Bài tập vật lý luyện thi đại học
Câu 1: !
"#$%&$'()*+,- !
.(/01&$2$./'
3
4
.".5'%./66)*6!738938 !:3
8+;1&$./9'
3
4."
<=<>?
A.
@3V
B.
@3
7
V
C.
A@3
A7
V
D.
A33
AA
V
Giải:
Giải:
;'
;'
A
A

B:38IIIIIJK


B9HK
B9HK
'A
'A
B
B
7
9R
;1'
;1'
9
9
B9'
B9'
3
3
IIIIIJK
IIIIIJK
'9
'9
B9K
B9K
'A
'A
B
B
7

U
R =
A7
A@3
V. Đáp án C
V. Đáp án C
Baì 3:M9NO !P.AQ-.2R6S%
T%0*")*UTVB93WX+P
T%6!3LYT+ZG"!Q>-.%U)[
& \OP !.OP6!+P=]G%9N"
\<>&+^./SR26!
A. A:L:+ B. 9A_L+ C. 9L@:+ D. 77Q@+
GiảiCP)\T%CλB YVB339B9
^$T5<N`2T%OP
^$T5<N`2T%OP


O
O
B
B
A
A
T
T
ω
ω




B
A
A
TF
TF
ω
ω
I
I
λ
π
A
9 d
E
E


P
P
B
B
9
9
TF
TF
ω
ω
abI
abI
λ

B90
b
b
IIIIIJIIIIJ"
IIIIIJIIIIJ"
A
A
g"
g"
9
9
BF0I
BF0I
9
A
E
E
λ
λ
IIIIIJ"
IIIIIJ"
A
A
g"
g"
9
9
B9F0I
B9F0I
9

B0aQ@
eN" \<>&>OPC3i"
eN" \<>&>OPC3i"
A
A
B0aQ@iAQ
B0aQ@iAQ
IIIIIJIQ
IIIIIJIQ
≤
≤
0
0
≤
≤
_+M>OP%AQN" \<>&
_+M>OP%AQN" \<>&
IIIIIJ)[&&2OPR00B3 !0BA+
IIIIIJ)[&&2OPR00B3 !0BA+
,N]G%9N" \<>& \%./SR
,N]G%9N" \<>& \%./SR
4 !G6!N" \<>&C` \0BIAHG
4 !G6!N" \<>&C` \0BIAHG
` \0B9
` \0B9
;U \C0BIAIIIIJ"
;U \C0BIAIIIIJ"
A
A
g"

g"
A
9
BALLIIIIIJF"
A
a"
9
EF"
9
g"
A
EBALLFhhE
MfFhE !FhhEIIIIJ"
A
a"
9
B
LQFhhhE
LQFhhhE
MfFhE !FhhhE"
MfFhE !FhhhE"
A
A
B99@
B99@


9
9
B"

@
YT !
9
B
L+A3
@
YT+<=<`%<)\T%
7
λ
B39
µ
4 j&2k
56!
O+@+A3
@
YTP+9
m
+A3
@
YT+
:
+A3
@
YTG+:+A3
@
YT
GiảiC
••
Wn
P

9
B9
A
IIIIIIJo
9
BLo
A
FAEIIIIIJL
A
λ
hc
BLOao
9
FApE
'RFApEgF9EHL
A
λ
hc
I
9
λ
hc
B7OIIIIJOB
7
hc
F
A
L
λ
I

λλλλλλ
+−
FhE
o
A
B
A
λ
hc
IOBF
A
A
λ
I
A
7
L
λ
a
9
7
A
λ
EB
9A
9A
7
λλ
λλ
−

= 2
m
.10
5
m/s. Chọn đáp án B
Bài 5+,N$.>)["#$A3364q.r
.6><>6+P=sTRr>0s(.>
)["#$U \"t>"# !<$.
>)["#<=A3u.\.
O+_3AP+Q__+Q@A@G+_A9@
Bài giảiC^vw6!sTRr>)["#
sTRx0)q.∆w
A
 !T0q.∆w
9

∆w
A
B
9
A
9
A
R
P
U
8\w
A
Bwa∆w
A

A
A3
P
U

9 9
A A 9 9 9
9 9
9 9 A A A
A33 A3
P P U U P
P P U U P
∆
= = ⇒ =
∆
w
A
Bwa∆w
A
w
9
Bwa∆w
9
Bwa33A∆w
A
Bwa∆w
A
I3__∆w
A
Bw

