When a dielectric material is introduced between the plates of a parallel plate capacitor the capacitance increases by a factor of 4. What is the dielectric constant of the material introduced between the plates?

Question

Quizplus · Accepted Answer

The capacitance of a parallel plate capacitor with vacuum or air in between is given by:
C = ε0 A / d
where ε0 is the vacuum permittivity, A is the area of the plates, and d is the separation between the plates.
When a dielectric material is introduced, the capacitance increases by a factor of κ, the dielectric constant of the material:
C' = κ C = κ ε0 A / d
Given that the capacitance increases by a factor of 4, we have:
κ C = 4C
κ = 4
Therefore, the dielectric constant of the material introduced between the plates is 4, which is option D.

When a Dielectric Material Is Introduced Between the Plates of a Parallel