三要素为： 5Ω 52 i(0)=i2(0*)=10/5=2A 2A 20 i,(∞)=10/5+20/5=6A x=L/R=0.6/(5/∥5)=1/55 0+等效电路 (0*)= (10-20) +1=0A 10 i1(∞)=10/5=2A i2(0*)= (20-10) +1=2A 2(∞)=20/5=4A 10 iz(t)=6+(2-6es=6-4e5tt≥0 i1(t)=2+(0-2)e5=2-2e5tA i2(t)=4+(2-4)es=4-2e5tA三要素为：  = L / R = 0.6/( 5// 5 ) = 1 / 5 s i L ( 0 ) = i L ( 0 ) = 10 / 5 = 2 A − + i L (  ) = 10 / 5 + 20 / 5 = 6 A ( ) 6 ( 2 6 ) 6 4 0 5 5 = + − = −  − − i t e e t t t Li t e e A 5 t 5 t 1 ( ) 2 ( 0 2 ) 2 2 − − = + − = − i t e e A 5 t 5 t 2 ( ) 4 ( 2 4 ) 4 2 − − = + − = − +– 2A 20V 5  5  +– 10V i i 2 1 0 ＋等效电路 i 1 0 A 10 (10 20 ) ( 0 ) 1 + = − = + i 1 2 A 10 (20 10 ) ( 0 ) 2 + = − = + i1 (  ) = 10 / 5 = 2 A i 2 (  ) = 20 / 5 = 4 A