The displacement current of $4.425 \mathrm{\mu A}$ is developed in the space between the plates of parallel plate capacitor when voltage is changing at a rate of ${10}^6 \mathrm{V} {\mathrm{s}}^{-1}$. The area of each plate of the capacitor is $40{ \mathrm{cm}}^2$. The distance between each plate of the capacitor is $x\times {10}^{-3} \mathrm{m}$. The value of $x$ is ,
(Permittivity of free space, ${\epsilon }_0=8.85\times {10}^{-12} {\mathrm{C}}^2{ \mathrm{N}}^{-1}{ \mathrm{m}}^{-2}$) _______

Hence, the correct answer is 8.