn.
B-
Khi tD
thdng
qua
not
vbng
ddy
bidn
thi€n
ddu
thi trong
vbng
dayxudt

hidn
moisudt
dieridong
cirn
drrg
xoay chid'.
C-
Khi cho
cdc
vdng
day
quay
trong
til'trudrrg
cd dinh thi
;6
rhd
rao
ra suat
di€n
d6ng
xoa|
chidu.
o
'"'r
'
D'
Khi cho
til'tr-udng
quay,

cdc vbng
day
cd
dinh thi c6 thd
tao
r-a
sudr
di6n
ddng
xoa!
"hi6u.
9ll zs
Trong
rndt
mOi trudng
c6
s6ng trn.
truydn
di vdi
tdc
d0 u
=
:4omlr."rdn
.rd
am
ndrn
rrong
khoing
350H2
< f <

450H2.
Khoing
crich gifia
hai didm
tien cing phuotrg
iruydn
am
dao
d6ng
pguo.c
pha
vdi
nhau
lI
2nr.
Khozing
cdch gAn
nhau nhdt
trOn
cing phuoqg
truydn
c6 dao
hong
am
vuong
pha
v6i
nhau
b[lg:
A.

1 m
8.0,4
m
C. 0,2jm
D.0,2
m
Cdu29.
Dat vio
hai
ddu doan
rnach
mdt dign
6p
xoay chidu:
uou
=
IJocos(l00nt
+
xl6)
(V).
Tropg
khoing
thdi gian
ti'0,003s
ddn
0,00tls
kd'tD'thbi
didin
ban adu,
aien

6p gifra
hai
ddu
doan
mach
clar gid
tri
u
=
-tJo/2
vfro
thdi
didrn:
A. 0,004s
B. 0,005s
C. 0,006s
D.
0,007s
CAu 30.
Trong
mach
dao
ddng
didn
ti',
n6u tiurg sd vdng
dAy cfia
cuon
crirn
thi :

A.
Tdn s6
dao
d6ng
cria
rnach
tdng.
B
.
TAn sd
dao
d6ng
c&a
rnach giirn.
C.
Tdn
sd dao
dd.ng
cfra
rnach
khdng ddi.
_
D
Kh6ng
ttrd
ket
ludn
vd
srr thay
ddicfra

tdn
sd clao
d6. ng.
CAu
3l:.Mqt
m6y
bidn 6ph4
6p
c6
ti
sd
vdng
day_cuon
so ct'p
v)
thrl
cdp
lh
10. Cu6n
so cdp
rnic vio
lgudn
di€'
xoay chidu
c6
hiOu
diOn
thd
hi0u
dung

U
=
1 BOV.
il6 quu
dien tid
thuAn
cria
cudn
so
.ef,
aien
ir
& thuri'
cta
cud'
rhrl
cdp
li
r
=
l,5f).
Hai ddu
cudn
thf
cdp
ndi v6i
mot di6n rrd
thudn
R
=

6f:.
Cu'dng
do
hieu dung
cfra
cid'g
di€n
tro'g
cudn
thit
ciip
bang:
A.
l,8A
B.2A
C.2,4A
D.2,8A
Ciu32-
Ding
einh
sdng^mit
trdi
chidu
vlo
cdc
loai vAt
lieu
sau:
tdrn
96,

chat
bdn
aau,
"ie,-r
gach,
ti'm
kirn
lorii.
Hi€n
tuong
quang
di6n
c6
thd
xiy
ra
6
_
A.
mQt
loai vdt
li6u.
B.
hai
loai vat
lieu.
C. ba
loai
var
lieu.

D. bdn
loai vat
li€u.
CAu
33.
Trong
thf
nghiem
giao
rhoa
dnh
.sdng
cfra
Y ang,
khoing
"a}r
gi",
z
khe s6ngffi;#,;;'illlng
c6cli
til 2
klre d0rr
min
l)
1,8rn.
chidu
s6'g
ddng
thdi
hai

bdc xa do'sfc
c6
bu6c
s6ng
?",
=
O,l4lrm
v)r
1",
=
0,7zpm Itong
kholrng
rdng
L
=
2an
tr€n
milt,
rnr chinh
gifra
li
vArr
sdng trung
tam,
sd viu
sirng
",i,i
hai
br-icxa
kh6ng

c6
miu
gidng
miu cfra
vAn
trung
tArn
biurg:
4.20
8.23
c.2s
D. 30
cA'
34.
Bi€r phdq
ni.o
sau
day
kh6ng g6p
phdn
rirng
rri€u
sut'r
cfra
rn6y
bien
irp:
A.
Dr)ng
l5i

sit c6
di€n
rr&
suit
nh6.
B.
Dilng
dAy
c6
diQn
rro
sudt
nh6
lim dAy qut'n
m6y bien
6p
.
C.
Ddng
l6i
s6t
gdm
nhidu
ld sdr
m6ng gh6p
cich
dlen
vdi
irhau.
D. Dit

cdc
lh
sirt
cfra
l,5i
sit song
song v6i
mirt phirng
chri.a
c6c
dudng
sfc ti
Cxu
35.
Mdt dao
ddng
didu
hoi,
vxt
di qua
vi tri
can
bang vdi
vdn
tdc
lorc(cmls).
Khi vAp
rdc
cira vdr
c6 d6

l6n
li
sn
Ji
(cmls)
thi
gia
tdc
cria
n6 c6
dd
l6n
li I
(rnls2
).
L{y n2
=
10.
Chu
ki
dao
d6ng
cria v1r
biurg:
A. 0,12-5s
B.
0,25s
C.
0,5s
D.

