合聚咖

合聚咖

某白炽灯上标有“220V 100W”字样,表明该灯正常发光时该灯两端的电压是______V,通过灯丝的电流是_____

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(1)由灯泡的铭牌可知,灯泡的额定电压为220V,额定功率为100W,

灯泡正常发光时的电压和额定电压相等,即为220V;

(2)正常发光时通过灯丝的电流:

I=

P
U
=
100W
220V
≈0.45A;

灯泡的电阻:

R=

U 2
P
=
(220V) 2
100W
=484Ω.

故答案为:220;0.45;484;100.