※ 引述《aacvbn ( 姿勢+)》之銘言： : http://www.lib.ntou.edu.tw/exam/electric/96/6.pdf : 第一題 圖在上面的連結@@ : An emf V is applied across a parallel-pate capacitor of area S. : the space between the conducting plates is filled with two different : lossy dielectrics of permittivities (ε_1) and (ε_2) , : and conductivities (σ_1) and (σ_2) respectively. : These two dielectrics have the same thickness d. : (1)Find the current density between the plates. : (2)Determine the electric field intensities in both dielectrics. : (3)Determine the surface charge densities on the plates and at the interface : of the dielectrics. : (Note: neglecting fringing effect at the edges of the plates) (20%) 令電流 I , J=I/S E1= J/σ1 = I/Sσ1 E2= J/σ2 = I/Sσ2 Id V = ∫E dr = E1*d+E2*d = ____(1/σ1 + 1/σ2) S VS I = ________________ ______(*) d(1/σ1 + 1/σ2) V J=I/S = __________________ d(1/σ1 + 1/σ2) V V E1=J/σ1 = __________________ , E2=J/σ2=________________ d(1/σ1 + 1/σ2)σ1 d(1/σ1 + 1/σ2)σ2 ρs(top) = D1 = ε1E1 =.. ρs(bottom) = -D2 = -ε2E2 = .. ρs(interface) = D2-D1 = .. --

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