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0 O•Qz π - 0 e Ž #02OOOOOOOOOOOOO # ()*+ ‰|#"2L?#02,1):ƒ‚ dt dq Q R ρεε q OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ ‰•>BV/%,-c/>/?a):/%>3K'7?bQWos[#‚ R ρεε t 2OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ ‰.9:)BH/%9FU`/%93K/Q‚ dt dq Q R ρεε Q os[#‚ R ρεε t 2OOOOOOŠŠŠŠŠŠŠOOOOOO # ()*+ '#()*+, /,83,>H393P',ƒ+ ul Q+Q3 € Qe g3  e g  "  0  u l 3 3  3 ) b L dt RiE di = − @94,sQe g3OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ >3,QR):3QR/T/ƒ7Na,=)>[>*/,|R9i/3L?,|R9i/,,1): 3Q 2"# L Rt e R E − − OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO  ()*+ 0,:/%9&/%,>H3)n>136>:1 83,>H393P','8)>93K/):ƒ 3Q3  ‰3  #"2 „ L q Li Ri Ri E c + = + = #02 „ • C L i q LCi= = #v2 #"2j#02j#v2Q‘ " " • „ R L L L E i i i RC LC RLC + + − = #’2OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO  ()*+ >3 0 " " 0LC RC   >  ÷   ,>c,|[>BV/%,-c/>#’2I+a-1,5/IJ%:) )_1U1.9F/%):%3;,-\ƒ 00 0 z "" CRLC −= ω L?3  Q R A R E + RC t e 0 − ).I#“,‰•2OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO  ()*+ 1+,>H3%31/9_U?3ƒ, ∞→ ,>c3  Q R E L?bQROOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ 1,%k,6>:1"@):'8)>O 3  Q R E L?bQR [U^/%9\/>7+p,<n.,.?//D/%7BC/%Q‘) u Q C L R E OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO  ()*+  '"()*+, O  /,'()*+, ’<3P+,>]),=/>9BC)'G'o/b+;/,=/>)_19X19&/%)>N,):<$U?aUs@<;/6=/>-@6>J3 7BC/%-3T/%Ž9J3LZ3,-^)b+1a93b+1,*'9X1L?/E', /%'4,[>t/%9X1ƒ 23"  4 U ” QU s ‰U a  0 0 dmr dI Z = OOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ U a QU s QU ” x0Q‘  dx r rdxrdI x z 2# 0 " O 0 " z 00 ρπ ρπ == OOOOOOOOOOOOOOOOOOOOOOOO # ()*+ ’<3P+,>]),=/>'G'o/b+;/,=/>)_19X19&/%)>N,):<$U?aUs@<;/6=/>-@6>J37BC/% -3T/%Ž9J3LZ3,-^)b+1a/E'/%1/%@93b+1 U  QU s ‰U'Os 0 Q‘ z 0 0 z O r dI dx r x dx ρπ ρπ = + OOOO$ #()*+ =/>9BC) 0 y( z O I mr= OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ 0,' ()*+, ‰3i,9BC)[>BV/%,-c/>9F/%7m)>•))>.)>+aP/9F/%b+1ab+1/>  •I3/v R ϕϕ Imgr =− OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO #()*+  ‰;)9\/>9BC))G/%,>]),>]),=/>)>+6c)_1)./7k)Lp,7–ƒ >+6—)./7k) y( 0 Ov v O I r T mg r g π π = = OOOOOOOOOOOOOOOOOOOO-$#()*+ 1,' ()*+, 3i,783ƒ y( y( y( "0 "zz 0 0 0 "0 r l r T g g g π π π = = = OOOOOOOOOOOOOOOOOOO-$#()*+ >BLpa)>+6—U1.9F/%)_1)./7k)Lp,7–%3J/%/>B'F,)./7k)9V/):)>3$+U?3 y( „ "zz l l= Oi,b+n7?/i+,1,-o.,>T'Lp,' " M93P'LZ3 y( „ "zz OK l l= = ,>c)>˜7?',D/% 6>J37BC/%)_1)./7k)@)`/)>+6cU1.9F/%6>G/%9w3OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO -$#()*+ "'"()*+, d>c/>OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO  ()*+ V9&,8.n/>  /, P•€QR,>cU v €Q™OOO |9:,1,c'9BC)U " QROpa9{/9BC)94,/%1a,-T/'4,)_1,>N+6=/> " OOOOOOOOOOOO # ()*+ 0, 3nIfb+;,-c/>,8.n/>)_1b+1>KU3š/-1/>B>c/>LdO •3);)%:)'M75/7BC,7?