* Dao dpng dieu hoa la dao dpng dupe mo ta bang djnh lu^t dang cos hoae sin: X = Acoscot+ p Vai: + CO la tan so goc ciia dao dpng, don vj : rad/s co cho biit dao dpng nhanh hay chants co
Trang 1530.076 pHAM DLfC CLfdNG (Chu bien)
L527TH E TAN Rl - BUI IRAN DLfC ANH THAI,
THAN THANH SANG
CAC DANG BAI TAP TQ CAC DE THI QUOC GIA
~ dang ke K h i khoa k dong dong dien qua mach cham pha hofn dien ap hai _ d^u mach la — K h i khoa k md dong dien qua mach nhanh pha
.i :4„: ,,_4_.i
horn dien ap hai dau mach la —
4 Moi lien he giOfa cam
dung khang Zc cua ma
Trang 2LE TAN Ri - BUr TRAN DISC ANH THAI - THAN THANH SANG PHAM DLfC CLfdNG (Chu bien)
LUYEN THI CAP TOC
•
CAC DANG BAI TAP TlT CAC OE THI QUOC GIA
(^at nqklift - ^tufln dnh)
V A T L Y
Cac de chinh thCfc va de luyen tap
Dap an va thang diem cua Bg Giao due va Dao tqo
(Tdi ban, sura chufa va bd sung) THt; V i a ; TNVH BiNH VHUAW
NHA XUAT BAN DAI HQC Si/ PHAM
Trang 3MUC L
UC
Phan 1: To
Dao dpng ca
3
Song ca
6
Dao dpng di^n tir - song difn tir
1 3
Dong di?n xoay chieu
17
Song anh sang
25
Lugng tir an
CO
58
Song ca
64
Dong di?n xoay chieu
66
Dao dpng di^n tu
69
Song anh sang
70
Quang di^n
80
Quang di$n
80
Tia
X (Ronghen) 8
2
Phan 3: Da
p a
n v
a hv&ng
dan giai ca
c d
e o
n luy
f n Dai h9
c Cao dang
190
Trang 4^han t: T d M T A T G I A O K H O A
Phan chujif cho ban of ban ad ndn^ eao
DAO DONG CQ
I Dao d9ng dien hoa :
* Dao dpng tuan hoan la dao dpng ma trang thai chuyen dpng cua vat dupe l$p lai nhu cij sau nhung khoang thai gian bSng nhau
* Chu ky la khoang thai gian ngan nhat de tr^ng thai dao dpng cua v^t l^p l^i nhu cu hay thai gian thvrc hi?n 1 dao dpng toan phan
* Dao dpng dieu hoa la dao dpng dupe mo ta bang djnh lu^t dang cos hoae sin:
X = Acos(cot+ (p) Vai:
+ CO la tan so goc ciia dao dpng, don vj : rad/s (co cho biit dao dpng nhanh hay chants co Id toe dp bien doi ciia goc phaj
+ (cot + cp) la pha dao dpng t^i thai diem t, pha chinh la doi s6 cua ham cosin va la mpt goc (Pha dao d0ng cho ta biet v/ tri vat dao d^ng, gid tri
vd each bien thien cua vgn toe va gia toe vat dao dgng Pha dao dgng xde dfnh trgng thai vat dao dqng)
+ (p la pha ban dau ciia dao dpng (Pha ban ddu xde dinh trgng thai ban ddu ciia vgt dao d(>ng, ph^i thuQc each chgn goc tog dp vd goc thai gian)
+ Vgn toe va gia toe v|it dao dpng dieu hoa bien thien cung tan so vai tan so v^t dao dpng
+ V$n toe nhanh pha ^ so vai li dp x
+ Gia toe ngupc pha so vai l i dp x
* Lye tac diing lam vat dao dQng dieu hoa:
Trang 5* V
oi go
c l^c
h nho, da
Vg
* H
f da
o dQDg :
+ thvr
c hi^
n da
o dpng
+ Da
o dpn
g t\
do la dao dpng xay
thuQC cac
dgc tinh ciia h^,
khong
phu thuQC
cdc yeu
to ben ngoai)
Vidu:
+ Con lac Id
vgt la ngi l\rc
+ Con lac dcm
va Trdi ddt (hay
con lac vgt It
vd Trdi ddt) Id
h? dao
n Cor nSng :
Do v
\\fc the
* Co ' nan
+ Th
e nang: E, = ^ kx
^ = ^ kA^cos^(co
t + cp)
+ Dpn
g nang: E
a = ^ mv
^ = ^ kA^sin^((o
—
kA^ =
—mco
^ = const
V$y trong suot qu
g lupn
g gi&
a
the nSng va dpng nSng nhung ca nSng khong doi v
a ti
III Da
o dgn
g t^
t dan :
Dao dpng tat da
* D^
c diem :
dao dpng
tat da
n
cang nhanh
t\r:
khong khi, nuac, dau, da
u ra
t nhot
4
Trang 6T
IV Dao d^ng duy tri:
Dao dpng dupe cung cap nSng lupng de bu l^i phan nSng lupng mat di do ma sat ma khong lam thay d6i chu ki rieng cua no gpi la dao dpng duy tri
* Dao dpng duy tri eo ngo^i l^rc tac dyng, ngo^i l^rc nay dupe dieu khiSn
+ de C O tin so goe bSng tan so goc dao dpng t\ do cua h?
+ boi chinh dao dpng ky qua mpt ca cau nao do
* Tan so va bien dp dao dpng duy tri vin bSng nhu khi h$ dao dpng t\ do
V Dao d^ng cir&ng birc:
la dao dpng dupe duy tri do tac dyng cua mpt ngo^ii l^rc bien doi dieu hoa:
F = FoCosQt + Dao dpng cu&ng buc la dao dpng dieu hoa
+ Tan so dao dpng eixong buc bSng tan so ngo^i Ivrc
+ Bien dp dao dpng cuong buc ti I9 vai bien dp Fo cua ngo^i lyre va phy thupc
tan so cuong buc D cua ngoai l\rc ( AQQ e | Q - CO| )
VI Sy C9ng hirong:
+ Hi?n tupng bien dp dao dpng cu&ng buc tang nhanh den mpt gia trj eye d^i
khi tan so f cua lyc cir&ng buc bang tan so rieng cua v^t dao d9ng gpi
la hi$n tupng cpng huong
+ Bien dp dao dpng d^t den gia trj khong doi va eye khi toe dp tieu hao nSng lupng do ma sat bSng toe dp cung cap nSng lupng cho h^
+ Bien dp eye d^i ciia dao dpng khi cpng huong phy thupc ma sat moi truong:
ma sat giam thi gia trj eye d^i bien dp ting
* Phan bi?t dao dpng cv&ng birc vol dao d9ng duy tri:
+ Dao dpng cu&ng buc la dao dpng xay ra dudi tac dyng ciia ngo^i lyc tuan
hoan C O tan s6 goc Q bat ki Khi on djnh dao dpng cuong buc c6 tan so biing
tan so ngo^i lyc
+ Dao dpng duy tri cung xay ra dudi tac dyng ngo^i lyc nhung ngo^i lyc dupe dieu khien (boi ehinh dao dpng ay) de c6 tan so goc bang tan so goc ciia dao dpng ty do ciia h?
