Dielectric Definition and 676 Threads

How much the dielectric loss tangent of 10 nm thick SiO2 at 1Ghz ? I am studying the MOSFETs i want to know the the dielectric loss tangent of SiO2 dielectric at such manometer thickness, So if anybody know any reference about it Please let me know..

Hi everyone, I'm new in physics forum and this is my first post. So basically, our lecturer grouped us and gave each group a project to carry out. And the only information that we got is the name ( The one we got is "Model of the capacitance and dielectric" ). With only this information, me...

Homework Statement I need to find the green function for a dielectric sphere (\epsilon_1) inside another dielectric medium (\epsilon_2) using the method of images. Homework Equations In gaussian units I have: \phi=\frac{q}{\epsilon|r-r1|} The Attempt at a Solution Due to the symmetry of the...

Homework Statement parallel-plate capacitor consists of two fixed metal semicircles of radius R and a dielectric plate (susceptibility \varepsilon). The plate is able to rotate without friction around the axis centered at the point O (axis O is perpendicular to the picture). Plate's thickness...

Homework Statement Show that (Grad dot E) =0 in the dielectric of a coaxial line. (Hint: apply the divergence theorem to a portion of the dielectric.) Homework Equations Divergence theorem The Attempt at a Solution I think I need to show that grad dot E = p/epsilon = 0 I don't know - I'm...

So I have seen some people doing making lichtenberg figures using a particle accelerator to blast electrons into a dielectric where they get stuck until the dielectric breaks down. Here is an example http://www.capturedlightning.com/ Are there other ways to get electrons into a dielectric other...

Hello all. I have a doubt about the derivation of energy in dielectrics formula (Griffiths pages 191 - 192). In a certain step of the formula derivation, we encounter the following operation: (view formula below). I do not undertand that operation. Can someone help me?

This is what we have in text-books and in Wikipedia: ρ=ρb+ρf and from there we get ∇.D=ρf. But I am unable to understand why we are not considering the bound surface charge in deriving this equation. Can anyone explain this to me.

Homework Statement An example I am reading has the following setup: a dielectric slab of dielectric constant εr exists between z=0 and z=d, whilst an external electric field E0=E0k is applied with k a unit vector in the z direction. This setup exists for all x and y. The rest of space is a...

...partially inserted between the plates of a parallel plate capacitor. I have a few questions about this - it is section 4.4.4 of Griffiths, 3rd edition. Imagine a parallel plate capacitor, of plate area l*d, separation d, filled with a linear dielectric of susceptibility X. Now imagine...

Hi, I would like to know what the theoretical implication is, as it pertains to RC circuits of the following hypothetical situation(s): If one were to connected an ideal discharged capacitor in parallel with an ideal voltage source with zero resistance in the loop, the calculated RC time...

Homework Statement How does a dielectric increase maximum electric field strength? From the two cases where a dielectric is inserted into a charged capacitor after it is disconnected and after it is remained connected it seems that E will either decrease or stay the same. But I read in...

Why do the capacitance increase with increase in dielectric constant(K) of the medium between the capacitor?

What I meant to ask is; When we double the electrical field passing through the insulator, the opposite electrical field that caused by the insulator is doubled too. How can this happen, what happens to the molecules in that time to increase the opposite electrical field? In my opinion, the...

I have a question regarind how to calculate the DOS for ferromagnetic impurities in a dielectric We have samples with ferromagnetic rare-earth ions implanted in a dielectric material. The concentration known and is quite high but the ions are probably only interacting weakly (they are on...

Hi, Does anyone know where I can find the dielectric function of PTFE (Teflon) ? Thank's

Hi everyone. I have been reading on capacitors and dielectrics , before that i was reading up on piezoelectric materials like quartz crystal. My question is , what would happen if we put a layer of quartz crystal between two parallel plates of a capacitor ? I think quartz is a dielectric...

Homework Statement A dielectric-filled parallel-plate capacitor has plate area A = 15.0cm2 , plate separation d = 5.00mm and dielectric constant k = 3.00. The capacitor is connected to a battery that creates a constant voltage V = 5.00V . Throughout the problem, use ϵ0 = 8.85×10−12C2/N⋅m2 ...

