R=5Ω时,其吸取功率最大 PRLMax= Uoc * Uoc/4 Ro
=20W
3、解:
R=2?时获得最大功率 UOC=0.5
0.521?瓦 Pmax=
4?2324、解:
10V电压源单独作用u'=4V 4A电流源单独作用u\?2.4= -9.6V 共同作用u=u'+u\5、解:
2V电压源单独作用,1A电流源断路I1=0, 1A电流源作用,2V电压源短路
I2=2/3A,共同作用电流I=2/3 6、解:可求出:uoc=4V, Req=20k, 故 R = Req=20k, 可获得最大功率
-
pmax2uoc??0.2 mW4Req
7、解:应用叠加定理,作10V、4A单独作用的等效电路,则有
?1?i1?1??i2?10?1??1??1A,u3??10i1?1??4i2??6V6?4
i1?2???4?2??2??2??4??1.6A,i2?4?i1?2??2.4A,u3??10i1?2??4i2?25.6V6?4
(1)(2)?u?u?u?19.6V333
47
8、解:该网络的VAR可表示为
u?uoc?Req i
S1: 求uoc
'\'%uoc?uoc?uoc?uoc
?is1
S2: 求Req
R1R1?R2R1?R2?R3?is2?R3?Us3R1?(R2?R3)(R1?R2)?R3R1?R2?R3 RRi?(R1?R2)R3is2?(R1?R2)Us3 ?13s1R1?R2?R3
Req?Rab?(R1?R2)//R3?(R1?R2)R3R1?R2?R3
9、解: uoc?(i?0.5 i)R2?R1i?10?10?(R1?0.5R2) i?10
isc?10?1 AR1?0.5R2150uoc?10?1500?isc1/150
Req?
48