•@• " @• 0 @•€O BH/%6=/>)_1);)Li,I;/%,-T/,>N+6=/>7? " @ 0 @ vO ‰.);)%:)'M9$+-N,<›/T/ƒ " " " " „D d d ϕ ϕ = = OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ 0 " 0 0 0 „D d d ϕ ϕ = = OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ v 0 v v „ „D d d ϕ ϕ = = OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ 5678/(9:;<=>(?)@1A/;B1<>)C&8D " 0 v " 0 v „O „O „ z O O „ d d d k d d d ϕ ϕ = = = OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ |9:,1,c'9BC)U " Q"R)'#7.83<S%3;,-\*'2 pa9{/94,);)> " 'F,9.8/7?"R)'OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ #'v()*+, I. Cơ sở lý thuyết: 1+6>3/8[93K/@)>.,^[>:/%93K/b+193K/,-MgO 3nIfI1+,>H3%31/U,@93K/7BC/%[>:/%b+1g7?Ub7?')>.>3K+93K/,>i,-T/>13 <n/)m),^<3i/,>3T/'F,7BC/%U+,>cƒUbQ‚U+@, /%9:UbQ3U,jU+Q‚gU3/T/ƒ ∫ ∫ −=⇒−=⇒−= i i t dt RCi di dt RCi di RCdiidt R R O "" O " 7/ R t RCi i −=⇒ OOOOOŠŠOŠOOOŠO  ()*+ >BLpa R 7/ i i − [>^,>+F),˜7KLZ3,>H3%31/,O II. Các bước tiến hành: "Ok['8)>93K//>BIV9&>c/>" 0O:/%6>:1@I1+6>3/8[s./%,>c'M6>:1O vO•)L?%>3)BH/%9FU`/%93K/I1+/>Y/%6>.n/%,>H3 %31/<E/%/>1+#L=U^)]"RI2L?,=/>9837BC/% R 7/ i i − ,BV/% ]/%O#,QR7‹)'M6>:12ŠŠŠŠŠŠOŠŠ ()*+ zOm1L?.<n/%IJ73K+@Um/%9&,>\[>^,>+F))_1 R 7/ i i − ,>o.,#9&,>\7?'F,9BH/% ,>t/%OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO #()*+ III. Xử lý số liệu: F/%>3T/%)_19BH/%,>t/%/?a7? " ,1/ RC α = OW+1>K,>])/?a@/i+9.9BC),1/α@,1 ,=/>9BC)O?'/>3$+75/9P,=/>%3;,-\,-+/%<c/>)_1ŠŠŠŠŠŠŠ #()*+ ,#I2 R "R 0R vR zR (R œR •R yR #µu2 ‚/3x3 R K R µ A Hình 1 C Hình 2 R 7/ i i − t(s) . ∫ −=⇒−=⇒−= i i t dt RCi di dt RCi di RCdiidt R R O "" O " 7/ R t RCi i −=⇒ OOOOOŠŠOŠOOOŠO  ()*+ >BLpa R 7/ i i − [>^,>+F),˜7KLZ3,>H3%31/,O II. Các bước tiến hành: "Ok['8)>93K//>BIV9&>c/>" 0O:/%6>:1@I1+6>3/8[s./%,>c'M6>:1O vO•)L?%>3)BH/%9FU`/%93K/I1+/>Y/%6>.n/%,>H3 %31/<E/%/>1+#L=U^)]"RI2L?,=/>9837BC/% R 7/ i i − ,BV/% ]/%O#,QR7‹)'M6>:12ŠŠŠŠŠŠOŠŠ. # ()*+ |9:,1,c'9BC)U " Q"R)'#7.83<S%3;,-*'2 pa9{/94,);)> " 'F,9.8/7?"R)'OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO # ()*+ #'v()*+, I. Cơ sở lý thuyết: 1+6>3/8[93K/@)>.,^[>:/%93K/b+193K/,-MgO 3nIfI1+,>H3%31/U,@93K/7BC/%[>:/%b+1g7?Ub7?')>.>3K+93K/,>i,-T/>13 <n/)m),^<3i/,>3T/'F,7BC/%U+,>cƒUbQ‚U+@,.      !"" Thời gian làm bài : 180 phút #$%&'()*+, /%0,-1/%2 (4 điểm). 13'4,)5+63'7.839&/%,*'):);)<;/6=/>7?1@<#1A<29BC)/%D/);)> />1+<E/%'F,'G3,-BH/%):>E/%IJ93K/'G3 ε L?):93K/,-MI+N, ρ O83,>H393P', QR'4,)5+/>S<T/,