Question

Three charges q, q, and -2q are fixed on the vertices of an
equilateral triangular plate of edge length a. This plate is in
equilibrium between two very large plates having surface
charge density o, and 0,, respectively. Find the time period
of small angular oscillation about an axis passing through its
centroid and perpendicular to the plane. Moment of inertia
of the system about this axis is l.
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Answer 1

Answer:

refer the above attachment

Answer 2

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