§2-3电阻的串联和并联(续) 2.电阻的并联:电压相等 /2 (等效) R1R2R3 weal i=i+i2+is=u/R,+u/R2+u/R3=Gu (据KVL(据VCR) 等效电阻:R=1/G 1(+D2+IR3)§2-3 电阻的串联和并联(续) 2. 电阻的并联:电压相等 u + - i R1 R2 R3 i1 i2 i3 u + - i Req (等效) i= i1+i2+i3= u/R1+u/R2+u/R3 = Gu ( 据KVL) ( 据VCR) 等效电阻: R = 1/G =1/ ( 1/R1+1/R2+1/R3 )