PH~NG GD&DT LONG BI~N KY THI HQC SINH GI~I QUAN NAM HQC 2012 - 2013 Men thi: V@f El Thai gian lh bii : 150 phit Ng& thi :31 thkng 01 ndm 2013 (£I$ chi gdm 02 trang ) Bhi 1 (4,O di$m) Hai quh ciu d$c, th& tich m8i quh la V = 200cm3, duqc nbi vui nhau bhg mGt sui diy mM, nhe, khbng co d&, thA trong nuuc (Hinh 1) . Kh6i 1uWg ri&ng cua qu~ ciu bbn tr&n la D~ = 300 kg/rn3, kh6i lugng ri&ng cua qu8 ciu b&n dubi 1s D2 = 1200 kg/m3, kh6i - - - lugng riBng cim nu& 18 D, = lOOOkgi rn3 . Hay tinh : 1. ~h$ tich phhn nh8 1Bn khbi mat nudc cim qu8 chu phia trh khi he v$t Hlrh I cbn bhg ? 2. Lpc cang cua sqi diiy ? Bhi 2 (3 digm) Dhg mot b6p diu ct& dun s8i m$t lugng nu& cb khbi luwg ml = 1 kg, dgng trong mQt irn bhg nhdm cb khbi luqng rn~ = 500g thi sau thbi gian tl = 10 phut nukc s8i . N$U dhng bep dau trdn dB dun sdi m$t lugng nubc c6 khbi lugng m3 dung trong dm tr@n trotlg cung di$u ki@n thi thky sau th&i gian 19 phut nudc s8i . Tinh khbi lugng nuuc rn~ ? ~i&t nhi@t dung riCng cua nub, nhbrn lin 1up.t 1s cl = 4200JIkg.K ; c2 = 880Jkg.K va nhiet luwg do b&p dhu toa ra m6t cach d&u dgn . Blli 3 (4 bi&r) Cho mach dien nhu hinh 2. ~i6t UAB = 12V, R1 = 0,4 n; R2 = 0.6 s2. ~i&n trb co di&n trb toan phin Rm = 8 n; djen trb cih vbn kd rit 1h. 1. Xac dj11l-1 s6 chi cia van k6 khi con chay C & chinh giBa MN. Tinh cang sdt toa nhi& tren bi&n trb. 2. Xac djnh vi trl C trCn bi&n tru d& cbng sdt tren toan mach la cuc bai. Tinh gia tr~ cuc dai do. Bhi 4 (4 dih~) Cho mach dien nhu hinh 3. ~i6t : R1 = 8R ; R2 = R3 = 4n; % = 61r : UAB = 6V khdng bdi. Dien tr6 ciia arnpe k& , kh6a K va cac diy nbi khBng dkng k& . 1. Hay tidl dien trh tumg dumg cha dogn mach AB va s6 chi cua anpe kk trong hai tnrbng hq~ : a. Kh6a K m& . b. Khba K d6ng . 2. Xet tmhg hqp khi K b6ng : Thay kh6a K bing dien trb R5. Tinh R5 d& cuhp de dhng dien chgy qua dien trir R2 bing khBng ? Hinh 2 I bF t-d AB! R3 Bai 5 (5 dm) Dgt mot miu but chi AB = 2 cm ( diu B v6t nhon ) vubng gbc viri trgc chinh ch mat thiu kinh hQi tu , A nim tr@n tryc chinh ( hinh 4 ) . Nhin qua th$u kith ngubi ta th& MI AB clia bfit chi chg chi& vci.i v4t vA cao 5 lh vgt . 1. VE A'B' cua AB qua thiu kinh . Dva vAo hhinh v6 chhg minh cbng thirc sau : 1 - 11 OF 0.4 OA' Khi miu blit chi djch chuykn da: theo t~c chinh lgi thiu kith thi a0 ch n6 djch chuy&n theo chi& nAo ? Vi sao ? 2. Bby gib. d$t mku but chi & doc theo tq~c chinh clia thhu kinh , diu A v& nhm Ir vi tri cfi, diu nhon B cb nb huhg thhg v6 quang t&m 0 . 'Lai nhin qua thhu kinh thi thhy Anh c6a but chi ciing n$m doc theo tryc chinh d co chi& &i binng 25cm . HHy tinh tiBu cy cim thbu kinh . 3. Dich chuybn diu A ch mku bht hi din vi tri Mc . Ggi A' 18 Anh b clia A qua A' F A thku khh , F lA tie~ dihm v$t cclia thhu kinh X Y (hinh 5). in^ phCp v& , My xhc djnh quang th O vh ti& diim Anh F' cb thh kinh . Hnh 5 1 Ho via Ign thi sinh., . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . So bcio danh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chi7 ki clia girjm fi I ,.,., ,. Lb; 2,,, , ,., *.Chi2 ki cia gidm thj 2 , ., , . PH~NG GD&DT LONG BI~N KY THI HQC SINH GI~I QUAN NAM HQC 2012 - 2013 Men thi: V@f El Thai gian lh bii : 150 phit Ng& thi :31 thkng 01 ndm 2013 (£I$ chi. AB qua thiu kinh . Dva vAo hhinh v6 chhg minh cbng thirc sau : 1 - 11 OF 0.4 OA' Khi miu blit chi djch chuykn da: theo t~c chinh lgi thiu kith thi a0. kg/rn3, kh6i lugng ri&ng cua qu8 ciu b&n dubi 1s D2 = 1200 kg/m3, kh6i - - - lugng riBng cim nu& 18 D, = lOOOkgi rn3 . Hay tinh : 1. ~h$ tich