Question

Define the dielectric constant of a medium.

Hint:

Dielectric constant is also called \(\textbf{relative permittivity}\). \[ K = \frac{\text{Permittivity of medium}}{\text{Permittivity of vacuum}} \] It has \textbf{no unit}.

Answer 1

Concept:
The dielectric constant (also called relative permittivity) measures how much a medium reduces the electric field compared to vacuum. It indicates how well a material can store electric energy in an electric field. Mathematically, it is defined as: \[ K = \frac{\varepsilon}{\varepsilon_0} \] where: \(\varepsilon\) = permittivity of the medium
\(\varepsilon_0\) = permittivity of free space

Step 1:
When a dielectric is placed in an electric field, it becomes polarized. This reduces the effective electric field inside the material.
Step 2:
The extent of this reduction is measured by the dielectric constant \(K\). A higher value of \(K\) means stronger polarization and greater ability to store electric energy.
Step 3:
Thus, dielectric constant is a dimensionless quantity that compares electrical behavior of a medium with vacuum.