(2013?安徽模拟)如图所示,灯L1、L2上分别标有“6V 6W”、“6V 3W”的字样,当开关S闭合时,灯L1、L2

2025-04-29 12:35:17
推荐回答(1个)
回答1:

(1)根据P=

U2
R
可得,L1的电阻:
R1=
U2
P1
=
(6V)2
6W
=6Ω;
(2)两灯泡的电阻之比:
R1
R2
=
U2
P1
U2
P2
=
P2
P1
=
3W
6W
=
1
2

∵串联电路总各处的电流相等,
∴根据欧姆定律可得:
U1
U2
=
IR1
IR2
=
R1
R2
=
1
2

∵串联电路中总电压等于各分电压之和,
U
U
=
U2
U1+U2
=
2
1+2
=
2
3

故答案为:6;2:3.