VII Tong h(fp dao d^ng:
* Xet hai dao dpng dieu hoa cung phuong, cung ikn so:
X] = Aicos(cot + cpi); X2 = A2cos(cot + 92)
Tong hpp hai dao dpng dieu hoa cung phuong, cung tin so la mpt dao dpng dieu hoa cung phucmg, cung tan so voi hai dao dpng thanh phan
+ Pha ban dau hai dao dpng tong hpp la 9, voi:
taiKp^ Aisincpi + A^sincp;
AiCOSCpi + A2C0S(P2
Trang 792 (Pi = 2kn
-=> A = A , + A2 ; (() = (pi =
92 (Pi = (2k + 1
)7t
A = A
| A2 ;
cp = (pi neu A
2 <
<A , +A
2
SONG c
a
I Son
g ca :
dpng
cang tre pha hon
* Son
g ngang :
j bien dang
l?ch
(Vd:
Song truyen tren mat nuac, sp
i da
y da
n hoi, ta
m ki
m lo^
i mong )
* Son
g d9c :
n s
o cii
a song : l
a ch
u ky , ta
* To
e d
9 truye
n song : l
tru&ng
toe dQ truyen song
c son
g
cung la quang duong ma song truyen dupe trong
f
6
Trang 8* Bien d9 song: Bien dp song t^ii mpt diem la bien dp dao dpng cua phan t i i
vat chat tai diem do khi c6 song truyen qua
lugng Nang lugng song tai moi diem t i I9 vai binh phuomg bien dp song tai diem do Mpt phan tir v$t chat dang dumg yen khi c6 song truyen den se dao dpng, nghia la phan tur do da nh$n dupe nang lugng tir song Vay qua trinh truyen song cung la qua trinh truyen nang lupng
I I I PhiroTig t r i n h song :
Xet song truyen tir nguon O den diem M each O mpt doan O M = x
Gia sOr phuorng trinh dao dpng t^i nguon O la : UQ = Acoscot
Song truyen tir O den M mat thai gian to = —
Uyj = A c o s ( © t - ^ ) hay U M = Acoscot-Y'') (*)
(•) cho ta xac djnh l i dp ciia phan tur song t^i diem M bat ki tren ducmg truyen song, gpi la la phuong trinh song
* Neu song truyen nguQc chieu vai chieu dircmg true Ox thi phmxng trinh
Tir (*) ta thay song c6 hai tinh chat:
+ Tinh tuan hoan theo thoi gian:
Khi xet mpt diem P tren song c6 toa dp x = d
Ta thay li dp u cua P bien thien theo ham cos => chuyen dpng cua diem P la mpt dao dpng tuan hoan vai chu ki T = —
(0
+ Tinh tuan hoan theo khong gian:
Khi xet tat ca cac diem tren song vao thai diem to,
Trang 9D^c bift:
)71=^ x = (
k + -
IV P ha
n x
a song :
V Son
g di rn g:
g khon
g gian
Dac d ilm :
-
Vj tr
-
Vj tr
e nha
u dfi
u bSn
g —
Dieu kif n c6 song dirng:
- Kh
=> tren day c6
so byng bang so
bo bang
k, con
so nut lak+ 1
- Kh
m =
1, 3,
=> tren day c6
so bung bang so
nut bangn = ~~~
-^on so
bo Ian -1
ifng dyn
g cu
a son
g dirng : D
o v$
n to
e truye
n song
8
Trang 10VI Giao thoa song:
* Hai nguon dao dpng cung tin s6 va c6 dp i?ch pha khong doi gpi la hai
ngu6n ket hgrp Song ma chiing t^o ra dugc gpi la song ket hgrp
* Giao thoa la s\c t6ng hgp cua hai song ket hgrp trong khong gian, trong do c6
nhixng cho c6 djnh ma bien dp song dugc tang cucmg ho^c bj giam bat
* Dieu kif n c6 giao thoa: Hai song la hai song ket hgrp va dao dpng cung phuong
* Ly thuyet ve giao thoa:
Gia sir A va B la hai ngu6n ket hgrp c6 cung phuorng trinh dao dpng la:
U A = U B = Acoscot
Xet diSm M bat ky trong moi truong each A mpt doan di va each B mpt doan d2
Phuorng trinh dao dpng t^i M do song tCr A den: ui = Acos(cot - )
Phuorng trinh dao dpng t^i M do song tir B den: U 2 = Acos(cot - )
nguyen Ian birffc song thi
bien dao d9ng tong h9rp
c^c dai va hpp thanh mpt hp
cac duong hyperbol nh?in A
va B lam tieu diem (ke ca
duong trung tr\rc cua AB)
Trang 11* Ta
i M
CO
bien dp c\rc tie
u =
0 (hai
dao dgng thanh phan
ngu^c pha
:
7t (d 2-
-k +
vai k = 0, ±1, ±2,
Vay: Ta
i nhirn
g die
m M c6 hi|u ducmg
B la
m tie
u diem
Chuy: DQ l^ch pha
cua hai dao d(mg
thanh phan la:
ta cung c6 the
tim ra
ditQC
cac kit qua nhu
tren
* Y nghia
cua hif n tuyng
giao thoa song: Kh
VI
L Nhie
u x
a song :
g hi?n tupng
giao
thoa song
VI II Son
g am :
Khi mgt vgt dao
dgng se lam khong khi a
ben bj nen roi
bi dan, xudt hi^n
luc
dan hoi trong khong
khi vd lam dao
dgng nay truyen din
cac phan tir khi
a xa
horn Dao dgng truyen
di trong khong khi
tgo thanh song dm
Nhu v$y:
a la
m man
g n
h T dao dpng gay ra cam giac
, An)
- Trong chat khi
vd chat long song
dm la song dgc
vi trong cac chdt
nay
l\K
dan hoi chi xudt
hi^n khi
co bien dgng nen,
dan
- Trong chdt ran
gom cd song ngang
vd song dgc vi
trong chdt rdn l\rc
dan
hoi xudt hi^n khi
c6 bien dgng l^ch
hogc nen, dan
10
Trang 12* Song am truyen dugc trong tSt ca cac moi truong k h i , long, ran nhimg
khong truyen dugc trong chan khong
+ Song am truyen di rat kem trong chat xop ; nhung ; bong ; val
+ Trong moi moi truong am dugc truyen di vai toe dg xac djnh
* Toe d9 t r u y e n am phu thugc :
- Tinh dan h6i va khdi lugng rieng cua moi truong
- Nhi$t dg ciia moi truong
Noi Chung Vri„ > vi6„g > vwhi
Chiiy: Trong chdt rdn song am c6 the Id song ngang hade song dqc
* Nhac am: la nhung song am c6 tan so xac djnh (va thuang keo ddi), c6 do thj
dao dgng la nhung duong cong tuan hoan Vidu : tieng hat, tieng dan
* Tap am: la nhung song am khong c6 tan so xac djnh, c6 do thj dao dgng la
nhung duong cong khong tuan hoan Vi du: tieng may no
IX: Cac dac trimg sinh ly cua nhac i m :
* D9 cao cua am:
La mgt dac tinh sinh ly cua am, gSn lien voi tan so am Am cd tdn so l&n gpi
la dm cao hogc dm bong Am c6 tdn so nhd gpi la dm thdp hodc trdm
A m cang cao khi tan so cang Ion, nhung dg cao ciia am khong t i I9 vai t i n so
* Am sac :
Khi mQt ngudn dm phdt ra niQt dm cd tdn sof (dm ca ban) thi cUng dong thai phdt ra cdc hga dm cd tdn so la bQi s6 ciia f TUy theo cdu trite cua ngudn
