K闭合前电路处稳态,求t0-4 时K闭合后的v(0)(0.(Wc×w1k (04)和v(0+) K vc(0)=4V=vc(04),i(0.)=02mA=i(04),运用替 代定理,有t0时刻的电路。 0.2mA +|20k40k 则有v1(04)=106-4=0,ic(04)=02-03=0.1mAK闭合前电路处稳态，求t=0 时K闭合后的vC(0+ )、iC(0+ )、 iL (0+ )和vL (0+ ) vC(0- )=4V=vC(0+ )，iL (0- )=0.2mA=iL (0+ )，运用替 代定理，有t=0+时刻的电路。 则有vL (0+ )=10-6-4=0，iC(0+ )=0.2-0.3=-0.1mA C 10V 30k 20k L v 40k K L C i + − 10V 4V 30k 20k 40k 0.2mA