giáo án vật lí lớp 9 cả năm



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GIÁO ÁN VẬT LÍ 9


NĂM HỌC
Ngày soạn: Ngày giảng:. Tiết 1:
CHƯƠNG I: ĐIỆN HỌC.
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1
1
Kin thc:
-!"#$%&'()*+(,-!.'/#01
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K/#.%3'.@19:;9<-
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(?O-1O+!
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!_47()*+F`+!';&-!=7+"+9O->-\->.)*->V!%(a-(%3-B$IS(%3-B
$@-.@B-71+!:1(%3-B(Z->+E(%3-!?O#(8->
K! năng:
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>!%2-+]7$D->#!`+->!%311G%P'7-!3>%H7(%3-#45#)E->()E->+67
(?O-1O+!-G%#%IS!?J+F?->F?->KR%+"+(%3-#45#!@-!S!L-K@A"+d./S
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KR%+!%Q'9@%B#%I#9%3-K@KR%K/#.%3'.@19:;9<-
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#45+679:;9<-
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$%I-#45(&(%Q'+!_-!+)M->(89N->(%3-#4?->1O+!
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/-9[->()*++"++Z->#!]+pejep#e#(&#C-!()*+18#
(O%.)*->V!%$%I#+"+(O%.)*->+N-.O%(G%KR%(?O-1O+!#%2'#![(%3--\->
2
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+=.%2-P'7-
%m%#!C+!()*+#"+!O%+67!%3-#)*->(?m-1O+!K@#"+9[->+67+L'+!T(&
(m1$m?7-#?@-(%3-
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(%3-K@Fo9[->#%I#V%31(%3--\->
Bài 1: SỰ PHỤ THUỘC CỦA CƯỜNG ĐỘ DÒNG ĐIỆN VÀO
HIỆU ĐIỆN THẾ GIỮA HAI ĐẦU DÂY DẪN.

fr%I-#!]+
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(89N->(%3-K@?!%3'(%3-#!I>%H7!7%(L'9:;9<-
sK@Fo9[->()*+(l#!,$%&'9%t-1G%P'7-!3B#uFG.%3'#!`+->!%31
2'()*+VI#.'/-KQF`S![#!'8++67+)M->(89N->(%3-K@?!%3'(%3-#!I
>%H7!7%(L'9:;9<-
hrY-\->n+1O+!(%3-#!c?FE(l

o9[->+"+9[->+[(?Z-VIB71ScVI
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( Bảng 1: Giáo viên làm thí nghiệm trước ở phòng thực hành-So sánh với kết
quả làm của học sinh).
hk%-!=1!w+F%-!
8#9:;9<-$D->-%+4Z1+!%Q'9@%fƒ••11B()M->VC-!•Bi11B9:;-@;
()*+P'U-F„-#42-#4[F]}>w%.@(%3-#451<'•
f71ScVI+=>%R%!O-(?f

fKZ-VI+=>%R%!O-(?…Bfh
f+Z->#n+
f->'l-(%3-18#+!%Q'…
+"+(?O-9:;-G%
 4`+P'7-B#!`+->!%31
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Đoạn dây dẫn đang xét
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56
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V%&1#47F`S![#!'8++67+)M->(8
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



Ngày soạn: Ngày giảng: Tiết 2:
ĐIỆN TRỞ CỦA DÂY DẪN-ĐỊNH LUẬT ÔM.
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9<-
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U
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I
—!/-Až#
!'#!/S#!Z->#%-`7K@?FG.%3'#!'()*+#u5$@%#4)R+
†|y‡|v
ˆyfrŽx•†•‘’
r%&1#47$@%+Ÿ
f2'VI#.'/-KQ1G%P'7-!3>%H7
!%3'(%3-#!I>%H7!7%(L'9:;9<-K@
+)M->(89N->(%3-+!O;P'79:;
9<-(=
hu$m->VI#P'mFG.%3'5$@%#4)R+
!”;A"+(,-!#!)E->FG
U
I
uVI#
P'm#!C->!%31!”;-2'-!/-Až#
f)M->(89N->(%3-+!O;P'718#
9:;9<-#_.3#!'/-KR%!%3'(%3-#!I
(J#K@?!7%(L'9:;9<-(=
Trình bày rõ, đúng 3 điểm.