dm ma cdc hpa dm c6 so li/tpig bien dp, thai gian ton tgi khdc nhau
Am phdt ra la tong hQp ciia dm ca ban vd cdc hga dm, no cd tdn sd fnhwig duong bieu dien cua nd khdng con la duong sin md tra thdnh mgt duong tudn hoan phirc tap cd chu ki Moi dgng cua duong bieu dien img vdi niQt
dm sdc nhdt djnh Do dd cdc ngudn dm khdc nhau se tgo ra nhirng dm sac khdc nhau
Vay:
+ A m sac la mgt d$c tinh sinh l i ciia am giup ta phan bi?t dugc cac am cung dg
cao nhung phat ra t u nhiJng nguon khac nhau
+ A m sic dugc hinh thanh dyra tren tan so va bien dg am
+ A m sac gan lien vai d6 thi dao dgng am A m sac khac nhau khi dang do thj dao dgng am khac nhau
+ Cdc nhac cu khdc nhau khi phdt ra dm cd cimg dp cao se cd dgng do thj dao dgng dm vdi tdn so giong nhau nhung cd li dd bien ddi khdc nhau => dd thi dao dgng dm khdc nhau
* Dg to cua am:
Nang lu-gng am: Nang lugng am t i 1^ voi binh phuong bien dg song am
11
Trang 13d9
am
I : la nSng lugng ma song am truyen
trong mpt do
n v
j tha
i
gian qua mpt do
Mire cirong dp am
L :
L = 10lgi-
(I la cif&ng dm
gay ra
a tai nguai; I„
la cirang
dm tieu chudn)
y dexibe
n (dB)
Chuy:
- Tai nguai phdn
bi?t dugc hai dm
c6 mice cuong dQ
chenh l^ch nhau it
nhdt la
I dB
- Am
md tai nguai nghe
duQC c6 cuong dQ
ta chgn
k =
10 ''^
W/m^ Id cuong dp
dm chudn cua
dm
- Am
md tai ngitai nghe
duQfc c6 ctrong dQ
Ion nhdt bdng 10
W/m^
- Muc cuong dQ
dm tieu chudn bdng
0 vd muc cuong
dQ dm manh nhdt
thupc cuong dp am
va
tan so
am Dp
to cua
dm gdn lien v&i
^ =k
| (voik=
l,2,3
.)ha
y
^-k
i
^ '
V
song dung xay ra khi ta
n s
o f = k —
1 2
Trang 14T
- Khi kich thich cho day dan dao dgng thl tren day c6 song dCmg va phat ra
CO cung tan so am ca ban (nen moi logi dan c6 dm sac khdc nhau)
- Cau t^o ong sao (hay ken) c6 bp ph^n chinh la mpt ong c6 mpt dSu kin,
mpt dau ha Khi th6i mpt lu6ng khi vao ong thi khong khi trong ong dao
dpng va trong 6ng c6 song dung khi chieu dai ong thoa dieu ki^n :
l = m- ( v a i m = 1 , 3 , 5 )hay ^ - m —
4 4f
- Noi each khac vai ong c6 chieu dai £ thi song dung xay ra khi tan so
f = m - : ^
- Khi thoi sao thi trong ong sao c6 song dimg va phat ra am ca ban (hay
ho9 am b^c 1) umg vai m = 1, cung cac ho? am b?c 3 ; b?c 5 irng vai
so am ca ban (nen moi logi sao hogc ken c6 dm sac khdc nhau)
- Chieu dai ong cang Ian thi tan so f cua am phat ra cang nho
* Hpp C9ng hirong : la mpt v^t rong c6 kha nang cpng huang vai nhieu tan so
am khac nhau d l tSng cuang nhung am do
DAO DONG OIEN TU' SONG DIEN TLF
I M^ch dao d9ng:
La mpt m?ch kin gom mpt ty difn c6 di^n dung C m4c noi tiep vai mpt cupn
cam L (difn tra ho?t dpng R = 0) M?ch dao dpng ho?t dpng d\ra tren hi?n
tupng t\ cam
I I Syr bien thien cua di^n tich trong m^ch dao dQng :
Di^n tich cua t\ dif n trong m?ch dao dpng bien thien dieu hoa vai tan so goc
1
V L C •
+ Chuki dao dpng rieng: T = 27tVLC
+ Phuang trinh dao dpng cua di^n tich : q = Qo cos(cot + (p)
+ Cuang dp dong di^n trong m^ch:
i = q' = -coQo sin(a)t + cp) = coQo cos((at + <p + )
13
Trang 15cp)
n va
i don
g dif
n i qua cupn day =>
tir truon
g v
a
di?n tnrcmg
trong m^ch dao dpng tuan hoan
V^y: S\ bien thien tuan hoan theo quy lu^t ha
m si
n cii
a i, q va
g m^c
h
dao dpng dugc gpi l
a da
o dpn
g t
g do
o t
y di?
n : W
< i = — C
u "^
= — cos^ (co
t +
9)
Nang lupng tir truon
g t^
p trun
g 6
cupn cam : W
t = — Li
^ = — sin^(co
t +
9)
Nang lupng cua mach dao dpng: W = W
d +
Wt = — Cu
^ + — Li
g o cupn cam
+ Ning lugng di^n truong va nang lupng tir truon
n s
o f (vai f =2
Thyc te cac m^c
o ma
y pha
t
ra bang tan so rieng cua m^ch
L C: f
a h
? t\
dao dpng
14
Trang 16VI Dao dQng dif n tir circrag bu-c - Sir CQng hirong:
+ MJc mach dao dpng LC c6 tin s6 dao dpng rieng la fo vai mpt nguon di$n
ngoai CO di?n ap bien thien dieu hoa: u = Uocos27ift => dong di^n trong mach
se bien thien theo tan so f cua di?n ap u chu khong bien thien theo tan so fo
nOa Luc nay dao dpng^ong m^ch la dao dpng cuong buc
+ Khi tan so f = fo thi bien dp dao dpng di?n trong m^ch d^t gia trj c\rc dai =>
trong m^ch c6 cpng huong dif n Vai di?n tra R cua m^ch cang nho thi bien
dp khi cpng huong rat Ian
+ Hifn tupng cpng huong di$n dugc umg dyng trong mach Ipc; mach chpn song ; m^ch khuech d^i
* Sir tirong tu- gifra dao dyng di?n tir va dao dyng co":
GiCra dao dpng di?n tu va dao dpng co c6 syr dong nhat ve hinh thuc (cac phuang trinh va cong thuc c6 cung mpt dang) ma con la syr dong nhat ve quy luat bien doi theo thai gian
VII Di^n tir trirong:
* Hai gia thuyet cua Macxoen (Maxwell):
+ Trong vung khong gian c6 tir truong bien thien theo thoi gian se xuat hifn trong khong gian do mpt dif n truong xoay
Dgc diem cua di^n truong xoay: Cac dic&ng sire la cac durang cong khep kin baa quanh cac dmmg cam vmg tir No khac han cac du&ng siec cua tru&ng tinh di^n di ra tic di^n tich duang va di vao di^n tich dm
+ Trong vung khong gian c6 di?n truong bien thien theo thai gian se xuat hi?n trong khong gian do mpt tu truong
Ban chat ciia tir truong la cac duomg cam img tir ludn xoay
* Difn tir trucmg :
Theo Macxoen: Trong vung khong gian c6 tir truong bien thien theo thoi gian se xuat hifn mpt difn trirong xoay, va c6 difn truong bien thien theo thai gian thi xuat hif n mpt tir truong trong vung do
+ Di?n truong hoac tu truong khong the ton tai dpc lap voi nhau Dif n truong