Homework Statement see attachment 2 Homework Equations a. The Attempt at a Solution see atachment 1 i am stuck at problem a. the question is to write down the boundary conditions for that the E field has to satisfy infinetly far away from the wire and at the boundary of...

Homework Statement Part (a): List the boundary conditions Part (b): Show the relation for potential is: Part (c): Find Potential everywhere. Part (d): With a surface charge, where does the Electric field disappear? Homework Equations The Attempt at a Solution Part (a) Boundary conditions...

Homework Statement Find surface and volume charge densities. Deduce electric field. Homework Equations The Attempt at a Solution Volume charge density: \epsilon_0 \epsilon_r \nabla . \vec E = \rho_f Using ##\vec P = \chi \epsilon_0 \vec E = (\epsilon_r -1)\epsilon_0 \vec E##...

Homework Statement Find the electric field inside dielectric and surface charge density on plates. Homework Equations The Attempt at a Solution \rho_b = -\vec {\nabla} . \vec{P} = -\vec {\nabla} . \epsilon_0 \chi \vec E = -\vec {\nabla} . (\epsilon_r - 1)\epsilon_0 \vec E \int \rho_b dV...

Here is an excerpt from my textbook: "Ordinarily, this charge would simultaneously generate so large an electric force as to swamp the magnetic one. But if we arrange to keep the wire neutral, by embedding in it equal amount of opposite charge at rest, the electric field cancels out, leaving...

Hello again I seen in this forum about this problem but not in the special case when the point charge is at the center of the sphere how do I solve the series legendre polynomials?

Hello as you see the problem and solution (see the attachment)the input electric filed is 2K v/m but in the glass the electric filed decrease approximately to 705.9 v/m.i want to know 1- The electric field in the dielectric is wasted? 2-why electric field decrease? Thanks

What happens To the force between 2 charges if a metal sheet or a dielectric sheet is kept in between the two charges ..(the charges are in vacuum)

capacitors don't require a "dielectric" material they? whenever i hear about capacitors, i hear about the 'dielectric' material, but a dielectric material as opposed to a non-dielectric insulator just means that the material is polarizable. but polarizability only affects the field strength...

Homework Statement There's a ring of radius R with linear uniform charge density \lambda=constant (which includes both free charges and polarization charges). The ring is in a dielectric region with \varepsilon_r. I have to find the electric field on any point of the axis of the ring Homework...

Homework Statement If a dielectric cylinder, say radius R, is placed with its axis parallel to a uniform electric field. What effect will it have on the field? Picture is included which makes it a bit clearer Homework Equations The Attempt at a Solution I know that the D-field...

Hello guys, I was searching for what voltage does IEC standard call for Di electric test that should be done to low voltage panels? is it 2.5 KV for 1 minutes? If yes how how low voltage cable rated 600/1000 V can withstand 2.5KV without insulation failure?

Hello all! My friend and I are having a bit of a discussion. We did an experiment on liquid crystals as dielectrics with changing voltage, and we came across some weird conclusions (capacitance decreased with increasing voltage? odd. Our theory is that liquid crystals don't act as normal...

Hi , I would like to know if there is any material , a dielectric like the one used in a capacitor , whose dielectric permittivity could be altered , like increased or decreases , I'm not talking about older type capacitors which had plates on a rotor that could be adjusted so that one could...

Question taken from Griffiths Pg 185, Problem 4.19: For part (b): -Why are the electric fields the same whether in dielectric or in air? In part (a), they are clearly different! -Why is σ_{tot} = ε_{0}E = ε_{0}\frac{V}{d} -In calculation of capacitance, why is the total charge (\frac...

Hi guys, I do not really understand the explanation bit where he describes the "term left out" of the integration. Why is there any term left out? I thought it's rather straight forward that E = E(inside) + E(outside)?