hb"+(,-!(–->#!)E->FG
U
I
(4 điểm)
7
7
V
A
+
-
>w%-!/-Až#+:'#4m.M%+67
$O-—("-!>%"+!?(%&1
yyR%9:;9<-#4?->5$m->f#7
#!U;-I'$^P'7F7%FG#!T#!)E->FG
U
I
+=
>%"#4,-!)-!7'/;KR%+"+9:;9<-V!"+
VI#P'm+=-!)K/;V!Z->•—x@%1R%
2'-!/-Až#VI#P'm!)E->FG
U
I
+=>%"#4,>L--!)-!7'KR%9:;9<-
A"+(,-!()*+.@1V%&1#475
$m->f(2 điểm)

ˆyh•Žr™y™“
v2'+L'#u->B9`7K@?$m->hB
A"+(,-!#!)E->FG
U

I
KR%9:;
9<-—2'-!/-Až#K@#4m.M%+:'h
!)R->9<-#!m?.'/-(&#4m
.M%+:'h
v2'+L'(w+S!L-#!Z->$"?+67
1[+hK@#4m.M%+:'!^%2'+Z->
#!]+#C-!(%3-#45
>%R%#!%3'VC!%3'(%3-#45#4?->
FE(l1O+!(%3-B(E-K,#C-!(%3-
#45v2'+L'KsFE(l1O+!(%3-
A"+(,-!(%3-#45+6718#9:;9<-K@
-2'+"+!#C-!(%3-#45
w%f.2-$m->KsFE(l1O+!
(%3-BV!"+-!/-Až#BFo7
+!H7-I'+L-
)R->9<-+"+!(p%(E-K,(%3-
#45
?F"-!(%3-#45+679:;9<-5$m->
fK@h—2'X->!Y7+67(%3-#45
y%3-#45+679:;9<-
fb"+(,-!#!)E->FG
U
I
(G%KR%
1k%9:;9<-
gR%1k%9:;9<-#!T#!)E->FG
U
I


+=>%"#4,A"+(,-!K@V!Z->(p%
gKR%!7%9:;9<-V!"+-!7'#!T
#!)E->FG
U
I
+=>%"#4,V!"+-!7'
h y%3-#45
Z->#!]+#C-!(%3-#45

e

rC!%3'(%3-#45#4?->1O+!(%3-
!?J+
E(l1O+!(%3-
r!?"r(=->



e

yE-K,(%3-#45.@01BVC!%3'ª
f
f
f
V
A
Ω =

r%.ZZ1jfVªef•••ªB
2>7Z1jfªef••••••ª

«->!Y7+67(%3-#45x%&'#!,1]+
(8+m-#459N->(%3--!%Q'!7;C#+67
8
r
8
9:;9<-
ˆyixŽšxŽ†y‰’0
!)R->9<-#u+Z->#!]+
U U
R I
I R
= → =
K@#!Z->$"?(:;+!C-!
.@$%&'#!]++67(,-!.'/#01v2'
+L'9`7K@?$%&'#!]+(,-!.'/#01
!”;S!"#$%&'(,-!.'/#01
y,-!.'/#01
f3#!]++67(,-!.'/#
U
I
R
=
trong đó: U đo bằng vôn (V),
I đo bằng ampe (A),
R đo bằng ôm (Ω).
h!"#$%&'(,-!.'/#
Cường độ dòng điện chạy qua dây dẫn tỉ
lệ thuận với hiệu điện thế đặt vào hai đầu
dây và tỉ lệ nghịch với điện trở của dây
ˆy~’‘Š•¤

;2'+L'
#4m.M%+:'!^%
fyw+B#=1#n#
i•2'+"+!
>%m%•
hu+Z->#!]+
U
R
I
=
B18#
S!"#$%&'-!)
F7'¦y%3-#45
+6718#9:;9<-
#_.3#!'/-KR%
!%3'(%3-#!I(J#
K@?!7%(L'9:;
9<-K@#_.3
->!,+!KR%+)M->
(89N->(%3-
+!O;P'79:;9<-
(=§!"#$%&'(=
(–->!7;F7%•O%
F7?•
v2'+L'#4m
f:'i
=1#n#
efhª
e•B€
e•

