LUYEN THI DAO DONG VA SONG DIEN TU

Dương Văn Nam – Trường THPT Tây Hồ - Hà Nội – ĐT: 0912777352
Chương 4
DAO ĐỘNG VÀ SÓNG ĐIỆN TỪ

I/. Dao động điện từ
1.  !"#$!"#
!%&'(')*$
2. +!(,)(-!&.%/
%&'01,2340356
7

ω =

89&
( )

, , 3 = ω + ϕ
:
( )

,
,
 3 
 
= = ω + ϕ
 ;<=>

( )
 
 ,? , 3  @ 3 
A

π
 
= = −ω ω + ϕ = ω + ϕ+
 ÷
 
B4
 
@ ,= ω
3. 9&  >  6  C      D  $  4  %'  (  :        $          E  
8 Tần số góc riêngF 
7

ω =
 8 Chu kỳ riêngF 
+ A = π
 8 Tần số riêngF 
7
G
A 
=
π
E)(;<1!H)(;<G!I
8J"42KKLF>M
N
7O
P'M
Q
7O
PRM
S

7O
'TM
7
7O
−
1M
A
7O
−
PM
N
7O
−
P!>
µ
M
Q
7O
−
P>M
S
7O
−
PK>KM
7A
7O
−
4. Năng lượng của mạch dao động LC: UV          6 
( )


, , 3 = ω + ϕ
89W"Xđiện trườngY#!F

A
A

7 7 7 ,
Z  ,
A A A 
= = =
F
( )
A
A


,
7
Z 3 
A 
= ω + ϕ
89W"Xtừ trườngY#!F

A

7
Z 
A
=


( )
A A A
 
7
Z  , 3 
A
= ω ω + ϕ

( )
A
A


,
7
Z 3 
A 
= ω + ϕ
89W"Xđiện từ)F

 
ZMZ Z+
M[35
A
A A

   
,
7 7 7 7
Z \ , \ @

A  A A A
= = = =
 ;<W"X]]
B2(!,C!:)(W"X$!"#W"X!"#>^
6("_W"X$>_
5. Dao động điện từ tắt dần.+!E!`O>6'W"X('W"X)
3a0b)3acW"Xd&H"X*$c
0 !e!4:3Ec0
6. Dao động điện từ duy trì. ^$>c0("#%5!;f%gW"X
hij("X%_3k35W"Xd%<'b)
6*$!:(6035l035!'H6*E

7. Dao động điện từ cưỡng bức.c6035!'m

4
6&

 \ 3 = ω
k-!4035
ω
)b
)6*$"n%Y
8Sự cộng hưởng.o
ω
Mm

:%'EH"X*3E"eRC
!<E)%'"eK!e0p)
II/. Điện từ trường
1. Liên hệ giữa điện trường biến thiên và từ trường biến thiên

+ +$!"#%&'1#Tf!"#TC "#3Y)!"#TC
."#VK(%,C"#3Y)$!"#
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Dương Văn Nam – Trường THPT Tây Hồ - Hà Nội – ĐT: 0912777352
89"X(!"#%&'1#Tf$!"# "#3Y)$!"#.
"#VK(%,C"#3Y)!"#
2. Điện từ trường. Jfj!"#%&'q3!$!"#%&'("X($!"#
%&'q3!!"#%&' !"#%&'$!"#%&'^6
l!!"#5f"X*$!"#
III/. Sóng điện từ
1. Sóng điện từ. rC!:!/$!"#*36$
2. Đặc điểm của sóng điện từ
+ +5!/)36$!L>%[5C3CMMN
s
7O
t3
8h6$36
u
ur
>64
J
ur
g>64K";!/36
vT
uuur

u(J(vT
ur ur uuur
2
u

ur

J
ur
/%&'01>#(>
K
8h6$!/"X!*>!"#^!L>
8J"436

+
G
λ = =
+!L>!>
( )
s
 N7O
+ 
G G
λ = = =
3. Tính chất của sóng điện từ
8h6$W"X+035:W"X364
8+L1C,2!/w(KT(kT
8+L1C,2(xT
IV/.Truyền thông bằng sóng điện từ
1. Mạch dao động hở. Anten
+!(&C%)(#CTC-:636
$    y  !  >    %'          "  &  *          e
z1e(6%YT36$f
2. Nguyên tắc truyền thông bằng sóng điện từ 1,!:F
8J&CLD:5!/C035fK*CL0D

<0
8bg36$0350CL0T,1KC
8bgC41^*f36$0#"X"e
8+C!y360!g^1Ld!/4Dg:^T1
:
3. 8 H5KCF0(56(&0(1KC
8H5F1(*36(C36(&L0(
4. hE!/36$,+!C fWY%"436(36$"XCFh6
{7OOOPh6!
7OOO  7OO ÷
Ph6c
7OO  7O ÷
Ph6Ec
7O  O(O7 ÷

8C36(!c/%<0KT4YC(6C366^
-,+!C f,/0KT.0DfC36"Xg!!/
(!/:!'Df
8h6Ec6WT',0(6W!/w$;KC&;h6
Ec"Xg^>!E>V(D!/>,
B. BÀI TẬP
CHỦ ĐỀ I. MẠCH DAO ĐỘNG
Dạng 1: ĐẠI CƯƠNG VỀ DAO ĐỘNG ĐIỆN TỪ
L7F+!$LC(&E!'Q
0


"#-E
!@
0 

:j$!
z+MAπ,
O
@
O
J+MAπ,
O
t@
O
+MAπ@
O
t,
O
b+MAπ
LAF$(6!e0>C^H&.%%&
'/-1#4035G|C%^3L3}
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Dương Văn Nam – Trường THPT Tây Hồ - Hà Nội – ĐT: 0912777352
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