有甲乙两只灯泡分别标有“6V,12W”和“12V,6W”的字样,把它们串联起来,两端允许的最高电压是______V

2025-01-02 05:59:11
推荐回答(1个)
回答1:

(1)灯泡电阻R=

U
P
=
(6V)2
12W
=3Ω,R=
U
P
=
(12V)2
6W
=24Ω;
灯泡的额定电流I=
P
U
=
12W
6V
=2A,I=
P
U
=
6W
12V
=0.5A;
(2)两灯串联时,流过电路的电流I=I=0.5A,
串联电阻两端的电压U=I(R+R)=0.5A×(3Ω+24Ω)=13.5V;
消耗的实际功率之比
P
P
=
I2R
I2R
=
R
R
=
24Ω
=
1
8

(3)两灯泡并联时,
1
R
=
1
R
+
1
R
,R=
RR
R+R
=