4T-!$@;(L;(6
+"+$)R+B(–->

}ƒ(%&1•
h!"#$%&'(=.@
F7%KT#_FG
U
I
.@
V!Z->(p%(G%KR%
18#9:;9<-9?
(=V!Z->#!&-=%
#_.3#!'/-KR%
B#_.3->!,+!
KR%
}h(%&1•
~T+Œ->f
!%3'(%3-#!I
(J#K@?!7%(L'
+"+9:;9<-V!"+
-!7'B#_.3
->!,+!KR%
2-
h
ei
f
#!T

f
ei

h

9
9
.M%~
ˆ0-.O%$@%fK@!w+VY$@%h
!'¨-$,1<'$"?+"?#!`+!@-!}#4f•r•+!?$@%F7'K@?K5
@1$@%#/Shx
¢r™



Ngày soạn:
Ngày giản: Tiết 3:
THỰC HÀNH: XÁC ĐỊNH ĐIỆN TRỞ CỦA MỘT DÂY DẪN
BẰNG AMPE KẾ VÀ VÔN KẾ.

fr%I-#!]+
2'()*++"+!A"+(,-!(%3-#45#u+Z->#!]+#C-!(%3-#45
Z#m()*++"+!$G#4CK@#%I-!@-!A"+(,-!(%3-#45+6718#9:;9<-
$D->KZ-VIK@71ScVI
hrY-\->n+1O+!(%3-#!c?FE(l
o9[->(–->+"+9[->+[(?Z-VIB71ScVI
rY-\->.@1$@%#!`+!@-!K@K%I#$"?+"?#!`+!@-!
i!"%(8
¨-#!/-BV%2-#4TB#4'->#!`+B+!–X7-#?@-#4?->Fo9[->(%3-
*S#"+#4?->!?O#(8->-!=1
v2'#!C+!1Z-!w+
x©x‰!Z#Z+!?1k%18#1<'$"?+"?
yG%KR%1k%-!=1

f(%3-#45+!)7$%I##4,FG}9"-VC-#4,FG•f->'l-(%3-…
f71ScVI+=yffKZ-VI+=y…Bfh
f+Z->#n+(%3-"+(?O-9:;-G%
 !`+->!%31
fr%&1#47S!L-+!'¨-$,.C#!';I#+67+!?$@%
h!%7#!@-!+"+-!=1B1k%-!=1#42-18#$89[->+[
iyO%9%3--!=1-2'4¬1[+#%2'K@+"+$)R+#%I-!@-!BF7'(=1R%#%I-!@-!
~?O#(8->-!=1
€!?@-#!@-!S!L-$"?+"?
…'G%>%M!w+#!'$"?+"?B-2'-!/-Až#KQX#!]+B#!"%(8K@#"+
S!?->
†|y‡|v
ˆyfrŽx•
v2'+L'.RSS!=!w+#/S$"?+"?
10
10
V
A
+
-
Đoạn dây dẫn đang xét
4
3
2
1
5
6
K
#T-!!T-!+!'¨-$,$@%+67+"+$O-
#4?->.RS

w%.2-$m->#4m.M%+:'!^%
g:'!^%+671[+f#4?->1<'$"?
+"?
gsFE(l1O+!(%3-A"+(,-!
(%3-#45+6718#9:;9<-$D->KZ-
VIK@71ScVI
V%&1#47S!L-+!'¨-$,+67
#4?->K5
w%-!/-Až#+:'#4m.M%+67
$O-—y"-!>%"S!L-+!'¨-$,$@%+67
+m.RS-=%+!'->K@("-!>%"+!?
(%&1()*+V%&1#47#42-$m->
ˆyh˜-®
+!%7-!=1BS!:-+Z->-!=1
#4)5->v2'+L'-!=1#4)5->+67
+"+-!=1S!:-+Z->-!%31K[+67
+"+$O-#4?->-!=1+671T-!
-2';2'+L'+!'->+67#%I#
KQ#!"%(8!w+#/SBX#!]+V_.'/#
%7?9[->+[+!?+"+-!=1
v2'+L'+"+-!=1#%I-!@-!
#!c?-8%9'->1[+#4•r
#!c?9¬%B>%–S(¯1n+1O+!
(%3-BV%&1#47+"+(%&1#%ISA–+B(J+
$%3#.@+"+!1n+KZ-VIB71ScVIK@?
1O+!#4)R+V!%(=->+Z->#n+)'X
+"+!(w+VI#P'm(?B(w+#4'->#!`+
5+"+.L-(?V!"+-!7'
v2'+L'+"+-!=1(Q'S!m%#!71
>%7

