Backup of Lt Bt Vatly12 Ltdh 01

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GV. TRÖÔNG ÑÌNH HUØNG ÑT: 0908.346.838 Trang 1 TRUNG TAÂM LUYEÄN THI ÑAÏI HOÏC ÑAÏI VIEÄT ( NGUYEÂN LAØ TTLT ÑAÏI HOÏC SÖ PHAÏM TP.HCM ) TÓM TT CÔNG THC VÀ LÝ THUYT VT LÝ 12-LUYN THI ĐẠI HC VÀ CAO ĐẲNG ÑOÄNG LÖÏC HOÏC VAÄT RAÉN 1. Chuyeån ñoäng quay ñeàu: Tc độ góc trung bình ω tb ca vt rn là : t tb Δ Δ = ϕ ω Tc độ góc tc thi ω: t t Δ Δ = Δ ϕ ω 0 lim hay ) ( ' t ϕ ω = Vaän toác goùc ω = haèng soá. Toaï ñoä goùc. t ω ϕ ϕ + = 0 Vaän toác daøi cuûa ñieåm caùch taâm quay khoaûng r : r v × = ω 2. Chuyeån ñoäng quay bieán ñoåi ñeàu: Gia tc góc trung bình γ tb : t tb Δ Δ = ω γ Gia tc góc tc thi γ: t t Δ Δ = Δ ω γ 0 lim hay ) ( ' t ω γ = Gia toác goùc: γ = haèng soá. Vaän toác goùc: t γ ω ω + = 0 Toaï ñoä goùc: 2 2 1 0 0 t t γ ω ϕ ϕ + + = Coâng thöùc ñoäc laäp vôùi thôøi gian: ) ( 2 0 2 0 2 ϕ ϕ γ ω ω = 3. Lieân heä giöõa vaän toác daøi, gia toác cuûa moät ñieåm treân vaät raén vôùi vaän toác goùc, gia toác goùc: γ r a t = ; r r v a n 2 2 ω = = ; 4 2 4 2 2 2 2 2 ω γ ω γ + = + = + = r r r a a a t n Vectô gia toác a r hôïp vôùi kính goùc α vôùi: 2 tan ω γ α = = n t a a 4. Momem: a. Momen löïc ñoái vôùi moät truïc quay coá ñònh: d F M × = F laø löïc taùc duïng; d laø caùnh tay ñoøn (ñöôøng thaúng haï töø taâm quay vuoâng goùc vôùi phöông cuûa löïc b. Momen quaùn tính ñoái vôùi truïc: = 2 i i r m I (kg.m 2 ) Vôùi : m laø khoái löôïng, r laø khoaûng caùch töø vaät ñeán truïc quay P 0 P A z Hình φ r O v r t a r n a r a r r O M α Hình 2 O r F r Δ Δ L R Δ Hình nptien.yd3@bacgiang.edu.vn NPTI[email protected]

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Transcript of Backup of Lt Bt Vatly12 Ltdh 01

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TM TT CNG THC V L THUYT VT L 12-LUYN THI I HC V CAO NGONG LC HOC VAT RAN1. Chuyen ong quay eu: Tc gc trung bnh tb ca vt rn l : tb = Tc gc tc thi : = lim Van toc goc = hang so. Toa o goc. = 0 + t t

z

hay = ' (t ) t 0 t

P0

Van toc dai cua iem cach tam quay khoang r : 2. Chuyen ong quay bien oi eu: Gia tc gc trung bnh tb: tb = t

v = rP

r

O

A Hnh

Gia tc gc tc thi : = limGia toc goc: = hang so. Van toc goc: = 0 + t

t 0

hay = ' (t ) t

Toa o goc: = 0 + 0t + t 2 22 2 Cong thc oc lap vi thi gian: 0 = 2 ( 0 )

1

r vr r a at r M r an O

Hnh 2r F

3. Lien he gia van toc dai, gia toc cua mot iem tren vat ran vi van toc goc, gia toc goc: v2 at = r ; an = = 2 r ; r2 a = an + at2 = r 2 2 + r 2 4 = r 2 + 4

O r

L

a r Vect gia toc a hp vi knh goc vi: tan = t = 2 an 4. Momem: M = F d a. Momen lc oi vi mot truc quay co nh: F la lc tac dung; d la canh tay on (ng thang ha t tam quay vuong goc vi phng cua lc b. Momen quan tnh oi vi truc: I = mi ri2 (kg.m2) Vi : m la khoi lng, r la khoang cach t vat en truc quay

R

Hnh

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* Momen quan tnh cua thanh co tiet dien nho so vi chieu dai vi truc qua trung iem: 1 I = mL2 12 * Momen quan tnh cua vanh tron ban knh R truc quay qua tam: I = mR2 * Momen quan tnh cua a ac det truc quay qua tam: 1 I = mR2 2 * Momen quan tnh cua qua cau ac truc quay qua tam: 2 2 I = mR R 5 b. Momen ong lng oi vi mot truc: Hnh

R

Hnh L = I (kg.m/s) c. Momen quan tnh cua vat oi vi truc song song va cach truc qua tam G oan d . I = I G + md 25. Hai dang phng trnh ong lc hoc cua vat ran quay quanh mot truc co nh: dL M = I va M = dt 6. nh luat bao toan ong lng: Neu M = 0 th L = hang so Ap dung cho he vat : L1 + L 2 = hang so Ap dung cho vat co momen quan tnh thay oi: I11 = I 22 7. ng nng ca vt rn quay quanh mt trc c nh

ng nng W ca vt rn quay quanh mt trc c nh l :

W =

1 2 I 2

trong : I l momen qun tnh ca vt rn i vi trc quay l tc gc ca vt rn trong chuyn ng quay quanh trc ng nng W ca vt rn quay quanh mt trc c nh c th vit di dng : W =trong : L2 2I

L l momen ng lng ca vt rn i vi trc quay I l momen qun tnh ca vt rn i vi trc quay ng nng ca vt rn c n v l jun, k hiu l J. 8. nh l bin thin ng nng ca vt rn quay quanh mt trc c nh bin thin ng nng ca mt vt bng tng cng ca cc ngoi lc tc dng vo vt. 1 2 1 W = I2 I12 = A 2 2 trong : I l momen qun tnh ca vt rn i vi trc quay 1 l tc gc lc u ca vt rn 2 l tc gc lc sau ca vt rn A l tng cng ca cc ngoi lc tc dng vo vt rn W l bin thin ng nng ca vt rn 9. ong nang cua vat ran chuyen ong song phang:TRUNG TAM LUYEN THI AI HOC AI

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W =

1 2 1 2 I + mvC m la khoi lng cua vat, vC la van toc khoi tam 2 2

DAO ONG IEU HOA - CON LAC LO XOI. Dao ong ieu hoa: Dao ong ieu hoa la dao ong ma trang thai dao ong c mo ta bang nh luat dang sin( hoac cosin) oi vi thi gian . 1. Phng trnh dao ong (phng trnh li o) x = A cos( t + ) trong o : A, , la nhng hang so. A [m] la bien o ; [rad/s] la tan so goc [rad] la pha ban au t + [rad] pha dao ong Gi tr i s ca li : x C = A ; x CT = AO Fh

N F

x

P ln: |x|max =A (v tr bin) ; |x|min =0 (v tr cn bng) 2. Van toc: v = A sin( t + ) (m) Gi tr i s ca vn tc: v C = A VTCB theo chieu dng ; v CT = A VTCB theo chieu am ln vn tc :

v max = A (v tr cn bng ) ;

v min = 0

( hai bien )l0

Chu y: vat i theo chieu dng v>0, theo chieu am v v = A2 x 2 ; A 2 =

a 2 v2 + 4 2

5. Tan so goc chu ky tan so: t k 2 m = ; hoac T = = 2 ; T= ; t la thi gian thc hien N lan dao ong. k m N

f =

1 = 2 2

k ; m

hoac f =

1 T

t m1 = 2 2 2 N1 k T1 m1 N 2 = = m2 N1 t m2 T2 T2 = = 2 N2 k T1 =

6. Moi lien he gia li o, van toc, gia toc: x = A cos( t + ) ;TRUNG TAM LUYEN THI AI HOC AI

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v = A sin( t + ) = A sin( t + + ) = A cos( t + + a = 2 A cos( t + ) = 2 A cos( t + + ) ** Van toc nhanh pha hn li o goc 2** Gia toc nhanh pha hn van toc goc

2

) = A cos( t + +

2

)

2 ** Gia toc nhanh pha hn li o goc 7. Nang lng dao ong 1 1 * ong nang: W = mv 2 = m 2 A2 sin 2 (t + ) 2 2 1 1 Wt = Kx 2 = KA2 cos 2 (t + ) * The nang : Vi: k = m 2 2 2 1 1 * C nang: W = W + Wt = kA 2 = m2A 2 = W max = Wt max = Const 2 2 lu y: Con lac dao ong vi chu ky T, tan so f ,tan so goc th the nang, ong nang dao ong vi chu Ky T / 2 , tan so 2f, tan so goc 2 . Con c nang luon khong oi theo thi gian. * ng nng v th nng trung bnh trong thi gian nT/2 ( nN*, T l chu k dao ng) l:W 1 = m 2 A2 2 4

* Ti v tr c W = nWt ta c: 1 1 A + To : (n + 1). kx2 = kA2 x = 2 2 n +1 1 n +1 1 n + Vn tc: . mv2 = m2A2 v = A n +1 n 2 2 * Ti v tr c Wt = nW ta c: 1 n n +1 1 2 + To : . kx = kA2 x = A n 2 n +1 2 1 1 A + Vn tc: (n + 1). mv2 = m2A2 v = 2 2 n +1 x 8. Lc phuc hoi: La lc a vat ve v tr can bang(lc ieu hoa), luon hng ve v tr can bang

O

Fh

N

P

P

= 300

r r F = kx ;

P

o ln F = k x ; Tai vi tr bien :

Tai VTCB: Fmin = 0 Tai v tr co li o x:

Fmax = kA

l0

9. Lc an hoi: la lc a vat ve v tr chieu dai t nhien l 0

Fh = k l x* Con lac co lo xo nam ngang: * Con lac co lo xo thang ng:

Vi l = l l0l = 0

l

Fh

do o Fh = F ph

O

mg = k l

P

(+)

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+ Chieu dng thang ng hng xuong: + Chieu dng thang ng hng len :

Fh = k l + x Fh = k l x

* Con lac nam tren mat phang nghieng mot goc so vi mat phang ngang: mg sin = k l + + Chieu dng hng xuong: Fh = k l + x + Chieu dng hng len :Lc an hoi cc ai: Lc an hoi cc tieu: Neu A l : Fh min = 0

Fh = k l x

Fh _ max = k ( l + A)( v tr lo xo co chieu dai t nhien: Fh = 0)

Neu A < l : Fh _ min = k ( l A)10. Chieu dai t nhien lo , chieu dai cc ai lmax , chieu dai cc tieu lmin v tr lo xo co chieu dai t nhien: Fh = 0 * lcb = l0 + l (tai v tr can bang lo xo b dan)M K

* lcb = l0 l * lmax = lcb + A * lmin = lcb A

(tai v tr can bang lo xo b nen)

lmax lmin MN = , vi MN = chieu dai quy ao =2A 2 2 l +l * lcb = max min 2 11. Con lac lo xo gom n lo xo: 1 1 1 1 = + + ... + Mac noi tiep: * o cng knt k1 k 2 kn

*

A=

K1

K1A

K2

FA

FB

K2

B

m

m

* chu ky Mac song song: * o cng * chu ky

Tnt = 2

m k nt

2 va Tnt = T12 + T22 + ... + Tn2

P

k // = k1 + k 2 + k3 + ... + k n

T// = 2

m k //

va

1 1 1 1 = 2 + 2 +K+ 2 2 T// T1 T2 Tn

Con lac lo xo khi treo vat co khoi lng m1 th chu ky la T1 , khi treo vat m2 th chu ky la T2. ** khi treo vat co khoi lng m = m1 + m2 th chu ky la : T 2 = T12 + T22** khi treo vat co khoi lng m =| m1 m2 | th chu ky la : T 2 =| T12 T22 | 12. Neu cac lo xo co o cng k1, k2kn, co chieu dai t nhien l1, l2, ln co ban chat giong nhau hay c cat t cung mot lo xo ko, lo th:

l0 k0 =l 1k1 = l3 k3 ... = ln k n

13. Khong thi gian ngn nht vt i t v tr c to x1 n x2 x1 T/4 co s 1 = A 2 1 -A t = = vi 0 -A/2 co s = x2 2 T/6 T/12 T/12 ATRUNG TAM LUYEN THI AI HOC AI

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14. Van toc trung bnh khi vat i t v tr x1 en x2 : A x x2 x1 -A vtb = = t t2 t1 15. Toc o trung bnh : ** Chu y:

2 2

A

3 2

A X

0T/8 T/6 T/12

V=

S t

T/8

4A T 16. Tnh qung ng ln nht v nh nht vt i c trong khong thi gian 0 < t < T/2 trong DH. Vt c vn tc ln nht khi qua VTCB, nh nht khi qua v tr bin nn trong cng mt khong thi gian qung ng i c cng ln khi vt cng gn VTCB v cng nh khi cng gn v tr bin. S dng mi lin h gia dao ng iu ho v chuyn ng trn u. Gc qut : = t

Trong mot chu ky van toc trung bnh bang 0 va toc o trung V =

Qung ng ln nht khi vt i t M1 n M2 i xng qua trc sin S

max

= 2 A sin

2

Qung ng nh nht khi vt i t M1 n M2 i xng qua trc cos S Lu : + Trong trng hp t > T/2Tch t = nT + t 2*M2 P M1

= 2 A(1 cos ) min 2M2

T trong n N ;0 < t < 2

-A

A P2 O P 1 x

-A

P O

A x

T qung ng lun l n.2A. 2 Do o, quang ng i c trong thi gian t > T/2 la: S Max = n 2 A + 2 A sin ) vi = t va S Min = n 2 A + 2 A(1 cos 2 2 + Tc trung bnh ln nht v nh nht ca vat trong khong thi gian t: S S vtbMax = Max v vtbMin = Min vi SMax; SMin tnh nh trn. t tTrong thi gian n

M1

CON LAC N1. Phng trnh dao ong ieu hoa: khi bien o goc 0 100

O1

vi : s = l ; S0 = l 0 = 0 cos(t + ) (rad) hoac (o) Vi s : li o cong ; So : bien o ; : li o goc ; 0 : bien o goc2. Tan so goc chu ky tan so: Khi bien o goc 0 100

s = S 0 cos(t + ) (m)

l

0

T

pt

A

(+)

