Th Dạng 3: NĂNG LƯỢNG ĐIỆN TRƯỜNG VÀ TỪ TRƯỜNG I. PHƯƠNG PHÁP Áp dụng các công thức sau: 1.    L W Li= 2.   C q W C = . 3.                 q q W Li LI CU C C = + = = = 4.   I q ω = 5.   q CU= Chú ý: !" #$%&≠' !()*+,-%' !%./ !01"2(%.3          C U U RC I R R L ω = = =P  II. BÀI TẬP VẬN DỤNG Câu 1:4 5 6 7 8 7 92 % 7 9 7  :  5  2 5 4 A.; 2 5  5 40 :  2 5  5 6 : 0< 5   5 < :  :  : < : = 7 >%0 5 < 7 %+ B.?0< 5  : < : 8 5 /%< @ %2 5  @ + C.?0< 5   5 < : 8 5 /%< @ % 5   5 4+ D.?0< 5   5 < :  : 0< 5  : < : % : = 7 %8 :  : A2 5 8 : (2 7 %+ Câu 2: !40B$" ! #CD' A+01 #E/%$%!F+ B+01 #G01C0%292 H+ C+01CE/%$I #+ D+01 #CJ 1=FG+ Câu 3:! ! #C4KI #" #%4G%!8%F" !DF+LM 8N" #$%92 9-G" ! #C+OP>  QR  0010G #B D G #/D JI #QS  0G !T #D +L-%UG(% 892 /F0G=-%UB01 #CV A+WX   4R   + B+WX C q    + C+WX   S   +  D+ W = L q    + Câu 4:! !K!IYG!%!FZ µ Q #$92 9-+#% #MD $ %I #0GR  XQ[\+B !T ##%I>%+  ]+^_] L+`_] 4+[_] ;+a_] Câu 5:! !492" #$%Q" ! #CDb !c+#% #MD d=FIG !T #D >%0010GR  GS  + - !T #"eS  f' !0g#% #Md=FI #0G ]+_R  f^+ L+ _ R  f 4+R  f+ ;+ _ R  f^  Câu 6:! !40B$"X^Q4X[hYQ #BD JI>  Xa+ i 4+ # BJI=j_+ i 4'T #" !0g+ ]+[+ i` ] L+a+ i` ] 4+_+ i` ] ;++ i` ] Câu 7:! !KI #" #% FC µ [ = G%!8" !DFX[+,#/D I #0Ga\+4 !T # - #/I #=j^\0G ]+Q_]+ L+Q[]+ 4+Qa]+ ;+Q^[]+ Câu 8:4 !T #U !40B$0GXQZ(bcb]c+4%!8" !D FX[+#% #Md=FI - !T #U=j ! 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Giá trò cực đại của điện áp giữa hai bản tụ điện bằng U 0 . Giá trò cực đại của cường độ dòng điện trong mạch là A. I 0 = U 0 LC . B. I 0 = U 0 C L . C. I 0 = U 0 L C . D. I 0 = LC U  . Câu 26: !KI #" #%^[/YG%!8%F" !DF[t+,#/D $ %I #0G\+4 !T #D 0G A+Q_]+ B+Qa]+  C+a+ i^ ]+ D+_+ i^ ]+ Câu 27: !"%!%F" !DFXQQI #" #%4XµY+% 4 X^\ 'X_]+'= !S  J !T #+ A+S  X[]+ B+S  X[]+ C+S  X^]+  D+S  X]+ Câu 28: !"%!%FXQQI #" #%4XµY+" ! #C+ #/d=FI0GZ\' !T #0Ga]+4 !T #D   !0G A+S  X[]+ B+S  X^]+C+S  X]+ D+S  XQ]+ Câu 29: !0u$QI #" #%4X[ µ YQ #BJI"eD 0GZ+ i [ 4+?01 ! #C0G ]+a+ i^ v+ L+QZ+ i^ v+ 4+aQ^+ i^ v+ ;+Z+ i^ v+ Câu 30:; ! #C0G ! p%G+#% #Md %%!F=GQ\ ' !T #=jQZ]+4T9#% #Md %%!F=jQl\' !T #=jQ^]+LM !DFJ%!8X[+,#%JIG01 ! #C=j ]+YG[+ i v+ L+YG_+ i v+ 4+YG[+ i v+ ;+YGQ[+ iZ v+ Câu 31:#% #MD d=FI9% !