(1)R-C串联电路中电压电流的瞬时值关系 设:i sin at u=un+u=iR+ idt √2 Rsin a√2IX, cos ct =√2l|z|sin(an+q) =√2Usin(o+g)后iφ)度 =lz2|=√R2+X2,Y 其中: X pp=tg <02 sin( ) 2 sin( ) 2 sin 2 cos 1 = + = + = − = + = + U t I Z t IR t IX t idt C u u u iR C R C (1) R-C串联电路中电压电流的瞬时值关系 其中: R X t g C U I Z Z R X X C C C − = = = + = −1 2 2 1 , , u落后i | |角度 设: i = 2Isint <0