(1)这盏灯正常发光时的灯丝电阻:
R=
U 2
P =
(220V) 2
40W =1210Ω;
(2)正常发光1min消耗的电能:
W=Pt=40W×60s=2400J;
(3)灯丝断了重新搭上时灯泡消耗的功率:
P′=
U 2
R ′ =
(220V) 2
1100Ω =44W.
故答案为:1210;2400;44.
(1)这盏灯正常发光时的灯丝电阻:
R=
U 2
P =
(220V) 2
40W =1210Ω;
(2)正常发光1min消耗的电能:
W=Pt=40W×60s=2400J;
(3)灯丝断了重新搭上时灯泡消耗的功率:
P′=
U 2
R ′ =
(220V) 2
1100Ω =44W.
故答案为:1210;2400;44.