The plates each of area `A` of a parallel plate caoacitor are given charges `Q` and `-Q`. The plates are joined by a non-conducting spring of force constant `k`. The natural length of the spring is `d`, the inital separation between the plates. The left plate is connected to a vertical wall through a massless non-conducting rope and the right plate is connected to a block of mass `m` through similar rope. Assume the pulley to be massless, neglect dielectric effect of the spring and `Q^(2) lt 2mAepsilon_(0)g`
If `T` be the time period of oscillation, then

Options

A. `T gt 2pisqrt((m)/(k))`
B. `T lt 2pisqrt((m)/(k))`
C. `T = 2pisqrt((m)/(k))`
D. `T` will depend on `Q`.

Explanation

`mg` is balanced by the electrostatic force.