Q_1 = C_11 V_1 + C_21 V_2 Q_2 = C_12 V_1 + C_22 V_2 Now consider the usual case in which Q_1 = -Q_2 = Q , => C_11 V_1 + C_21 V_2 = Q C_12 V_1 + C_22 V_2 = -Q then by Cramer's rule, V_1 = Q(C_21+C_22)/det(C_ij) V_2 = -Q(C_11+C_12)/det(C_ij) => V = V_1-V_2 = Q Σ_ij C_ij / det(C_ij) = Q/C thus the capacitance we have learned before is given by C = det(C_ij)/Σ_ij C_ij 我猜chungweitw大的意思应该是这样 ※ 引述《mouwat (QQ)》之铭言： : : 我有再看了课本 但不是很懂= = : : 老师上课有讲一个简单例题 : : 半径a跟b的同心圆壳 算出来的C11=-C12=-C21=/=C22 : : 最後就取C=C11 这怎麽去决定? : : C11=ab/(b-a) C12=C21=-ab/(b-a) C22=b^2/(b-a) : the coefficients Cij are capacities : or capacitances while Cij,i=/=j,are called coefficients of induction. : thecapacitance of a conductor is therefore the total charge on the conductor : when it is maintained at unit potential, : all other of conductors beingheld at zero potential. : sometimes the capacitance of a system of conductors is also defined. : for example, : the capacitance of two conductors carrying equal and opposite charges : in the presence of other grounded conductors is defined as the ratio : of the charge on one conductor to the potential difference between them. : the equations Qi=summation CijVi can be used to express this capacitance : in terms of the coefficients Cij : 如果没错你应该是说这段吧 : 可是除了提到V=V1-V2 : 我不太了解哪里叙述可以导出你提到的C=det(Cij)/sum(Cij) : 是我英文不好吗~"~ --

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