?@-#!@-!$"?+"?47?(p%
-!=1(&-!/-Až#KQ->';2--!:-
>:;47F`V!"+-!7'+67+"+#4,FG
(%3-#45Ku7#C-!()*+#4?->1k%.L-
(?
!=1#4)5->+o(O%9%3-.2--!/-
9[->+[BS!:-+Z->$O-#!)VC
>!%+!žSVI#P'mK@XV%I-#!m?.'/-
+67+"+$O-#4?->-!=1
"+-!=1#%I-!@-!
U#+m#4?->-!=1(Q'#!71>%7
1n+!?J+#!c?9¬%BV%&1#47+"+!
1n++67+"+$O-#4?->-!=1
yw+VI#P'm(?(–->P';#n+
"-!:-!?@-#!@-!$m-$"?+"?
1[+7•B$•
47?(p%-!=1!?@-#!@-!-!/-Až#
+•
ˆyiršByy‡’
#!'$"?+"?
!/-Až#4–#V%-!->!%31KQ
g!7?#"+
g!"%(8!w+#/S+67-!=1
g«#!]+V_.'/#
ˆy~Š•¤
11
11
0-.O%V%I-#!]+KQ1O+!1n+-G%#%ISBF?->F?->(”!w+5.RS‚
¢r




Ngày soạn:
Ngày giảng: Tiết 4:
ĐOẠN MẠCH NỐI TIẾP.

fr%I-#!]+
';.'/-(&A:;9`->()*++Z->#!]+#C-!(%3-#45#)E->()E->+67(?O-
1O+!>l1!7%(%3-#451n+-G%#%IS
#(
e
f
g
h
K@!3#!]+
f f
h h
U R
U R
=
#u+"+V%I-
#!]+(”!w+
Z#m()*++"+!$G#4CV%&1#47.O%+"+!3#!]+F';47#u.C#!';I#
/-9[->()*+-!H->V%I-#!]+(”!w+(&>%m%#!C+!18#FG!%3-#)*->K@>%m%
$@%#/SKQ(?O-1O+!-G%#%IS
hrY-\->
rY-\->Fo9[->+"+9[->+[(?(%3-Z-VIB71ScVI
rY-\->$G#4CB#%I-!@-!.nS4"S#!C->!%31
rY-\->F';.'/-B./S.'/-.Z>%+
i!"%(8

/-9[->V%I-#!]+(”!w+(&>%m%#!C+!18#FG!%3-#)*->(E->%m-+=.%2-
P'7-#4?->#!`+#I
v2'#!C+!1Z-!w+
x©x‰yz{
yG%KR%1k%-!=1
i(%3-#45.L-.)*#+=>%"#4,…ΩBf•ΩBf…Ω>'l-(%3-18#+!%Q'…
f71ScVI+=yffKZ-VI+=y…
f+Z->#n+(%3-"+(?O-9:;-G%
 !)E->S!"S#!`+->!%31
548->#!21+!?(?O-1O+!>l1i(%3-#45—a-#)9';V!"%P'"#+!?
†|y‡|v
ˆyfrŽx•†•‘’
r%&1#47$@%+Ÿ
f
f!"#$%&'K@K%I#$%&'#!]++67
(,-!.'/#01•
f!"#$%&'K@K%I#(–->$%&'#!]+
(,-!.'/#01
)M->(89N->(%3-+!O;P'79:;9<-
#_.3#!'/-KR%!%3'(%3-#!I(J#K@?
!7%(L'9:;9<-K@#_.3->!,+!KR%
(%3-#45+671k%9:;
12
12
h!H7$@%#/Shf}x•
+m.RS+!–X.n->->!cB-2'-!/-
Až#à("-!>%"+!?(%&1
yy4?->S!L-(%3-(”!w+5.RS
‚B+!–->#7(”#T1!%&'KQ(?O-1O+!
-G%#%IS%3'+=#!&#!7;#!I!7%(%3-