ls
CAu
36.
Chon
dhp
t'ur
sai
trong
cdc
cXu
san:
4
C1o
chdt
quarg
dAIr,
khi
c6 hnh
sdng
thich
hop chidu vi\o
rh)
dd1di€p
tdt.
B'
Mudn gny
dud.9
hi6n
tu'ong
quang

di6n trong
thi
6nh
sdng
kicir
thfch
phii
c6
bu6c
s6ng
nh6
hcnr gi6i
1ia'
quang
dAn
crizr
chdt quang
d6r-r.
q
G-i6i
hau
quang
dan
cua
cdc
chit quang
din
uh6
hon
gi6i

han quang
di6n
cria
c6c
kirn
loai.
D
Quang
di€n
trd vi
pin
quang
di€n
hoat ddng
du'a trerihien
tLrclrg
quang
di€p
tropg.
CAU 37'
Mot doarr
mach gdm
nrot
di€n
trdR
m.{c noi tldp
v6i
rnot
"uoir
"rim."oii

vr\o
hii
ddu doan
rnach
rn6t
di6'
dp
xoiryclridu:u=lJtficos(l00nt)V,khicl6di€n
6ptfrcthdihai
dducudnciml€chphaT5osc.rdridi€.6ptfic
thdi
hai
dAu
didn
tro.
C.':rc
di€n
6p
hiOu dung
hai ddu
rli€n
tr&
R vi
hai
ddu cu6n
ciirn
ldr-r
luot
li
-sO

rD
V
vri
100V.
H0
sd c6ng
sr"rlit
crla
rnach
bing
D.
112
A.0,965
s.
,lt
n
c.
Jin
N, ,/
n-/
n f,
c
-
Vn-rt
4'-(L
fl
>l
CAu
38.
Trong thi

nghi€rn vd giao
thoa s6ng
trOn mit
nu6c, hai
ngudn
kdt hop
A vi
B dao d6ng
ctng pha
v6i
tAn
s6 5OHz.
Didm
M nltn trOn
doan
AB
c6ch trung didm O
cria
AB li\
3crn, ihuoc
van cuc
rid;thll
i.
fO"
Oo
CAu 39.
Mach dao d6ng gdm
cuOn
dAy c6 dO tu cim L, tu diOn
c6 di€n

dung
C
vi
di6n
tro
thudn
R. Io vi\
I li
gi6
tLi
cuc
dai vd gi6
tri hi6u dung
cria
cubng
d0
dbng di€n trong
mach, Uo vi
U
lI
gi6
tri cuc dai vi girir
rri
hi€u
dung cria
.
hi6u di€n
thd hai bAn tu.
Tirn d6p
5n

sai
vd
cOng
thrlc tfnh c6ng
suat
toi nhiOt
tror-rg
rnach:
A.
P= CRU'z/L
B.
P= LRUO2I(}C). C. P=
RIO2/2
D. P
=
RC'U2ro2
CAu
40. Khi
lfir
luot chidu
6nh
sdng don sic c6 bu6c s6ng 0,2pLm vi
0,25pLrn vio
rndt
mdt tAm
kirn loai
thi €lectron
quang
di€n c6
c6c ddng udng ban

ddu cuc dai
hon
k6m nhau 1,5
ldn. Gi6i han quang
di€n
cfra
kim loai la\
A.0,5
pun
8.0,33
pLn
C.0,14
pLm
D.0,11
prm
CAu
41. Mdt vAt dao
dOng
didu
hoi vdi bi6n dq
A
=
10
crn.
Tai thdi didm
t
=
0 v4t c6li
d6 lir
6

crn
vi dang
di theo
chi€u du'orrg
cfra truc
Ox.
Quing
dudrg vAt di du-d. c trong thdi
gian
ll4 chu
ki
kd
tD'
t
=
0 birng
A. 6 cnl
B.8cm
C. 10 cm
D. 14 crn
Cdu
42. Chon dip
6n sai
vd
thuydt
luong trt iinh siing
A. ClrDrn
iinh siing
lh
clrirn

cdc phOtOn .
B.
M6i
phdtOn
mang ndng
luoug x6c dinh e
=
hf
(f
h t6'n sd cria
s6ng 6nh sdng
don s6c tuong
frrg)
C.
C6c
ph6t6n
bay v6i
tdc dd c
=
3.108
rnls
doc theo tia s6ng.
D.
M6i
l{ln rnQt nguyOn
tfr'hay
phdn
tir'
ph6t
xa hay hap

thu
6nh
s6ng thi chring ph6t
ra hay hap thu ph6t6n.
Cltu
43.
Khi truydn thdrlg qua
v0
tinh, tdn sd cfra s6ng thuOc diip
dn nho?
A.2,5.105H2
B.3,5.l03KHz C.42,5.104
kHz
D.4.1014H2
Cdu 44.
Dirt
vlo
hai ddu
doan
mach ndi tidp
gdrn
rn6t bidn
tr&
R,
mdt cuOn
cirn thuAn
c6 cim
khiing ld
Zrvit m6t tu
di€n c6

dung khdng
Z" mQt diOn
6p xoay chidu c6 di€n 6p hi€u dung
U. Khi thay
dtii
gi6
tri
cria bidn trcr
R
blng
R, vI
bing R, thi cOng
sudt ti€u thu diOn
cfra doan mzrch ddu bang P;
khi R
=
Ro thi cdng
sudt ti€u thu
dien cfra
doan
mach
dat cuc d+i
P*"^. Bidu
thric niLo sau diy
li sai?
A.
RrR2
=
(ZL-Z)z
B. R'+ Rz

