(1)标有“12V 8W”的灯泡的额定电流I1=
=P1 U1
=8W 12V
A,电阻R1=2 3
=
U
P1
=18Ω;(12V)2 8W
标有“6V 2W”的灯泡的额定电流I2=
=P2 U2
=2W 6V
A,电阻R2=1 3
=
U
P2
=18Ω;(6V)2 2W
(2)为保证电路安全,两灯泡串联时,电路电流I=I2=
A;1 3
(3)加在电路两端的电压U=I(R1+R2)=
A×(18Ω+18Ω)12V.1 3
故选B.