ĐỀ THI HỌC SINH GIỎI 12
Môn: Vật Lý
Thời gian làm bài: 150 phút
I. PHẦN TỰ LUẬN
Câu 1. (2,0 điểm)
m
 !"#$k"#% &'$($)
*+,Hình 1a $/'01234
567F!84"#0 9.
-:;<0=2;(&  &(
 >=2;(?<*@'%A2346
> 3@)A$?.
'-B>2"#% &*+&
! M,Hình 1b)CD
M &&
µ
.:;<#1!56F*
2 m3E2".
Câu 2 (2,0 điểm).F?G2H>+I2
JK3 !L0M 
+ I
2 JJK ,-2 J,JK  -,
= π = π + π
 F
2<E NKOP.Q'7.
R.>L0)*S?G+I&S+NT
SINRJ.
       J.QU&*?G+IQU&0D
+UNRV.W1*36))IUX
Y.S
R

S
J
&*)+I+A&RJ &RZ.W1
C35S
R
 &S
J
X
Z.[\]&2*5)QU.W1*BQUA]?3
6)X
Câu 3 ,R*-
QLCH23/<+IU^0 9
.I>"#
$)3/<SB3&
l
>#_ !
2 &*2<*1>
3\82.:C@(E2
`La$@
B
ur
 2 !5
2 &E20 9.bccSB3.IG=2Cd2A5
23/<.Q$SB3E2" &c203
A2IU !4C32Q.
Câu 4.,R*-
e

k
Hình 1a

A
F

k
Hình 1b
S

+
S
I
U
^
B

⊕
Sở GD và ĐT Tỉnh Bắc Ninh
Trường THPT Lý Thái Tổ
:0J
S%LH3/<83&
R, -m=l
%A2 ! .
f?<NRK,P
J
-π
J
NRK.B(8%L% &A#8
33AE2 !V,P
J
I>3YK
K

 !
L.Fc2035%(.
Câu 5 (2,0 điểm).
Q)C0 9YHCdg4
CQ &2aCd2A%>.
h &A2))C#<E2
RJK. ,RKK -.=
AB
u c
π
IG=2Cd53/<
&5b.
R.IA2bCC234A2)+S &SIA&M
R J
ZK i JK RK .= =U V U V
-FcC2?5)).
'->'*2$5C$(A2Cdg.
J.hC3254C
Y
RK
.
−
=C F
π
bbd0CC234D*
SI&
RJ RK .=
MB
U V
Fc15Cdg &6af.

II. PHẦN TRẮC NGHIỆM
Câu 1:S%LE23&NOZ &NRKK.b`%C
G 1c/'O
K
Haj3.k2JK200'
l"&Y
K
.f?<Nm
J
NRKP
J
.h*%332<0 !'O
K
0a
3n'<HH*'72o2?2'0&M
+.Kppq. I.KKrJq. Q.Rpq. U.KKppq.
Câu 2.bsSNYTTK
 !('"#$
RBP.)NRK'<8L ! 

K
NOKP !"#> &s &3cs.k2 )C 
3 !'&
+.YK I.JK Q.J U.Y
Câu 3. St'%A2'<8L$ !NY.F
t8%L3&
R l m=
'%A2'<0H(cc%
6C 3G. IG=2  6 <  7   L  63  8   . f?<
J J

RK P i RK.g m s
π
= ≈
h>) 
RVKKh m=
0%;6C3
&M
+.JK. I.RZ. Q.RK. U.Rr.
Câu 4. F)"8)) 1cMS$(/)@2H&
pV3I$(/a#)d'$(c2&pJ3I.Q(/&A
) 1c'2'>'$(?4/.
+.pp3I. I.pT3I. Q.rR3I U.rY3I
Câu 5. u5?G2H>AB2RK3
8L$ !L0A& u
+
NY,ZKπt v
O
π
-
S
b


K
w w
R
L
C
K
A B

M
N
:0Y
u
I
NZ,ZKπt v
J
Y
π
-.Q'>2<E&ZKP.S("/
&2*5AB!'cZ.k*3 !'
V("&
+.YK. I.YJ. Q.YZ. U.YO.
Câu 6. S%"#$NZKBPA2D1"c3!
% .B/> 1c"#'>3)Haj 3E2"
8L$ !'JV.f?<NRKP
J
.F=203
\652?$(6)'
+.KZRq I.KOZq Q.KVq U.KYJq
Câu 7. S%"#3E2"8L !o3
Rx &6&H6)&RKB.[\y&A215"#a(%
?DJA>y123456`V
Y
B&KR.y2;(!
?& KZ&
+.OK. I.VK. Q.VV. U.VK
Y
.
Câu 8. F!)*k

R
k
J
(2HL>3
E2 &  8L$  !L  0 2
+
 NOZKπ & 2
I
 N
r,ZKπ-,2+ &2Ic'c' I>2<E!
&ZKP'72<E.F)k
R
k
J
*3
 !'R &2*5)k
R
k
J
)A?&
+.KJV I.KV Q.KpV U.R
Câu 9. S) gfQ f< 7  & A2)  C2 C>
JKK J RKKu tV
π
=
.hE2lf0?<fNf
R
N
R
π

: &fNf
J
N
Y
π
:E2
2?'2($((C
2RJK
K
.[1g &Q&M
A.

Z
RK RKK

J
Y
C F R
π
−
= = Ω
B.

Z
RK
 RKK YC F R
π
−
= = Ω
C.

Z
RK RKK

Y
C F R
π
−
= = Ω
D.
Z
RK
 RKK
J
C F R
π
−
= = Ω
Câu 10. Q)C#<E20 9.hC
32Q1<7 &23/<2Aa.
hE2l15Q0?<Mdn(*
l5
R
6)0l5
R
?l5
J
.:Gl5
J
6)
0l5

J
?'2Al
R
X
+.JA. I.RVA. Q.JVA. U.
J J
A