【例41】长方形盒的长为A宽为B、高为G,上盖 电位为,其余接地,求盒内的电位分布 V2(r)=0 C (O,y,=)=0,y(A,y,=)=0 少(x,0,=)=0,y(x,B,=)=0 少(x,y,O)=0,0(x,y,C)= d)=x(x)()z() B d2x 1 dy 1 d2Z A x d y dy2 z dz2 (A,y,=)=0.,y,z)=0→X(A)=X(0)=0 (x,B,=)=y(x0,)=0→Y(B)=Y(0)=0 (x,y.0)=0→z(0)=0C A B ( ) ( ) ( ) ( ) ( )  ( ) ( )       = = = = = =  = 0 2 , ,0 0, , , ,0, 0, , , 0 0, , 0, , , 0 0         x y x y C x z x B z y z A y z r 【例4-1】长方形盒的长为A、宽为B、高为C，上盖 电位为 ，其余接地，求盒内的电位分布。  0 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )  ( ) ( )         =  = = =  = = = =  = = + + = 0 0 0 0 0 0 0 0 0 0 0 0 0 d 1 d d 1 d d 1 d 2 2 2 2 2 2 x, y, Z x,B,z x, ,z Y B Y A, y,z , y,z X A X z Z y Z Y x Y X X      (r) = X(x)Y(y)Z(z)  0