=

g l

T=

2

= 2

l g

f =

1 = 2 2

g l

O

p

pn

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l t = 2 1 2 2 N1 g T1 N l = 1 = 2 N la so lan dao ong trong thi gian t l 2 N1 l 2 T2 t T2 = = 2 N2 g

T1 =

3. Con lac vat ly: Tan so goc: =

mgd 2 I = 2 ; Chu ky: T = I mgd

4. phng trnh van toc khi bien o goc 0 100 :

v = S 0 sin( t + ) (m/s)Gi tr i s ca vn tc : vC = S 0 VTCB theo chieu dng ;

I0 H

vCT = S 0 VTCB theo chieu am ln vn tc :

v max = S 0 v tr cn bng ; v min = 0 hai bien5. Phng trnh gia toc (gia toc tiep tuyen) khi bien o goc 0 100 :

A

K O

a = 2 S 0 cos( t + ) = 2 s (m/s2)Gi tr i s ca gia tc :

a C = 2 S 0 v tr bien am ; ln gia tc :

a CT = 2 S 0

v tr bien dng

a min = 0 v tr can bang r r Chu y: a luon hng ve v tr can bang (gia toc tiep tuyen), a n l gia tc hng tm.2 Gia tc ton phn atp = an + a 2 =

a max = 2 S 0 v tr bin ;

6. phng trnh oc lap vi thi gian:S0 = s 2 + v2

v4 + 4s2 2 l a2 + v2

2

;

0 = 2 +

v2 gl

; S o2 =

4

2

; a = 2 S = 2 l

7. Van toc: Khi bien o goc o bat ky. * Khi qua li o goc bat ky: v 2 = 2 gl(cos cos 0 ) =>

v = 2 gl(cos cos 0 ) vCT = 2 gl(1 cos 0 )

* Khi qua v tr can bang: = 0 cos = 1 vC = 2 gl(1 cos 0 ) ;

* Khi hai bien: = 0 cos = cos 0 v = 0 Chu y: Neu 0 10 0 , th co the dung: 1 cos 0 = 2 sin 2 vmax = 0 gl = S0

02

=

022

8. Sc cang day: Khi bien o goc 0 bat ky * Khi qua li o goc bat ky: * Khi qua v tr can bang :T = mg (3 cos 2 cos 0 )

= 0 cos = 1 Tvtcb = Tmax = mg (3 2 cos o )

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* Khi qua v tr bien:

= 0 cos = cos 0 Tbien = Tmin = mg cos 0 02 =

Chu y: Neu 0 10 0 , th co the dung: 1 - cos 0 = 2 sin 2

022

2 Tmin = mg 1 0 ; 2

2 Tmax = mg (1 + 0 ) ;

*** Lc phuc hoi cua con lac n : Fph = mg sin = mg = mg 9. Nang lng dao ong: ong nang: The nang: C nang:W =

s = m 2 s l

1 2 mv0 = mgl (cos cos 0 ) 2 1 Wt = mgh = mgl (1 cos ) = mgl 2 Vi h = l(1 cos ) 2 W = W + Wt = mgl (1 cos 0 ) = W max = Wt max0 2

Chu y: Neu o 10 th co the dung: 1 cos 0 = 2 sin

02

=

022

1 1 mg 2 1 1 2 2 W = m 2 S02 = S0 = mgl 0 = m 2l 2 0 2 2 l 2 2

* Ti cng mt ni con lc n chiu di l1 c chu k T1, con lc n chiu di l2 c chu k T2. ** Con lc n chiu di l1 + l2 c chu k T 2 = T12 + T22** Con lc n chiu di l1 - l2 c chu k T 2 = T12 T22

10. Con lc n c chu k ng T cao h1, nhit t1. Khi a ti cao h2, nhit t2 th ta c: T h t = + T R 2 Vi R = 6400km l bn knh Tri t, cn l h s n di ca thanh con lc. 11. Con lc n c chu k ng T su h1, nhit t1. Khi a ti su h2, nhit t2 th ta c: T h t = + T 2R 2 12. Con lc n c chu k ng T ti ni c gia tc g1. Khi a n ni c gia tc g2, th ta c: T g l l = vi g = g 2 g1 . con lc chy ng gi th chiu di dy tha: 1 = 2 T 2g g1 g 2 Lu : * Nu T > 0 th ng h chy chm (ng h m giy s dng con lc n) * Nu T < 0 th ng h chy nhanh * Nu T = 0 th ng h chy ng T * Thi gian chy sai mi giay la: = T T 86400( s ) * Thi gian chy sai mi ngy (24h = 86400s): = T 12. Khi con lc n chu thm tc dng ca lc ph khng i: Lc ph khng i thng l: ur r ur r * Lc qun tnh: F = ma , ln F = ma ( F a ) r r r Lu : + Chuyn ng nhanh dn u a v ( v c hng chuyn ng)TRUNG TAM LUYEN THI AI HOC AI

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[email protected]: 0908.346.838 Trang 9 r r + Chuyn ng chm dn u a v ur ur ur ur ur ur * Lc in trng: F = qE , ln F = |q|E (Nu q > 0 F E ; cn nu q < 0 F E ) uu u ur r r u r Khi : P ' = P + F gi l trng lc hiu dng hay trong lc biu kin (c vai tr nh trng lc P ) ur uu u F r r g ' = g + gi l gia tc trng trng hiu dng hay gia tc trng trng biu kin. m l Chu k dao ng ca con lc n khi : T = 2 g Cc trng hp c bit: ur * F c phng ngang: F + Ti VTCB dy treo lch vi phng thng ng mt gc c: tan = P p g F g = + g ' = g 2 + ( ) 2 ; p = cos cos m E ur F * F c phng thng ng th g ' = g m ur F T + Nu F hng xung th g ' = g + m F ur F + Nu F hng ln th g'= g m P' P 13. o chu k bng phng php trng phng xc nh chu k T ca mt con lc l xo (con lc n) ngi ta so snh vi chu k T0 ( bit) ca mt con lc khc . Hai con lc gi l trng phng khi chng i qua VTCB cng mt lc theo cng mt chiu. TT0 Thi gian gia hai ln trng phng lien tiep : = T T0 GV. TRNG NH HUNG

Nu T > T0 = nT = (n+1)T0. vi n Z+ Nu T < T0 = nT0 = (n+1)T.

CAC LOAI DAO ONG1. Dao ong t do: Dao ong t do la dao ong co chu ky hay tan so ch phu thuoc vao ac tnh cua he dao ong, khong phu thuoc vao cac yeu to ben ngoai. VD: + Con lac lo xo dao ong trong ieu kien gii han an hoi. + Con lac n dao ong vi bien o goc nho,bo qua sc can moi trng va tai mot a iem xac nh 2. Dao ong tat dan: Dao ong tat dan la dao ong co bien o giam dan theo thi gian. Nguyen nhan: Nguyen nhan dao ong tat dan la do lc ma sat hay lc can cua moi trng. Cac lc nay luon ngc chieu vi chieu chuyen ong, nen sinh cong am v vay lam giam c nang cua vat dao ong. Cac lc nay cang ln th s tat dan cang nhanh. x * Mt con lc l xo dao ng tt dn vi bin A, h s ma st . + Qung ng vt i c n lc dng li l: 2 O kA 1 W W0 = mgS 0 kA2 = mgS S = ; 2mg 2T

t

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Neu lo xo nam nghieng goc th: S =+ o giam bien o trong mot chu ky:

kA2 2mg cos

1 1 4mg 4g k ( A A) 2 kA2 = mg 4 A => A = = 2 2 2 k 2 A kA A = = + So lan dao ong trc khi dng: N = A 4mg 4g T kA A = + Thi gian dao ong cho en luc dng: t = T N = 4mg 2g m * e m luon nam yen tren M th bien o cc ai la: m k M g (m + M ) g M A 2 = k * e m khong trt tren M th bien o dao ong la: Hnh 1 g (m + M ) g A 2 = la he so ma sat gia m va k 3. Dao ong cng bc: Dao ong cng bc la dao ong cua he di tac dung cua mot ngoai lc bien thien ieu hoa, co dang: F = F0 cos t gom hai giai oan.* Giai oan chuyen tiep: dao ong cua he cha on nh, gia tr cc ai cua li o (bien o) c tang dan, cc ai sau ln hn cc ai trc. * Giai oan on nh: khi o gia tr cc ai khong thay oi(bien o khong oi) va vat dao ong vi tan so cua lc cng bc f Lu y:Dao ong cua vat trong giai oan on nh goi la dao ong cng bc. Bien o phu thuoc vao quan he gia tan so ngoai lc f vi tan so rieng cua he f0. ** S cong hng c Bien o A cua dao ong cng bc at gia tr cc ai khi tan so cua lc cng bc bang tan so rieng cua he dao ong. ( ieu chnh tan so cua lc cng bc, ta thay khi ) flc=f rieng A = AMax Neu lc ma sat nho th cong hng ro net hn(cong hng nhon) Neu lc ma sat ln th cong hng t ro net hn(cong hng tu)

TONG HP DAO ONG1. Tong hp 2 dao ong ieu hoa cung phng, cung tan so Gia s mot vat thc hien ong thi 2 DH cung phng, cung tan so: x1 = A1 cos(t + 1 ) va x2 = A2 cos(t + 2 ) Dao ong hp la: x = x1 + x2 = A cos(t + )2 Vi A2 = A12 + A2 + 2 A1 A2 cos( 2 1 ) ;

y Ay A2yA2 M2 A M

tan =

A1 sin 1 + A2 sin 2 A1 cos 1 + A2 cos 2

* Neu hai dao ong thanh phan Cung pha: = 2k th Ngc pha: Vuong pha: = (2k + 1)

A=Amax = A1 + A2A1yO2 1 2 2

= ( 2k + 1) th A=Amin = A A2

2

th A = A + A 2 Lech pha nhau bat ky: A A2 A A1 + A2TRUNG TAM LUYEN THI AI HOC AI

1

A1

M1

x Ax

A2x

A1x

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** Chu y: Neu e cho x1 = A1 cos(t + 1 ) va cho phng trnh tong hp x = x1 + x2 = A cos(t + ) . Tm x2 = A2 cos(t + 2 ) Th:A2 = A2 + A12 2 A1 A cos( 1 ) ;2

tan =

A sin A1 sin 1 A cos A1 cos 1

2. Tong hp n dao ong ieu hoa cung phng, cung tan so: x1 = A1 cos(t + 1 ) , x2 = A2 cos(t + 2 ) , xn = An cos(t + n ) Dao ong hp la: x= x1 + x2 + ... + xn = A cos(t + ) Thanh phan tren truc nam ngang ox: Thanh phan tren truc thang ng oy:2 A = Ax2 + Ay

Ax = A1 cos 1 + A2 cos 2 + ... + An cos nAy = A1 sin 1 + A2 sin 2 + ... + An sin n

;

tg =

Ay Ax

SONG C HOCI. nh ngha: Song c hoc la cac dao ong c hoc lan truyen theo thi gian trong mot moi trng vat chat. Co hai loai song: Song doc la song co phng dao ong trung vi phng truyen song Song ngang la song co phng dao ong vuong goc vi phng truyen song. * Lu y: song ngang ch truyen c trong moi trng ran va tren mat chat long II. Cac ai lng ac trng cua song 1. Van toc song (toc o truyen song ) v = van toc truyen pha dao ong, van toc phu thuoc vao nhiet o, tnh an hoi cua moi trng,mat o phan t. Trong mot moi trng xac nh v = const. * Moi si day c keo bang mot lc cang day va co mat o dai la th toc o truyen song tren day la:v=

Chu y: Toc o truyen song khac toc o dao ong cua phan t vat chat co song truyen qua 2. Chu ky va tan so song Chu ky song = chu ky dao ong cua cac phan t co song truyen qua = chu ky cua nguon song

Tan so song = tan so dao ong cua cac phan t co song truyen qua = tan so cua nguon song: f =

1 T

A

o

3. Bc song: la quang ng song truyen trong mot chu ky, bang khoang cach gia hai iem v = vT = gan nhau nhat tren cung mot phng truyen song giao ong cung pha. f 4. Bien o song A A song = A dao ong= bien o dao ong cua cac phan t co song truyen quaTRUNG TAM LUYEN THI AI HOC AI

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5. Nang lng song W: Qua trnh truyen song la qua trng truyen nang lng 1 Wsong = Wdao _ dong m 2 A2 2 a. Neu song truyen tren mot ng thang ( mot phng truyen song) nang lng cua song khong oi, bien o khong oi W = const => A = const b. Neu song truyen tren mat phang(song phang) nang lng song giam t le quang ng 1 1 A~ truyen song va bien o giam t le vi can bac hai quang ng truyen song WM ~ rM rM c. Neu song truyen trong khong gian (song truyen theo mat cau) nang lng song giam t le bnh phng quang ng truyen song va bien o giam t le vi quang ng truyen song 1 1 WM ~ 2 A ~ rm rM III. Phng trnh song Phng trnh song tai mot iem trong moi trng truyen song la phng trnh dao ong cua iem o. 1. phng trnh truyen song a. Gia s phng trnh song tai O: u = A cos t r v Th phng trnh song tai mot iem M cach O mot khoang d la: M O * Neu song truyen t O en M th d d d d u M = A cos (t ) = A cos(t ) = A cos t 2 vi t v v v * Neu song truyen t M en O th d d d r u M = A cos (t + ) = A cos(t + ) = A cos t + 2 v O M v v Tai mot iem M xac nh trong moi trng: d = const : u M la mot ham bien thien ieu hoa theo thi gian t vi chu ky T. Tai mot thi iem xac nh: t = const: d = x : u M la mot ham bien thien ieu hoa trong khong gian theo bien x vi chu ky . b. Gia s phng trnh song tai O: u = A cos(t + ) Th phng trnh song tai mot iem M cach O mot khoang d la: * Neu song truyen t O en M th d d d d u M = A cos[ (t ) + ] = A cos[(t ) + ] = A cos[ t 2 + ] vi t v v v * Neu song truyen t M en O th d d d u M = A cos (t + ) + = A cos (t + ) + = A cos t + 2 + v v IV. o lech pha: o lech pha dao ong gia hai iem M,N bat ky trong moi trng truyen song cach nguon O lan lt la d M va d N : : d dM d dM MN = N = 2 N v * Neu M va N dao ong cung pha th:TRUNG TAM LUYEN THI AI HOC AI

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MN = k 2

2

dN dM

* Neu M va N dao ong ngc pha th: d dM 2 N = (2k + 1) MN = (2k + 1)

= k 2

d N d M = k

(k Z )

* Neu M va N dao ong vong pha th: d dM d N d M = (2k + 1) MN = (2k + 1) 2 N = (2k + 1) (k Z ) 4 2 2 * Neu hai iem MN nam cung tren cung mot phng truyen song cach nhau oan d: d 2 MN = = d ( d = d N d M = MN ) v d = k * Neu M va N dao ong cung pha th: k N* * Neu M va N dao ong ngc pha th: 1 d d1 d = (2k + 1) d = ( k + ) hoac (kN ) 2 2 O M N * Neu M va N dao ong vong pha th:

d N d M = (2k + 1)

2

(k Z )

d = (2k + 1)

4

(k N )

d2

SONG AM1. nh ngha: Song am la song c hoc lan truyen trong moi trng vat chat nh ran, long, kh. Con ngi co the nghe tan so 16 Hz f 2.10 4 Hz (Am thanh) Song co tan so nho hn 16Hz la song ha am, song co tan so ln hn 20.000 Hz la song sieu

am.