Homework Statement A parallel plate capacitor consists of two plates, each of area A, separated by a small distance d. in this gap, a dielectric of relative permittivity εr and thickness d/2 is fitted tight against one of the plates, leaving an air gap of thickness d/2 between it and the other...

Hello! How do I calculate the capacitance of a twisted wire pair in 3D? The pair of wire would have two different dielectric(air and insulation) mediums and hence I am not able to figure out how to calculate it by hand. My plan was to create a 3D Model, mesh it and put it up in...

Hi, I am currently making an effort to solve a boundary value problem of electromagnetic field. The problem is as follows: The region ##y<0## is vacuum. The region ##y \geq 0## is filled with material with ##\mu=\mu_0## and dielectric tensor ## \left( \begin{array}{ccc} \alpha & i\beta &...

Homework Statement Two related questions (from Electromagnetics by Notaros) The dielectric of a parallel-plate capacitor has two homogeneous parts, referred to as dielectric 1 and dielectric 2. The boundary surface between the parts is flat and parallel to the capacitor plates. The dielectric...

If we know that the Polarization P in LIH dielectrics is proportional to the net field inside the dielectric according to: P = ε0χeE...(1) And we know that D = εE...(2) Does it not follow that we can ascertain the polarization directly from the applied (free charge) field, since we...

Homework Statement The space between the plates of a parallel plate capacitor is filled with a dielectric material whose dielectric constant ϵr varies linearly from 1 at the bottom plate (x=0) to 2 at the top plate (x=d). The capacitor is connected to a battery of voltage V. Find all the bound...

MODERATOR'S NOTE: problem statement is mistaken, please see https://www.physicsforums.com/showthread.php?t=723342 Homework Statement The space between the plates of a parallel plate capacitor is filled with a dielectric material whose dielectric constant $\epsilon_r$ varies linearly from 1 at...

Homework Statement A long cable consists of two coaxial conducting cylindrical shells of radius b and 3b. The region with radius ##\delta## between b and 2b is filled with a material of relative permittivity ##\epsilon_r \neq 1## and relative permeability ##\mu_r = 1##; the remaining space...

What Is The Difference Between These "Dielectric" Terms? Can someone please explain to me what the difference between these terms are? 1. Dielectric constant 2. Relative dielectric constant 3. Dielectric loss I came across them on this website: http://www.lsbu.ac.uk/water/microwave.html#pen...

Homework Statement A parallel plate capacitor has a capacitance C when there is no dielectric inside of it. Suppose a wedge of material with dielectric constant K is inserted in between the plates of the capacitor (see figure). The bottom face of the wedge has the same area as the plate of...

I made the experiment up myself so my errors may be a result of this, but I heated up marshmallows, eggs and cheese in the microwave and measured the distance between the hotspots in order to get the wavelengths. For the marshmallows I got 0.13cm, for the eggs I got 0.16cm and for the cheese I...

Maxwell-Wagner polarization is generally described in literature as the polarization of interfaces, such as grain boundaries, with an applied electric field. In the Wikipedia article (http://en.wikipedia.org/wiki/Maxwell–Wagner–Sillars_polarization), it's mentioned that "the charges are often...

A parallel-plate air capacitor of area A= 21.0 cm2 and plate separation d= 3.20 mm is charged by a battery to a voltage 50.0 V. If a dielectric material with κ = 4.80 is inserted so that it fills the volume between the plates (with the capacitor still connected to the battery), how much...

Homework Statement two point charges in free space are separated by distance d and exert a force 2.6 nN on each other. The force becomes 1.5 nN when the free space is replaced by a homogeneous dielectric material. Calculate the dielectric constant of the material. Homework Equations I...

Homework Statement When the bound charges in a dielectric arrange themselves in an electric field, this is called: A) Bound Charge Alignment B) Dielectricity C) Polarization D) Reactance Homework Equations - The Attempt at a Solution I know that this is a straightforward...

Homework Statement In a slab of Teflon (epsilon=2.1), the electric field is E= 6Ux+12Uy-20Uz V/m. Find D and P (BTW epsilon stands for the relative dielectric constant) Homework Equations Upload The Attempt at a Solution Upload