A capacitor of capacitance C is charged to a potential V . The flux of the electric field through a closed…

 The charge enclosed is given by $q_{inc}=CV$  

Gauss' law states that the flux through any closed surface is equal to the charge enclosed by the surface.

 Using Gauss' law the flux is,  $\varphi =\frac{q_{\text{inc }}}{{\epsilon }_0}=\left(\frac{CV}{{\epsilon }_0}\right)$