va tir truong la hai mjt the hifn khac nhau cua mpt lo^i truong duy nhat gpi
la dif n tir truong
+ Truong difn tu la mpt d^ng v^t chat, dong vai tro truyen tuong tac giOa cac difn tich Tuong tac difn tir Ian truyen trong khong gian voi v^n toe bang v^n toe anh sang
Di4n truong tinh va tir truong tinh la trirong h(/p rieng cua di?n tir truong
VIII Song di?n tir :
Song difn tir la qua trinh truyen di trong khong gian ciia mpt difn tir truong bien thien tuan hoan theo thoi gian
15
Trang 17* Son
g di
f n tir
+ l
a son
g ngang T^
CO buac song trong chan khong
la
+ +
XI
(vai c
la vgn toe dnh
sang ;fla tan so
cua song di^n tir)
truyen trong moi triron
n tupn
g : phan x^, khii
c xa, gia
+ C
O man
g nan
g lugng Nh
Nguon phat son
a lir
a di?n, ca
a ca
c son
g v
6 tuyen
IX Ma ch dao dQng
hit
Angten :
Trong m?ich dao dpng kin: ha
Trong m^ch dao dpng ha: di$n tir truan
Trong thyc
y na
y gp
i l
a Sngten Angte
Quy trinh chung:
i l
a a
m
tan (ho^c thj tan)
theo dao dpng di?n
am
tan
(qua trinh nay con
gqi la bien di^u
Trang 18+ Dung anten de thu song di?n tir cao tan
difn)
+ Dung m^ch tach song cao tan va am tan
+ M^ch khuech d^i dao dpng am tan nh^n dugc va loa phat am nh^n dugc
XI Song di^n tir va thong tin v6 tuyen:
+ Song dai (buac song A> 1 km): it bj nuoc hap thu nen dugc dCing de thong
tin duai nuoc
+ Song trung (bir&c song X tir 100 m den 1000 m) : ban ngay bj tang di^n l i
hap thy m^nh nen khong truyen di xa dugc ; ban dem bj tang di?n li phan x?i
nen truyen di xa dugc
+ Song ngan (biroc song A tir 10 m den 100 m): co nang lugng Ion va it bj
Cac dai phat song ngan cong suat Ion co thk truyen song nay di mgi noi tren
mjt dat
+ Song cu-c ngan (btr&c song X tir 0,01 m den 10 m) : co nSng lugng 1cm nhat,
khong bj tang di^n li hap thy hoSc phan x?, co kha nang truyen di rat xa theo duong thing va dugc dung trong thong tin vu try
! Dai truyen hinh dung cac song eye ngin Song nay khong truyen dugc xa tren m^t dat, phai diing cac dai tiep song trung gian ho$c cac v^ tinh nhan
t^io de thu song cua dai phat roi phat tra ve trai dat
(dai FM)
DONG DIEN XOAY CHII^U
I Cach tao dong dif n xoay chieu (Dif n ap dao d^ng dieu hoa):
Dya vao hi?n tugng cam ung di?n tir
Cho mgt khung day dan di^n tich S va co N vong day, quay deu quanh mgt tryc
I doi xung xx' ciia no trong mgt tir truong deu B ( B vuong goc voi xx') vai v ^
V | y : Suat difn dgng trong khung b i l n thien dieu hoa vai tan so goc co va gay ra
+ Khi noi m^ch tieu thy vao di^n ap xoay chieu u = UoCOs(cot + cpu) thi trong
<p,)-THI/ VIEW TlrJHBiNH THUAN
17
Trang 19Vay : Don
dieu
hoa
theo phuong
trinh
i = Iocos(cot +
(p,)
(Trong do : i
la cu&ng
dQ tiec thai, lo
la cu&ng
dQ circ dgi ;
l^ch pha
so vai ddng di^n
gdc (p = %
- (p, ; dQ
l?ch pha
<p
nay phu thuQC linh
chat cua mach di^n
Cuong dp hi|u dyng ciia dong di$n xoay chieu bSng cuong dp ciia mpt don
g
di|n khong doi m
trong nhung
D9 Ion cua circmg hi^u
n a
p hi^
u dyng:
a ha
i don
g di?n bang
nhau)
II Doa
* Lie
n U
R v
a i :
Di?n ap giua hai da
i don
g di?
n tron
g m^ch
=>
khi i = lQCOs(a>
t + 9;) th
i UR
= UoRCOs((O
t + 9 j)
voi UQ
R = I
- = —^ vo
Trang 20* Lien hf Uc va i:
Di^n ap giua hai dau doan mach chi c6 ty di^n bien thien di^u hoa cung tan
so nhung tre pha hon dong di?n ^
* Gian do vecta
O
Uoc
IV Doan mach xoay chieu chi c6 cu9n thuan cam :
* Cam khang: = Leo vai L la dp ty cam cupn day
* Lien u va i:
D i f n ap giua hai dau do^n m^ch chi c6 cupn cam bien thien dieu hoa cung
tan so nhung som pha hon dong di^n
Gian do v e c t a :
U O L
o
V Doan mach xoay chieu R L C :
Gia sir dong di?n xoay chieu qua do^n m^ch la: i = lo coscot
=> UR = UoR coscot v a i UOR = loR
UL = U o L C O s ( c o t + ^ ) v a i UOL = I O Z L
Uc = U o c C O s ( o ) t - ^ ) v a i Uoc = IoZc
Di?n ap giira hai dau doan m^ch A B la: u = UR + U L + U c
=> Uo = UOR + UoL + Uoc
* Quan giira dif n ap va dong dif n:
^ U O = I O 7 R - + ( Z L - Z C ) ' ( 1 )
19
Trang 21l i :
UO L- UO C_
ZL -Z
cung tan so nhumg l$ch pha cp
so
vai don
g difn
1
coC
=>(p <
0
: u tre ph
Djnh lu^t 6
m ch
o doa
n mac
h RL C:
D^t Z = ^R
^ + (ZL
- Z
c f
la tong tra cua do^n mach
Tir(
l)tac6 Uo = lo
Z (*
) ; Chia
Tir bie
u thu
c I =
—, ne
u U xac djnh thi I„
„ kh
i Z
„i
„ o Z
+ U
L = UcvauL
= -u
c
+ UR = U
VL Cong
suat cu
a don
g di
f n :
Cong suat trun
P = UIcos(p
;
P = RI^
hay P
=—cos^cp
R
20
Trang 22Vai coscp dirgrc ggi la so cong suat cua m^ch:
cos(p = —=^ocoscp = —
U„ Z
* Doi voi doan mach xoay chieu R L C noi tiep:
+ Khi cos (p = 1 ((j) = 0 ) => P = U I : do^n m^ch chi c6 difn tra thuan R hay do?in m^ch RLC c6 cpng huong
+ Khi cos(p = 0 ( ( t ) = = ± ^ ) = > P = 0: do?in m^ch chi c6 cam khang ho^c dung khang ho^c ca hai
+ K h i O < c o s ( p < 1 ( - ^ < ( t ) < O h o $ c 0 < ( | ) < - ^ )
=> P = UIcoscp : cong suat tieu thy tren do^n m^ch nho horn cong suat cung cap cho m^ch (UI)
* Doi voi doan mach xoay chieu bat ki:
Vai cung di?n ap U va cuong dp dong difn I , khi do^in m^ch c6 coscp cang Ian thi P cang Ian Neu coscp nho de cong suat van b^ng P va di?n ap hai dau m^ch la U thi I phai Ian => khong c6 Igri (toa nhi^t nhieu) Trong thyc te thiet
bj su dyng di^n xoay chieu phai c6 coscp > 0,85
V I I May phat di^n xoay chieu 1 pha:
* Hai each t^o ra suat di^n dQng trong cac may dif n:
+ Tir truang c6 djnh, cac vong day quay quanh trong tu truang