=
U2lP C. Ro
=
JR&
D. RlR2
=
f]tpn,"*
CAu 45.
MOt ngudr-r
s6ng
co
c6 phu'ong
trinh uo
=
6cos20nt(cm),
t6c dd truydn
s6ng
lh 80cm/s.
Tai thdi
didrn t
li d6
.
s6ng tai
A l) 3cm vi vAn
tdc dao
ddng c6 d0 lm dang tdng,
khi
d6
rnOt phAn
t&

s6ng tai
B
cdch
A lb 2crn
c6
li d6
A.3."6crn
B.
-3
J3
crn c.3
",,11
cm
D. 4 Ji ctn
Ciu 46.
MOt
doa^n
mach
xoay chidu
gdm
rndt
cudn
dAy kh6ng thuAn
cim vi
rndt tr-r di6n
C, hi6u diOn
the
hai ddu cu6n
diy
l0ch

pha
900 so v6i hi0u
di€n the hai ddu doan
rnach. Ndu
giim
diOn dung
cira tu
di€n thi hi€u
di€n thd
hieu dung
hai ddu
cudn dAy
thay ddi the
nio?
truydn
s5ng tr0n
rnit
nu6c lh:
A. 30crn/s
B.
60crn/s
A.
Tf,ng.
C.
Ban ddu tf,ng,
sau d6
giim.
A. di6n 5p cfra
tu di6n biurg
khdng.

C. di€n
tich crla
mdt bin tu di€n
dat cuc dai.
A.u"
-
100\tD cos(lOOrut
+ nl6)Y
C.u.
-
100J3
cos(l00nt
+
nl3)Y
C.
90cm/s
D.
l2Ocmls
B. Giirn.
D.
Ban ddu
giim,
sau d6 ting.
B. di€n
6p cira tu
di6n dat cuc
dai.
D.
plra
ban

ddu cria
dbng di€nld
rc12.
B. u"
=
200\fzcos(100rut
+
nl4)Y
D. u"
=
200cos(100nt
+
2nl3)Y
Cdu41. Corll6cdondaod6ngtainoic5g=
l0rn/s2vdibi€ndOg6cnh6liO,lrad.Khiquavirr-icdnbirng,c6vAn
tdc 50cm/s.
Chidu dii
dAy treo bing
A.2m
B.2,5rn C. 1,5m
D, 1rn
Cdu
48. MOt mach dao
d6ng di€n ti'tu
do LC, khi cu'drg d6
dbng
di€n
trong
mach dat
cuc dai th)

Ciu 49.
Mdt
doan
rnach
AB
gdm
mOt
cu6n
dliy
vi
rn6t tu di€n rnic
ndi tiep.
Dat vz\o
hai ddu doan
rnach
m6t di€n dp
xoay
chidu
uas
=
100"l2cos(100nt +
nlL)Y thi di€n irp gilra
hai ddu
cuon .lAy
c6
bidu thrhc
n
=
1
00

J-
sin(
I 00n t + 4nl3)Y
. Bidu
thfrc di6n iry
gifr'a
hai biin tu di6n
li
CAu 50.
Chon d6p 6n
sai
vd quang
phd
phdt
xa
A.
Quang
phd cria
6.nh
s6ng do c6c chat
rin, l6ng, khi khi
bi ntrng
n6ng d&r
nhi€t dO
cao ph/rr
ra li\ quang phd
phiit
xa cria chring.
B.
Quang

phd
phft
x4
gtirn
quang
phd Ien tuc
v)
qlrang phd
vach.
C.
Quang
phd
vach do chAt
khi 6 dp sudt
thlip phdt
ra, khi bi
kich thich
bdng nhiet
hay bing
dien.
D.
Quang
phd
tien tuc
li dii
rniu li€n
tuc til d6 ddr.r
tfin &
moi nhi6t dd.
I{UONG

nAro
cIAr
pi
rHr
rHr}lAn
3
(ngiy
}stlttzlrr)
Ma dd
301
CAu
1. Dd crilg
k
=
mor2
=
0,2.(5n)2
=
50N/m.
Lrrc
k6o vd
F
=
-kx+
-
3cos(5nt
x
=
0,06cos(5nt
-

n/3)
m
-+
A
=
6cm
-+
Chon A
Cdu
2. tdn
sd
g5c
or
=
,[g
I t
=
Jlu
0,64
=
m/0,8
(radls).
T4i t
=
0 var
& didm
N 11€n
vbng
rrdn
Siru0,2s g6c

quay
o,
=
crlt
=rrl4 ,
vt
&M
c6li d6
xr=
AlJi
-+
v
=
u".n*f
J2= l}n/Ji
cm/s
-+
D0ng
rrdng Wo
=
n/12
=
0,1.(
O,h/Ji
f
p=2,5.10iJ->
Chon
B
CAu
3. S6ng

cotruy€n
trong
nudc
ld
s6ng dgc
*+
phuotrg dao
d6ng
tring
v6i
phuong
truydl
s6ng
*+
tr€'
dudng
'di
hai
ngudn thi
hai
s5ng c6 cing
phuong
dao ddng
-+
N thoi
rnln
didu
ki0rr
s6ng
kdt

hoD,
cdn
didrn
M, hai
s6ng til
hai ngudn
truydn
ddn
c5
phuotrg
dao ddng
AM vi
BM
khdc
nhal
elz[
Ar r
sB
N
*+.
kh6ng
thoA
rndn didu
ki€n s6ng
kdt hop
n€n khdng c6
giao
thoa
tai
M

