本题目来源于试卷: gc textbook chapter 18 Electric Currents，类别为 IB物理学
[问答题]
Explain why lightbulbs a,(xojwpw9mm5 /vlow3f9ql t 3lmost always burn out justphw 2f i-4ee3y as they are turned on and not a32y epf-weih4fter they have been on for some time.
参考答案:
When
a light bulb is first turned on, it will be cool and the filament will have a
lower resistance than when it is hot.
This lower resistance means that there will be more current through the
bulb while it is cool. This momentary
high current will make the filament quite hot.
If the temperature is too high, the filament will vaporize, and the
current will no longer be able to flow in the bulb.
本题详细解析:
暂无
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