+ Tu truang quay, cac vong day d^t c6 djnh
* May phat dif n xoay chieu 1 pha: gom hai bp ph$n ca ban
+ Phan cam: t^o ra tu truang, thuang la nam cham dif n
+ Phan ling: t^o ra suat di?n dpng cam ung, la mpt khung ciay g6m nhieu vong day
Mpt trong hai phan c6 thk quay quanh mpt tryc gpi la roto, phan kia dung yen gpi la stato Cac cupn day ciia hai phhn dupe quan tren cac loi thep silic
de tang cuong tu thong qua cac cupn day Cac loi thep nay dupe lam bing
nhung la thep mong ghep each di^n voi nhau dk tranh dong di$n Phuco
Neu phan ung quay, nguai ta lay di?n ra ngoai bSng bp gop Day la mpt h? thong gom hai vanh khuyen gan vai hai dau khung va hai choi quet c6 djnh
ti len hai vanh khuyen de dua di?n ra m^ch ngoai
* Tan so dong di?n xoay chieu do may phat ra :
60
(p : so cap cue cua roto; n : so vong quay ciia roto/phut)
21
Trang 23VI II Ma
+ Stat
o l
a pha
n ung, go
n van
h tron
+ Rot
o l
a pha
n cam, l
a na
m eha
m di^n
u d
e tran
h don
g di?n Phuco
Hoat d9ng : Dy
Luc eye bac cu
r thon
g qu
a cup
n 1 eye
r thon
g qu
a cup
n 2 eye d^i v
r thon
g qu
a cup
n 3 eye dai Nh
Tuang ty suat di?n dpng
so, cun
g bien dp va l?ch pha nha
i ta
i di?n ta tiet kif
IX D
^ng CO
+ Nguye
n tic
ho^t dpng: Dy
g quay Tron
i na
m cha
m quay, ti
r thon
g qu
a khun
g bien thien
lam
xuat
hi^n mpt don
cua tir thong Ly
c di?n tir ta
Dpng ca ho^t dpn
Trang 24* Tao tir tru-oiig quay bang dong di?n ba pha :
Cho dong di$n ba pha vao ba cupn day giong nhau d^t l?ch nhau 120° tren • mpt vanh tron Dong di?n ba pha qua ba cupn day da tao ra tir trircmg B c6
dp Ion khong doi va quay trong m§t phSng song song vol ba tryc cupn day
vai v^n toe goc co (hay v&i tan so bang tan so cua dong di^n)
* Cau tao cua d9ng ca khong dong bg ba pha :
Gom hai phan chinh :
+ Stato : Gom ba cupn day cua ba pha di?n quan tren loi sat d§t i|ch nhau 120° tren vanh tron de t^o ra tir trucmg quay
+ Roto : Hinh try t^o bai nhieu la thep mong ghep l ^ i Trong cac ranh xe a
mjt roto CO dat cac thanh kim io^i Hai dau moi thanh noi vao cac vanh
kim loai thanh chiec 16ng Long nay each di$n vai loi thep va c6 tac d\ing nhu nhieu khung day dong tryc d§t l?ch nhau Roto nay gpi la roto long soc
Khi mSc dpng ca vao m^ng di?n ba pha, tir truang quay do stato tao ra se lam roto quay tren tryc Chuyen dpng quay ciia roto vai v^n toe nho han v$n t6c quay cua tir truang dupe tryc may truyen ra ngoai de v§n hanh cac may ho$c ca cau khac
+ Cong suat tieu thy cua dpng ca 3 pha hkng cong suat tieu thy ciia ba cupn day a stato cpng l^i
+ Hi$u suat dpng ca la ti so giua cong ca hpc Pci ma dpng ca sinh ra vai
p cong tieu thy P ciia dpng ca: H =
ifu diem cua dpng car khong dong bp 3 pha :
+ Cau tao don gidn, de che tao
+ Sit dung ti^n l^ri, khong can vanh khuyen, choi quet
+ Co the thay doi chieu quay de dang
So sank Roto va Stato cua may phdt di^n xoay chieu 3 pha vd dpng cff khong dong bp 3 pha :
+ Stato giong nhau: gom 3 cupn day giong nhau dat l?ch nhau 12(f tren mpt
Trang 25Cau tao :
Hoat d9n g
^ , U2
0 —
2
Va y: ^
+ Kh
u Ian
* Cong dung may
bien dp:
+ Bien doi di^n
dp thick h(rp vai
nhu cdu
+ Tang
di4n dp
khi truyen tai di^n
nang de giam hao
phi
+ Han di^n, ndu
chdy kim logi
XI Truye
n ta
i di
f n nSng :
p <
= > I = Ucoscp
(vai U
la di^n
dp a dau duang ddy; I
Id cuang
dq dong di?n tren
day)
24
Trang 26+ Cong suat hao phi tren duong day c6 di?n tra R do tac d\ing nhift:
'ng
am
ucr :
cos^ 9 + Voi P va coscp xac djnh, muon giam AP, ta can :
- Giam R bSng each tang tiet difn day din Cach nay khong th\rc hi^n dugrc
vi ton kem
- TSng U bang each dung may bien ap tSng di^n ap a nai phat, a nai thu
diing may bien ap de giam di?n ap
SONG ANH SANG
I Hi^n tuqrng tan sac:
Hi?n tugrng tan sSc anh sang la svr phan tach mpt chiim sang trang (hay anh sang phuc t^p) thanh nhieu chiim sang c6 mau sSc khac nhau Dai cau vong : do, cam, vang, lyc, lam, cham, tim gpi la quang pho ciia anh sang trSng
II Thi nghi^m cua Niu-ton vol anh sang don s^c :
Khi cho tung chum sang h^p (trong dai mau cau vong) vai mau sac khac nhau qua iSng kinh, Niu - torj thay rang nhiJng chitm sang nay chi bj l|ch ma khong
doi mau Niu-ton gpi cac chum sang nay la chiim sang dorn skc
V^y: Anh sang don sic
+ la anh sang khong bj tan sac khi di qua iSng kinh
+ CO mpt mau nhat djnh gpi la mau dom sSc
+ CO mpt tan so xac djnh (hay buac song xac djnh trong moi moi truong)
III Anh s^ng tr^ng :
Anh sang trSng la t^p hprp (hay hon hpp) ciia v6 so cac anh sang dorn sic khac
nhau CO mau biln thien lien tyc tir do den tim
Anh sang tring la mpt truong hpp cua anh sang phuc t?ip, hay anh sang da sic
* Ifng dyng tan s^c anh sang:
- Trong may quang pho
- Giai thich hi§n tugng cau vong
IV Hif n tirgmg nhieu xa anh sang:
La hi?n tupng anh sang khong tuan theo djnh lu^t truyen thang, quan sat dupe khi anh sang di qua 16 nho hojc gan mep nhung v^t c6 kich thuac, trong suot ho$c khong trong suot
Giai thich: Do anh sang c6 tinh chat song, 16 nho dupe chieu sang c6 vai tro nhu mpt nguon phat song anh sang mai
25
Trang 27V Th
i nghi
f m Y
Hi^n tugng giao thoa anh sang la mpt ban
Si va S2
+ T0 9
Si de
n A lad
n A la d:
Taco: d , -
d, = —
* Ta
i A CO van sang khi :
dj
d, =
kX,
=> T0
9 d
p ca
c va
n sang: Xs
=k —
i:
dj -d , =
(k + ^))
h nhau
1 = —
VI Bira
c djnh Ma
a ma