-+
N c6
hi€u
khoing
cichtli
A
v)
B beurg
rndt
sd b6n
nguy€n
lAr-r budc s6ng
-+
N dao
d6ng v6i
bi€p
dQ cgc
tidu,
n6 drirrg y€n
cdn
M thi
dao d6ng
+
Chon
A
Cau
4. C6 thd
d€
ding chrirrg
minh

khi
di€n dung
C thay ddi
rn} Un,
dat gi6
td
nh6 nhdt
thi
mfihi6iqng
hudng
*>
Zt=Zc=
40f); {Jru=
I."*r=
60V,
ln}I,,,"*
=U/(R
+r)-+
6Ah=
n0K30
+
0+
r
=
30O -+
tdpg trdcriacu6n
day
t
2,,,=
.rl

r' +
Z;
=
50f);
I,,,"*
=
U/(R +
r)
=
12916A
=2A,+
Di€n 6p
hi€u dung
hai ddu
cu6p
dAy {J"a
=
I,."*
Z"o
=
2.50
=
100 V-+
Chon
C
Cliu 5.
KhoAng
thdi gian gifa
hai
ldn cu'dtrg

d6 dbng
diOn c6 dd
ldn
dat cuc
dai
li l/2 chu
ki
->
5.l}sTl}=
ls
-)
chu
ki dbng
di€n
li
T
=
4.10'6s -+
o)
=
2rcff
=
5.lOsrc(rad/s) -+
di0n tich
crc
dai
crja
tu clien
go
=

Ilco
=
5.10r/(5.10'n)
=
1O€/?r(C).
6p dung
cOng
thr.'rc
(i[J'
+
(q/qJ'=
1; thay
i= 4mA,t
=
5rnA, go
=
10
8/n(C)
-
q
=
1,91(pC)
->
Cthon
D.
Cdu
6. Budc
s6ng
cfra 6nh
sdng

d6 trong
chAn
khOng Lo
=
clf
=
3.1031(4,2.1014)
=
0,714.10{m
*>
Bu6c
s6ng
cria dnh
slmg
d6 trong
thuf
rinh
l"
=
}"oln
=
A,714.10611,52
=
0,47(pm)
-+ Chon
A
Cdu 7
- Nguy€n
til
hay

phAn
tri c6
thd phr{t
ra nhidu
loai phdton
tric
I) c6
thd ph6t
ra
nhidu
loai luong
rfi'
nirng lu_o.
ng
-+
Chon
D.
CAuS.Tac6hc/}".,in=eUer(1);
ht,,"-=e(Uer<+8000) (2).L{y(2)-(l)=hf.,"^-ltc/",,,,,,=8000e.Thayh,cvif,n,i,,
I f,,"*
=
2,53.1018H2
-)
Chon
B.
Cdu
9. Khi c6
s6ng
dirng
tr€n

mdt
dAy din
hdi
- Nhflrrg
didrn tr0n
dAy
nirn gifra
hai
nLit kd tidp dao
ddng cing pha
v6i
nhau-+
A sai vz\
B sai
-
Nhirng
didm
tr'6n
dAy
narn &
hai b€n
cfra
rn6t nfrt thi dao
d6ng
ngudc pha v6i
nhau-+
D sai.
-
Hai didm
bung

cdch
nhau
)"12:
3Xl2;
5)"121 lttic
1) crich nhau
mOt
sd
16 ldn
nria
bu6c
s61g t6)
dao d6pg
rgrr y. c pha-+
Chon
C.
Cdu
10.
Tac6 a,,,",
=
cD2A
*)
A
=
a',",/cD'=
tOr,5/(tOru)'=0,01
n6,r
=
1/J.,n.
Lai c6

A,
=
A,t+Ar2
+ 2A,Arcosq;
thayA=
"u5",r,Ar =
lcrn,
e=nl3taduocAz=
lcm+Cho1
A.
Cdu
I 1. Sau thdi gian
0,2s th)
s6ng
truydn
tii'ngudn di
du'oc rn6t quing
du'dng
s
=
vt
=
20.0,2=
4rn; t+i
didrn
c6 toa
d0
x
=
25m

s6ng
chua truydn
ddn, didnr
n)y v5r-r
dritrg yOn
chua dao
d6ng
-+
li d6
dao d6ng
uu
=
0
-)
Chon
B.
Cdu
12. DOng
cd khdng
ddng
b6 ba pha
st dung
tit trLldtrg quay
cfra
ddng
di€n
xoay chi€u
ba
pl-ra
chfr

k60'g
sri
dung
tt trudng
cria
nam chArn
vJnh
criu
->
C
sai
-+
Chon
C.
CAu
13.
Tdrr s6 cria
rnach
dao
dOng
f
=
ll{ZnJ
LC
)+
f thay cldi
16 llin
thi
C
phii

thay
ddi
162
=
Z56lAn-+
khoii'g
cltch
gifra
hai
bin tu phang
thay
ddi
256
lAn
-+
Chorr
D.
CAu14.Tac6i,
=XtDla)1",
=i1
afD=0,2.10r.2.10-3ll=0,4(!Lrn).Theobi\ira3i,
=krir_>31",
=kr)"r_>
)"r=3X1k2=
1,2lkr(pn'r);
lai c6l,
>
l,
-+
1,21k2>

0,4
->
k,
<
3
-)
k,
=
l;Z-V6i
kz
=
1
-+
)"r= l,Z(pyrt):
loai vi
tlrudc vilug
hdng
r"rgoai;
vdi
k,
=
2
-+
),r=
0,6(Lim)
->
Chop
C.
Cdu
1.5.