#451n+-G%#%IS$D->18#(%3-#45(&
9N->(%3-+!O;P'71O+!V!Z->#!7;
(p%V!Z->•àx@%1R%
x%&'#!]++67(,-!.'/#01
U
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Ngày soạn: Ngày giảng: Tiết 5:

ĐOẠN MẠCH SONG SONG.
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f+Z->#n+f->'l-(%3-…"+(?O-9:;-G%
 !Z->P'7$@%#/SB1548->+!?(?O-1O+!>l1i(%3-
#451n+F?->F?->K@+=#4,FG(%3-#45$D->-!7'K@$D->
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4?->(?O-1O+!>l1h$=->(a-1n+F?->F?->B!%3'
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P'7+"+1O+!4s#_.3->!,+!KR%(%3-
#45#!@-!S!L-
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f Z->#!]+#C-!(%3-#45#)E->
()E->+67(?O-1O+!>l1h
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f h
f f f
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%m%T
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M
+Z->#!]+}~•%I-!@-!V%&1
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9[->+[(%3-+=+Œ->y(,-!1]+K@
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(=+!–->(Q'!?O#(8->$T-!#!)M->K@+=
#!&Fo9[->(8+./SKR%-!7'B-I'y
+671O+!(%3-$D->y(,-!1]++67+"+
9[->+[
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f h
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h !C->!%31V%&1#47
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gL-fn+
f
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()E->
f h i

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gI'+=-(%3-#45>%G->-!7'1n+
F?->F?->#!T

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=
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+Œ->y(,-!1]+.@hh•—ya-K@
P'O#()*+1n+F?->F?->K@?->'l-
hh•(&+!–->!?O#(8->$T-!
#!)M->
gE(l1O+!(%3-
gI'(a-V!Z->!?O#(8->#!TP'O#
K<-!?O#(8->K@P'O#K<-()*+1n+
K@?y(”+!?}+!–->!?O#(8->(8+
./S-!7'•
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

Ngày soạn:.
Ngày giảng Tiết 6:
BÀI TẬP VẬN DỤNG ĐỊNH LUẬT ÔM.
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


Ngày soạn:
Ngày giảng: Tiết 7:
SỰ PHỤ THUỘC CỦA ĐIỆN TRỞ VÀO CHIỀU DÀI DÂY DẪN.
 
f r%I-#!]+
2'()*+(%3-#45+679:;9<-S![#!'8+K@?+!%Q'9@%B#%I#9%3-K@K/#.%3'
.@19:;9<-
x%I#+"+!A"+(,-!F`S![#!'8++67(%3-#45K@?f#4?->+"+;I'#G}+!%Q'9@%B
#%I#9%3-BK/#.%3'.@19:;9<-•
20
20
';.'/-K@#%I-!@-!V%&1#47F`S![#!'8++67(%3-#459:;9<-K@?+!%Q'
9@%
2'()*+(%3-#45+67+"+9:;9<-+=+Œ->#%I#9%3-K@()*+.@1#u+Œ->18#
K/#.%3'#!T#_.3KR%+!%Q'9@%+679:;
hrY-\->n+1O+!(%3-K@Fo9[->9[->+[(?(&(?(%3-#45+679:;9<-
i!"%(84'->#!`+B+=#%-!#!L-!*S#"+#4?->!?O#(8->-!=1
xyz{|v
yG%KR%1k%-!=1
f->'l-(%3-if+Z->#n+f71ScVI+=y.@f
fKZ-VI+=y.@…i(%3-#45
f

e
h
e
i
+Œ->.?O%K/#.%3'
.
f
e•••11j.
h
efƒ••11j.
i
eh‚••11
"+(%3-#45+=¶e•Bi11
 !'#!/S#!Z->#%-—9`(?"-—F';.'/-9%t-9,+!#u
#4)M->!*S+!'->+!?18##4)M->!*S4%2->—r%&1#47$D->#!`+->!%31—
r!£->(,-!#C-!(–->(n-
†|y‡|v
f!H7$@%#/S…hS!L-7•
}x•
+=#!&V!Z->+L-#C-!+[#!&
-!)->>%m%#!C+!(–->(&(%(I-+"+!
1n+}€(%&1•
sFE(l(–->}€(%&1•
h
f4?->(?O-1O+!>l1h(%3-#451n+
-G%#%IS+)M->(89N->(%3-+!O;P'71k%
(%3-#45+=1G%P'7-!3-!)#!I-@?KR%
+)M->(89N->(%3-1O+!+!C-!•
%3'(%3-#!I>%H7!7%(L'(?O-1O+!.%2-
!3-!)#!I-@?KR%1k%(%3-#45#!@-!

