(单选题)1: 已知某0.5F电容支路电压uC(t)=3+1.5e-2t(V),可知uC (∞)、uC (0+)、时间常数τ、iC (t)分别为( )。 1: 3V,4.5V,0.5S, -1.5e-2t A 2: 4.5V,3V,0.5S, -3e-2t A 3: 3V,4.5V,2S, -1.5e-2t A 4: 3V,1.5V,0.5S, -1.5e-2t A 标准选择: (...