Ttong dao
ddng ditiu
hoi cila
con
l6c
don,
sd dao dQng
tirirc
hion
cluo.c
trong
I
giay
li tdn
so dao d6'g.
Khi
con
l6c chuydn
ddng
nhanh
din
ddu
cli l€n theo phuong
thing dfrrg
thi gia
tdc tiong tru'Ong
bidu
kidn
g'= g
*

a
>
g
-)
chu
ki
T'
<
T
-+
f'
>
f
-+
tAn
sd dao
d6ng ting
->
Chon
A.
- khi con
lirc chuydn
ddng
chtrn
ddn ddu
theo
phuong
ngang rhi
g'
-

^l
s'
*
a'
> g-+
f'
>
f
*+
B
sai.
- khi
con
lfc
chuydn
ddng
chAm
ddn dtiu di xr-rdng
theo phuong
tlrfrng
dfrrg gidng
nhu con
l6c chuydr-r
d6ng
nhanh
dAn ddu
di l€n theo
phuong
thing
dd'ng -+ f tiurg -+

C sai.
V.(,p1";-
- khi con lac chuydn
d6ng ddu theo
phuong ngang
thi tdn sd dao ddng khdng ddi bang tdn
s6 dao dong
khi
con
l5c
treo 6
rnot
vi tri
nhAt dinh
->
D sai.
CAu 16. Tac67-=2nftL
=
200f); Zc= 1l(2nf
rC)
=
50fl
->Z'2.=
LlC 10000
(i).
Khi f
=fz=
40Hz thi di6n dp
lrai
ddu

R
datcuc dai
-+
mach c6 c6ng huong
)
fr=40H2=
UQIILC
)
(2).
Til(1)
vn
Q)
-+
C
=
103/(8lr)F-)
f
t
=
ll(ZrcZcC)
=
80(Hz)
-+
Chon D.
CAu
17.
Khi s6ng Am
truydn
trong mdt rndi
tnrhrg

thi
phAn trl vAt chAt
m6i trudng dao ddng cu'6ng bLic v6i tdn
sd
brlng tdn sd
cfra
ngudn
vi bi€n dO dao d6ng cu'&rg
bric nly
phu thudc tdn sd dao ddng cita ngudn
-+
Chon A.
-
Tdc dQ s6ng
truydn
chi
phu
thuOc bin chdt mOi
tru'bug
rni khdng
phu
thu6c
v)o
tdn sd
s6ng
-+
B sai.
-
Bu6c s6ng l"
=

vlf -+
l"
phu thu6c v)o tdn sd s6ng
+ C
sai.
-
Chu
ki s6ng
vi tdc
d6 truydr-r s6ng trong mOt
mdi
tru'dng li
kh6ng ddi
-+
D sai.
Cxu
18.
Co ning cira
vat W
=
mo:2A2l2
-+
aA
=
JzW
l*
-+ ZaAIT
=
JZW
I

^.
Tdc
dQ trung binh v,r,
=
4Aff
-
z^7Zw l,u
/x=2Jr.0,04,t01
/n=0,4(m/s)
=
40crn/s
-+
Chor-r
A.
CAu 19. C6ng sua't hao
phf tr€n dudng
day AP
=
P'RAJt
(l)-+
U'z
=
p'RAp
=
400002.1012560
_+
U
=
2500V. Khi
congsudthaophichicbnbangAP'=257oLP-+257oLP=P'R/(U')'(2).Tac6(l):

(2)=4
=(U'/U)2
-+IJ'N=2-t
IJ'
=2U =2.2500 =
5000V
-; fJ'-U
=
5000-
2500
=
2500V
-+
Chon
B.
CAu
20. Tai
rnot rtidm bit ki tr6n
phuung truydn s6ng,
vectd cu'bng d6 di6n
trudng E
vi vecto cirn frrg tt
E
ddu
bidn
thiOn tudn hoin vi ciurg
pha v6i
r-rhau
chri'khdng
phii

vu6ng
pha
+ B sai-+ Chon
B.
Ca'u 21. Khi nguy€n tri'chuydn
til
trang
th6i dung
c6 nlng
luong En
vd
trang th6i
co
bin
thi vdi
su chuydn mfc udug
luong til'E*
vd
E, s6
cho vach quang phd
c6 tdn sd l6n
nhdt
thu6c ving
nhln thdy
-+
hf
=
E" -
E,-
-)

f
=
(EN
-
EL)/h
=
[-
0,84
-
(-
3,4)]1,6.10le16,625.10-3a
=
6,18.10r4H2-+
Chon
C.
Cdu 22. MOt lb xo
c6 d6 crlng li k, khi
crit l)rn 2
phdn bing nhau th) do cring cria rndi nila bing 2k, sau
d6 gh6p
clrfrrg song sor-Ig
v6i
nhau thi
dO cdrrg cfra lb xo
m6i bing
4k.
Ban ddu chu
ki
dao dOng f
=

2n
J
nr/ k,
sau d6 chu ki
birrg T
=2nJrr14k
-+
tn'14= m
-+
m'=
4m
-+
Chon
C.
Ciu 23. Xem liinli
vd v0 su khfc xa cria
tia
sdng
til'nu6c
vilo khdng
khi
Ta
sd c6 kdt ludn
g6c
hqp
bdi
tia khfc xa
miu
ving vh mit
phAn

cdch l6n
'hon
g6c
hop b6i tia khdc xa mhu
chirn vi rnat
phAn ci{ch-+
Chon A.
Khdng khf
Ving
Ciu24. Gii srl ban
ddu bi6n d6 dao ddng li A,
sau rn6t
chu ki
biOn dd giirn
di Al thi
quing dLrdrrg vat di du'oc trong
m6t
clru ki d6 li s
=
4A - ZLl. Co
n[ng
cria vAt
giim di AW
=kA2lZ
-
k(A
-
Ll)'Z,
phdn
co nf,ng

giim di
bidn th)nh
c6ng
cincrialtrcrnasdtA,,,,=F,,,.s=ftixgs=pLrng(4A
-ZLl) +
AW
=An,,4
kA'12-k(A-Alf/2=pLmg(4A
-2L1)-+
kAl(2A-Al)=4prmg(ZA-Al)+Al=
pmg/k=4.0,02.0,05.10125=0,0016rn=0,l6cm.SochukirndvltthrchiOn
duo.c li n
=
A/Al
=
[3/0,16
=
50
-+
Chon
B.
Ctu25.
Anh
s6ng hd
quang
Ii su
phdt sdr-rg
do c6 su
ph6t xa
nhi€t €lectron chft