Song am truyen c trong chat ran, long, kh khong truyen c trong chan khong, van toc song am phu thuoc vao mat o phan t va tnh an hoi va ca nhiet o. Toc o truyen am giam dan t ran, long, kh. 2. o cao cua am. La ac trng sinh ly cua am phu thuoc vao tan so. Am co tan so ln goi la am cao(thanh), am co tan so thap goi la am thap ( tram ) 3. Cng o am I: la nang lng am truyen qua mot n v dien tch at vuong goc vi phng truyen am trong mot n v thi gian. W p I= = (n v : W / m 2 ) ; P = cong suat ; S la dien tch; t.S S p Cng o am tai iem cach nguon oan R trong khong gian: I = 4R 2 I I L( B ) = lg = 10 L 4. Mc cng o am L: suy ra (B n v Ben) I0 I0L(dB) = 10 lg I I0

1B =10 dB

(dB: e xi ben)

I 0 = 1012W / m 2 cng o am chuan ng vi f=1000Hz I I I I L2 L1 = lg( 2 ) lg( 1 ) = lg( 2 ) 2 = 10 L 2 L1 cong thc ben L phai co n v Ben I1 I0 I0 I1Chu y: Tai con ngi ch phan biet c hai am co mc cng o am hn kem nhau 10dB. 5. Tan so cua am: Am c ban hay con goi la hoa am bac 1 la: f0TRUNG TAM LUYEN THI AI HOC AI

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Hoa am bac 2: f2=2f0 ;

Hoa am bac 3: f3=3f0 ;

Hoa am bac n: fn=nf0

* Mt day an hai au co nh co chieu dai l song dng co tan so: f k = k

v ( ch co 1 bo song); hoa am bac 2 th k=2; bac 3 th k=3; 2l * Mot ong sao hoac xaxophon co chieu dai l (mot au kn mot au h ) co tan so: v fm = m (m=1,3,5,7) ch co hoa am bac le. 4l v Am c ban ng vi m=1 th f1 = (song co 1 nut va1 bung) 4l 3v Hoa am bac 3: m=3 th f 3 = (song co 2 nut 2 bung ) 4l 5v Hoa am bac 5: m=5 th f 5 = (song co 3 nut 3 bung ) 4l 6. Am sac: la ac trng sinh l cua am, phu thuoc vao tan so va bien o (o th am) giup ta phan biet cac nguon am. 7. o to cua am: la ac trng sinh l cua am, phu thuoc vao tan so va mc cng o am 8. Ngng nghe: La am co cng o nho nhat ma tai ngi con co the nghe c. Ngng nghe phu thuoc vao tan so cua am.(moi tan so khac nhau th ngng nghe khac nhau). 9. Ngng au: Neu cng o am len ti 10W/m2 ng vi mc cng o am 130dB, oi vi moi tan so, song am gay cam giac nhc nhoi trong tai. Gia tr cc ai o cua cng o am goi la ngng au. Ngng au ng vi cng o am la130dB va hau nh khong phu thuoc vao tan so cua am. 10. Mien nghe c: Nam gia ngng nghe va ngng au. Vi tan so chuan 1000Hz ngng nghe la 0 dB, ngng au la 130 dB 11. Hieu ng op_Ple: vM la toc o chuyen ong cua may thu v vM f= f vs la toc o chuyen ong cua nguon am v m vSAm c ban ng vi k=1 : f1 =v la toc o truyen am trong moi trng Chu y: * khi nguon am hay may thu tien lai gan nhau th lay dau (+) trc vM va dau (-) trc vS va lay dau ngc lai cho trng hp may thu va nguon tien ra xa nhau. * khi may thu ng yen th vM=0, khi nguon am ng yen th vS=0

v ( k=1,2,3) 2l

GIAO THOA SONGGiao thoa song la s tong hp hai hay nhieu song ket hp trong khong gian, trong o co nhng cho co nh bien o song tong hp c tang cng hay giam bt. I.Giao Thoa Ca Hai Sng Pht Ra T Hai Ngun Sng Kt Hp S1,S2 Cch Nhau Mt Khong l: Xt im M cch hai ngun ln lt d1, d2 1. TRNG HP CO PHA BAT KY: S1 Phng trnh sng ti 2 ngun u1 = Acos(2 ft + 1 ) v u2 = Acos(2 ft + 2 ) Phng trnh sng ti M do hai sng t hai ngun truyn ti: d d u1M = Acos(2 ft 2 1 + 1 ) v u2 M = Acos(2 ft 2 2 + 2 ) s2

Phng trnh giao thoa sng ti M: uM = u1M + u2MTRUNG TAM LUYEN THI AI HOC AI

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d1 + d 2 1 + 2 d d uM = 2 Acos 1 2 + cos 2 ft + 2 2 d d Bin dao ng ti M: AM = 2 A cos 1 2 + 2 vi = 1 2 l l Ch : * S cc i: + f2>f3 C. f1=f2=f3 D. f1>f2 = f3 A. f1 = f2 > f3 Cau 19: Dng in chy qua mt on mch c biu thc i = I 0 sin 100 .t ( A) . Trong khong thi gian t 0 n 0,01s, cng tc thi c gi tr: bng 0,5I0 vo nhng thi im: 1 2 1 3 1 2 1 5 A. s; s B. s; s C. s; s D. s; s 400 400 500 500 300 300 600 600 Cau 20: Mch dao ng LC dao ng iu ho vi tn s gc 7.103 rad/s.Ti thi im ban u in tch ca t t gi tr cc i. Thi gian ngn nht k t thi im ban u nng lng in trng bng nng lng t trng l: B. 1,008.10-4s. C. 1,12.10-4s. D. 1,12.10-3s A. 1,008.10-3s. Cau 21: Trong mach dao ong ien t LC, neu ien tch cc ai tren tu la Q 0 va cng o dong ien cc ai trong mach la I 0 th chu ky dao ong ien t trong mach la: A. T = 2 Q 0 L B. T = 2 LC C. T = 2

Q0 I0

D. T = 2

I0 Q0

Cau 22: Chn cu sai A. Nguyn tc to ra dng in xoay chiu da trn hin tng cm ng in t. B. Khi o cng dng in xoay chiu, ngi ta c th dng ampe k nhit. C. S ch ca ampe k xoay chiu cho bit gi tr hiu dng ca dng in xoay chiu. D. Gi tr hiu dng ca dng in xoay chiu bng gi tr trung bnh ca dng in xoay chiu. Cau 23: in nng mt trm pht in c cng sut in 200KW c truyn i xa di hiu in th 2KV. S ch cng t in trm pht v ni tiu th sau mi ngy ch lch nhau 480KWh th hiu sut ca qu trnh truyn ti in nng l: A. 80%. B . 85% C. 90%. D.95%. Cau 24: t mt hiu in th xoay chiu c gi tr hiu dng U v tn s f thay i vo hai u mt in tr thun R. Nhit lng to ra trn in tr A. t l vi f2. B. t l vi U2. C. t l vi f. D. B v C u ng. Cau 25: Chn pht biu sai khi ni v ngha ca h s cng sut cos A. tng hiu qu s dng in nng, chng ta phi tm cch nng cao h s cng sut. B. H s cng sut cng ln th cng sut tiu th ca mch in cng ln. C. H s cng sut cng ln th cng sut hao ph ca mch in cng ln.TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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Cau 26 : Chiet suat cua moi trng trong suot oi vi cac anh sang n sac khac nhau la ai lng: A. Co gia tr khac nhau bc song n sac cang dai th chiet suat cang ln . B. Co g tr khac nhau, ln nhat oi vi n sac o va nho nhat oi vi n sac tm. C. Co gia tr bang nhau, oi vi moi n sac t o en tm. D. Co gia tr khac nhau, tan so n sac cang cao th chiet suat cang ln. Cau 27: Chon phat bieu ung khi noi ve s quang phat quang: A. Bc song cua anh sang phat quang bao gi cung nho hn bc song cua anh sang kch thch B. Tan so f cua anh sang phat quang bao gi cung nho hn tan so f cua anh sang kch thch C. S huynh quang la s phat quang ma thi gian phat quang dai, thng xay ra oi vi chat long va chat kh. D. S lan quang la s phat quang ma thi gian phat quang ngan thng xay ra oi vi chat ran. Cau 28: Tia t ngoai: A. Co ban chat la song ien t co tan so ln hn tan so anh sang trong thay B. Co ban chat la song c hoc co tan so ln hn tan so anh sang trong thay C. Co ban chat la dong electron co van toc rat ln D. Co kha nang am xuyen rat manh. Cau 29: Tnh chat nao sau nay khong phai la tnh chat cua tia X? A. Tac dung manh len knh anh, lam oxi hoa khong kh B. Tac dung lam phat quang nhieu chat C. Co kha nang huy diet te bao, vi khuan D. Co the xuyen qua tam ch day c cm. Cau 30: Trong th nghiem young ve giao thoa anh sang trang ( 0, 4 m 0,76 m ) , hai khe sang cach nhau 0,3 mm, t hai khe sang ti man la 1m. Be rong quang pho lien tuc bac hai la: A. 1,44mm B. 0,72mm C. 1,2mm D. 2,4mm Cau 31: Trong th nghiem young ve giao thoa anh sang n sac, ngi ta thay tren man quan sat khoang van la 0,3mm. iem M cach van sang chnh gia 3mm, iem N cach van sang chnh gia 1,2mm. Hoi t iem M en iem N co bao nhieu van sang ? Biet M va N cung mot ben cua van sang chnh gia. A. 7 B. 5 C. 8 D. 6 Cau 32: Trong hien tng quang ien , electron bt ra khoi be mat kim loai khi: B. Cac mang tinh the trong kim loai b bien dang B. Tam kim loai b nung nong nhiet o cao C. Co anh sang thch hp chieu vao no D.Tam kim loai b nhiem ien do tiep xuc Cau 33: Hien tng quang dan la hien tng: A. Giam mach ien tr tc la tang o dan ien cua ban dan khi c chieu sang thch hp. B. Electron bat ra ngoai chat ban dan khi c chieu sang thch hp C. Giam manh ien tr tc la tang o dan ien cua ban dan khi c ot nong. D. Electron bat ra ngoai kim loai khi c chieu sang thch hp. Cau 34: Trang thai dng cua nguyen t la: A. Trang thai ma nguyen t khong bc xa khong hap thu B. Trang thai ma nguyen t ch hap thu mot t nang lng C. Trang thai ma nguyen t ch bc xa mot t nang lng D. Trang thai ma nguyen t ng yen khong chuyen ong. Cau 35: Chieu anh sang co bc song = 0,546 m len be mat kim loai dung lam catot cua mot te bao quang ien thu c dong quang ien bao hoa co cng o Ibh = 2.10-3 A. cong suat cua anh sangTRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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1,515W. t so gia so electron bc ra khoi katot va so photon ap vao catot trong moi giay ( goi la hieu suat lng t) co gia tr: B. H = 3.10-4 C. H = 5.10-3 D. H = A. H = 2.10-4 -3 3.10 Cau 36: Trong quang pho hiro, vach pho au tien va vach pho th hai cua day laiman co bc song lan lt la 0,1216 m va 0,1026 m . Tm bc song cua vach quang pho au tien cua day banme. A. 0,6566 m B. 0,7066 m C. 0,7576 m D. 0,6056 m Cau 37: Khi so sanh phan ng nhiet hach va phan ng phan hach ta thay: A. Khong the ieu khien c ca hai loai phan ng B. Neu tnh theo khoi lng nhien lieu th s nhiet hach toa nang lng nhieu hn C. Muon co cac phan ng xay ra phai can nhiet o rat cao D. Khac nhau v s nhiet hach can co nhiet o rat cao mi xay ra phan ng nen la phan ng thu nang lng. Cau 38: Mot hat nhan co o hut khoi cang ln th: A. Nang lng lien ket rieng cang nho B. Cang de b pha v C. Nang lng lien ket cang nho D. Nang lng lien ket cang ln Cau 39: Chn cu sai trong cc cu sau : A. Phng x l phng x i km theo cc phng x v . B. Phtn do ht nhn phng ra c nng lng rt ln. C. Tia - l cc lectrn nn n c phng ra t lp v nguyn t. D. Khng c s bin i ht nhn trong phng x Cau 40: Cho mt on mch in gm mt bin tr R mc ni tip vi mt t in c C =

100

vo hai u on mch mt hiu in th xoay chiu n nh u vi tn s gc 100 rad/s. Thay i R ta thy vi hai gi tr: ca R1 R 2 th cng sut ca on mch u bng nhau. Tch R1 .R 2 bng: A. 10 B. 100 C. 1000 D. 10000 238 206 9 Cau 41: U phn r thnh Pb vi chu k bn r T = 4,47.10 nm. Mt khi c pht hin c cha 46,97mg 238U v 2,135mg 206Pb. Gi s lc khi mi hnh thnh khng cha nguyn t ch v tt c lng ch c mt trong u l sn phm phn r ca 238U.Tui ca khi hin nay l: A. gn 2,5.106 nm. B. gn 3,3108 nm. C. gn 3,4.107 nm. D. gn 6.109 nm. 238 Cau 42: Hat nhan 92 U ng yen phong xa . Biet hat co ong nang W = 1,5MeV. Coi t sokhoi lng cac hat nhan bang t so so khoi tng ng. Nang lng toa ra t phan ng la: A. 3,225MeV B. 1,715MeV C. 2,5MeV D. 1,526MeV Cau 43: ac iem nao sau ay khong phai la cua laze? A. Tia laze co mat o cong suat ln B. Tia laze rat n sac C. Tia laze la chum sang hoi tu D. Tia laze la anh sang ket hp Cau 44: Ngi ta da vao cac ac iem nao di ay e phan cac hanh tinh trong he mat tri lam hai nhom: A. Khoang cach en mat tri. B. Nhiet o be mat hanh tinh. C. So ve tinh nhieu hay t. D. khoi lng ring. Cau 45: Chon phat bieu khong ung khi noi ve cac thien ha: A. Co ba loai thien ha: thien ha xoan oc , thien ha elp va thien ha khong nh hnh B. He mat tri nam trong thien ha cua chung ta C. Moi thien ha gom co hang tram t sao D. Thien ha cua chung ta hoan toan oc lap vi cac thien ha khac.