A
G%
G%
A
9
U
U
BA3
BA3
A
9
P
P
BA3
BA3
A
AA
__3
P
PP ∆−
BA3
BA3
A
AA
A3+__3
P
PP −
BA3+FAI33__EB_3A
BA3+FAI33__EB_3A
Vậy U

_Q3
93
B393L3
•
3
B393A9F"E
'&q2"#0k$k /x#<=\)*./
ls`MBpF7g9T•
3
E
r"pB
99
ag +
FB
m
Eq
B9YT
9
E
pB
99
9Q_ +
BA3339YT
9
+
7g9T•
3
B7g9FAg9T
9
9

BTωFEH
<
BTFωabEFE
e%fOP

O
BT•ωI
λ
π
EF9 db +
‚H
P
BT•ωabI
λ
π
EF9 db −
‚


B
O
a
P
B9TF
9
π
a
λ
π
d9

π
ETFωa
9
π
I
7
b
π
E
;"Bm

BI9ωTF
7
@
π
ETFωa
9
π
I
7
b
π
EFhE
;"BA3
~
BI9ωTF
9
π
a
7

v
v
B
7
@
T
E
7
@
9
TF
π
ππ
+
BI
7
@
π
BI
7
IIIIIJv
N
= - v
M
7
= 9 cm/s+
Đáp án C
Bài 9 :RN[">n%)r4

A

A
-
7
9
+
L
7
-
@
9
G+
7
9
-
7
L
GiảiC8„{ dr)4 „C
cd.nO
A
O
ϕ
T
9
A
B
:
T
A
π
A

B
9
T79L
ϕ
−
IIIIIIIJ
LT
9
ϕBLI9
7
Tϕ
9
7
TϕBLFAIT
9
ϕEBLT
9
ϕIIIIIJ9TϕF9TϕI
7
EB3FhhhE
IIIIIJTϕB3-TϕB
9
7

> ϕ =
9
π
> ϕ
2
=

>
9
ϕ
ϕ
=
9
A
Chọn đáp án A
Bài 10."#0s$ \
%.BD
3
T…F8E4"tT\r.6!†
A
 !
.""#6!738+~
A
B74"tj
r%†
9
B_3
3
I†
A
 !.""#6!_38+^./2D
3
6!
O+
@
:3
F8E+P+:3F8E+73

9
9
IIIIIIJ
9
aFK
'
gK
A
E
9
B_
9
a_FK
'
I
7
AC
Z
E
9
IIIIIJ2(R
2
+Z
L
2
) = Z
L
Z
C1
(*)

B
R
ZZ
CL A
−
Hϕ
A
B
R
ZZ
CL 9
−
B
R
Z
Z
C
L
7
A
−
R
ZZ
CL A
−
R
Z
Z
C
L

9
aK
'
9
EgQF
9
aK
'
9
Ea
9
AC
Z
B3IIIJ
9
AC
Z
=
5(R
2
+ Z
L
2
)FhhE
MfFhE !FhhEIIIIIJ
9
AC
Z
B9@K
'

gK
A
E
9
BA3
9
IIIIJK
A
B
A3
 !K
"A
B
99
L
ZR +
B
@
A
A
d
d
Z
U
B
A
Z
U
IIIIIIIJDBD
"A

kA
 !ƒ

B0OIIIIJ
9
9
kA
B93+A3
I7
FˆE !0OB9F~EIIIIIJOB339B
9
,Ny/."26&0d !6&d%U6\<=
9
đh
F
0 j%6
B‰
9
A
M[Rf0 jf6
9
A
>I
9
A
6!
:
T
B3AFTE
IIIJMB3:FTE

6!
A. L39Lm@T+ B. L39L9@T+ C. L39@9@T+ D. L39@m@T+
Giải: 04"MB
ω
π
9
B9T
^%./&NCB30 jk8MPIIIJB3
B93TFb
A
I
:
@
π
EB3IIIIJFb
A
I
:
@
π
EB‰
9
π
a0
9
π
IIIIIJ
A
B
:

IIIIIIIIIIIIIIIJ

9
B
A9
m
a90 !p
9
B
A9
A_
a90+f
9
i93A7MBL39:FTE

9
B
A9
m
a90iL39:IIIIJ0≤93A9Hp
9
B
A9
A_
a90iL39:IIIIJ0≤93A9

9
B
A9
A_

A33
L
B3LbFTE
,N"2 j9 \ jA%<>"&4[<s
j90 jA /x<>#`6![NBF90aAE
9
T
BF90aAE+39b+
G%[N$<s jF9EN"2F9E \FAE%<>"
&%N6!Ct =
@
7
π
( ứng với k =1. Đáp án D
Bài 14C0jN>sTRAL9Q_o%."
0!<4)["6!9938+,
2"#$frR0jN6!+;0jN0s"U
.<.N."20!<4)[4
"rR6!7@_80%`[9"#
20jNbY:T \"t`[v+;0j
N"U.<.6x)%1T~
A
Y~
9
BA@N."20
! Ž<4)[)00s"U.<.4
"rR6!F<TsTRTrR2.<
.<=AEC
O+A:@L8P+773_8+L_:78G+::A:8
Giải:

9
aDp
Dp6!.TrRDpBD
9
9
N
N
BA@DB7733F8E
,T.>)["#ŠD
9
Byp \yp6!)["tkTr
RC
ypBy
9
A
N
N
B
A@
I
B@FOEIIIIIJŠD
9
BypB@+
m@
A7_
B_9mB_7F8E
Do đó U
2
= ∆U
2

B9~
A
FAE8\~
A
BAA3A9BA79 t
^v6!T t"#</)*+;%%

9:L
AA3
9
9
9:L
AA3
9
A
A
9
A
=
−
⇒=
−
N
nN
N
nN
F9E
M~
A
BA79 t4)*BAA t+Chọn đáp án B

A
9
A
9
A
9
A
=
−
⇒===
−
N
nN
U
U
E
E
e
e
N
nN
Câu 16CM>-)\%.T%0*6!NO !P.
73"l)r4
O
B
P
BT93b+<>T%
0s(k.4T%+~)[)*0$.]
N`>6>>OP6!7+cd9N
A

‚

P
BT•93bI
λ
π
E
9
F9 d
AB
−
‚


B
O
a
P
B9T
λ
π
d+9
TF93bI
λ
π
AB+
EB9T
7
+d
π

7
9
T
π
π
BI
7
A
IIIIJv
M2
= -
7
A
v
M1
= 4
7
cm/s. Đáp án D
Câu 17CWT%0*>-)\e
A
e
9
" \)r4C
A

BTFωE
9
BTFωEe
A
e

A


Be
9
B"F"‘L@λE

A
BTFωI
9
π
I
λ
π
d9
EH
9
BTFωI
λ
π
d9
E


B
A
a
9
BTFωI
λ

L
π
I
9
π
B90πIIIIIIIJ"BF
Q
A
a0Eλ
"BF
Q
A
a0Eλ‘L@λIIIIIIJ0‘L7m@IIIIIJ0‘@IIIIIIJ0

B@
d
min
=
Q
LA
λ . Chọn đáp án B

•
e
9
•
e
A
•
•

3
B
C
Q
9
9
3
B7:
3
;By
3
IIIJo
'
B
9
9
3
LI
B7:
3
~q6)*20%o
A
Bo
9
B3
e0
9
"2"pB7
3
W&>"#2"T%‹x6!

B
P
BT93b+<>T%
0s(k.4T%+~)[)*0$.]
N`>6>>OP6!7+cd9N
A
 !
9
>OP
.NW2OP]66)*6!3@ !9+M[N
A

j2
A
6!gA9YT4 j2
9
6!
O+L
@
YTP+LYT+7
9
YTG+L
7
YT
GiảiCM%<)\T%λB97B:+
cdN>OP.WCWB"HOPB73
e%fOPC
O
BT•93bI
λ

π
AB+
EB9T
7
+d
π
TF93bI@bE


Bp

BIL3bT
7
+d
π
TF93bI@bEIIIIJ
A
9
M
M
v
v
B
7
T
7
T
A
9
d

GiảiC
G~"U>~B0λ+e*6xR0~k /x
#<Z
;%~B0λBLλIIIIIJλB~YLB3A9@
Do đó tốc độ truyền sóng trên mặt chất lỏng là: v = λf = 0,125. 120 = 15m/s.
Đáp án A
Câu 21
66t%T%>ωB9@"YTr&"!6tZ
` j-<>")\+~06% jL9YT4>6t</]
6+Mx j&26+
O+:3YTP+@QYT+m7YTG+:mYT
GiảiC;r&"6t.0s</<"F.0sv
6)*E+'Œ j% #
3
BL9YT4>6t</]6 jT„"
k8MP \T%ωB9@"YTH8MP. /x2 j6Œ6t
)*]6!

