Capacitance Questions

A $40\mu \text{F}$ capacitor is connected to a $200\text{V}$, $50\text{Hz}$ ac supply. The rms value of the current in the circuit is, nearly:

The capacitance of a parallel plate capacitor with air as medium is $6\mu \text{F}$. With the introduction of a dielectric medium, the capacitance becomes $30\mu \text{F}$. The permittivity of the medium is:(${ϵ}_0=8.85\times 10^{-12}{\text{C}}^2{\text{ N}}^{-1}{\text{ m}}^{-2}$)