F . t

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Trang 173

Cau 46: Mt my bay bay cao h1= 100 mt, gy ra mt t ngay pha di mt ting n c mc cng m L1=120dB. Mun gim ting n ti mc chu c L2 = 100 dB th my bay phi bay cao: A. 316 m. B. 500 m. C. 1000 m. D. 700 m. Cau 47: Chon phat bieu ung khi noi ve hat s cap: A. Tat ca cac hat s cap eu mang ien B. Tat ca cac hat s cap eu rat ben C. Tat ca cac hat s cap eu khong mang ien D.Cac hat s cap eu co khoi lng va the tch rat nho. Cau 48: Mot vat dao ong ieu hoa vi bien o 10cm, chu ky T. Quang ng nho nhat ma vat i c trong thi gian T/4 la: A. 7,07cm B.5,857cm C. 10cm D. 20cm Cau 49: Trong mot th nghiem ve giao thoa song tren mat nc, hai nguon ket hp A va B dao ong vi phng trnh: u A = u B = sin 40 t ( cm ) .Van toc truyen song tren mat nc la 40 cm/s. Bien o song xem nh khong oi. Xet iem M tren mat nc cach A va B lan lt la 27cm va 24cm, cho biet trang thai dao ong cua M la: A. M dao ong khong ac sac. B. dao ong vi bien o cc ai. C. khong u d kien e xac nh. D. ng yen. 2 Cau 50: Mt khung dy hnh ch nht c tit din 54cm gm 500vng, quay u xung quanh trc vi vn r tc 50vng/giy trong t trng u 0,1Tesla. Chn gc thi gian lc B song song vi mt phng khung dy th biu thc sut in ng hai u khung dy l :

A. e = 27sin(100t +

2

) V.

B. e = 27sin(100t ) V. D. e = 27sin(100t +

C. e = 27sin(100t + 900) V.

2

) V.

Phan danh cho ban nang cao (gom 10 cau t cau 51 en cau 60)

Cau 51 : Hai cht im c khi lng 1 kg v 2 kg c gn hai u ca mt thanh nh c chiu di 1 m. Momen qun tnh ca h i vi trc quay i qua trung im ca thanh v vung gc vi thanh c gi tr bng A. 0,75 kg.m2. B. 0,5 kg.m2. C. 1,5 kg.m2. D. 1,75 kg.m2. Cau 52 : Tren mat mot chat long, tai O co mot nguon song c dao ong co tan so f =30Hz. Van toc m m truyen song la mot gia tr nao o trong khoang 1,6 < v < 2.9 . Biet tai iem M cach O mot khoang s s 10cm song tai o luon dao ong ngc pha vi dao ong tai O .Gia tr cua van to o la: A. 2m/s B. 3m/s C. 2,4m/s D. 1,6m/s Cau 53: Khoi lng cua mot vat co khoi lng ngh m0=1kg chuyen ong vi toc o v=0,6c la: A. 1,25kg B. 0,8kg C. 1,25g D. ap an khac Cau 54: Hop X cha hai trong ba phan t: ien tr thuan, cuon day, tu ien. Khi at vao hai au AB mot hieu ien the xoay chieu co tan so f, th ngi ta nhan thay hieu ien the gia hai au AM lech pha /2 so vi hieu ien the gia hai au MB. Hop X cha: R X A. ien tr thuan va tu ien. B. cuon day thuan cam va ien tr thuan. C. cuon day thuan cam va tu ien. D. cuon day khong thuan cam va tu ien. Cau 55: Nguyen t hyro ang trang thai dng co nang lng En. thap chuyen len trang thai dng co nang lng Em cao hn (Em En =10,2 eV) khi no hap thu mot photon co nang lng. A. 10 , 2 eV B. > 10 , 2 eV C. = 10 , 2 eV D. 10 , 2 eV .A M

B

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6 Cau 56: Phn ng: 3 Li + n3T + + 4,8MeV . Gi s ban u ng nng cc ht khng ng k . ng 1 nng ca T v ln lt l: (lay t so so khoi bang t so khoi lng ) B. WT = 2,06MeV, W = 2,74MeV. A. WT = 2,47MeV, W = 2,33MeV.

C. WT = 2,40MeV, W = 2,40 MeV.

D. WT = 2,74MeV, W = 2,06MeV

Cau 57: Tren mot ng ray thang noi gia thiet b phat am P va thiet b thu am T, ngi ta cho thiet b P chuyen ong vi van toc 20m/s lai gan thiet b T ng yen. Biet am do thiet b P phat ra co tan so 1200Hz, van toc am trong khong kh la 340m/s. Tan so am ma thiet b T thu c la: A. 1129Hz B. 1275Hz C. 1000Hz D. 1340Hz Cau 58: Mt vt rn ang quay quanh mt trc c nh xuyn qua vt vi tc gc 20 rad/s th bt u quay chm dn u v dng li sau 4 s. Gc m vt rn quay c trong 1 s cui cng trc khi dng li (giy th t tnh t lc bt u quay chm dn) l A. 37,5 rad. B. 2,5 rad. C. 17,5 rad. D. 10 rad. Cau 59: Mot a ac co ban knh 0,25m, a co the xung quanh truc oi xng i qua tam va vuong goc vi mat phang a. a chu tac dung cua 1 momen lc khong oi M = 3Nm. Sau 2s ke t luc a bat au quay vi van toc goc cua a la 24 rad/s. momen quan tnh cua a la: B. I = 0,25 kgm2 C. I = 7,50 kgm2 D. I = 1,85 kgm2 A. I = 3,60 kgm2 Cau 60: ong nang cua vat ran lan khong trt cua vat ran c xac nh bi cong thc: A. wd =

1 mv c 2

B. wd =

1 2 mv c 2

C. wd = Het

1 1 2 mv c + I 2 2

D. w d =

1 1 mv c2 + I 2 2 2

************************************************

(Thi gian lam 90 phut) Cau 1: Pht biu no sai khi ni v dao ng tt dn? A. Pha ca dao ng gim dn theo thi gian B. C nng ca dao ng gim dn theo thi gian C. Bin dao ng gim dn theo thi gian. D. Lc cn v lc ma st cng ln th s tt dn cng nhanh Cau 2: Mt vt dao ng iu ho xung quanh v tr cn bng theo phng trnh

e 3

E THI TUYEN SINH AI HOC

s th ng nng ca vt li bng x = Acos(t + )cm .Bit rng c sau nhng khong thi gian bng 60 2 th nng. Chu k dao ng ca vt l: s 15 60 20 30 Cau 3:Mot con lac lo xo gom vat co khoi lng M=1kg va lo xo co o cng k=400N/m, ang nam yen tren mat phang nam ngang khong ma sat. Mot vien an co khoi lng m=5g bay vi toc o 400m/s theo phng ngang cam vao vat M. Toc o goc va bien o dao ong cua con lac la: A. 20rad/s; 10cm B. 10rad/s; 1cm C. 2rad/s; 10m D. ap an khac Cau 4: Mt vt dao ng iu ho theo phng trnh: x = 2sin(5t + /6) + 1 (cm).Trong giy u tin k t lc bt u dao ng vt i qua v tr c ly x = 2 cm theo chiu dng c my ln? A. 2 ln. B. 3 ln. C. 4 ln. D. 5 ln. Cau 5:Vat dao ong vi phng trnh chuyen ong co dang x = A cos(2t )(cm) .Vat i qua v tr can bang lan th 7 vao thi iem:A. B. C. D.TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

s

s

s

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A. 6,5s B. 6s C. 3,25s D. 3s 0 Cau 6: Mot ong ho qua lac co chu ky 0 C la T = 2 s (chay ung gi). Qua lac ong ho c xem nh mot con lac n, day treo bang ong co he so n dai = 170.10-6 o-1. Khi nhiet o tang len 500C th ong ho chay nhanh hay cham mot ngay (24 gi) la: A. Cham 367,2s B. Nhanh 367,2s C. Cham 4,25.10-4 s D. Nhanh -4 4,25.10 s Cau 7: Phat bieu nao sau ay sai? E. Tan so cua dao ong cng bc luon bang tan so rieng cua he dao ong F. Khi cong hng dao ong xay ra, tan so dao ong cng bc cua he bang tan rieng cua he dao ong o G. Dao ong tat dan la dao ong co bien o giam dan theo thi gian H. Dao ong cng bc la dao ong chu tac ong cua mot ngoai lc bien thien tuan hoan ( Cau 8: Tc truyn sng c trong mt mi trng ng tnh v ng hng ph thuc vo A. Bn cht mi trng v nng lng sng B. Bn cht mi trng v cng sng C. Bn cht mi trng v bin sng D. Bn cht v nhit mi trng Cau 9: Tai iem O tren mat nc, co mot nguon song dao ong theo phng thang ng vi chu ky T = 0,4s. T O co gn song tron lan rong ra xung quanh, khoang cach gia hai gn song ke tiep la 18cm. Van toc truyen song tren mat nc la: A. v = 7,2cm/s B.v=22,5cm/s C. v=45cm/s D. v=3,6cm/s Cau 10: Bc sng ln nht to ra sng dng ca mt ng c chiu di L, mt u h v mt u kn l: A. 4L. B. 2L. C. L. D.L/2. Cau 11: Khi cng o am tang gap 10 lan, th mc cng o am tang 10dB; khi cng o am tang gap 100 lan th mc cng o am tang: A. 100dB B. 20dB C. 30dB D. 50dB Cau 12: Mch nh hnh v

A

cuon day

M

C

B

uAB = 120 2 sin (100t)V. Dng vn k c in tr rt ln o gia A v M th thy n ch 120V, v uAM nhanh pha hn uAB

A. u MB = 120 2 sin(100t + )V2

2

Biu thc uMB c dng : B. u MB = 240 sin(100t )V4

C. u MB = 120 2 sin(100t + )V4

D. u MB = 240 sin(100t )V2

Cau 13:

Mch R-L-C:

B

C

M

L

R

A

1 100 H, f = 50 Hz. Lc u C = F, sau ta gim in dung C. Gc lch pha gia 2 uAM v uAB lc u v lc sau c kt qu: A. rad v khng i B. rad v tng dn R = 50 , L = C.2

Cau 14: Cho mt my bin th( H=1) c cun s cp c 150 vng, cun th cp c 300 vng. Hai u cun th cp ni vi mt cun dy c in tr hot ng 100, t cm 1/ H. Hai u cun s cp c t hiu in th xoay chiu c U1 = 100V c tn s 50Hz. Cng sut mch th cp l : A. 200W B. 150W C. 250W D. 142,4WTRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

2

rad v gim dn

D.

4

2

rad v dn tng

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Cau 15: Muon ong nang cua electron khi ve en anot con lai mot na so vi ong nang ban au cc ai th at vao hai au anot va catot hieu ien the:A. UAK = 2 mv0 max 4e

B. UAK =

2 mv0 max 4e

C. UAK =

2 mv0 max 2e

D. UAK =

2 mv0 max . 2e

Cu 16: t mt hiu in th xoay chiu u = U0sint vo hai u on mch ch c in tr thun R. Gi U l hiu in th hiu dng hai u on mch; i, I0, I ln lt l gi tr tc thi, gi tr cc i v gi tr hiu dng ca cng dng in trong mch. H thc lin lc no sau y khng ng?

A.

U I = 0. U0 I0

B.

u i = 0. U I

C.

u2 i2 2 =1 2 U0 I0

D.

U I + = 2. U 0 I0

Cau 17: Cho on mch khng phn nhnh RLC, R = 80 cun dy c in tr trong 20 c t cm L = 0,318H, t in c in dung 15,9F. t vo hai u mch in mt dng in xoay chiu c tn s f thay i c c hiu in th hiu dng l 200V. Khi cng dng in chy qua mch mch t gi tr cc i th gi tr ca f v I l: A.70,78Hz v 2,5A. B. 70,78Hz v 2A.. C. 444,7Hz v 10A. D. 31,48Hz v 2A. Cau 18: m thanh truyn nhanh nht trong mi trng no sau y? A. Khng kh B. Nc C. St D. Kh hir Cau 19: at hieu ien the xoay chieu hieu dung 220V_60Hz vao hai au mot bong en huynh quang. Biet en ch sang khi ien ap at vao hai au bong en khong nho hn 110 2 V. Thi gian en sang trong moi giay: 1 2 1 1 s s s s A. B. C. D. 4 3 3 2 Cau 20: Mt mch dao ng in t gm t in c in dung C =1 F v mt cun dy thun cm, 16

ang dao ng in t c dng in cc i trong mch l I 0 = 60mA . Ti thi im ban u in tch trn t in q = 1,5.10 6 C v cng dng in trong mch i = 30 3mA . t cm ca cun dy l: A. 40mH B. 50mH C. 60mH D. 70mH Cau 21: Sng trung l sng c c im: A. Ban ngy b tng in li hp th mnh, ban m b tng in li phn x B. Khng b tng in li hp th hoc phn x C. t b nc hp th nn dng thng tin di nc D. B tng in li phn x tt Cau 22: Trong vic truyn ti in nng i xa, gim cng sut hao ph trn ng dy k ln th hiu in th u ng dy phi B. gim k ln. C. gim k2 ln. D. tng k ln. A. tng k ln. Cau 23: in nng mt trm pht in c truyn i xa vi hiu in th 2KV, hiu sut ca qu trng truyn ti l 80%. Mun hiu sut ca qu trnh truyn ti tng ln n 95% th ta phi A. tng hiu in th ln n 4KV. B. tng hiu in th ln n 8KV. C. gim hiu in th xung cn 1KV. D. gim hiu in th xung cn 0,5KV Cau 24: Mt t in c ni vi ngun in xoay chiu, in tch trn t in t gi tr cc i khi: A. in p gia hai bn t t cc i cn cng dng in qua n bng 0. B. Cng dng in qua t in v in p gia hai bn t u bng 0. C. Cng dng in qua t in v in p gia hai bn t u t cc i. D. in p gia hai bn t bng 0 cn cng dng in qua n cc iCau 25: Mch in xoay chiu c t in C ni tip vi cun dy. H s cng sut ca mch bng 1 th: A. Trong mch c cng hng, cun dy khng thun cm B. Trong mch c cng hng, cun dy thun cm C. lch pha gia cng dng in i v hiu in th u hai u on mch l TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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D. lch pha gia i v u bng 0, cun dy thun cm Cau 26 : Chieu tia sang trang i t nc ra khong kh (khong co phan xa toan phan) th: E. Tia lo ra khoi mat nc van la anh sang trang. B. Chum tia lo ra ngoai la chum sang lien tuc tia o nam gan mat nc nhat. C. Chum tia lo ra ngoai la chum sang lien tuc tia tm nam gan mat nc nhat. D. Chum tia lo ra ngoai la chum sang lien tuc tia tm nam xa mat nc nhat. Cau 27: Quang ph vch c pht ra khi nung nng sng

