(2009?沈阳)如图所示,小灯泡L上标有“6V 3W”字样.闭合开关,小灯泡正常发光,电流表的示数为1.5A.

2025-04-24 10:53:57
推荐回答(1个)
回答1:

解答:已知:UL=6V,PL=3W,I=1.5A,t=1min=60s
求:RL,R0,W
解:(1)灯泡正常发光时灯丝的电阻为 RL=

U
PL
6V×6V
3W
=12Ω;
(2)U=U0=UL
IL
PL
UL
3W
6V
=0.5A,
I0=I-IL=1.5A-0.5A=1A,
故定值电阻R0的阻值为 R0
U0
I0
6V
1A
=6Ω;
(3)W=UIt=6V×1.5A×60s=540J.
答:(1)小灯泡L正常发光时灯丝的电阻为12Ω;
(2)定值电阻R0的阻值为6Ω;
(3)通电1min电路消耗的总电能为540J.