(1)求I sc 电路如图(a)所示。由KVL和元件的VAR得 3I 1 +4I sc =30 由KCL和元件的VAR得 联立上述两式解得 I 1 =2A,I sc =3I 1 =6(A压束) (2)求R 0 。电路如体北拉今非女府什菜氢图(b)所示。由KCL和元件的360问答VAR得 由KVL和元件的VAR得 U 0 =4I 0 -3I 1 =4间画观于答班钟属校×(-3I 1 )-3I 1 =-15I 1 所以 (3)求电流I。电路如图(c)所示,则