3
B∆6B
k
mg
+
8j&26)*./ls`C
9
9

mv
B
9

ω
 !∆6B
k
mg
+B
9
ω
g
B
9
A333
ω
FE
9

v
B
9
3
v
a
m
lk
9
EF∆
B
9
3
v
a

•

<#FIOEn-f<>")rOn !B
L
T
+G j%
L
T
B
33@bIIIIJMB39bIIIJωBA3"YT
;$[6t</d<=B
L
T
>[ jNf6B
IŠ6<>BIO6!
A
BY9B
Q
T
M[ jfv6BIŠ6
6!
L
T
I
Q
T
B
Q
T
>Š6B

eN" \<>&9OFT<T%EC
IA3≤0
9
λ
≤A3IIIIIJIA3≤90≤A3IIIIIIJI@≤0≤@M>~%AAN"
 \<>&0N$ !~+^]N60" \<>
&LO%9N" \<>OY9+M~%93N"
 \<>OY9++Do đó trên đường tròn thuộc mặt phẳng chất lỏng nhận
MN làm đường kính có 20x2 = 40 điểm có biên độ dao động bằng A/2. Đáp án C
Đõ Viết Doanh Toại
Câu 24C66t)*-=6t%`0B@3~Y !
j-06)*B933+; j /x#<=4."6&ƒ
0s("vl26t !%6\6!9~0$[3AT+
PSkvT.6RBA3YT
9
Hb
9
BA3+c./&2 jT0
6&ƒf."?
O+93bYT+P+93b
9
YT++9@bYT+G+L3bYT+
GiảiC
MT%266tCωB
m
k
B
93
@3
B@

= ωA = 10π
AL
cm/s. Đáp án khác????
.$2% Rl6
M !<G%N0$.6!")\!
^vn6! /x6t0s</<"n
A
6! /x#<q0%6&ƒ."
P>"0%6&."ƒ6!OBnn
A
P>O)*xC,;#<=0OBƒ
cmm
k
F
A L3L3
@3
9
====→
046
s
k
m
T L39 ==
π
e3AT)r`6!MYL 4 jf /x<>.nNTMYLT„ \
/xn
A
 #6Œ!6! B
A
ω

 /x#<="#l* \)rZ`%α%αB7YLH
6Œ!6"S \0”M
A
+~()[!T
dr)[")[%)rZ`)\6> !)[0s
(40”"S266Œ!6!C
A.
A
M
@
+ B. M
A
m
@
+ C. M
A
@
m
+ D. M
A
@
+
^$
;)[|%)r46&)[%)r
ƒ k| 7 L
 T
w  L @
α = = = => α =
6" \"
" A

Một con lắc lò xo đặt nằm ngang gồm vật M có khối lượng 400g và lò xo có hệ số
cứng 40N/m đang dao động điều hòa xung quanh vị trí cân bằng với biên độ
5cm. Khi M qua vị trí cân bằng người ta thả nhẹ vật m có khối lượng 100g lên M
(m dính chặt ngay vào M), sau đó hệ m và M dao động với biên độ
A.
9 @cm
B. 4,25cm C.
7 9cm
D.
9 9cm
Giải
Khi M về vị trí cân bằng thì vận tóc của M là:
A
M
k
Av +==
ω
Khi vật m nhỏ đặt lên M thì đây là va chạm mêm nên tốc đọ của vật là
mM
Mv
V
+
=
đậy của là tốc độ c]c đại của M+m
Nên:
cm
mM
k
mM
A

 7=
4
"tjr.6!
9 A
9
π
ϕ ϕ
= −
 !."
"#6!_38+P>
3
?U =
O+
:3V
+ P+
73 9V
+
:3 9V
+ G+738
^$C
D
"A
B73F8ED
"9
B_3F8EIIIIJ
A
9
d
d
U

AC
Z
E
9
IIIIIJ9F
9
aK
'
9
EBK
'
K
A
FhE
9 A
9
π
ϕ ϕ
= −
IIIIIJϕ
A
aϕ
9
B
9
π
IIIIIJϕ
A
ϕ
9

