L1电阻为R1= U P1 = (12V)2 8W =18Ω;R2= U P2 = (6V)2 2W =18Ω.根据串联电路电阻的分压特点可知,两只灯泡电阻相同时,分得的电压相等;即U2=U1=6V,串联电路的电流为I= U R1+R2 = 12V 18Ω+18Ω = 1 3 A,实际功率为P1=P2=U1I=6V× 1 3 A=2W.故选A.