Question

What is the dielectric constant (k) and how does it relate to capacitors?

A) The dielectric constant is the resistance to electrical flow in a capacitor.
B) The dielectric constant measures the physical size of a capacitor.
C) The dielectric constant is the relative permittivity of a dielectric material and is important for characterizing capacitors.
D) The dielectric constant determines the voltage rating of a capacitor.

Answer 1

The dielectric constant (k) is a measure of how much a dielectric material increases the capacitance of a capacitor, relative to the capacitance in a vacuum. It is defined as the ratio of the electric field in a vacuum to the electric field in the dielectric material.

Step-by-step explanation:

The dielectric constant (k), also known as relative permittivity, is a measure of a material's ability to reduce the electric field, and thus increase the storage capacity of a capacitor, when used as an insulating material between the plates of the capacitor. This constant k is the ratio of the electric field (Eo) in a vacuum to the electric field (E) in the dielectric material, which is related to the polarizability of the material. When a dielectric is inserted into a capacitor, the capacitance is increased by a factor of k due to the induced electrical field opposing the field of the free charge on the capacitor plates. Hence, if 'C' represents the capacitance of the capacitor with the dielectric and 'Co' represents the capacitance of an empty capacitor (vacuum), the relationship is C = k * Co, where k > 1 for all dielectrics. The value of k is characteristic for different materials and determines how much more capacitance can be achieved compared to an empty capacitor.