A. Mt cht lng hoc kh (hay hi) C. Mt cht rn, lng, kh (hay hi)Cau 28: Tia t ngoai co the phat ra t : A. Mat tri B. Ho quang ien vat tren

B. Mt cht kh (hay hi) p sut thp D. Mt cht kh (hay hi) p sut caoC. Vat nong tren 30000C D. Tat ca cac

Cau 29: Ong Rnghen co bc song ngan nhat la 6,625.10-10m va cng o dong ien trong ong la I = 2mA. Tnh nhiet lng lam nong oi catot. Biet 90% ong nang electron ap vao oi catot la lam nong oi catot. A. 0,375(J) B. 33,75(J) C. 33,75.1019(eV) D. 3,375(J). Cau 30: Trong th nghim giao thoa I ng i vi nh sng trng khong cch t 2 ngun n mn l 2m, khong cch gia 2 ngun l 2mm. S bc x cho vn sng ti M cch vn trung tm 4mm l: A. 4. B. 7. C. 6. D. 5 Cau 31: Mot lang knh co goc chiet quang A = 50 (c coi la goc nho), co chiet suat oi vi anh sang o va anh sang tm la n = 1,643, nt = 1,685. Mot chum tia sang hep roi vao mat ben cua lang knh di goc ti i. Goc hp bi tia o va tia tm khi lo ra khoi lang knh la: A. 210 B. 0,210 C. 300 D. 450 Cau 32: mt cht bn dn tr thnh vt dn th: A. Bc x in t chiu vo cht bn dn phi c tn s ln hn mt gi tr f 0 ph thuc vo bn cht ca cht bn dn B. Cng ca chm bc x in t chiu vo cht bn dn phi nh hn mt gi tr no ph thuc vo bn cht ca cht bn dn. C. Bc x in t chiu vo cht bn dn phi c bc sng ln hn mt gi tr 0 ph thuc vo bn cht ca cht bn dn D. Cng ca chm bc x in t chiu vo cht bn dn phi ln hn mt gi tr no ph thuc vo bn cht ca cht bn dn Cau 33: Hien tng quang hoc nao c s dung trong may phan tch quang pho lang knh? A. hien tng khuc xa anh sang B. hien tng giao thoa anh sang C. hien tng phan xa anh sang D. hien tng tan sac anh sang Cau 34 :Bc song ngan nhat cua bc xa phat ra trong day laiman ng vi electron chuyen t:(ch xet cac trng hp di ) A. mc nang lng E 2 ve mc nang lng E1 B. mc nang lng E 6 ve mc nang lng E1 C. mc nang lng E 3 ve mc nang lng E2 D. mc nang lng E 6 ve mc nang lng E2 Cau 35: Mt con lc n dao ng iu ho, neu tang them chieu dai 25% th chu ky dao ong cua no

A. tang 24%

B. tang 11,8%

C. giam 25%

D. giam 11,8%

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Cau 36: Bc sng ca vch u tin trong dy Lai-man v vch H trong quang ph nguyn t hir ln lt bng 0,122m v 0,435m. Bc sng ca vch th t trong dy Lai-man c gi tr A. 0,313m. B. 0,557m. C. 0,053m. D. 0,095m. Cau 37 : Qu trnh bin i phng x ca mt cht phng x: A. Xy ra nh nhau trong mi iu kin B. Ph thuc vo cht trng thi n cht hay thnh phn ca mt hp cht C. Ph thuc vo cht th rn hay th kh D. Ph thuc vo nhit cao hay thp Cau 38: Phn ng ht nhn no sau y l phn ng thu nng lng? A. Phn ng m trong tng ht khi ca cc ht nhn sinh ra b hn tng ht khi ca cc ht nhn tham gia phn ng B. S phng x C. Phn ng nhit hch D. Phn ng m trong tng ht khi ca cc ht nhn sinh ra ln hn tng ht khi ca cc ht nhn tham gia phn ng Cau 39: Chn cu pht biu ng : A. phng x cng ln nu khi lng cht phng x cng ln . B. phng x ch ph thuc vo bn cht ca cht phng x . C. Ch c chu k bn r mi ph thuc phng x . D. C th thay i phng x bi yu t ha, l ca mi trng bn ngoi Cau 40: Nang lng ion hoa nguyen t Hyro la 13,6eV. Bc song ngan nhat ma nguyen t co the bc ra la A. 0,122m B. 0,0913m C. 0,0656m D. 0,5672m Cau 41:210 84

Po la chat phong xa hat . Ban au ta co 1g, PO vi chu k ban ra T = 138 ngay. The tch

khi heli thu c sau 1 nam ieu kien tieu chuan la: B. 8,96cm3 C. 0,896cm3 D. 89,6cm3. A. 896cm3 r 7 Cau 42: Mt proton c vn tc v bn vo nhn bia ng yn 3 Li . Phn ng to ra 2 ht ging ht nhau mX bay ra vi vn tc c ln bng nhau v v cng hp phng ti ca proton mt gc 600. Gi tr v l 3m p .v m .v m .v 3mX .v B. v ' = C. v ' = p D. v ' = A. v ' = X mp mX mp mX Cau 43: Chum sang do laze Rubi phat ra la: A. trang B. xanh C. o D. vang. Cau 44: Hay ch ra cau truc khong la thanh vien cua mot thien ha: A. Sao sieu mi B. Punxa. C. Lo en. D. Quaza. Cau 45: . Loa cua mot may thu thanh co cong suat 1W khi m to het cong suat. e tai iem cach nguon am 4m co mc cng o am la 70dB th phai giam cong suat i bao nhieu lan: A. 300 lan B. 400 lan C. 500 lan D. 600 lan Cau 46: Cho on mch RLC ni tip c gi tr cc phn t c nh. t vo hai u on ny mt hiu in th xoay chiu c tn s thay i. Khi tn s gc ca dng in bng 0 th cm khng v dung khng c gi tr ZL = 100 v ZC = 25. trong mch xy ra cng hng, ta phi thay i tn s gc ca dng in n gi tr bng: A. 40. B. 20. C. 0,50. D. 0,250. Cau 47: trong cac hat s cap sau hat nao khong ben: A. ntron B. electron C. notrino D.photon. Cau 48: Mot vat dao ong ieu hoa vi bien o 10cm,chu ky T. Quang ng ln nhat ma vat i c trong thi gian T/4 la:TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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Trang 179 D.

20cm Cau 49: Hai ngun kt hp S1, S2 dao ong cung pha cch nhau 11cm, c chu k sng l 0,2s. Vn tc truyn sng trong mi trng l 25cm/s. S cc i giao thoa trong khong S1S2 l: A. 5. B. 1. C. 3. D. 7. Cau 50: Mt ng c khng ng b ba pha c hiu in th nh mc mi pha l 220 V. Bit rng cng sut ca ng c 10,56 kW v h s cng sut bng 0,8. Cng dng in hiu dng qua mi cun dy ca ng c l: A. 2 A B. 6 A C. 20 A D. 60 A Cau 51 : khi nguon sang chuyen ong toc o truyen anh sangtrong chan khong co gia tr A. nho hn c. B. ln hn hoac nho hn c, phu thuoc vao phng truyen va toc o cua nguon C. ln hn c. D. luon bang c, khong phu thuoc vao phng truyen va toc o cua nguon. Cau 52 : Mt sng c hc truyn trong mt mi trng n hi. Mi cht im ca mi trng trn

Phan danh cho ban nang cao (gom 10 cau t cau 51 en cau 60)

phng truyn sng u dao ng theo phng trnh: x = 8 cos( t + )cm. Cho bit tc truyn sng v 3 = 50 cm/s. Chn kt qu ng v lch pha ti cng mt im M sau thi gian cch nhau 1s. 2 A. = . B. = . C. = D. = 4 6 3 3 Cau 53 : Ngi ta o c mc cng m ti im A l 90 dB v ti im B l 70 dB. Hy so snh cng m ti A ( I A ) vi cng m ti B ( I B ) . A. I A = 9 I B / 7 B. I A = 30 I B C. I A = 3I B D. I A = 100 I BCau 54: Mch nh hnh v A R,L N R,L B uAB = 80 2 cos100 t(V), R = 160 , ZL = 60 Vn k ch UAN = 20V. Bit rng UAB = UAN + UNB . in tr thun R v t cm L c gi tr: 1 1 H B. R = 160/3 (); L = H A. R = 160 (); L = 2 3 1 1 H D. R = 160/3 (); L = H C. R = 160 (); L = 5 5 Cau 55: Mot nguon sang iem n sac at cach te bao quang ien oan d th e triet tieu dong quang ien can co hieu ien the ham Uh = 2V, khi a nguon sang cach te bao quang ienoan d = 0,5 d th hieu ien the ham se la: B. Uh = 2V C. Uh = 0,5V D. Uh = 1,5V A. Uh = 1V Cau 56: Cho phan ng A. 10MeV234 92

U + 230 Th . Biet nang lng lien ket rieng cua 230Th la 7,7MeV cua 90B. 14MeV C. 17MeV D. 26MeV.

hat la 7,1MeV cua hat 234U la 7,63MeV. Nang lng phan ng la:

Cau 57: Mt ngi quan st ng trn b bin nghe thy ting ci tu bin. Khi c tu v ngi quan st ng yn th ngi nghe c m thanh c tn s f = 420 Hz. Khi tu chuyn ng vo b th ngi nghe c m c tn s f' = 430 Hz. Tnh tc ca tu nu tc truyn m trong khng kh l v = 338 m/s. A. 6,86 m/s B. 7,86 m/s C. 9,86 m/s D. 5,86 m/s 2 quay u vi vn tc 90 Cau 58: Mt rng rc c momen qun tnh i vi trc quay c nh 5 kg.m vng/pht. ng nng quay ca rng rc i vi trc quay l A. 125 J B. 225 J C. 12,5 J D. 200 JTRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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Cau 59: Mt bnh xe quay nhanh dn u t trng thi ngh (quanh mt trc quay c nh), sau 10s u tin n t tc gc l 20 rad/s. Trong thi gian , bnh xe quay c mt gc c ln (tnh bng rad) l: A. 4 B. 200 C. 2 D. 100 Cau 60: Mt lc tip tuyn 0,71N tc dng vo vnh ngoi ca mt bnh xe c ng knh 60cm. Bnh xe quay t trng thi ngh v sau 4 giy th quay c 1 vng u tin. Momen qun tnh ca bnh xe l: B. . 1,08 kgm2 C. 4,24 kgm2 D. 0,54 kgm2 A. 0,27 kgm2 Ht ********************************************************************

e 4

E THI TH TUYEN SINH AI HOC

(Thi gian lam 90 phut) Cau 1: Mt con lc l xo nm ngang c k=400N/m; m=100g; ly g=10m/s2; h s ma st gia vt v mt sn l =0,02. Lc u a vt ti v tr cch v tr cn bng 4cm ri bung nh. Qung ng vt i c t lc bt u dao ng n lc dng li l: A. 1,6m B. 16m. C. 16cm D. p n khc. Cau 2: Con lc l xo c kch thch dao ng t do vi chu k T = 2 s . Bit ti thi im t = 1s

th ng nng v th nng bng nhau ln th nht. Ln th t ng nng v th nng bng nhau vo thi im l: A. 2,5s B.3 s C. 4s D. 5sCau 3:He gom hai vat (m=1kg va M=3kg) va mot lo xo co o cng k=100N/m, c at tren mat phang nam ngang, khong ma sat. He so ma sat ngh gia hai vat la 0,4. Hoi bien o dao ong toi a la gia tr nao sau ay e khong xay ra s trt gia hai Hnh 1 vat: A. 0,1568m B.0,1568cm C. 1,568m D. ap an khac Cau 4: Mot con lac dao ong tat dan cham. C sau moi chu ky, bien o giam 3%. Phan nang lng b mat i trong mot dao ong toan phan la: A. 3%. B. 9%. C. 6%. D. 27%. Cau 5:Vat dao ong vi phng trnh chuyen ong co dang x = A cos(2t + tr x = Ak

m M

6

)(cm) .Vat i qua v

3 lan th 2009 theo chieu am( ke t t=0) vao thi iem: 2 A. 1004,5s B.2009 s C. 2008s D. 2010s Cau 6: ong ho qua lac (coi nh la con lac n ) chay ung khi at mat at ( ban knh Trai at R = 6400 km) . Khi at ong ho o cao h = 500m (cung nhiet o) th moi ngay khoang thi gian ong ho chay nhanh hay cham la bao nhieu? A. Cham 6,75 s. B. Cham 5,55 s. C. Nhanh 6,25 s. D. Nhanh 5,75 s. Cau 7: S t dao ng l mt dao ng: A.C bin khng i v tn s dao ng l tn s dao ng ring ca h B. C bin khng i v dao ng vi tn s dao ng ca lc cng bc C. C bin thay i v tn s dao ng l tn s dao ng ring ca h D. C bin khng i nhng tn s dao ng thay i Cau 8: i lng no sau y ca sng m khng chu nh hng khi tnh n hi ca mi trng thay i? A. Tn s B. Bc song C. Bin D. Cng Cau 9: Tren mat nc hnh thanh mot song tron tam O co tan so 16 Hz. Tai A va B tren mat nc, cach nhau 6 cm tren ng thang qua O, cac phan t luon dao ong cung pha. Biet toc o truyen song nam trong khoang 0,4m / s v 0,6m / s. Toc o truyen song tren mat nc nhan gia tr .TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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C. v = 44 cm/s D. v= 24 cm/s. d Cau 10: Mt sng dng trn dy c dng: u = 2 sin cos(20 t + ) cm, trong u l li ti thi 4 2 im t ca phn t N trn dy m v tr cn bng ca n cch u c nh M ca dy l d (cm). Vn tc truyn sng trn dy l: A. 80cm/s B. 40cm/s C. 100cm/s D. 60cm/s 2 Cau 11: Ngng au cua tai ngi chng 10 W/m . Gia s mot nguon am kch thc nho S at cach tai mot khoang d=1m. e am do nguon am phat ra gay ra cam giac au cho tai ngi, th cong suat am toi thieu cua nguon la: A. 125,6W B. 12,56W C. 125,6W/m2 D. ap an khac Cau 12: Mt mch in xoay chiu gm R, L, C mc ni tip. Bit L, C khng i v tn s dng in thay i c. Bit rng ng vi tn s f1 th ZL =50 v ZC = 100 . Tn s f ca dng in ng vi lc xy ra cng hng in phi tho: A. f > f1. B. f < f1. C. f = f1. D. c th ln hn hay nh hn f1 tu thuc vo gi tr ca R. Cau 13: Cho mt on mch in RLC ni tip. Bit L = 0,5/ H, C = 10-4/ F, R thay i c. t vo hai u on mch mt hiu in th n nh c biu thc: u = U 2 sin 100t (V). Khi thay i R, ta thy c hai gi tr khc nhau ca bin tr l R1 v R2 ng vi cng mt cng sut tiu th P ca mch. Kt lun no sau y l khng ng vi cc gi tr kh d ca P? A. R1.R2 = 2500 2. B. R1 + R2 = U2/P. C. |R1 R2| = 50 . D. P < U2/100. Cau 14: . Trong my bin th l tng, khi gi nguyen so vong day hai cuon va cng dng in hiu dng cun th cp tng n ln th cng dng in hiu dng mch s cp thay i nh th no? A. Tng n ln. B. tng n2 ln C. Gim i n ln D. C A, B, C u sai. Cau 15: Cng o dong trong te bao la 0,32mA. Biet rang 80% so electron tach ra c chuyen ve anot. So electron tach ra khoi catot trong 20s la:

A. 25.1016 B. 25.1015 C. 50.1016 D. 5.1016. Cu 16: Mt bn i c coi nh mt on mch c in tr R c mc vo mng in AC 110V50Hz.Khi mc n vo mng AC 110V 60Hz th cng sut to nhit ca bn i: A. Tng ln. B. Gim i. C. Khng i. D. C th tng, c th gim. Cau 17: Mch RLC ni tip c 2 . f LC = 1. Nu cho R tng 2 ln th h s cng sut ca mch: A. Tng 2 ln B. Gim 2 ln C. Khng i D. Tng bt k Cau 18: Hnh dng sng truyn theo chiu dng trc Ox mt thi im c dng nh hnh v. Sau thi im chiu chuyn ng ca cc im A, B, C, D v E l: u A A. im B, C v E i xung cn A v D i ln. B. im A, B v E i xung cn im C v D i ln. E B C. im A v D i xung cn im B, C v E i ln. D. im C v D i xung v A, B v E i ln. C D Cau 19: Cho hai dao ong cung phng cung tan so 2 x1 = 2009 cos(2010t + )cm va x2 = A2 cos(t + 2 )cm . Dao ong tong 3hp cua chung la x = x1 + x2 = 2009 3 cos(2010t + A. x1 = 2009 3 cos(2010t +

x

2 )cm 3

2

)cm . Phng trnh dao ong cua x2 la: B. x1 = 2009 cos(2010t +

6

)cm

TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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5 )cm 3 6 Cau 20: Mt mch dao ng in t LC c C = 5F , L = 50mH , cng dng in cc i trong mch I0 = 0,06A. Ti thi im m hiu in th trn t l u = 3V th cng dng in trong mch i c B. 0,03 A C. 0,02 2 A ln: A. 0,03 3 A )cm D. x1 = 2009 cos(2010t +

D. 0,02 3 ACau 21: Chn cu sai khi ni v sng in t: A. sng in t mang nng lng. B. sng in t c th phn x, nhiu x, khc x, giao thoa. C. c thnh phn in v thnh phn t bin thin vung pha vi nhau. D. sng in t l sng ngang truyen c trong chan khong. Cau 22: Trong vic truyn ti in nng i xa, gim cng sut hao ph trn ng dy k ln th u ng dy phi may bien the co he so: B. k. C. k2 . D.1/ k . A. k . Cau 23 : Ngi ta truyn ti in xoay chiu mt pha t mt trm pht in cch ni tiu th 10km. Dy dn lm bng kim loi c in tr sut 2,5.10-8m, tit din 0,4cm2, h s cng sut ca mch in l 0,9. in p v cng sut truyn i trm pht in l 10kV v 500kW. Hiu sut truyn ti in l: A. 93,75% B. 96,14% C. 92,28% D. 96,88% Cau 24 : Hin tng cng hng trong mch LC xy ra cng r nt khi A. in tr thun ca mch cng nh. B. cun dy c t cm cng ln. C. in tr thun ca mch cng ln. D. tn s ring ca mch cng ln. Cau 25 : Dng in xoay chiu l dng in c: A. cng bin thin tun hon theo thi gian. B. chiu bin thin tun hon theo thi gian. C. chiu bin thin iu ho theo thi gian. D. cng bin thin iu ho theo thi gian. Cau 26 : Chn pht biu sai khi ni v nh sng n sc: A. nh sng n sc l nh sng c mu sc xc nh trong mi mi trng. B. nh sng n sc l nh sng c tn s xc nh trong mi mi trng. C. nh sng n sc l nh sng khng b tn sc. D. nh sng n sc l nh sng c bc sng xc nh trong mi mi trng. Cau 27: Hien tng ao vach quang pho cho phep ket luan rang: A.Trong cung mot ieu kien ve nhiet o va ap suat , moi chat eu hap thu va bc xa cac anh sang co cung bc song. B. Trong cung mot ieu kien, mot chat ch hap thu hoac ch bc xa anh sang . C. nhiet o xac nh, mot chat ch hap thu nhng bc xa nao ma no co kha nang phat xa va ngc lai, no ch phat nhng bc xa ma no co kha nang hap thu. D. Cac vach toi xuat hien tren nen quang pho lien tuc la do giao thoa anh sang. Cau 28: Chn Cu sai : A. Tia t ngoi l nhng bc x khng nhn thy c c bc sng ln hn bc sng ca nh sng tm (0,4 m) c pht ra t ngun c nhit rt cao. B. Tia t ngoi c bn cht l sng in t .

C. Tia t ngoi pht hin cc vt nt trong k thut ch to my. D. Tia t ngoi dng dit vi khun, cha bnh ci xng.Cau 29: Van toc cua electron khi ap vao i catot cua ong Rnghen la 45000km/s. e tang van toc len them 5000km/s, phai tang hieu ien the at tai au ong len them bao nhieu? (Bo qua ong nang phat ra)TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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Trang 183

D. 1307V

Cau 30: Trong th nghim Ing v giao thoa nh sng vi nh sng n sc, khong cch gia hai khe l 1mm, khong cch t hai khe ti mn l 2m. Trong khong rng 12,5mm trn mn c 13 vn ti bit mt u l vn ti cn mt u l vn sng. Bc sng ca nh sng n sc l: A. 0,5m B. 0,46m C. 0,48m D. 0,52m Cau 31: : Trong th nghiem Iang a = 1 mm , D = 1m . chieu ong thi 1 = 0,5 m va

2 = 0,75 m . Xet tai M,N cung ben van trung tam th tai M co van sang bac 6 cua 1 va tai N co van sang bac 6 cua 2 . Tm tong so van sang cua 2 bc xa tren oan MN ( ke ca MN)

A. 7 van sang B. 5 van sang C. 9 van sang D. 3 van sang Cau 32: Hien tng quang dan la hien tng A. mot chat cach ien tr thanh dan ien khi c chieu sang. B. giam ien tr cua mot kim loai khi c chieu sang. C. giam ien tr cua mot chat ban dan khi c chieu sang. D. truyen dan anh sang theo cac si quang uon cong mot cach bat k. Cau 33: Mot chat phat quang co kha nang phat ra anh sang mau vang khi c kch thch phat sang. Hoi khi chieu vao chat o anh sang kch thch ay th chat o se phat quang: A. vang B. da cam C. luc D. o Cau 34 : Chn cu ng. Trng thi dng l: A. Trng thi n nh ca h thng nguyn t B. Trng thi electron khng chuyn ng quanh ht nhn C. Trng thi ng yn ca nguyn t. D. Trng thi ht nhn khng dao ng Cau 35: Hai con lc n treo cnh nhau c chu k dao ng nh l 4s v 4,8s. Ko hai con lc lch mt gc nh nh nhau ri ng thi bung nh th hai con lc s ng thi tr li v tr ny sau thi gian A. 8,8s B. Cau 36 : Cho bc song cua bon vach quang pho nguyen t hiro trong dai Ban-me la vach o H = 0,6563m vach lam H = 0,4860m , H = 0,4340m va vach tm H = 0,4102m . Bc song cua ba vach quang pho au tien trong day Pa-sen vung hong ngoai la: 43 = 1,8729 m. 43 = 1,8729 m. 43 = 1,7829 m. A. 53 = 1,093m. B. 53 = 1,2813m. C. 53 = 1,2813m. = 1,2813m. = 1,093m. = 1,093m. 63 63 63 Cau 37 : Trong cac hat nhan sau hat nhan nao ben nhat: 20 40 A. 10 Ne B. 20 Ca C.56 26

12 s 11

C. 6,248s

D. 24s

43 = 1,8729 m. D. 53 = 1,2813m. = 1,903m. 63

Fe

D.

238 92

U

Cau 38: Mt ngun phng x nhn to va c to thnh c chu k bn r l 2 gi, c phng x ln hn mc phng x cho php 64 ln. Thi gian c th lm vic an ton vi ngun phng x ny l: A. 6 gi B. 12 gi C. 24 gi D. 32 gi Cau 39: Khc bit quan trng nht ca tia i vi tia v l tia : A. Lm m phim nh. B. Lm pht hunh quang. C. Kh nng xuyn thu mnh. D. L bc x in t. Cau 40: Chieu anh sang co tan so f vao ban kim loai vi cong thoat A, se co hien tng quang ien vi ong nang ban au cc ai cua electron va Wo. Neu tan so anh sang len 2f th ong nang ban au cc ai cua electron la: A. 2Wo + A B. 2Wo C. 2Wo A D. Wo + ATRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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Cau 41: Vo lc t=0, ngi ta m c 360 ht phng ra ( t mt cht phng x) trong mt pht. Sau 2 gi m c 90 ht trong mt pht. Chu k bn r ca cht phng x :A. 45 phut phut. B. 60 phut. C. 20 phut. D. 30

Cau 42: Thi gian s ht nhn phng x gim i e = 2,7 ln gi l thi gian sng trung bnh ca cht phng x. C th chng minh c rng = 1/. C bao nhiu phn trm nguyn t phng x b phn r sau thi gian t= ?

A. 35%

B. 37%

C. 63%

D. 65%

Cau 43: Laze Rubi co s bien oi dang nang lng nao di ay thanh quang nang : A. ien nang B. C nang C. Nhiet nang D. Quang nang. Cau 44: . Phat bieu nao sau ay sai khi noi ve He Mat Tri? A. Mat Tri la mot ngoi sao. B. Hoa tinh ( sao Hoa) la mot ngoi sao trong He Mat Tri. C. Kim tinh ( sao Kim) la mot hanh tinh trong He Mat Tri. D. Trai at la mot hanh tinh trong He Mat Tri. Cau 45: Mt nhc c pht m c tn s m c bn c f = 420Hz. Mt ngi c th nghe c m n tn s cao nht 18000Hz. Tn s m cao nht m ngi ny nghe c do dng c trn pht ra l: A. 17640Hz B. 18000 Hz C. 17000Hz D. 17850Hz Cau 46: t mt in p xoay chiu c tn s f thay i vo hai u on mch RLC ni tip th thy khi f=40Hz v f=90Hz th in p hiu dng t vo in tr R nh nhau. xy ra cng hng trong mch th tn s phi bng A. 60Hz B. 130Hz C. 27,7Hz D. 50Hz Cau 47: S huy mot cap electron _ pozitron trang thai ngh sinh ra hai photon co tan so la: B. 2,468.1020Hz C. 1,23.1017Hz D.2,468.1017Hz. A. 1,23.1020Hz Cau 48: Mot vat dao ong ieu hoa vi bien o 10cm,chu ky T=1s, pha ban au =

2

. Quang

ng ma vat i c trong thi gian t=31/6(s) au tien la: A. 208.66cm B.28,66cm C. 200 3cm D. ap an khac Cau 49: Trong th nghiem ve giao thoa song tren mat nc, hai nguon ket hp A va B dao ong vi tan so f = 20 Hz va cung pha. Tai mot iem M cach A va B nhng khoang d1 =16 cm; d2= 20 cm song co bien o cc ai . Gia M va ng trung trc cua AB co ba day cc ai khac. Toc o truyen song tren mat nc la: A. 20 cm/s B. 10 cm/s C. 40 cm/s D. 60 cm/s Cau 50: Chn cu sai khi ni v ng c khng ng b ba pha: A. T trng quay c to ra bi dng in xoay chiu ba pha. B. Stato c ba cun dy ging nhau qun trn ba li st b tr lch nhau 1/3 vng trn. C. T trng tng hp quay vi tc gc lun nh hn tn s gc ca dng in. D. Nguyn tc hot ng da trn hin tng cm ng in t v s dng t trng quay. Cau 51 :ong nang cua mot electron co ong lng la : A. Wd = c p 2 + (m0c) 2 D. Wd = c p 2 + (m0c) 2 m0c 2

Phan danh cho ban nang cao (gom 10 cau t cau 51 en cau 60)B. Wd = c p 2 + (m0c) 2 + m0c 2 C. Wd =p 2 + (m0c) 2

Cau 52 : Tren mat nc hnh thanh mot song tron tam O co tan so 16 Hz. Tai A va B tren mat nc, cach nhau 6 cm tren ng thang qua O, cac phan t luon dao ong cung pha. Biet toc o truyen song nam trong khoang 0,4m / s v 0,6m / s. Toc o truyen song tren mat nc nhan gia tr .TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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A. v = 52 cm/s B. v = 48 cm/s C. v = 44 cm/s D. v= 24 cm/s. Cau 53 : Mt xe my chy trn ng, c 3m li c mt ci rnh nh. Bit rng chu k dao ng ring ca xe trn cc gim xc l 0,2s. Xe b xc mnh nht khi chy vi vn tc: A. 15 m/s B. 0,6 m/s C. 6 km/h D. 1,5 km/h Cau 54: Hai a trn c momen qun tnh I1 v I2 ang quay ng 1 I1 trc v cng chiu vi tc gc 1 v 2 (hnh bn). Ma st trc quay nh khng ng k. Sau cho hai a dnh vo nhau th h hai a quay vi tc gc xc 2 I2 nh bng cng thc

A.

