本题目来源于试卷: DC Circuits，类别为 IB物理学
[问答题]
(Fig. Below) is a diagram of a capacitor (or co c;/ a nmm*raqy6n9; uyndenser) m szq s*x-zcr:(icrophone. The changing air pressure in a sound wave causes one plate of the capacitor C to move back and forth. Explain how a current of t qsz zsrc*(-x:he same frequency as the sound wave is produced.
参考答案:
As the sound wave is
incident on the diaphragm, the diaphragm will oscillate with the same frequency
as the sound wave. That oscillation will
change the gap between the capacitor plates, causing the capacitance to
change. As the capacitance changes, the
charge state of the capacitor will change.
For instance, if the plates move together, the capacitance will
increase, and charge will flow to the capacitor. If the plates move apart, the capacitance
will decrease, and charge will flow away from the capacitor. This current will change the output voltage. Thus if the wave has a frequency of 200 Hz,
the capacitance and thus the current and thus the output voltage will all
change with a frequency of 200 Hz.
本题详细解析:
暂无
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