Find the relative permittivity

In summary, the conversation discusses a commonly-used capacitor with two circular parallel plates and a ceramic dielectric between them. The plates have a diameter of 12.5 mm and a thickness of 3 mm, resulting in a capacitance of 10 nF. The question is posed regarding the relative permittivity of the material between the plates in order to achieve this capacitance. The conversation also touches on the importance of accounting for the finite thickness and insulation of the plates. It is unclear whether this calculation is an underestimate or overestimate of the relative permittivity. In SI units, the equation for capacitance is given as C = (relative permittivity) * (area/ distance).
  • #1
Tom555
4
0
Consider a commonly-used capacitor made from two circular
parallel plates with a ceramic dielectric between them. The plates have 12.5 mm diameter and the whole thing is 3 mm thick with a capacitance of 10 nF. Neglecting the finite thickness and extent of the plates, what
relative permittivity must the material between the plates have to provide this capacitance?
Allowing for the finite thickness of the plates, and of the insulation wrapping the outside of
the whole thing, is this an underestimate or overestimate of the permittivity?

I'm really not sure how to start at all. Without filling in details, can someone please explain how I would go about this problem?
 
Physics news on Phys.org
  • #2
Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
 
  • #3
In SI units,
C=(relativity permittivity)*A/d
 

What is relative permittivity and why is it important?

Relative permittivity is a measure of how well a material can store electrical energy in an electric field. It is important because it affects the capacitance and dielectric properties of a material, which can impact the performance of electronic devices.

How is relative permittivity measured?

Relative permittivity is typically measured using a device called a capacitance meter, which measures the capacitance of a material. The relative permittivity is then calculated by dividing the measured capacitance by the capacitance of a vacuum or air.

What factors can affect the relative permittivity of a material?

The relative permittivity of a material can be affected by factors such as temperature, pressure, and frequency of the electric field. Additionally, the chemical composition and structure of a material can also impact its relative permittivity.

What is the difference between relative permittivity and absolute permittivity?

Relative permittivity is a dimensionless quantity that compares the permittivity of a material to that of a vacuum or air. Absolute permittivity, on the other hand, is a physical constant that represents the actual ability of a material to store electrical energy in an electric field.

Why do different materials have different relative permittivity values?

The relative permittivity of a material depends on its atomic and molecular structure, as well as the electric field strength and frequency. Different materials have different arrangements of atoms and molecules, which can affect how well they can store electrical energy.

Similar threads

  • Other Physics Topics
Replies
2
Views
1K
  • Other Physics Topics
Replies
1
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
1K
Replies
10
Views
1K
Replies
1
Views
1K
  • DIY Projects
Replies
2
Views
1K
  • Other Physics Topics
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
5K
  • Introductory Physics Homework Help
Replies
29
Views
2K
Back
Top