=

I 11 + I 2 2 . I1 + I 2

B.

=

I 11 I 2 2 . I1 + I 2

C.

=

I1 + I 2 . I 11 + I 2 2

D.

=

I 1 2 + I 21 . I1 + I 2

Cau 55: Mt qu cu c, ng cht, khi lng 1 kg, bn knh 10 cm. Qu cu c trc quay c nh i qua tm. Qu cu ang ng yn th chu tc dng ca mt momen lc 0,1 N.m. Tnh qung ng m mt im trn qu cu v xa trc quay ca qu cu nht i c sau 2 s k t lc qu cu bt u quay. A. 500 cm. B. 50 cm. C. 250 cm. D. 200 cm Cau 56: Hai moi trng co he so hap thu la va 2 . Cung mot cng o sang truyen qua hai moi trng vi cung quang ng truyen d th cng o sang con lai co t so tang giam ra sao so vi nhau? A. (ln 2) lan. B. (e 2 ) lan. C. (e d ) lan . D. T so khac A, B, C. Cau 57: Khi xy ra hiu ng p-ple i vi mt sng m th tn s sng thay i cn bc sng: A. cng thay i. B. ch thay i khi c ngun ln my thu chuyn ng. C. khng thay i. D. khng thay i khi ngun ng yn cn my thu chuyn ng. Cau 58: Trong chuyen ong quay cua vat ran quanh mot truc, toc o goc tc thi xac nh bi: A. ao ham bac nhat cua toa o goc theo thi gian. B. Ham so bac nhat cua toa o goc theo thi gian. C. Ham so bac hai cua toa o goc theo thi gian. D. Thng so gia goc quay va thi gian quay goc o Cau 59: Mt bnh xe c bn knh 35cm quay nhanh dn u t ngh, sau 10s t ti tc 120 (vng/pht) . Trong 10s , mt im trn vnh bnh xe vch ra qung ng: A. 22m B. 32m C. 40m D. 62m Cau 60: Pht biu no sau y l khng ng i vi chuyn ng quay nhanh dn u ca vt rn quanh mt trc ? A. Tc gc l mt hm bc nht ca thi gian. B. Gia tc gc ca vt l khng i v khc 0. C. Trong nhng khong thi gian bng nhau, vt quay c nhng gc khng bng nhau. D. Phng trnh chuyn ng (phng trnh to gc) l mt hm bc nht ca thi gian. Het

e 5

*************************************************************

E THI TH TUYEN SINH AI HOC

(Thi gian lam 90 phut) Cau 1: Co hai con lac lo xo co cung o cng gom cac vat co kho lng m va 2 m. a cac vat ve v tr e lo xo khong bien dang roi tha nhe ( khong van toc ban au). T so nang lng cua hai con lac la:TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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A. 1 B. 2 C. 4 D. 8 Cau 2: Mot vat dao ong eu hoa. Khi van toc toc vat bang 40 cm/s th li o cua vat la 3 cm ; khi van toc bang 30 cm/s th li o cua vat la 4 cm. Chu k dao ong cua vat la: 1 A. ( s ) B. ( s ) C. 0,5 (s) D. ( s ) .5 5 10

Cau 3: Con lac lo xo dao ong ieu hoa( theo ham sin) tren mat phang ngang vi T = 1,5 s va bien o 5 A = 4 cm , pha ban au la . Tnh t luc t=0 , vat co toa o x = - 2 cm lan th 2005 vao thi iem6

A. 1503 s

B. 1503,25 s

C. 1502,25 s

D. 1504,25

s. Cau 4: mot thi iem , van toc cua vat dao ong ieu hoa bang 20% van toc cc ai, t so gia ong nang va the nang cua vat la: 1 A. 24. B. . C. 5 . D. 0,2 . 24 Cau 5: Con lac n dao ong ieu hoa tai ni g = 10 m/s2. Luc t = 0 vat qua v tr thap nhat theo chieu dng vi van toc 40 cm/s . Tai li o goc = 0,05rad th vat co van toc 20 3 cm/s. Sau bao lau ke t luc t = 0 vat i c quang ng 56 cm? A. 2,3 s. B. 4,1 s. C. 5,12 s. D. 3,2 s. Cau 6: Mot con lac n c treo tran mot thang may. Khi thang may ng yen, con lac dao ong ieu hoa vi chu k T. Khi thang may i len thang ng, cham dan eu vi gia toc co o ln bang mot na gia toc trong trng tai ni at thang may th con lac dao ong ieu hoa vi chu k T bang T T A. T 2 B. C. D. 2T 2 2 Cau 7: Khi con lac n dao ong ieu hoa vi bien o nho th A. tai v tr can bang lc cang day nho nhat, gia toc cua hon bi ln nhat. B. tai v tr can bang lc cang day nho nhat, gia to cua hon bi nho nhat. C. tai v tr bien lc cang day nho nhat, gia toc cua hon bi ln nhat. D. tai v tr bien lc cang day nho nhat, gia toc cua hon bi nho nhat. Cau 8: Song phan xa: A. Luon luon b oi dau B. Luon luon khong b oi dau C. B oi dau khi phan xa tren mot vat can co nh D. B oi dau khi phan xa tren mot vat can di ong Cau 9: Nguon song O c truyen i theo phng Oy. Tren phng nay co hai iem P va Q cach nhau 15 cm. Biet tan so song la 10 Hz, toc o truyen song v = 40 cm/s, bien o a = 1 cm khong oi khi song truyen. Neu tai thi iem nao o P co li o 1 cm th li o tai Q la: A. 0 B. 0,5 cm. C. 1 cm . D. 2 cm. Cau 10: Hai hoa am lien tiep do mot day an phat ra co tan so hn kem nhau la 56 Hz . Hoi hoa am th ba co tan so la bao nhieu? A. 28 Hz . B. 56 Hz. C. 84 Hz. D. 168 Hz. Cau 11: Nguon am co cong suat 1 W phat am truyen ang hng, bo qua mat mat nang lng. Cho biet cng o am tai mot iem t le nghch vi bnh phng khoang cach t iem o en nguon. Cng o am tai iem cach nguon 1 m va 10 m la: A. I1 = 79,58 mW/m2 ; I2 = 0,8 mW/m2 . B. I1 = 79,58 mW/m2 ; I2 = 7,96 mW/m2 . C. I1 = 79,58 W/m2 ; I2 = 0,8 W/m2 . D. I1 = 97,58 W/m2 ; I2 = 0,6 W/m2 Cau 12: Trong moi hop X va Y cha hai trong ba phan t: ien tr thuan, cuon day, tu ien. at vao hai au A, B mot hieu ien the xoay chieu co tan so f = 40Hz th i = 2sin(80t)A, M X YTRUNG TAM LUYEN THI AI HOC AI VIET Hnh * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007 A

B

www.MATHVN.com Gv: TRNG NH HUNG T: 0908346838uX =120sin(80t-/2)V va uY = 180sin(80t)V. Cac hop X va Y cha: A. X ch cha tu ien va Y ch cha ien tr thuan.

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B. X cha tu ien va ien tr thuan; Y cha cuon day thuan cam va ien tr thuan. C. X cha cuon day thuan cam va tu ien; Y cha cuon day thuan cam va ien tr thuan. D. X cha cuon day thuan cam va tu ien; Y cha cuon day khong thuan cam va tu ien. Cau 13: t mt in p xoay chiu vo hai u on mch RLC ni tip c R thay i th thy khi R=30 v R=120 th cng sut to nhit trn on mch khng i. cng sut t cc i th gi A. 150 B. 24 C. 90 D. 60 tr R phi l Cau 14: Mt my bin p l tng c t s vng dy cun s cp v th cp l 2:3. Cun th cp ni vi

ti tiu th l mch in RLC khng phn nhnh c R=60, L =

0,6 3

vi in p xoay chiu c tr hiu dng 120V tn s 50Hz. Cng sut to nhit trn ti tiu th l: A. 180 W B. 90 W C. 135 W D. 26,7 W

H ;C =

103 F , cun s cp ni 12 3

Cau 15: Mot ong Rnghen co cong suat trung bnh 400W, hieu ien the gia anot va catot co gia tr hieu dung 10kV. Cng o dong trung bnh va so electron trung bnh qua ong la: A. 40(A); 2.5.1017(e) B. 0,04(A); 25.1017(e) C. 4(A); 2.5.1017(e) D. 0,04(A); 2.5.1017(e). Cu 16: . Dong ien xoay chieu co bieu thc i = 2 cos100 t( A) chay qua mot day dan. ien lng chay qua mot tiet dien cua day trong khoang t 0 en 0,015s la: 4 3 6 A. 0 . B. (C). C. (C). D. ( C ). 100 100 100 Cau 17: . Mot khung day dan phang hnh ch nhat, kch thc 40 cm x 60 cm, gom 200 vong day. 0,625 Khung day c at trong mot t trng eu co cam ng t B = (T ) va vuong goc vi truc oi r xng cua khung. Ban au vect cam ng t B vuong goc vi mat phang cua khung. Khung day quay vi toc o 120 vong/phut. Suat ien ong tai t = 5s ke t thi iem ban au , co the nhan gia tr nao trong cac gia tr sau? A. e = 0. B. e = 120 V. C. e = 60 V. D. e = 80 V. Cau 18: Hnh dng sng truyn theo chiu dng trc Ox mt thi im c dng nh hnh v. Sau thi im chiu chuyn ng ca cc im A, B, C, D v E l: u A A. im A v D i xung cn im B, C v E i ln. B. im C v D i xung v A, B v E i ln. E B C. im B, C v E i xung cn A v D i ln. D. im A, B v E i xung cn im C v D i ln. C D Cau 19: Cho hai dao ong cung phng cung tan so 8 x1 = 2009 cos(2010t + )cm va x2 = A2 cos(t + 2 )cm . Dao ong tong 3 5 hp cua chung la x = x1 + x2 = 2009 3 cos(2010t + )cm . Phng trnh dao ong cua x2 la: 2 2 A. x1 = 2009 3 cos(2010t + )cm B. x1 = 2009 cos(2010t + )cm 3 6 5 C. x1 = 2009 cos(2010t + )cm D. x1 = 2009 cos(2010t + )cm 3 6 Cau 20: Mach dao ong co C = 6 nF, L = 6H . Do mach co ien tr R = 0,5 , nen dao ong trong mach tat dan. e duy tr dao ong vi ien ap cc ai gia hai ban tu ien la U0 = 10 V, th phai bo sung nang lng cho mach mot cong suat la bao nhieu? A. 0,025 W. B. 0,05 W. C. 0,25 W. D. 0,005 W.TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

x

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Cau 21: Trong mch in xoay chiu mc ni tip gm t in C, cun dy thun cm L v hp kn X. Bit Z L > Z C v hp kn X cha hai trong 3 phn t Rx, Cx, Lx mc ni tip. Cng dng in i v hiu in th u hai u on mch cng pha vi nhau th trong hp kn X phi c: B. RX v LX C. LX v CX D. Khng tn ti phn t tha A. RX v CX mn Cau 22: Mach chon song gom cuon cam L va hai tu ien C1 , C2 . Neu ch dung L va C1 th thu c song co 1 = 100m . Neu ch dung L va C2 th thu c song 2 = 75m . Khi dung L va hai tu C1 va C2 mac song song nhau th mach thu c song co bc song la: A. 25 m B. 60 m. C. 125 m. D. 175 m. Cau 23: Mot tram bien ien can tai ien nang i xa. Neu hieu ien the tram phat la U1= 5KV th hieu suat tai ien la 80%. Neu tang hieu ien the len U2= 5 2 KV th hieu suat tai ien la A. 85% B 90% C. 95% D. 92% Cau 24: khi co s cong hng ien t trong mot mach dao ong khong ly tng th A. khong co s tieu hao nang lng trong mach B. S tieu hao nang lng trong mach la nho nhat C. S tieu hao nang lng trong mach la ln nhat D. S tieu hao nang lng trong mach mc trung bnh Cho rang bien o cua suat ien ong cng bc c gi khong oi Cau 25 : Quang pho vach phat xa cua cac nguyen to khac nhau th khac nhau ve: A. So lng cac vach B. V tr cac vach C.o sang t oi cua cac vach D. Ca A, B va C eu ung Cau 26 : Chieu anh sang co bc song 0,50m vao 4 te bao quang ien co catot lan lt bang canxi, natri, kali va xesi. Hien tng quang ien se xay ra A. Mot te bao B. Hai te bao C. Ba te bao D. Ca bon te bao Cau 27: Chon y ung. Tam knh o A. Hap thu anh sang o B. Hap thu t anh sang o C. Khong hap thu anh sang xanh D. Hap thu t anh sang xanh Cau 28: Chon cau ung A. Tia hong ngoai co tan so cao hn tia sang vang cua natri B. Tia t ngoai co bc song ln hn cac tia H cua hiro C. Bc song cua bc xa hong ngoai ln hn bc song bc xa t ngoai D. Bc xa t ngoai co tan so thap hn bc xa hong ngoai Cau 29: Mot may bien the khi at hieu ien xoay chieu 100V vao hai au cuon s cap th hieu ien the hai au cuon th cap la 500V. e tnh so vong day moi cuon ngi ta quan them vao loi may 20 vong va o hieu ien the hai au 20 vong o la 4V. So vong day s cap va th cap lan lt la: A. 2500; 500 B. 500; 2500 C. 100; 500 D. 500; 100 Cau 30: : Trong th nghim giao thoa sng trn mt nc hai ngun kt hp A, B dao ng cng pha vi tn s 10Hz. Tc truyn sng trn mt nc l 20cm/s. Hai im M, N trn mt nc c MA=15cm, MB=20cm, NA=32cm, NB=24,5cm. S ng dao ng cc i gia M v N l: A. 4 ng. B. 7 ng. C. 5 ng. D. 6 ng. Cau 31: Trong th nghiem giao thoa vi anh sang trang , tai v tr van sang bac 6 cua anh sang co bc song 0,497 m co van sang bac 7 cua bc xa co bc song la: A. 0,597 m . B. 0,579m . C. 0,462m . D. 0,426m Cau 32: Hien tng quang ien trong khac hien tng quang ien ngoai cho A .ch xay ra khi c chieu bang anh sang co bc song thch hp. B. van toc ban au cc ai cua electron ban ra ch phu thuoc anh sang kch thch.TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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C. giai phong electron lien ket thanh electron dan khi chat ban dan c chieu bang anh sang co cng o thch hp. D. giai phong electron lien ket thanh electron dan khi chat ban dan c chieu bang anh sang co bc song thch hp. Cau 33: Anh sang phat quang cua mot chat co bc song 0,50 m. Hoi neu chieu vao chat o anh sang n sac nao di ay th no se khong phat quang A. 0,30 m B. 0,40 m C. 0,50 m D. 0,60 m Cau 34 : Cau nao di ay noi len noi dung chnh xac cua khai niem ve quy ao dng? A. Quy ao co ban knh ty le vi bnh phng cua cac so nguyen lien tiep B. Ban knh quy ao co the tnh toan c mot cach chnh xac C. Quy ao ma cac electron bat buoc phai chuyen ong tren o D. Quy ao ng vi nang lng cua cac trang thai dng Cau 35: : thu c quang ph vch hp th th: A. nhit ca m hi hay kh hp th phi ln hn nhit ca ngun sng trng. B. nhit ca m hi hay kh hp th phi nh hn nhit ca ngun sng trng. C. nhit ca m hi hay kh hp th phi bng nhit ca ngun sng trng. D. khng ph thuc vo nhit m ch cn p sut ca m hi hay kh hp th thp. Cau 36 : Xet nguyen t hiro nhan nang lng kch thch, electron chuyen len quy ao N, khi electron chuyen ve cac qu ao ben trong se phat ra A). Mot bc xa thuoc day Banme B). Hai bc xa thuoc day Banme C). Ba bc xa thuoc day Banme D). Khong co bc xa thuoc day Banme Cau 37 : Trong cac hat nhan sau hat nhan nao ben nhat: 20 40 56 A. 10 Ne B. 20 Ca C. 26 Fe D. 238U 92 Cau 38: Hat nhan co khoi lng mHe = 4,0015 u. Nang lng toa ra khi tao thanh 1 mol Heli la: Biet : mp=1,0073u , mn=1,00867u, 1u=931MeV/c2 B. 27,3.1012 MeV C. 2,73.1012 J D. 27,3.1012 J A. 2,73.1012 MeV 2 3 Cau 39: . Xet phan ng 1 H + 1 H -> 4 He + 1 n + 18,6 MeV. ieu nao sau ay sai khi noi ve phan ng 2 0 nay A). ay la phan ng nhiet hach C). ieu kien xay ra phan ng la nhiet o rat cao B). ay la phan ng toa nang lng D). phan ng nay ch xay ra tren mat

