本题目来源于试卷: gc textbook chapter 18 Electric Currents，类别为 IB物理学
[问答题]
When you turn on a wa*1rh9j*zw xb0otym/6musl 8 stg p3z+tx qg f/*e8wpr)ca pn,3er faucet, the water usually flows immediately. You don’t have to wait for water to flow from the faucet valve cg*8fn/w3a,xpr e pq )to the spout. Why not? Is the same thing true when you connect a wire to the terminals of a battery?
参考答案: Water flows immediately from the
spout because there is already water in the spout when you turn on the
faucet. Since water is (essentially)
incompressible, a push on the water from some distant location (at the valve or
pump) causes all the water to move almost immediately, pushing the water out of
the spout. In a battery, a similar
phenomenon exists in that the wires are “full” of charges (free
electrons). The voltage “push” from the
battery pushes all the electrons along the wire almost immediately, and the
first ones at the other end of the wire are the beginnings of the electric
current.
本题详细解析:
暂无
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