Example l u(t=100sin 2tv r=v/R=10 sin 2nA =Ccv/dt=4丌×103cos2m4 100sin 2np QMI 20uF Cv=0.lsin 2nutJ 2 t=0→1 0 physical-capacitor t=1/4s,>wc=0.1J t=1/2s 0 1/2 1/2 R R dt Rindt=2.5m/Example 1: i C Cdv / dt 4 10 cos 2t A −3 = =  t = 0 → wC = 0 1/ 2 , 0 1/ 4 , 0.1 = → = = → = C C t s w t s w J   = = = 1/ 2 0 1/ 2 0 2 wR pR dt RiR dt 2.5mJ (t) = 100sin2tV i R v / R 10 sin2tA −4 = = wC Cv 0.1sin 2tJ 2 1 2 2 = = physical − capacitor 100sin2tV − +  R i C i  M1 20F