kh6ng
phii su
phdt quang -+ Chon
D.
Clru
26. Didrn tr€n diy
cdch
bung sSng
Xll} n€n
cdch nrit
s6ng li ),14 - Xll}
=
)"16. Bi€n
dd dao ddng
cfia
rndt
didm
trOn dAy liL A
=
l}acos(Zndl)"
+
nlL)l=l2.6cos(7n16
+
nlT)l=
AJ3 mm
-+
Chon C.
Ctu21. Khi
tn'thor-rg
qua

rndt
vbng dAy bidn thi€n
didu hoi
thi
trong
vdng
dAy xudt hiOn
mdt sudt diOn ddng
chrn iirrg
xoay
chidu cl-rf
khdng
phii
tD'thdng
bidn thiOn
ddu + B
sai+ Chon B.
CAu 28. Ta
c6
(2k
+ 1)n
=
2ndlL=Zndflv
-+
f
=
(2k+
l)v|26=
(2k+
l)34W

(2.2)
=
(2k
+ 1).85
+
350<
(2k
+
1).85
<450-+k=Z-+t{insds6ngf=(2k+l).85=475(Hz)*}},.=vlf=3401425=0,8(rn).Khoingcirrchgdnnhaunht't
trOn cing
phuong truydn c6 dao ddng irn
vuOng
pha v6i nhau
bdng ),,14
=
0,2(m)
+
Chon D. N
Cnu29.
Tai
t
=
0 chdt
didrn chuydn ddng trbn
dtiu 6 M, khi
dien 6p u
=
-Uo/2 thi chdt didni
o didrn N hoirc E. Tai N

lir thdi didrn t
=
T
16
+ T
I
12
+
kT
=
Tl4
+
kT
=
0,0214 + 0,02k
=
0,005+0,02k(s)-+0,003<0,005+0,02k<0,008-+k=0-+VAytaithdididmt=0,005s
tlri n
=
-IJolZ.Didn E lirn
tuong tu khdng
tl-roi indn
di6u ki€n
dAu
bii-+
Chon
B.
Ciu 30. Trong mach
dao dOng di€n tt. ndr-r
truig

sd
vdng
day
cfia cuOn
cArn thi dO tu cim L
tang
-+
tdn sd dao ddng
crla rnach f
=
llQn^[rc
:
girrrr
+ Chon
B.
CArr 31.
Vdi
miiiy
bien zip ha dp ta c6U,l(U,
+
Irrr)
=
N,A{z
-+ U'/(U, +
UrrrlR)
=
Nr/N,
-+
1[t0/(U,
+ 1,5U2l6)

=
l0
-+IJ2+U214=lll-+Ur=14,4Y-+Cudngd0ddngdi0nquadiOntrtvRbangl=UrlR=14,416=2,4Y+ChonC.
CAu 32. Hi€n
tuong
quang
di€n
chi c6 thd
xiy ra
&
kim loai
(quang
di6n ngoii) hoic
chAt quang dAn
(quang
di€n
trong)
-+
xiy
ra & chtt b6n d5n vi tdrn kirn
loai
-+ Chon B.
Nu6c
cAtr
33.
Khoing vAn
i,
=
xlDla=
0,54.106.1,8/0,8.103

=
1,215(rnm),
khoing
vdl
i,
=
)v2D/a=0,72,106.1,g/0,g.10-3
=
1,62(mn).SdvAnsdngcfra)',
lis6kreZthoirndn-
10/1,215<kr
<10/l,Zl5-+-g,Z<kr
<g,2,+c6lTgidtri
cirak,
thoimln-)c6
17vensdngcia)"r
,SdvAnsdng
crta),"rl)sdk,
e
Zthoitpfll1-
10/1,62<kr
<
lO/1,62
+-
6,2 <
k2< 6,2 -+
c5
13 gi6
tri
cfra

k, thoii m6lr
-)
c6
13
van
s6ng
cria
1",
-+
Tdng
sd
vAn
s6ng
cu.
hai
h€
va'
l) 30.
Tfrrhsdvdnsfirgtlr)ngnhau
crlahai
h€vAn:
tac6n,l",
=flzLz-+O,54nt=0,'IZn2-+ 3
r;
={12_)
ltl
=4
_+khoilg
cdcl-r gifra
hai vi

tri
trirng
nhau
kd tidp
xo
=
4it
=
4.1,215
=
4,86(rnm)
-+
sd vi
tri trilg
lhau
ctra
hai vdn
siing
cria
hai
bricxalisdk
ezthoh6ft1-1014,86<k<10/4,86 >-2,06<k<2,06-+c65giatri"i,ukthoi,na,.,]c65vi
tri
tring
nhau
cfrng
ld 5 vi
trf cirng
miu
v6i vAn

trung
tam,
ndn c6
10
vln
shng
cfra
hai
bric
xa
nim
6, 5 vi
tri
'dy
-+
sd
vi
tri
khdng
cdng
rniu v6i vAn
trung
tArn le 30
-
I0
=
20
-+
Chon
A.