tri Cau 40: Khi chieu bc xa co bc song 0,405m vao catot cua mot te bao quang ien th quang electron co van toc ban au cc ai la v1 . Thay bc xa khac co tan so 16.1014 Hz th van toc ban au cc ai cua quang electron la v2 = 2v1. Cong thoat cua electron kim loai lam catot va o tang hieu ien the ham e triet tieu dong quang ien cua hai lan chieu lan lt la: A. A = 2.1019 J ; U = 7,65V B. A = 4.1019 J ; U = 2,56V C. A = 9.1019 J ; U = 3,64V . D. A = 3.1019 J ; U = 3,56V Cau 41 : Ht nhn Plni 210 Po l cht phng x . Bit ht nhn m ang ng yn v ly gn ng 84 khi lng cc ht theo s khi A. Hy tm xem bao nhiu phn trm ca nng lng to ra chuyn thnh ng nng ca ht . A. 89,3% B. 98,1% C. 95,2% D. 99,2% 235 Cau 42: Nang lng trung bnh toa ra khi phan hach mot hat nhan 92 U la 200 MeV. Mot nhamay ien hat nhan dung nguyen lieu urani tren co cong suat 500 MW, hieu suat 20%. Khoi lng urani tieu thu hang nam cua nha may tren la bao nhieu? A. 865,12 kg. B. 926,74 kg. C. 961,76 kg. D. ap so khac. Cau 43: Hieu suat cua mot lazeTRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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A. Nho hn 1 B. Bang 1 C. Ln hn 1 D. Rat ln so vi 1 Cau 44: . ng knh cua mot thien ha vao c A. 10 000 nam anh sang. B. 1 000 000 nam anh sang. C. 100 000 nam anh sang. D. 10 000 000 nam anh sang. Cau 45: Mt day an co the phat ra cac am co tan so 15Hz, 105Hz, 135Hz, 180Hz th am c ban ln nhat ma day an co the tao ra la: A. 3Hz B. 5 Hz C. 15 Hz D. ap an khac 1 10 4 Cau 46: Cho mach RLC co u = 100 2 sin t (V) ; L = (H) ; C = (F) ; R = 150 . Cuon cam

thuan co he so t cam L , co the thay the c. Thay oi e cong suat cua mach la gia tr cua khi o la bao nhieu? A. 1 = 200 rad/s. C. 1 = 125 rad/s hoac 2 = 50 rad/s.

100 (W), 3

Cau 47: Cong suat bc xa mat tri la 3,845.1026W. Hang so mat tri H co gia tr nao sau ay: A. 13,6 W/m2 B. 1360 W/m2 C. 136 W/m2 D. 1630 W/m2. Cau 48: : Mot vat dao ong ieu hoa vi bien o 10cm, chu ky 1s. Toc o trung bnh ln nhat ma vat i c trong thi gian 1/4 s la: A. 28,28cm/s B. 23,428cm/s C. 40 2cm / s D. 80cm/s Cau 49: Tren mat nc co hai nguon song ket hp S1 , S2 phat ra hai song co phng trnh u 01 = 2 sin 100t (cm) ; u 01 = 2 cos100t (cm) . Cho S1 S 2 = 10,5 . So ng cc ai, cc tieu tren oan

B. 1 = 50 rad/s. D. 1 = 200 rad/s hoac 2 = 50 rad/s.

S1 S 2 la: A. 22 cc ai va 23 cc tieu. B. 21 cc ai va 19 cc tieu. C. 20 cc ai va 21 cc tieu. D. 21 cc ai va 21 cc tieu. Cau 50: Mot ng day tai ien ba pha co 4 day a, b, c, d. Mot bong en khi mac vao gia hai day a va b hoac gia hai day b va c hoac gia hai day b va d th sang bnh thng. Neu dung bong en o mac vao gia hai day a va c th A. en sang bnh thng. B. en sang yeu hn bnh thng. C. bong en b chay. D. en sang len t t.

Cau 51 : Khoi lng tng oi tnh cua mot vat co khoi lng ngh m0 chuyen ong vi toc o v la:

Phan danh cho ban nang cao (gom 10 cau t cau 51 en cau 60) 1 / 2

v2 A. m = m0 1 2 c 1/ 2

.

v2 B. m = m0 1 2 c

.

1

v2 C. m = m0 1 2 c

.

D.

v2 m = m 0 1 2 c Cau 52 : . Mot iem M chuyen ong eu vi toc o 0,60 m/s tren mot ng tron co ng knh 0,40 m .Hnh chieu P cua iem M len mot ng knh cua ng tron dao ong ieu hoa vi bien o , tan so goc va chu k lan lt la: A. 0,40 m ; 3,0 rad/s; 2,1 s . B. 0,20 m; 3,0 rad/s ; 2,48s. C. 0,20 m ; 1,5 rad/s ; 4,2s D. 0,20 m ; 3,0 rad/s ; 2,1s. Cau 53 : Mt xe my chy trn ng, c 3m li c mt ci rnh nh. Bit rng chu k dao ng ring ca xe trn cc gim xc l 0,2s. Xe b xc mnh nht khi chy vi vn tc: A. 15 m/s B. 0,6 m/s C. 6 km/h D. 1,5 km/hTRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

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Cau 54: Mot banh a co momen quan tnh oi vi truc quay co nh bang 0,14 kg.m2 . Do tac dung cua mot momen ham, momen ong lng cua banh a giam t 4,2 kg.m2/s xuong con 0,6 kg.m2/s trong thi gian 0,8 s. Momen lc ham trung bnh trong khoang thi gian o bang: A. 3,6 kg.m2/s2. B. -4,5 kg.m2/s2. C. -0,75 kg.m2/s2. D. 5,25 kg.m2/s2. Cau 55: Mt qu cu c, ng cht, khi lng 1 kg, bn knh 10 cm. Qu cu c trc quay c nh i qua tm. Qu cu ang ng yn th chu tc dng ca mt momen lc 0,1 N.m. Tnh qung ng m mt im trn qu cu v xa trc quay ca qu cu nht i c sau 2 s k t lc qu cu bt u quay. A. 500 cm. B. 50 cm. C. 250 cm. D. 200 cm Cau 56: Co hai mau chat phong xa A va B thuoc cung mot chat co chu k ban ra T = 138,2 ngay va co H khoi lng ban au nh nhau. Tai thi iem quan sat, t so o phong xa cua hai mau la B = 2,72 . HA Lay ln2 = 0,693 . Tuoi cua mau A nhieu hn mau B la: A. 199,5 ngay. B. 199,8 ngay. C. 190,4 ngay. D. 189,8 ngay

Cau 57: e hieu ng op ple xuat hien th ieu kien can va u la: A. Nguon am va may thu chuyen ong tng oi vi nhau B. May thu ng yen va nguon am chuyen ong C. Nguon am ng yen va may thu chuyen ong D. Nguon am va may thu chuyen ong ngc chieu nhau Cau 58: : Cong e tang toc mot canh quat t trang thai ngh en khi co toc o goc 200 rad/s la 3000 J. Hoi momen quan tnh cua canh quat bang bao nhieu? A.3kgm2 B. 0,075kgm2 C. 0,3kgm2 D. 0,15kgm2 Cau 59: Mot momen lc khong oi 60Nm tac dung vao mot banh a co khoi lng 20kg va momen quan tnh 12kgm2. Thi gian can thiet e banh a at ti 75 rad/s t ngh la: A.15 s C. 25s B. 30 s D. 180 s Cau 60: Momen ong lng cua vat ran A. luon luon khong oi B. Thay oi khi co ngoai lc tac dung C. Thay oi khi co momen ngoai lc tac dung D. Thay oi khong di tac dung cua momen ngoai lc th con phu thuoc vao chieu tac dung cua momen lc. Het ************************************************************

e 6

E THI TH TUYEN SINH AI HOC

(Thi gian lam 90 phut) Cau 1: Mot con lac lo xo dao ong ieu hoa co phng trnh gia toc la: a = 200 cos(2t + )(cm) . Biet vat co khoi lng m=1kg va lay 2 = 10 . Xac nh v tr ma tai o lc phuc hoi cua lo xo la 0,8N. A. x = 4 cm B. x = 2 cm C. x = - 2 cm D. x = 2 cm Cau 2: Vat dao ong ieu hoa vi tan so f = 4Hz, van toc cua vat qua v tr can bang la 16 cm/s. Chon goc thi gian la luc vat qua v tr x = 2 cm va ang ra xa v tr can bang. Phng trnh dao ong la:TRUNG TAM LUYEN THI AI HOC AI VIET * TRUNG TAM GDTX KP.3- TH TRAN CU CHI- HUYEN CU CHI. T: 08.22483793 -0984786115 WWW.MATHVN.COM * 67 THEP MI P.12-Q.TAN BNH- TP. HO CH MINH T: 08.38118948-0909254007

www.MATHVN.com Gv: TRNG NH HUNG T: 0908346838A. x = 2 cos 8t cm B. x = 2 cos(8t +

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) cm 4 3 C. x = 2 cos(8t ) cm D. x = 2 cos(8t + ) cm 4 4 Cau 3: Vat dao ong ieu hoa vi phng trnh x = 10 cos(2t + ) cm. Trong thi gian t= 13/6(s) au tien vat i c quang ng la : A. 85cm B. 45cm C. 50cm D. 40cm Cau 4: Vat dao ong ieu hoa vi phng trnh x = 10 cos(2t + ) cm. Trong thi gian t=13/4 (s) au tien vat qua v tr x=5cm may lan: A. 5 lan B. 6 lan D. 7 lan D. 8 lan Cau 5: Chiu di mt con lc n tng thm 44% th chu k dao ng s: A. Tng 20% B. Tng 44% C. Tng 22% D. Gim 44% Cau 6: Mot con lac lo xo dao ong ieu hoa theo phng thang ng. Thi gian vat i t v tr thap nhat en v tr cao nhat cach nhau 20 cm la 0,75s. Goc thi gian c chon la luc vat ang chuyen 0,2 ong cham dan theo chieu dng vi o ln van toc la m / s , phng trnh dao ong cua vat la: 3 5 4 4 A. x = 10 cos t (cm) . B. x = 10 cos t (cm) 6 6 3 3 5 3 3 C. x = 10 cos t (cm) . D. x = 10 cos t (cm) . 6 6 4 4Cau 7: : Mt cht im dao ng ieu ho c th vn tc nh hnh v. Phng trnh li lA. x=5sin (10t + C. x=5sin (10t +

3

)cm B. x=10sin (10t )cm 3

v( m / s )3,14 1,57

)cm D. x=10sin (10t + )cm 0 6 3 1/12 Cau 8: Pht biu no di y l sai? A. to l c trng sinh l ca m, gn lin vi mc cng m. B. m sc l mt c trng sinh l ca m, c lin quan mt thit vi th dao ng m C. Ngng nghe l gi tr cc tiu ca cng m cn gy c cm gic m cho tai ngi, khng ph thuc vo tn s m D. cao l mt c trng sinh l ca m, gn lin vi tn s m Cau 9: Mt dy n hi rt di c u A dao ng vi tn s f v theo phng vung gc vi si dy. Bin dao ng l 4 cm. Vn tc truyn sng trn dy l 4m/s. Xt im M trn dy v cch A on 28cm. Ngi ta thy M dao ng lch pha vi A mt gc = (2k + 1)

t (s )

2

vi k l s nguyn. Bit tn s

f c gi tr trong khong t 22 Hz n 26 Hz . Bc song tren day la: A. 12cm B. 16cm C. 18cm D. 20cm Cau 10: V sao trong i sng dng in xoay chiu c s dng rng ri hn dng in mt chiu? Chn cu sai: A. V dng in xoay chiu c th ti i xa nh ny bin th B. V dng in xoay chiu c mi tnh nng nh dng in mt chiu C. V dng in xoay chiu d sn xut hn do my pht pht in xoay chiu c cu to n gin D. V dng in xoay chiu