R
Z
Z
C
L
7
A
−
BIAIIIIIIJFK
'
gK
A
EFK
'
I
7
AC
Z
EBI
9
IIIIIIIJ
7
9
a7K
'
9
gLK
'
K
A

9
AC
Z
B9@K
'
K
A
IIIIIJK
A
B9@K
'
9F
9
aK
'
9
EBK
'
K
A
B9@K
'
9
IIIIJK
'
B9 !K
A
B@FhhhE
M‡V""TTCK
A

A
Z
U
IIIIIIIJDBD
"A
A
A
d
Z
Z
BD
"A

9

Do đó U
0
= U
9

= 2U
d1
= 60V. Chọn đáp án A
Câu 28
MNO !P>-R6S%.T%C
O
BL+T…FE !

P
B9+TF…abY7EFE<>T%0s(0+Mx<>

@7
Fe%n6!T%"(*2T%
On
!
Pn
E
~’8qM>
#9_. Trong thông tin liên lạc bằng sóng vô tuyến, người ta sử dụng cách biến
điệu biên độ, tức là làm cho biên độ của sóng điện từ cao tần (sóng mang) biến
thiên theo thời gian với tần số bằng tần số của dao động âm tần. Cho tần số sóng
mang là 780kHz. Khi dao động âm tần có tần số 1kHz th]c hiện một dao động
toàn phần thì dao động cao tần th]c hiện được số dao động toàn phần là:
O. 780 P. 390 . 1560 G. 195
^$C Gọi n
1
và n
2
là số dao động toàn phần sóng mang và sóng âm th]c hiện
trong thời gian t
t = n
1
T
1
= n
2
T
2
>
A
A

9
.
N=>)[&2n
A
n
9
"U \n6!_+eN
" \<><=&N>n
A
n
9
6!CA. 18 B. 16 C.
20 D. 14
n
A
n
9
n

^$C
%n
A
9
Bnn
A
9
an
9
Tn
A

3
I†

B9b%CI9LbY—a73bY—B9b
G%:bY—B9be—B7+
M>nn
A
%TN"&6!A9YF—Y9EBQF;s0NNnE
G%>nn
A
%QN" \<>&N
8j>nn
A
%A:N" \<><=&N
'>8qP4.s !.<Œ˜™
#7A+M>-.2R6S%T%0*OP"l
)r4
O
B
P
BT93
π
FE+<>T%0s(
T% B:3YT+WN
A

9
U=>l6jOP6!>N
%
A

w)r4T%N<R0” UC


B9TF
v
dd
9
EF
9A
−
ω
ETF…I
v
dd
9
EF
9A
+
ω
E
ŒšC
aTF…I
v
dd
9
EF
9A
+
ω
E[N6s0s(0.NU=>

M
−
=
%C
9
+TF
7
π
EB
A
+TFbE)r)r
9
A

9

BI
A

8j
9
BI9+
9
W[N62
A
6!
9
4N
9
%6

A 7 s
B.
A Q s
C.
A : s
D.
A A9 s
Giải :
L = x
2
- x
1
= 4
9
Cos( 4πt +π/12) - 4 Cos( 4πt +π/3) = 4 Cos( 4πt -π/6) cm
2
7
cm
Coi đây là một vật dao động điều hòa.
Thời điểm t
1
= 1/24s vật có li độ x
01
= 4cm
Thời điểm t
2
= 1/3 s vật có li độ x
02
= - 2
7

Bài 33:WRN !~U"t>UvnF
n6! /x#<=2ŒEk.4"RN0s 
 !+P)r4"2Œ66)*6! x
1
=10Cos( 4πt
+π/3)  ! x
2
= 10
9
Cos( 4πt +π/12)cm+WRN.@[N
>0Nf6Œ
3t =
6!
A.
A Q s
B.
A _ s
C.
@ 9L s
D.
AA 9L s
L = x
2
- x
1
= 10
9
Cos( 4πt +π/12) - 10Cos( 4πt +π/3) = 10Cos( 4πt -π/6) cm
Với L = 5cm
Coi đây là một vật dao động điều hòa.

