Question

Are dielectric constant and relative permittivity the same?

Answer 1

Yes, dielectric constant and relative permittivity essentially refer to the same thing, but they are used in slightly different contexts.

1. Relative Permittivity (or just permittivity in many cases) is the more scientific term. It measures how much a material can store electrical energy in an electric field, compared to the vacuum. It's the ratio of the material's permittivity (how much it resists electric field) to the permittivity of free space (vacuum).
   

1. Dielectric Constant is an older term and it often refers to the same concept as relative permittivity. It’s simply a more commonly used name, especially in practical or engineering contexts.
   

So, in short, they're the same, but relative permittivity is the more accurate and widely accepted term today.