本题目来源于试卷: DC Circuits，类别为 IB物理学
[问答题]
Explain why birds ca 7o+qry*kynrjr* /c: b:m 5y2dnv1lspn sij ld-8jht.-w;b kvlv:t on power lines safely, whereas leaning a metal ladder up against a power line to fetchhdj-kb:-v v8;l .tjl w a stuck kite is extremely dangerous.
参考答案:
The birds are safe because
they are not grounded. Both of their
legs are essentially at the same voltage (the only difference being due to the
small resistance of the wire between their feet), and so there is no current
flow through their bodies since the potential difference across their legs is
very small. If you lean a metal ladder
against the power line, you are making essentially a short circuit from the
high potential wire to the low potential ground. A large current will flow at least
momentarily, and that large current will be very dangerous to anybody touching
the ladder.
本题详细解析:
暂无
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