Four point $+ve$ charges of same magnitude $(Q)$ are placed at four corners of a rigid square frame in $xy$ plane as shown in figure. The plane of the frame is perpendicular to $z-$ axis. If a $-ve$ point charges is placed at a distance $z$ away from the above frame $(z << L)$ then

826-647

  • A

    $-ve$ charge oscillates along the $z-$ axis

  • B

    it moves away from the frame

  • C

    it moves slowly towards the frame and stays in the plane of the frame

  • D

    it passes through the frame only once

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