本题目来源于试卷: Electromagnetic Induction and Faraday’s Law，类别为 IB物理学
[问答题]
A bar magnet falling imah 7z2fc 4sq7nsm x-6xxbpb*,r48h2fl n ;hdf cide a vertical metal tube reaches a terminal velocity even if the tube 4 fxldf8r*hbhxb;x- ,cpm 26nis evacuated so that there is no air resistance. Explain.
参考答案:
As a magnet falls through a
metal tube, an increase in the magnetic flux is created in the areas ahead of
it in the tube. This flux change induces
a current to flow around the tube walls to create an opposing magnetic field in
the tube (Lenz’s law). This induced
magnetic field pushes against the falling magnet and causes it to slow
down. The opposing magnetic field cannot
cause the magnet to actually come to a stop, since then the flux would become a
constant and the induced current would disappear and so would the opposing
magnetic field. Thus, the magnet reaches
a state of equilibrium and falls at a constant terminal velocity.
本题详细解析:
暂无
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