A parallel plate capacitor has charge 5 × 10^-6 C. A dielectric slab is inserted between the plates and almost fills the space between the plates. If…

A parallel plate capacitor has charge $\displaystyle 5 \times 10^{-6} \mathrm{C}$. A dielectric slab is inserted between the plates and almost fills the space between the plates. If the induced charge on one face of the slab is $\displaystyle 4 \times 10^{-6} \mathrm{C}$ then the dielectric constant of the slab is $\displaystyle \_\_\_\_$.