代入元件VCR,得 ⅠR1+u+R,+/R =0 R1=19+ls2=4V su 2=1A tr+ P.=-L。I=-10W us=lov R2,=2 R3=3g P=L。I=4W1A 1 2 3 1 2 = + + − = R R R u u I S S 1 10 W 1 Pu = −uS I = − S 2 4W 2 Pu = uS I = S 0 2 1 IR1 + uS + IR2 + IR3 −uS = 代入元件VCR，得 R1=1 + uS2=4V - I - R3=3 + uS1=10V R2= 2   