Question

How does permittivity affect electric field intensity?

Answer 1

Permittivity determines how an electric field affects or is affected my some material medium.

If the electric field in a space is E is vacuum and we put a a material medium with permittivity `epsilon` in that region, the electric field reduces by a factor of `epsilon/(epsilon""_0)` which is equal to the dielectric constant `K""_D` of the medium.

Due to presence of the material medium, the polarized field in the medium due to the electric field somewhat cancels it's effect and as a result the decrease in net electric field is observed.