Z
9
CS
N!5%" \<>&.N
9
S
SR<=
A.
m9Q mm
B.
:m_ mm
C.
@m9 mm
D.
mA9 mm
^$C—B YVBA@

3

•
n
›

9

A

•
n
›

9
<=:3
3
T%<=73
3
+
^v0$.e
9
WBTe
A
WBFA3gE
M%Ce
9
B9+ !WB+
7

M.e
A
W%Ce
A

9
BW
9
ae
A
W
9
BF+
7

9
TA33b8+,.OT\r)["t
%73
3
+,P1%%"()*+1
N(."D
O
aD
P
%./6\R+;%."
6!
O+LL38P+993
7
+993G+993
9
8
GiảiC
8„{ dr)4 „
,-œBFD
O
aD
P
E
9
+
M(FD
O
aD
P
E./&0œ./&

B
9
AM
U
a
9
C
U
I9D
O
D

T:3
3
B
9
AM
U
a
9
C
U
ID
O
D


D
9
B

O
D

FLE
œBœ

0cBD
O
D

%.6\RcBc

cBD
O
D

By
9
K
O
+K

B
9
9
+
Z
ZZU
CAM
B


BK
O
IIIIIJcBD
9
F@E !D

BD
O
73
3
D
D

D
O
:3
3
MfFLE !F@ECœBFD
O
aD

E
9

BD
9
a7D
9
BLD

7
λ
Bm7@+M>!
0$ #T.6>% ##kT.)*
<> T.rT` \<`69?
O+AAP+_+mG+:
P•y^yžy+
Bài 1
• ;
A
λ
A
B0
9
λ
9
BJ
A9
A@
L
@
A
9
9
A
===
λ
λ
k
k

7
39L:Q
~) j #T.6>% ##%AA #
T.2λ
9
)%@•U \λ
A
 !λ
7
>%: T.rT
` \<`λ
9
+,ŸwŸ~G
Câu 37C<"#$'
!+,- !.%./"DB
A338 !TV0s(+,1NB
A
B@3•4sTR>2
6!w
A
B:3o !%62. !"t6!ϕ
A
+,1NB

9
B9@•4sTR>26!w
9
 !%62. !"t
6!ϕ
9

A

A
BDTϕ
A
IIIIJy
A
B9Tϕ
A
FAE
w
A
BDy
A
Tϕ
A
B9DT
9
ϕ
A
IIIIIJT
9
ϕ
A
B
U
P
9
A
B

9
ϕ
9
B
L
7
IIIJT
9
ϕ
9
B
L
7
IT
9
ϕ
A
B
L
7
I
A3
7
B
93
_
FLE

A
9

9
9
T
T
ϕ
ϕ
B9+
A3
7
93
_
B7+Chọn đáp án C
Câu 38CPNn~U=>5)[ZR.fn+Mn
-N.T%#Z)\0ss)[0sR
#+`)[#6!m3"P~6!73"P+~N#%
T /x4`)[#N~0%6!
O+7:A"P+P+LA9"P++77L"P+G+L9A"P+
GiảiC^vw6!sTR2#
yB
9
L R
P
π
'

g'
~
B6
N
M

E
9

B969B3:39PFhE
'p
~
g'
~
B6
N
N
I
I“
B6F
MN
ON
E
9
B96
:973
:97A
B339QPIIIIIJ'p
~
B'
~
a339Q

B739QP
FhhE
L


λ
hc
B|
~
g|

B|
L
g|
7
BA7:F
_
A
I
A:
A
EBA7+:+
_+A:
m
>


λ
λ
=
m
A7@
. Đáp án C
Câu 40:66tk$SxkBa@+A3

+A3
L
YA3B@
P>\C
9@“
9
9
9
=+=
ω
v
xA

M1TxC
9
““
==
A
A
v
v
Câu 41:MxœI# .T.0l}e.[7
<`rT U.T.4R%<)\T%66)*
A 9
3L9 H 3@:m m
λ µ λ µ
= =
 !
7
λ

L
L
7
λλ
λ
λ
=→=
9 #T.U! \ #T.#%%7 #U
^]9 #!%9 #U2<`A !9x$ # !4%L
#)rŒ70$ #
8#"!29 U!##
a
D
L
A
L+7
λ
=
aT U2<`A !76!@)r`L0$ #CLB'
n
m
=
7
A
λ
λ
6!#TT$
7L+7L
AA
→==→

