Re: [理工] [電磁]-雲科96-光電所

看板Grad-ProbAsk作者 (包)時間14年前 (2010/01/07 01:32), 編輯推噓0(000)
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※ 引述《aacvbn ( 姿勢+)》之銘言: : 96雲科光電所 http://www.lib.yuntech.edu.tw/exam_new/96/de.pdf : [最末頁第五題] : Find the resistance between two concentric spherical surfaces : of radii R1 and R2 (R1<R2) if the space between the surfaces : is filled with a homogenous and isotropic material having a : conductivity σ. 令中央灌入電流 I , J=I/(4πR^2) , E = J/σ=I/(4πR^2)σ R2 R2 I *[1/R1-1/R2] v = ∫E dR = ∫ I/(4πR^2σ) dR =-I/(4πRσ)︳= ______________ R1 R1 4πσ 1/R1-1/R2 resistance = V/I = __________ 4πσ 有錯誤請多多指正.. -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 118.171.102.115
文章代碼(AID): #1BHCabG7 (Grad-ProbAsk)
文章代碼(AID): #1BHCabG7 (Grad-ProbAsk)