u da
n sac
26
Trang 28VII Chiet suat moi trircmg va hvt&c song anh sang:
+ Chiet suat moi truomg trong suot c6 gia trj phy thupc vao tan so va buac song anh sang
+ Doi vai moi tmong trong suot nhat djnh chiet suat urng vai anh sang c6 birac song cang dai thi c6 gia tri cang nho hom chiet suat ung vai anh sang c6 buac song ngan
+ D6 thi bieu dien s\ phy thupc chiet suat vao buac song anh sang ggi la duong cong tan sic Cac duong cong tan s5c c6 dang gan diing vai hyperbol
g
(Vai A, B let Mng so phu thuQC ban chat moi trircmg)
+ Biet duong cong tan sac, do dugc chiet suat n ta suy ra buac song anh sang
VIII May quang pho lang kinh:
May quang pho la dyng cy dung de phan tich chiim sang phurc t^p thanh nhiJng thanh phan don sSc kJiac nhau (hay may quang pho dung de nh^n biet cac thanh phan cau t^o cua mgt chum sang phuc tap do nguon sang phat ra)
May quang pho hogt dgng dya tren hi?n tugng tan sac anh sang
May quang pho lang kinh gom ba b? ph§n chinh:
+ 6ng chuan tryc: la bp ph^n t^o ra chum tia song song Gom mpt khe h^p S a tieu di?n cua thau kinh hpi ty L i
+ Lang kinh P: c6 tac dyng tan sSc anh sang Chum sang qua lang kinh gom nhieu chiim song song, moi chum c6 mpt mau
+ Buong anh: de thu anh quang pho Gom mpt thau kinh hpi ty L2 va mpt kinh anh F t^ii tieu difn
IX Quang pho lien tuc:
+ Quang ph6 lien tyc la quang pho g6m mpt dai mau bien doi lien tyc (hay
gom nhieu dai sang mau sac khdc nhau, noi lien nhau mgt each lien tuc)
Vai anh sang trang, dai mau bien doi tir do den tim
+ Do cac v^t ran, long ho$c khi c6 khoi lugng rieng Ion bj nung nong phat ra + Quang pho lien tyc khong phy thupc vao thanh phan cau tao cua v^t phat sang ma chi phy thupc vao nhi^t dp ciia vat Khi nhi?t dp ciia vat tang dan thi cuaiig dp buc cang manh va mien quang pho lien tyc Ian dan tir buc xa c6 buac song dai sang buc xa c6 buac song ngan
+ Quang pho lien tuc dung de xdc djnh nhi?t dO ciia vat nong phat sang
X Quang pho vach phat xa:
+ Quang pho vach phat x? la quang pho gom mpt h? thong cac vach mau rieng bi^t tren mpt nen toi
+ Do cac chat khi hay hai a ap suat thap bj kich thich phat sang (do dot nong
ho^c CO dong di^n phong qua) phat ra
27
Trang 29CO
buac song xac djnh va cho rngt quan
j tr
i ca
c v^ch, ma
u sic
v^ch va cuong dp sang cua cac v^ch
phdn (djnh tinh va
djnh
lif(37tg) cua cac nguyen
to c6 trong mQt
mau vgt
XI Quan
t\fc
(hay quang pho lien
t\ic thieu vgch mau
do bj chdt khi
hay hoi
hap thyi dw^c gqi
la quang pho vgch
hap thu ciia khi
hay hai do)
cua chinh nguyen
+ Djn
h lu$
t Kie
c sop:
i
+ LTn
g dyng: Quan
phap v^t
n gian, nhan
o h\k
ham lupng cac than
t hi^
n
dupe ham lupng rat nh
o cii
a cha
t tron
g mau
t Trai, ca
c sa
o
XI II Ti
a hon
g ngoai :
Ban chat:
Tia hong ngo^ii l
CO
buac song Ian han buac song ciia anh sang do va nho
hon
buac
song ciia song v6 tuyen di^n (tu>.>
0,76 ^m den vai milimet)
28
Trang 30Nguon phat tia hong ngoai:
+ Tat ca cac v^t du a nhift dp thap deu phat ra tia hong ngo^i : M$t Trai, ca
the ngirai, ban u i
+ Nguon phat ra tia hong ngo^i thuang dung la cac bong den c6 day toe bang vonfram nong sang, 16 than
Tinh chat:
+ Tac dyng noi b^t ciia tia hong ngo^i la tac dyng nhift
+ Tia hong ngo^i c6 kha nang gay ra mpt so phan umg hoa hpc, c6 the tac dyng len phim anh hong ngo^i
+ Tia hong ngo^i c6 the bien di?u (dieu bien) nhu song cao tan
+ Tia hong ngo^i con c6 the gay ra hif u urng quang di^n trong a mpt so chat
ban dan
iTng d\ing:
+ Dung de suoi am hay say kho
+ Chyp anh hong ngo^i
+ Sur dyng a bp 6\hu khi^n tir xa
+ Trong quan sy c6 nhieu umg dyng cua tia hong ngo^i nhat: diing de do tim myc tieu, chyp anh ban dem
XIV T i a tir ngoai:
Ban chat:
Tia til ngo^i la nhung buc x^ khong nhin thay dugc va c6 ban chat la song
difn tu, CO buac song ngSn han buac song cua anh sang tim (tir X, < 0,38 f^m
den ca 10"'m)
Nguon phat tia tir ngoai:
+ Cac v^t bj nung nong tren 2000° C se phat ra tia tu ngoai
+ Nguon phat ra nhieu tia tu ngo^i la : M^t Trai, ho quang difn, den thuy ngan
Tinh chat:
+ Tac dyng m^inh len phim anh
+ Kich thich nhieu chat phat quang
+ Lam ion hoa khong khi
+ Gay ra nhung phan ung quang hoa, quang hgrp
+ Bj thuy tinh va nuac hap thy rat m^nh Tia tu ngoai c6 buac song tu 0,18 \xm
den 0,4 Jim truyen dugc qua th^ich anh
+ Co mpt so tac dyng sinh ly
+ Co the gay ra hi^n tugng quang dif n
iTng dyng :
+ Diing de khu trung, chiia b^nh coi xuang
+ Phat hifn vet nut, vet xuac tren be m^t kim lo^i
29
Trang 31So sanh tia hong ngoai v
a ti
a t
u * ngoai :
XV Ti
a X (Tia Roughen):
Tia Ronghen
la song di?n tir c
6 bua
c son
g ra
t ngan, khoan
g ti
r 10"
" m den 10
> irn
g
dyng : d
e chie
u dipn, chy
p dif
n tron
g y hpc; Tron
g con
g nghi?p, ti
a Ronghe
n
dung de do khuyet t^
lugng
tia Ronghen
- Ti
a X gay ra hi^n tugng quang di^n
y ho^
i t
e bao, dif
t v
i khua
n un
g dyng: chir
Mac
- xoen: n = —
30
Trang 32XVII Thang song di?n tir :
Cac song v6 tuy^n, tia hong ngo^i, anh sang nhin thay dugc, tia tir ngo^i, tia Ranghen, tia gamma (xuat hi?n do s\ phan ra h^t nhan nguyen tir) deu c6 chung ban chat la song di^n tir Diem khac nhau ca ban giua chung la buac song dai, ngSn khac nhau nen tinh chat cua cac tia khac nhau
-r Cac tia c6 buac song cang ngdn (tia gamma, tia Ranghen) c6 tinh dam
xuyen cang m^nh, de tac d^ing len kinh anh, d l lam phat quang cac chat va
