A parallel plate capacitor is of area 6 cm^2 and a separation 3 mm. The gap is filled with three dielectric materials of equal thickness (see figure)…

A parallel plate capacitor is of area $\displaystyle 6 \mathrm{~cm}^2$ and a separation $\displaystyle 3$ mm. The gap is filled with three dielectric materials of equal thickness (see figure) with dielectric constants $\displaystyle \mathrm{K}_1=10, \mathrm{~K}_2=12$ and $\displaystyle \mathrm{K}_3=14$. The dielectric constant of a material which when fully inserted in above capacitor, gives same capacitance would be :