S!L-•
hsFE(l1O+!(%3-Fo9[->KZ-VIK@
71ScVI(&(?(%3-#45+6718#9:;9<-
("-!>%"+!?(%&1h
yy!–->#7$%I#KR%1k%9:;9<-#!T
.@V!Z->(p%/;(%3-#451k%9:;9<-
S![#!'8+-!)#!I-@?K@?$m-#!:-9:;
9<-(=•—x@%1R%
x@%…hS!L-7•
7• Th+"+!1n+(Q'()*+1n+
K@?+Œ->18#!%3'(%3-#!I
e…

f
y%3-#45#)E->()E->+67(?O-
1O+!.@
#9 f
f
…
 f€
•B~
td
U V
R
I A
= → = = Ω

h
y%3-#45#)E->()E->+67(?O-
1O+!.@

h h
h
f h
… f•
fBƒ i
td td
td td
U V
R R
I A
R R
= → = = Ω
>
—"+!f
f
-#
h

"+!h
f
²²
h

f h f h
f h
f h
R ntR I I I
U U U
R R R
→ = =

= +
= +
s(–->FE(l1O+!(%3-B+!_4¬
+!G#-G%KZ-VIB71ScVI}€(%&1•
ˆyh•Žy™“œv•‡›vš
‘•
v2'+L'P'7-F"#+"+(?O-9:;9<-5
b"+(,-!F`S![#!'8++67(%3-#45
21
21
!T-!‚f+!?$%I#+!–->V!"+-!7'5;I'
#G-@?•y%3-#45+67+"+9:;9<--@;.%3'
+=-!)-!7'V!Z->•
—vI'#G-@?+=#!&>:;m-!!)5->(I-
#45+679:;9<-
v2'+L'#!m?.'/--!=1(Q47S!)E->"-
V%&1#47F`S![#!'8++67(%3-#459:;9<-
K@?+!%Q'9@%9:;9<-
v2'+L'()747S!)E->"-#p->P'"#
(&+=#!&V%&1#47F`S![#!'8++67(%3-
#45K@?f#4?->i;I'#G+67$m-#!:-9:;
9<-
9:;9<-K@?18##4?->-!H->;I'#G
V!"+-!7'
T-!‚f"+9:;9<-V!"+-!7'
g!%Q'9@%9:;
g%I#9%3-9:;
g!U#.%3'.@19:;9<-
ˆyiby‰˜‡y™“¤
œv•

`V%I-+"+!.@1
v2'+L'-2'9`(?"-KQF`S![
#!'8++67(%3-#45K@?+!%Q'9@%9:;
$D->+"+!#4m.M%+:'f—#!G->
-!U#S!)E->"-—n+1O+!(%3-
#!c?FE(l!T-!‚h7—v2'+L'+"+
-!=1+!w-9[->+[B#%I-!@-!
#!c?-!=1B>!%VI#P'mK@?$m->
f@1#)E->#`#!c?FE(l!T-!
‚h$j‚h+
#!'VI#P'm+67+"+-!=1
—w%+"+$O--!=1V!"+-!/-Až#
v2'+L'-2'VI#.'/-P'7V%&1
#479`(?"-
R%h9:;9<-+=(%3-#45
#)E->]->
f
B
h
+=+Œ->#%I#9%3-K@
()*+.@1#u+Œ->18#.?O%K/#.%3'B
+!%Q'9@%9:;#)E->]->.@.
f
B.
h
#!T
f f
h h
R l
R l

