Hard rubber has a dielectric constant of 2.8 and a dielectric strengh (maximum electric field) of `18xx10^(6)` volt/meter. If it is used as the dielectric material filling the full space in a parallel plate capacitor. Minimum area may the plates of the capacitor have in order that the capacitance be `7.0xx10^(-2) mu F` is equal to `(pi)/(n) m^(2)`. What should be the value of n if capacitor be able to withstand a potential difference of 4000 volts . (`in_(0)=(10^(-9))/(36 pi ) ` S.I unit)

Options

A. `0.62m ^(-2)`
B. ` 0.32m ^(-2) `
C. ` 0.42 m^(-2) `
D. ` 0.52 m^(-2)`

Answer

A