=ja\Q #%JI=jµY+LM ! #C9%01 1=FGQ01CD E/%$%!F=j ]+Z+ na v L+Ql+ na v 4+l+ na v ;+QZ+ na v  Câu 32:!I #" #% FC π   _ − =  1/!01 #B. e+w% "o=FIG %%!8%F" !DF HL π [  = +Lx>% #$8o+w%9F*.= %8b9-C0yoc01CJ%!8=j_001 #IV ]+f_( L+[f_( 4+f( ;+^f_( Câu 33:! !4" #$%92 9-QI #" #%Q[tY+; ! #C bDcJ4g#% #MD $ %I #=ja\+#% #M$ %I # 0G^\'01C=j ]+Q^µv L+Q[µv 4+Qlµv ;+Qµv Câu 34: !4KI4XaµYG%!F%+LMeD J #/d %I #0GR  X^\+ - #/d=FJI0G%XZ\01C=j ]+[ZZµv L+_laµv 4+_lQaµv ;+[ZQZµv Câu 35: !40B$"! ! #CDg(oz  X{+?01 C"e=jseD J"(%d9F0G ]+( L+Q[( 4+Q[( ;+( Câu 36:40u$(o"3|X+ ^ f(QXQ[Q#% #MD =FI \+?01 #CJ 20G ]+[v+ L+Q[v+ 4+Q[v+ ;+Q[+ i^ v+ Câu 37:I #J !" #%4XhYQ= % 1 #B M#% #M\Q(% " D# ! #C*+?01.JC9=* %D# ! M 9 ! #C*}0G=%V ]+ ∆ WX9v L+ ∆ WX[v 4+ ∆ WX[9v ;+ ∆ WXv Câu 38:! ! #C40u$  !g #BD =FDJI #0G O03%09k0+,3l`l_[Z_Z Th >  +4U(%d9F=j%G=j ia ('01C0" !0g=j C q ^   + (oJ !3 ]+Q[+ [ {+L+ a {+ 4+^Q[+ [ {+ ;+ ia {+ Câu 49:! ! #C" #%JI0G4X^µY+>%' ! #/D  d=FI0G\+ #/d=FI0Gl\'01CJ0G A+QZZ+ i^ v+ B+Qa+ i^ v+ C+Qa+ i^ v+ D+^+[+ i^ v+ Câu 403! !4"%!%FXQ[GI #4X[tY+#% #MD d =FI0G[\+?01 !JG%9' !J0G A. 2,5.10 -4 J ;  π s. B. 0,625mJ;  π s. C. 6,25.10 -4 J ;  π s. D. 0,25mJ ;  π s. Câu 41:! !K!I #_[/YQ!%!F_ H µ G! #$%Q[ Ω +F% ./!2(%.=j=% -%' !J"Q9 #/D I #0G[\+ ]+Qal+ i_ W L+Q`l+ i_ W 4+Ql`+ i_ W ;+Q`+ i_ W Câu 42:! !K!%!F" #$XQ[ΩQ !DF`[µQG!I #" # %^/Y+x/F%./!2(%.0G=% -%' !J"g #/D I0Ga\+ ]+[_µW L+Q[W  4+_`W ;+_`µW  Câu 43: !K%!8"X i^ G4XZYQ'%!8" #$% -%'! #% #MD [\d=FDJI/F%./!2(%.XaW+,#$J%! 8"e ]+Ω L+Ω 4+[Ω+ ;+Ω Câu 44:! !4K%!8"X[GI #"4X[tY+?M% " #$ %&X i ~Q' -%' !0%2"eD J#% #-d=FI #0G R  X\Q/F%./!2(%.0G A+`W+ L+`W+ 4+`tW+ ;+`W+ Câu 44: !0B$4 1%./!01 J µ ^ C!%K #!p%"(%. # !Z\+• e #%JI #V ]+Q^[ J µ L+Q[ J µ 4+Q_[ J µ ;+Q[ J µ Câu 45: !0B$4 1%./!01 J µ ^ C!%K #!p%"(%. # !Z\+LM(o"J !^f(+• e !DFJ%!8V ]+Q^[ L+Q[ 4+Q[ ;+Q_[ Câu 46: !0B$4KI #" #%4G%!8" !IFXQ[+; %K #!p%"(%. # ! ξ %./!01[ J µ 'T #U 0GSXS  (^b]c+• e ξ V ]+\ L+_\ 4+\ ;+\ Câu 47 :! !K"%!8%FGI #4%%9+F 00M/01 #I=j01C%!80G3 ]+ LC π L+  LC π 4+ ^ LC π ;+ _ LC π Câu 48: ! #C4K!