=
`F`S!'8++67(%3-#45K@?
+!%Q'9@%9:;9<-
f`V%I-+"+!.@1
h!C->!%31V%&1#47
irI#.'/-
y%3-#45+67+"+9:;9<-+=+Œ->#%I#
9%3-K@()*+.@1#u+Œ->18#.?O%
K/#.%3'#!T#_.3#!'/-KR%+!%Q'9@%
+671k%9:;
ˆy~’‘Š•¤
v2'+L'+"-!:-!?@-#!@-!h
)R->9<-#!m?.'/-+:'h
)E->#`KR%+:'~
h!%Q'9@%9:;+@->.R-}.+@->
.R-•—y%3-#45+67(?O-1O+!+@->
.R-}+@->.R-•I'>%Hy}•
V!Z->(p%—)M->(89N->(%3-
+!O;P'7(?O-1O+!+@->-!^}
+@->-!^•—ya-F"->+@->;I'
~Ty(J#K@?h(L'9:;V!Z->
(p%-2-#_.3->!,+!KR%9?
f h h f
•h€ •h€I I R R= → =
!7;
f h
~R R=

22
22

@
f f
f h
h h
~
R l
l l
R l
= → =
)R->9<-KQ-!@
w+$@%K@.@1$@%#/S‚x
¢r™



Ngày soạn:
Ngày giảng: Tiết 8:
SỰ PHỤ THUỘC CỦA ĐIỆN TRỞ VÀO TIẾT DIỆN DÂY DẪN.

fr%I-#!]+
';.'/-()*+4D->+"+9:;9<-+=+Œ->+!%Q'9@%K@.@1#u+Œ->18#.?O%K/#
.%3'#!T(%3-#45+67+!–->#_.3->!,+!KR%#%I#9%3-+679:;
xG#4CK@#%I-!@-!V%&1#471G%P'7-!3>%H7(%3-#45K@#%I#9%3-9:;9<-
2'()*+(%3-#45+67+"+9:;9<-+=+Œ->+!%Q'9@%K@.@1#u+Œ->18#K/#
.%3'#!T#_.3->!,+!KR%#%I#9%3-+679:;
hrY-\->
n+1O+!(%3-K@Fo9[->9[->+[(?(&(?(%3-#45+679:;9<-
i!"%(84'->#!`+B+=#%-!#!L-!*S#"+#4?->!?O#(8->-!=1
xyz{|v
yG%KR%1k%-!=1

h(%3-#459:;P'U-+Œ->.?O%

f h h f f h
j ~ } •i j •… •l l S S mm mm= = Φ = Φ =
f->'l-(%3-f+!%Q'…f+Z->#n+
f71ScVI+=y.@fK@y••h
fKZ-VI+=y.@…K@y•f"+(?O-9:;-G%
 !'#!/S#!Z->#%-—9`(?"-—F';.'/-9%t-9,+!#u
#4)M->!*S+!'->+!?18##4)M->!*S4%2->—r%&1#47$D->#!`+->!%31—
r!£->(,-!#C-!(–->(n-
†|y‡|v
ˆyfrŽx•†•‘’
f4?->(?O-1O+!>l1h(%3-#45
1n+F?->F?->ByK@+)M->(8
9N->(%3-+67(?O-1O+!+=P'7-!3
#!I-@?KR%yK@+)M->(89N->
(%3-+67+"+1O+!4s•%I#+Z->
#!]+#C-!(%3-#45#)E->()E->+67
f4?->(?O-1O+!>l1
23
23
(?O-1O+!(=
h'G-A"+(,-!1G%P'7-!3>%H7
(%3-#45K@?+!%Q'9@%9:;9<-#!T
S!m%(?(%3-#45+679:;9<--!)#!I
-@?•
isFE(l1O+!(%3-V%&1#47F`
S![#!'8++67(%3-#459:;9<-K@?
+!%Q'9@%9:;
w%-!/-Až#+:'#4m.M%+67$O-B

Fo7+!H7-I'+L-—y"-!>%"+!?
(%&1
yyy%3-#45+6718#9:;9<-S![#!'8+
-!)#!I-@?K@?#%I#9%3-9:;—x@%1R%
f h
f h
f h
fh f h
²² 
f f f
R R
I I I
U U U
R R R
= +
= =
= +
hy&A"+(,-!F`S![#!'8++67(%3-
#459:;9<-K@?+!%Q'9@%+679:;#7
S!m%(?(%3-#45+67+"+9:;9<-
()*+.@1#u+Œ->18#.?O%K/#.%3'B
+=#%I#9%3--!)-!7'-!)->+!%Q'
9@%V!"+-!7'
is(–->FE(l1O+!(%3-
ˆyh˜y¤˜‡y™“š
™œv
v2'+L'K/-9[->V%I-#!]+KQ
(%3-#45#)E->()E->#4?->(?O-
1O+!1n+F?->F?->(&#4m.M%+:'
!^%f