de ion hoa khong khi
+ Doi vdi cac tia c6 buac song cang dai, ta cang de quan sat hifn tugng giao thoa cua chung
Thyc ra ranh giai cac vCing khong ro r$t
I Thi nghi^m Hecxa :
Khi chieu mpt chiim sang thich hgrp (c6 buac song ngSn) vao m$t mpt tam kim loai thi no lam cho cac electron a m$t kim lo^i do b$t ra Hi^n tugng do la hi^n tugmg quang difn Cac electron b^t ra gpi la electron quang difn
+ Neu tarn kim loai tich di^n ducmg thi khong c6 electron bgt ra \i & be mat tdm kim logi co mpt di^n tru&ng c6 tdc dying ngdn can cac electron bgt ra
(Th\K ra van c6 cac electron bgt ra khoi tdm kim logi nhung Igp tuc bf hut
tra Igi)
+ Khi chdn chun: tia sang ciia ho quang bang mpt tdm thiiy tinh khong man thi cac electron cung khong bgt ra vi thuy tinh hap thu mgnh cac tia tir ngogi
II Ket qua thi nghifm vol te bao quang difn :
+ Ddi vai moi kim logi catot, anh sang kich thich phdi c6 buac song A, nhd horn mpt giai hgn X „ ndo do
thich
+ Muon dong quang di^n tri^t tieu hoan toan thi phdi co UH = - UAK, UH gpi Id
di4n dp ham Di^n dp ham phy thupc vao buac song anh sang kich thich Chuy:
+ Khi UAK = 0 thi van c6 dong quang di?n vi cac electron khi bgt ra khoi catot
CO vgn toe ban ddu nen vd?i chuyen dpng ve Anot tgo ra dong quang di^n
+ Khi tang di^n dp UAK thi cuang dp ddng quang di^n chi tang tai gid trj hh thi
khong tang nCta vi so photon chieu vao catot trong Is co giai hgn nen so electron bgt ra trong Is cung co giai hgn
31
Trang 33VI
II
I Ca
n tugng
quang di^n
chi
x ay
ra khi bua
c son
g X
cua anh sang kich thich nho hon giai h^i
(X<Xo)
thi
cuong dp dong quang di|n bao hoa t
n toa
n xa
c djnh, gp
6 gi
a tr
j bang:
tan s6 anh sang)
Do Anh-xtanh
de xuat, go
i photo
n c
6
nang lupng xac djnh
n tii, electro
n dpng, khon
n khon
g b
j tha
y doi, khon
+ MQt chum sang
du yeu cung chira
rat nhieu photon, do
vgy ta cam thdy
chum
sang lien tyc
V Lu-orn
g tin
h son
g h^t cu
-a ^n
h san
g :
Hi^n tupng giao thoa chumg to anh sang c6 tinh chat song
h dup
e hiqn
tupng giao thoa, co
32
Trang 34- Nh&ng song di^n tir c6 buac song cang ngin thi photon ung vai chung c6 nSng luQfng cang Ion; tinh h^t cang the hif n ro, tinh song cang it the hi^n
- Nhihig song difn tir c6 buac song cang dai thi photon tmg vai chung c6 nang lu<7ng cang nho; tinh h^it cang it the hif n, tinh song cang the hi§n ro
VI Hi^n tirgrng quang dif n trong:
Hi?n tugrng t^o thanh cac electron ddn va 16 trong trong ban dan do tac dyng cua
anh sang c6 buac song thich hgrp, ggi la hifn tugrng quang difn trong
De gay ra hifn tugrng quang di^n trong thi anh sang kich thich phai c6 buac
song nho han ho^c bang mpt gia trj XQ , gpi la giai h?m quang di?n ciia ban dan
Giai h ^ nay thuang nam trong vung anh sang hong ngo^i
VII Hif n tirgng quang dan:
Hi?n tugmg giam m^nh di^n tra suat (nghia la tang dQ dan di^n) cua chat ban
dan khi c6 anh sang thich hgp chieu vao gpi 1^ hi§n tugng quang d i n
Giai thich:
Hi?n tugmg quang dan dugrc giai thich dvra tren hi?n tugmg quang di^n trong: M6i electron lien ket khi hap thy mpt photon se tra thanh electron dan va de
\^\t 16 tr6ng mang di?n duang Nhung 16 tr6ng nay cung c6 the chuyen
dpng X\f do tir nguyen t u nay sang nguyen t u khac Do do khi chat ban dan dupe chieu sang thich hgrp se hinh thanh cac h^t mang difn i\f do, tra nen
dan di?n tot
So sdnh hiffi tugrng quang difn ben trong vd hifn tiegrng quang di^n ben ngodi:
+ Cd hai khi duxrc chieu sang thich h(jp deu lam but electron, nhimg doi voi hi§n tir(mg quang di^n ben ngodi thi cac electron but ra ngodi khoi chat con doi vai hi^n tw^g quang di^n ben trong cac electron chi but khoi lien kit vd van a trong khoi chat
+ Cd hai deu c6 buffc song giai hgn nhung giai hgn quang di^n ben trong
CO Ao Ian (anh sang hong ngogi) do nang Iwpig can Idm but cac electron
lien kit thanh electron dan khd nho
VIII Quang di^n tror:
Quang tra dupe che t^o d\ra tren hi^u ung quang di^n trong Do la tam ban dan
(hay tarn cd tinh quang dan) c6 gia trj di?n tra thay doi khi thay d6i cuang dp
chum sang chieu vao no (tirvdi megaom xudng con vdi chyc 6m)
Quang tra dupe lap vai m^ch khuech d^i trong cac thiet bj dieu khien bang anh sang, trong cac may do anh sang
IX Pin quang di^n (pin M$t Troi):
Pin quang di|n la mpt nguon difn ch^iy bang nang lupng anh sang Pin quang dif n bien d6i tryc tiep quang nang t h ^ h dif n nang
33
Trang 35Hoat d9ng :
giira hai ban dan
g ca
o (khoan
g 1
0 %)
iTng dyng :
Pin quang difn
la
nguon cung
cap
di^n cho
+ viin
g sau, vun
h nha
n t^o, ma
y tin
h b
o tiii, ta
u v
u try, ma
y d
o an
h sang, ot
o
X Ha
g :
Nguyen tu
i a
trang thai dirag , nguye
CO
ban kinh hoan toan xac djnh, gp
c na
y nguye
n ti
r a trying thai c
+ Kh
(Vorin=
1,2, var
o = 5,3.10'"
a electro
n v
a h^i
t nhan
Tien de ve biirc x
„ „ = E
„ E„
(v&if„ „ : tan
so anh
sdn^
phdtra)
Ngu^c l^i, neu nguyen
tu &
tr^ng thai dung c6
nSng lufrng thap E„
mi
hap thfi dufTc mptphoton
co nang lugrng hf„
„ = E„-E„ thi
no chuyen
lea
tr^ng thai dimg c6
nang lugrng E„ cao
hem,
34
Trang 36XI Quang pho vach cua Hidro:
Dung mau nguyen t u Bo, nguai ta d3 giai thich thanh cong cac quy lu$t cua quang pho v^ch nguyen tit hidro
Quang pho v^ch cua hidro co cac d3y:
+ D a y Laiman gom v^ch quang pho (cac buc x^) thupc vung t u ngo^i Day
