.换路定律 lc(1)=5d5 C i(d5+a。i(5)d5 C =(0.)+n灿5 q=Cuc ()=0)+r (d2 t=0时刻uc(0+)=c(0)+。id5 (04)=9(0)+(5)5 当(为有限值时M→0 ll(04)=ul(0)9(04)=q(0)电荷守恒 结论换路瞬间,若电容的电流保持为有限值, 则电容电压(电荷)换路前后保持不变。二. 换路定律 ( )d 1 ( ) − = t C i C u t   ( )d 1 ( )d 1 0 0   − − = + − t i C i C ( )d 1 (0 ) 0  − = − + t C i C u q =C uC t = 0+时刻 ( )d 1 (0 ) (0 ) 0 0  + − + = − + i C uC uC ( ) (0 ) ( )d 0  − = − + t q t q i 当i()为有限值时 i uc C + - q (0+ ) = q (0- u ) C (0+ ) = uC (0- ) 电荷守恒 结论 换路瞬间，若电容的电流保持为有限值， 则电容电压（电荷）换路前后保持不变。 1.  + − + = − + 0 0 q(0 ) q(0 ) i( )d  + − → 0 0 i( )d 0