%!8%F" !DFGI #" #% F µ π Q +B9FC0y#% #MID R   M0U#% #MI   U + V ]+_ s µ L+ s µ 4+ s µ ;+a s µ Câu 49: !I # 1./!01 J µ C%K #!p%"(%. # ! ^\+4U(%d9F% s µ '01I #G%!F0=j%+ • e !DFJ%!8V ]+ H µ π  _^ L+ H µ π  _[ 4+ H µ π  _ ;+ H µ π  _ Câu 50: ! #C4K!%!8%F" !DFGI" #%+;%K #!p%"(%. # !a\%./!01[ J µ 'U(%9F* . s µ T ##%+• eV ]+ H µ π  _ L+ H µ π  aQ 4+ H µ π  aQ ;+ H µ π  aQ_ O03%09k0+,3l`l_[Z_Z Th Câu 51: !40B$Q !T #U=MA/<'X Q^( t ω b]c+• e4VLMU(%d9F*.Q[ s µ '01 #G 01C=j%G=j J µ π ZQ + A. pF π [ B. pF π  C. pF π  D. pF π [ BÀI TẬP THỰC HÀNH Câu 1:; ! #C0G ! p%G+#% #Md %%!F=GQ\'  !T #=jQZ]+4T9#% #Md %%!F=jQl\' ! T #=jQ^]+LM !DFJ%!8X[+,#%JIG01 ! #C=j ]+YG[+ i v+ L+YG_+ i v+ 4+YG[+ i v+ ;+YGQ[+ iZ v+ Câu 2:#% #MD d=FI9% !=ja\Q #%JI=jµY+LM ! #C9%01 1=FGQ01CD E/%$%!F=j ]+Z+ na v L+Ql+ na v 4+l+ na v ;+QZ+ na v  Câu 3:!I #" #% FC π   _ − =  1/!01 #B. e+w% "o=FIG %%!8%F" !DF HL π [  = +Lx>% #$8o+w%9F*.= %8b9-C0yoc01CJ%!8=j_001 #IV ]+f_( L+[f_( 4+f( ;+^f_( Câu 4:! !4" #$%92 9-QI #" #%Q[tY+; ! #C bDcJ4g#% #MD $ %I #=ja\+#% #M$ %I # 0G^\'01C=j ]+Q^µv L+Q[µv 4+Qlµv ;+Qµv Câu 5: -= %Q #BI #J !4"BeD >  X iZ 4+ -I/"M #B0G µ (+4 !#%I0G ]+`QZ[]+ L+`ZQ[]+ 4+[Q[[]+ ;+[Q`]+ Câu 6:4 !T #U !4"XQ(b]c+I #" #%[hY+,!DFJ%!F0G ]+X[ L+X[+ a −  4+X[+ Z −  ;+X[ Câu 7:! !4QKI #" #%4XZYG!%!8%F" !DFX +LM#% #MD Ia\+ !T #=ja]Q'#% #Md %%!F=j+ ]+^\ L+[Q\ 4+_Qa\ ;+_\ Câu 8: !4" ! #CDb !cg(o" ^ f(+,#BD I #0G il 4+ !T #=ja+ ia ]' #BI #0G ]+Z+ i 4+ L+^+ i 4+ 4++ i 4+ ;+a+ i 4+ Câu 9:4 !T #U! !0G cb([Q Ati π = +#(oDFJ%! 80G+.   = π +,#%G=-%U #BJI #"eG(% 8V ]+ FC  +[ − = G ccb  (b +[ ^ Ctq π π π −= − L+ FC _ +[ − = G ccb  (b +[ ^ Ctq π π π −= − 4+ FC _ +[ − = G ccb  (b +[ ^ Ctq π π π += − ;+ FC  +[ − = G cb( +[ ^ Ctq π π − = Câu 10: !0B$4KI #" #%[YG%!8" !IF+;T # =MA/<'XQ(Zb]c+B01 #G - st ^Z π = V ]+_ZQ[ J µ L+_lQ[ J µ 4+l_Q`[ J µ ;+_aQ[ J µ O03%09k0+,3l`l_[Z_Z Th O03%09k0+,3l`l_[Z_Z . Th Dạng 3: NĂNG LƯỢNG ĐIỆN TRƯỜNG VÀ TỪ TRƯỜNG I. PHƯƠNG PHÁP Áp dụng các công thức sau: 1.    L W Li= 2.   C q W C = . 3.      . cuộn cảm có độ tự cảm L và một tụ điện có điện dung C thực hiện dao động tự do không tắt. Giá trò cực đại của điện áp giữa hai bản tụ điện bằng U 0 . Giá trò