Cnu
34. -
Dir.rg
l6i
s6t c6 di€n
tr'&
sudt
nh6
khOng Anh hu&ng gi
ddn
hi€u
sudt cfra
rnriy
bidn dp -+
Chon
A.
-
Dirrg
ddy
96
diQn
tr&sudt
nh6 lim
dxy qudir
rn6y bien 6p
th) didn
rr&
nh6
n€n
hao

pi-,i
ao toA
nhiet
ii.
-
Ding
l6i sit.gdm
rfiidu
ld
sit
rn6ng
gh6p
cdch"di€n v6i
nhau
dd giAm
r6c
dung
nhilt
cta
ddlg phu-co.
-
Dit
cdc l5
sit cria
l5i
sit song
song v6i
mil phang
chfra c6c
du'dng

sric ti'ati
talp
trung
c6c duoTtg
sfc
tir.
Cdu
35.
Ta c5
(v/v","*)'+
(u/a","*)'=
7
-+
1SnJ3
lfin)2
+
(100/a,,,"*)2
=
l-)
(100/a,,,"")2
=
l/4
->
a,,,"_
=
200(cm/s2)
->
,4" t9g6c
cfra
dao

ddng
0r
=
ik"*/vn,"^
=20Oll0rc=Z}/x(radls)
-+ chu
ki
T
=
\n/a
=
l(s)
-+
Chon
D.
lau
36
ChAt quang
dell
:g
thd
ding.tia
hdng
ngoai dd tao
ra hi€n
tu'ong
quang
di€n
troirg,
cbn

c6c
kim
loai phii
ding
6nh siing
nhin
thdy
(vdi
kim
loai
kidrn)
hoac tia tri'
ngoai
vdi
cic
kim
ioii
kh?c,
do vAy
gi6i
han qr-iarrg
dai
cfra
c6c
chdt
quang
dl'16'hon
gi6i
han qua'g
di€n cta c6c

kim
loai -+
chon
c.
cdu 37.
Theo giin
dd vecto
thi di€n
6p
hi6u dung
hai ddu diOn
tr&
cira
cudn
cim
u,
=
u.ocos750
=
100(
",16
"5)14
=25
"6
atj
-
l)v
-+
up +
U,

=
50
^[t
+
25
^lit
.,/J
- rl
=
25
nE.(
",6
+
t)V. Dirrh
li him cos ra
c6
fJ2=lJo2+U.u'+2URU"dcos750-)U2=(50rli)'*1002+2.50Jt.100cos750=(50nD)t*1002+
2.50\1ry 100("v6
-
,D)/+
=
so'
1./3+
l)2-+ U
=
50
(J5+
t)
+
H€ s6

c6ng
sudr cua
doan
rnzrcl.r
cosq
-
(UR
+
U,)ru
=
Ji
/Z
-+
Chon
C.
CAu
38.
Didm
M
nim trdn
AB vi
ci'rch
trung didrn
O cfra
AB l)
3cm
-+
hieu drrdrg
di cfra
hai

s6ng
tir
A vh
B dd'
M
bing6cm.Mthuocvat]cuctiduthfi
3 -+
(2k+
l)Xl4=6cm,v6ili=
2-+5X/4=O
-+
)1"=4,gcrn
*+rdcd0rruy€n
s6ng v
=
}.f
=
4,8.50
-
l2(crn/s)
-+
Chon
D.
Cdu
39.
Ta c6
CUo2
=
LIo'
-+

Io'
=
Cllr'lL.
C01g suat
toi nhi€t
trong
rnach
p
=
Rlorl2
-+
C dfpg
-Tlray
Io2
=
CIJo'lL
ta
du'oc
P
=
RCU',/(2L)
=
p6gz/
L
-+
A dfng
-
Thoy
L
=

l/(cco'?)
J P
=RC2U2co2-+
D dfing.
B cho
bidu thric
sai -+
cho'
B.
C0u40.Tac6hcl\",=A+Wr
0);hclXr=A+Wz(2).Vil,
<lr)'W,
=1,5Wr-+hcft,",-A+l,5Wr(3).Tn(2)_+
l,Shcl'r=
l,5A +
1,5W,
(4)
-+
(4)
-
(3)
-+
l,Shcl\,'r-hcl)"t
=
0,5A
=
0,51-rcA.o->
1,5/)"2-
l[.t
=

l/L6.
Thay
),r=
0,25ptm,
Lt
=
0,2
prn
ta duoc
l"n=
0,5pLm -+
Chon
A.
cau 41.
Tai t
=
0
ch#
didm
&
M
tren
vbng
rrdn
(tuong
rlng
didrn
I
rr-€n
rruc

ox),
sau
1/4
chu
ki chat
didrn quay
duo. c g6c
nlz den
N tr€n vdng
trdr-r
(tu'ong
dng
didrn
J
trOn truc
ox),
vdt
di duo.
c quiurg
du'irng
s
=
IC +
cJ. Ta c6
oI
=
6crn
-+
IC=4crn;
OJ=IM

=.|rc'-62
=8c1n->CJ=
10-8-
2cn-+s=4+
Z=6crn-+ChonA
Cnu
42. c:ic
pl-rOt0n
bay
trong
chdn
kh6ng
v6i t&
do 3.l03rn/s
+
c
sai -+chon
c.
cAu
43.
Truydn
thdng
qua v6
rinh
dtrng
s6ng cuc
ngin
c6 tdn
sd tir'
102

MHz ddn
425
MHz
ndrn
trong
khoing trOn
*)
Chon
C.
103
MHz.
TIin so
42.5.10^
kHz
=
Cliu
44.
Khi thay
ddi gi6
tri cfra
bidn
tr&
R
biurg
R, vr\
bf,ng
R, tl-ri
c6ng
sudt ti€u
thu

di€p
cfra doa'
rnach
ddu
ba'g
F
ta
d0 ding
chring
rninh
du-o.c
RlR,
=
(Zr-2.)2
vift,+
R,
=IJ'lP
+ A vi\
B
dfng.
Khi
R
=
R0 rl;i corig
sudt
ti€u
rhu
iiiOn
cfra
doan

rnach
dqt cp
dai
P,,,.,-+
Rn
=
JRd,
+ c
dirng.
D6p
6n
D
sai
+ chon
D.
CAu
4-5.
Tai thdi
didm
t li dd
s6ng
ttri
A
li 3crn v) vAn
tdc
dao ddng
c5 d0
l6n clang
ring
-+ chdt

didrr
dang
di vd
pliia
vi
tri
ccn
biing, rr€n
vdng
trdn
li didm
M
(tren
t1.rcli
I
co
li dd
3crn)
J
ue
-
6cos20nt
=
3cm -+
z}nt
=
nl3.
Tai didrn
B cich
A 2ctn

c6 phuong
trirth
uu
=
6cos(20rct
-
Zndl?"),
v6i
d
=
2crn vi
X
=
vlf
=
80/10
=
Scm -)
us
=
6cos(20
rct -
nl})
=
6cos(nl3
-
rc12)
=
3
",6.,n

