先把 Us 、R1、R2 等效为一个电源 E 与内阻 R 串联:
E = US / 2 = 5 V,R = R1//R2 = 0.5 K
(1)uc(0+) = 0 V, ic(0+) = 5 /1.5 = 3.333 mA
(2)uc(∞) = 5 V , ic(∞) = 0 A
(3)τ = 1.5 * 10 ^ 3 * 100 * 10 ^ (-6) = 0.15 s
(4)uc(t) = 5 - 5 e ^ (- t/0.15) , ic(t)= 3.333 e ^ (- t/0.15)