A particle of charge q and mass m is suspended from a point on the wall by a rigid massless rod oflength `L = 3//m` as shown. Above the point of suspension another particle is clamped which has a charge -q at a distance L .from point of suspension. On slight displacement from the mean position, the suspended particle is observed to executes SHM. Find the time period of SHM. (For calculations consider `Kq^(2) = 2mgL^(2) `and `g = pi^(2)) [4s]`