u+:'!^%f—`(?"-F`S![
#!'8++67K@?P'7+:'h
`(?"-F`S![#!'8++67(%3-#45
K@?#%I#9%3-9:;9<-
f
h i
j
h i
R R
R R= =
h4)M->!*S!7%9:;9<-+=+Œ->
+!%Q'9@%K@+Œ->()*+.@1#u+Œ->
18#.?O%K/#.%3'B#!T(%3-#45+67
+!–->#_.3->!,+!KR%#%I#9%3-9:;
ˆyi™rŽ˜y
sFE(l1O+!(%3-V%&1#47—2'
9[->+[+L-#!%I#(&.@1B+"+
$)R+#%I-!@-!
v2'+L'.@1V%&1#47#!c?
-!=1(&!?@-#!@-!$m->f#4hi
#!'VI#P'm+67+"+
-!=1—)R->9<-#!m?.'/-+!'->
+m.RS
v2'+L'F?F"-!KR%9`(?"-(&4–#
47VI#.'/-
v2'+L'(w+;2'+L'S!L-i
!/-Až#C-!#_FG
h
h h
h

f f
S d
S d
=
K@F?
F"-!KR%#_FG
f
h
R
R
#!'()*+#u$m->f
T-!ƒi
"+$)R+#%I-!@-!
gn+1O+!(%3-#!c?FE(l
g!7;+"+(%3-#45()*+.@1#u
+Œ->18#.7w%K/#.%3'B+Œ->+!%Q'
9@%B#%I#9%3-V!"+-!7'
gy?>%"#4,B—C-!
g?F"-!KR%9`(?"-(&4–#47-!/-
Až#P'7VI#P'm
%I-!@-!
rI#P'm
!/-Až#S9[->+Z->#!]+#C-!
9%3-#C+!!T-!#4N-
24
24
w%f-!n+.O%VI#.'/-KQ1G%
P'7-!3>%H7K@—/-9[->
h
h

h

 
h ~
d d
S R
π
π π
 
= = =
 ÷
 
_FG
h
h
h
h h
h
h
f
f f

~

~
d
S d
d
S d
π

π
= =
—–#47VI#P'm
h
f h h
h
h f f
R S d
R S d
= =
rI#.'/-(%3-#45+67+"+9:;9<-
+=+Œ->+!%Q'9@%K@()*+.@1#u
+Œ->18#.?O%K/#.%3'#!T#_.3->!,+!
KR%#%I#9%3-+679:;
ˆy~’‘Š•¤
v2'+L'+"-!:-!?@-#!@-!i
w%V!"+-!/-Až#—;2'+L'
+!H7$@%K@?K5
v2'+L'!?@-#!@-!$@%ƒh
x
`7K@?VI#P'm$@%ƒh—;2'+L'
!?@-#!@-!€
#!'$@%+67fFGV%&1#47B
-2'-!/-Až#
w%()747+"+.C.'/-V!"+(&
#C-!(%3-#45
h

iTh9:;9<-(Q'$D->(l->B+=
+Œ->+!%Q'9@%

h
f h
f h
h
h f
…
i i
h
R S
mm
R R
R S mm
→ = = = → =
y%3-#45+679:;#!]-!U#>USi.L-
(%3-#45+679:;9<-#!]!7%
x@%ƒh
!%Q'9@%.R->US~#!T(%3-#45>US
~.L-B#%I#9%3-.R->USh#!T(%3-#45
-!^!E-h.L-BK/;
f h
hR R=

€"+!f:;9<-#!]!7%+=
+!%Q'9@%
f
h
h
l
l =
-2-+=(%3-#45-!^

!E-!7%.L-B(l->#!M%+=#%I#9%3-
h f
€S S=
-2-(%3-#45-!^!E-€.L-
rI#P'm.@9:;#!]h+=(%3-#45-!^
!E-9:;#!]-!U#f•.L-
f
h
ۥ
f•
R
R
→ = = Ω

"+!hbž#f9:;
i
+Œ->.?O%+=
+Œ->+!%Q'9@%
f
h
ۥ
h
l
l m= =
K@+=#%I#
25
25