-+
Chol
A.
CAu
46.
Khi
hiOu di6n
the
hai ddu
cu6n
ddy
l€ch
pha
900 so v6i
hi€u di€p
rhd
hai ddu
doan
mach
rhi
hi€u
di€'
thd
lriOu
dnng
hai ddu
tu
di6n
C dat
cuc

dai-+
Z"
=
(R2
+
Zrr)lZr=RrlZ,
+
ZL
^+
Z.>
Zr_+
mach c6
tfnh dulg
kh6ng
_+
,)
o
\'i7
\/M
rrrt(p4aJ
khi
giirn C
th\Z.tdng, mach
vAn
c6 tinh
dung khdng
-+
(2,
- Zr) titng
-+

tdng tr'6
Z
ting -+
I
giim
+ hiOu di0n thd
lri0udurrg hai
dliu cudn ciiy U
=
I./R'
* Zl
giilm
-+
Chon B.
CLu
47. Khi
con
lic
don dao
dOng
di6u
hoh,
"vAt
qua vi
tri
citr bdng thi vQn tdc cqc d+i b[ng
Chon B.
6p
cira tu diOn
v,,,"*="l2gl(1

-cosao).Thayg=10m/s2,vn,"*=50cn-)/s=0,5rn/svic{.0=0,
lradtadu'ocI=7,5tn-+
CAu 48.
M6t
mach dao
dOng di€n tir'tu do
LC,
kl-ri
cubrrg
dd ddng di€n
trong
mach
dat cuc dai thi di€n
bdng kh6ng
vi
i vi u l6ch
pha
nhau 900
*>
Chon
A.
CAu 49. Ta
c6 u^s
=
u + uc
->
tlc
=
u^s
-

Ll
=
l}0.[tcos(l00nt
+
I00
vDcos(lggnt
+
nl2)
-
rc1Jtcos(l00.rt
+ 5nl6)
=
I00
J2
cos(l00nt
200Jtcos(100d
+ ru/6)cos(n/3)
=
100J2cos(100nt
+
n/6)(V).
V4y
uc
=
100
J2
cos(100rt
+
n/6XV).
-+

Chon
A.
'
CAu
-50.
Quang
phd
lien
tuc li diri rniu
li€n
tuc tt
d6
ddn
tfm chi khi
vdt c6
nhi€t
dd cao
(
khoing
& nhi€t
d0 thdp, ching
han & 5000C
quang
phd licn
tuc chi
c6
ving d6 -+ D sai
->
Chon
D.

20000C tr& lon),
cdn
D6p
6n dd thi
thrl
lAn 3(neby09/0u2011)
iilL)
-
100.",4sin(100nt
+ 4n/3)
=
+ nl})
+ 100rDcos(lO0nt
- 116)
=
bidu
thrlc
diOn 6p hai ddu
tu diOn
Me
dc 301
Me dd 302
Ma dd
303
Ma
de304
I
A
26
C

C
26
A
I
C
26
D
I
D
26
B
2
B
27
B
2
A
27 B 2
B
27
B 2
A 27
C
J
A
28
D 3
C
28 D 3
D

2B
C
3
B
za\
C
4
C
29
B
4
B
29
B
4
B
29
A
4
D
29
A
5
D
30
B
.5
B
30
D

5
C
30
B
5
A
30
B
6
3I
C 6
C
31
C
6
A
31
C
6
C
31
7
D
32
B 7
A
32 B
7
B
32

D
D
32
D
8
B JJ
A
8
C JJ
D B
A
-7
-t
B
8
A
JJ
A
I
C
34
A
9
A 34 A
9
A 34
A
9
B
34

B
t0
A 35
D
10
C
35 B
t0
A
35
C 0
D
35
D
ll
B 36
C
t1
A 36
C
1
B
36
D
I
A 36
B
12
L
3t

C
l2 A
-',
I
B
2
A
JI
B
2
C 37
C
t3
D
38 D
13
A 3B
A
3
C
38
A J
C
38
B
T4
C
39 B
t4
C

39
C
4
B
39
D
4
C
39
C
l5
A 40
A
15
D
4A
B
5 A
40
C
5
B
40
C
t6
D
4I
A
T6 A
41

C
6
C
4I
B
6 A
4I
B
17
A
,1a
+L
C
l7
A
42
B
7
A
42
D
1
B
42
B
1B
A
43
C
18 A

43
A
8
D
43
D
8 A
+J
D
t9
B
44
D
t9
C
44
A
9
A
44
C
9
A
44
C
20
B
45
A 20
D

45
A
20
A
45
C
20
A
45
A
21
C
46
B 21
D
46
C 21
B
46
A
21
D
46
B
22 C
47
B
22
B
47 B

22
C
47
C
22
D
4',7 B
23
A
48
A
L't
D
48 D
23
D
48
A 23
A
48 D
24
B
49
A
24
D
49 B
24
B
49

A
.\/
A
49
C
25
D
50
D
25
D 50 B
25
B
50
D 25
C
50
A