 !%6\6!AA3QYT
9
^$C
e56r /
046
g
l
T
π
9=
N04$4
"
q
~>
"
Ba
ag
l
T
+
=
π
9“
l<!
9
YA3Q3_@33@3
“
A3@3
“
sma

+ C. 6
A
+ D. 6
L
+
^$
B93YT
04"2!6!
MB
:9@3
93
@A9
==
v
S
04"2L66!
:793
A3
A3
99
A
A
===
ππ
g
l
T
M)r&CM
9
B3@9_THM

P
H
bx
=
wBD+y
w
<
B~+
λ
hc
u3Q3uA33+
33A3+A3+@3+A3
A3+7+A3+:9@:+A3+9
7A3
Q7LA7
==→
−
−
H
Câu 46:Mx \<!kN"j"tk
)[$"U{%./798+M.U}l6l
k !)\% !f)[%PB7+A3
g@
MT j2
l6l s% \
B
r
+P.0xk 6\R2.l6lk6!C
A. L3 B. L C. 93 D. 9
^$C

−
Câu 47:,-.%BDTF‡E8 !
% !$%$'PD'
0s(1V4R0VBV
A
4."•5
'66)*6!938L38:38;VB9V
A
4.$6!
O+93P+L9+Q3G+:L
GiảiC;VBV
A
%D
'
B9D

HD

B7D

IIIII+K
'
B9HK

B7 !%DB93
9
8
;VB9V
A
4K


III+D
p
BA3@8IIIII+U
L’
= 4U
R’
= 42V.
Đáp án B
Câu 48COPO \$
%&$6()*+,P \
%"+,- !OP.(/B
D
9
TωF8E4"0.K

26\R76+;'B'
A
4
."]O%./<=D
A
 !.`[
]OP6%ϕ
A
T \"t+;'
B'
9
B9'
A
4."]O%./<=D

G+ϕ
A
Iϕ
9
B:3
3
Giải:D
A
B
9
A
9
99
E7F RZR
ZRU
L
C
−+
+
B
9
A
9
E7F
A3
RZR
UR
L
−+
Hϕ

−+
Hϕ
9
B
R
RZ
L
7
9
−
B
R
RZ
L
79
A
−
D
9
B3@D
A
IIIIJ
9
A
9
E79F
A
RZR
L
−+

L
79
A
−
B9IIIIJϕ
9
B:7L7@
3
> ϕ
2
- ϕ
1
= 90
0

Câu1:.<%TRQ3u+TrR%A@3 t`R%
733 t+W`R \"#%A33Ω
&$7AQW+WTsTRTrR<=A+WTrR)*-
%D
A
BA338T@3WX+Mx)["Tr
R+
A. AQO B. 93O C. A@O D. 9@O
hD
9
BD
A
+~
9
Y~

9
y
9
Tϕ
9
B3QD
A
y
A
Tϕ
A
BJy
A
B9@O ,ŸwŸ~G
P!9.AR%VB:3WK~
s2%<=s0.%r-& !VB:3WK4T
tk2s[(m933 tT-2s<6!
O+A3P+L+A@G+@
hM%CVB
A
Y:3B:3BJ
A
B7:33Y
h!CVB
( )
A
:3
9
+p
n

ag73B3BJB@ ,ŸwŸ~G
P!7 !"#`R2.<.6x) !
%.BDq9TA334."
"#ŒN6!AA38~"#` !
>4.4."#`RN6!LL38,."
26!
O+A938P+AA38+A338
G+9938
h; !"#`R !C
UU
U
N
N
AA3
9
A
9
==
h; !"#` !C
LL3
AA
9
U
U
U
N
N
==
BJ
U

=
e T.<`76!
a
AA
:3
m
=
ae U2<`A !9
7
9
m
9@
@
L
AA9
9
A
=→==→= mmii
i
i
%(: #
aT U<`A !76!C
A7
B7
A
BA9
@
9A
m
=

Bài 2+M>-R6S%T%0*OPUOPBA3
N.O !P.OB:HPBQ<)\T%6!7+,)[
W s% \OPW+M>W%TN"U \
6!
O+7P+9+AG+3
Giải: M%WBLQHOWB7:HPWB:L
cdN~>W+
,-"
A
BO~H"
9
BP~ \7:¥"
A
¥:FE
"
9
"
A
~•
•

•
•
y
•
W
•PO•