A parallel plate capacitor contanins a mica sheet (thickness ` 0. 5+xx10^(-3) m`) . And a sheet of fiber (thickness `0. 5 xx 10^(-3) m`) . The dielectric constant of mica is `8` and that of thye fiber is `2.5` Assuming that the fiber breaks down when subjected to an electric field of ` 6.4 xx 10^6 Vm^(-1)`. , find the maximum safe voltage that can be applied to the capacitor.

Answer

`2.08 KV`

Explanation

Let `E_(0)` be the electric field due to charges on plates (not due to induced charges). Given `E_(0)=6.4xx10^(6)Vm^(-1)`
.
`V-V_(1)+V_(2)=E_(1)d_(1)+E_(2)d_(2)=E_(0)/K_(1)d_(1)+E_(0)/K_(2)d_(2)`
`=(6.4xx10^(6)xx10^(-3))/8+(6.4xx10^(6)xx0.5xx10^(-3))/(2.5)`
`=2.08xx10^(3) V=2.08 kV`.