Laiman dugc hinh thanh khi cac nguyen t u chuyen tir cac muc nSng lugng
cao ve muc nSng luc^ng thap nhat Ei (tircmg ung vai cac electron chuyen tir
cac quy dgo ben ngoaivi quy dgo gdn hgt nhdn nhdt la quy dgo K)
+ Day Banme c6 4 v?ich trong viing anh sang thay dupe: v^ch do Ha , v^ch lam
H p , v^ch cham H^ , v^ch tim H j va mpt phan trong vung t u ngo^i D a y
Banme dugc hinh thanh khi cac nguyen t u chuyen t u cac muc nSng lupng
cao ve muc nSng lupng kich thich thu nhat E2 (tuxmg ung vai cac electron
chuyen tir cac quy dgo ben ngoai ve quy dgo L )
+ Day Pasen gom cac v^ch quang pho (cac buc x^) thupc vung hong ngo^i Day Pasen dupe hinh thanh khi cac nguyen t u chuyen t u cac muc nSng
lupng cao ve muc nSng lupng kich thich thu hai E 3 (ttromg ting vai cac
electron chuyen tir cac quy dgo ben ngoai ve quy dgo M)
XII Hap thy i n h sang :
Hap thy anh sang la hi^n tupng moi truang v$t chat lam giam cucmg dp ciia dong anh sang truyen qua no
* Djnh lu|it ve sy hap thy anh sang (djnh luyt Bughe - Lambe):
Cuang dp I cua chCim anh sang dan sac truyen qua moi truang hap thy giam theo djnh lu^t ham mu ciia dp dai d cua duang di tia sang: I = IgC""^
Vai lo la cuang dp chum anh sang tai moi truang
a la h4 so hap th^i ciia moi truang
* Hap thy lyc lya:
Anh sang c6 buac song khac nhau bj moi trudng hap thy nhieu it khac nhau
N o i each khac sy hap thy anh sang c6 tinh Ipe lya, h f so hap thy cua mc truang phy thupc vao buac song anh sang
+ NhiJng chat gan nhu khong hap thy anh sang trong mien nao cua quang pho dupe gpi la gan trong suot trong mien quang pho do
+ Nhihig v^t khong hap thu anh sang nhin thay dupe gpi la v^t trong suot khong mau V i dy: Khong k h i ; thuy tinh khong mau
+ Nhihig v^t hap thu hoan toan anh sang nhin thay sS c6 mau den
+ Nhung v^t hap thu Ipe lya anh sang nhin thay dupe gpi la v^t trong suot co mau
XIII Phan (tAn xft) lyc ly^:
Anh »sang co buac song khac nhau phan nhieu it khac nhau tijr v$t => phan
CO tinh Ipe lya
35
Trang 37hk m
$t
phan x?
Vi dy:
V^t
son do
cua anh sang tai
va tinh
chat quang hpc cua
be
m^t tan
xg
XV Mi
u s ic cac v^t:
^t
c6 mau trSng
+ Ne
u v
^t
hap thy tat c
+ Ne
u v
$t
hap thy da so cac buc x?
chinh thi the
$t
CO mau xam
Phan Ion cac v
^t
c6 mau sS
t
?io tir nhirn
g v
^t
li^u xac
djnh
Mau s3c ca
c v
^t
con phy thuQc mau sS
i d
y ta
m
go san do: Kh
f n tu-9tig
phat quang :
* Sy phat quang : l
a nhi
^t
dO
binh thuong
va la
tv
nhien
+ Mo
buc x^
phat
quang la buc x^
rieng cua v^t pha
t quang
g tron
g mp
t
khoang thai gia
n na
o do Khoan
g tha
i gian tijr lu
g gg
i l
a tha
i gian phat quang
Sy huynh quang la sy phat quan
g c
6 tha
i gian phat quan
t lon
g v
a khi
t r4n
Anh sang phat quan
n hinh, so
n pha
t quan
g tre
n bien bao
giao thong
36
Trang 38XVII Sff liryc ve Laze:
* Laze la may khuech d^i anh sang d\ra vao phat cam ung (hay phdt xg kick thick)
* D$c diem chum tia Laze:
+ CO tinh don sSc cao
+ la chum sang ket hgrp
+ Tia Laze (ban dan) dung trong cac dau dpc dTa CD
+ Tia Laze diing trong khoan, cSt chinh xac cac v^t li?u
+ Tia Laze dung trong trSc dja d l do khoang each, ngSm duong thing
HAT N H A N N G U Y E N TO'
I Cau tao hat nhan nguyen tu*:
H^t nhan nguyen tur dugc cau tao bai nhung h^t nho gpi la nuclon Co hai lo^i nuclon:
- Proton: ki hi^u p, mang di^n tich nguyen t6 duong +e
- Natron: ki hifu n, khong mang di^n
Tong so A = Z + N gpi la so khoi
Vf du: Nguyen tu ]] Na gom 11 proton va 12 natron
+ 'W: Hidro ngng (con ggi la Dateri: D)
+ ] H ; Hidro sieu ngng (con ggi la Triti: T)
37
Trang 39y hi^
u u, bSn
g ^ khoi lugn
cd 4 nuclon nen
m =
- :=
> khoi lupng con
cd don v/ la
5 MeV/c
^
IV Ly
c ha
t nhan :
g
hgt nha
n vin ben vung
a Ivr
c hg
t nhan Lvr
De tach cac nuclo
n ra, ca
lir^'ng lien ket:
Khoi lugn
g m ciia hgt nha
n do Ngua
* NSn
g Ivqmg
Hen ket:
^I kr ie ng "
Trang 40VI.SVPH6NGXA:
Phong la hi?n tugng mpt h^t nhan t\ phan ra, phong ra tia phong xa va bien doi thanh h^t nhan khac Qua trinh phan ra phong xa la qua trinh dan den s\bien doi h^t nhan
* Ban chat cua tia phong xa:
Cho tia phong x^ di qua di?n truong giiJa hai ban ty di?n, ta thay c6 3 lo^ii tia
phong x^
dif n tich duong
+ Bj Ifch trong d i | n truong
+ V§n toe khoang 2.10^ m/s
+ Lam ion hoa cac nguyen tu tren duong di nen mat nang lugng nhanh va chi
di dupe toi da 8 cm trong khong khi
+ Tinh dam xuyen yeu
* Tia beta : gom tia p~ la dong cac electron mang difn tich am va tia (hiem
hon) la dong cac electron duong hay pozitron
+ Bj l^ch nhieu trong di^n truong hon tia a
+ V^n toe gan bang v^n toe anh sang
+ Lam ion hoa moi truong yeu hon tia a nen di dupe quang duong dai hon (vai met) trong khong khi
+ Tinh dam xuyen m^nh hon tia a
notrino {v): cac h^t nay khong mang difn, khoi lupng nghi bang 0 va eo toe
dp e& toe dp anh sang)
* Tia gamma (y): la song di^n tir c6 buoc song rat ngin (X < 10""m), la hat
photon CO nang lugng cao
+ Phong x? gamma xay ra khi h^t nhan con trong phong x^ a hoae p o trang thai nang lugng kieh thich chuyen ve tr^ng thai nSng lugng eo ban
+ Tia y khong bj l?ch trong di^n truong, eo tinh dam xuyen rat manh
+ Trong thang song di^n tu, tia y lam ion hoa khong khi m^nh nhat
* Dinh luat phong xa:
Qua trinh phong x^
+ CO ban chat la mpt qua trinh biSn d6i h^t nhan
+ CO tinh ty phat va khong di8u khiln dupe, hoan toan khong phy thupe vao tac dpng ben ngoai
39