题目内容

【题目】如图所示，我们可以探究平行板电容器的电容与哪些因素有关。平行板电容器已充电，带电量为Q，静电计的指针偏角大小，表示两极板间电势差的大小。如果使极板间的正对面积变小，发现静电计指针的偏角变大，我们就说平行板电容器的电容________（填“变大”或“变小”）；如果使两极板间的距离变大，发现静电计指针的偏角变大，我们就说平行板电容器的电容________（填“变大”或“变小”）。我们之所以能够得出这些结论是因为电容器的电容C=________。

【答案】变小 变小

【解析】根据C=，正对面积变小说明电容减小，又C=，电压增大则发现静电计指针的偏角变大；使两极板间的距离变大，根据C=，说明电容减小，又C=，电压增大则发现静电计指针的偏角变大。我们之所以能够得出这些结论是因为电容器的电容C=。

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