A light bulb rated 110V 40W...

2010-02-01 2:44 am

A light bulb rated 110V 40W...work at 220V會點???

回答 (3)

2010-02-01 7:12 am

✔ 最佳答案

1. R = V²/P = 110*110/40
= 302.5Ω
2. P = V²/R = 220*220/302.5Ω
= 160W

如果唔爆炸或燒毀就有四倍亮度。

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2010-02-02 3:06 am

Is my answer is correct?

the current of light bulb:
40/110=0.36A

the power of the loght bulb:
0.36A x 220V
=80W

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2010-02-01 2:50 am

It certainly would burn away as the heat developed is too large.

The power under 220v = 40 x (220/110)^2 w = 160 w

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