# Tagged Questions

The tag has no usage guidance.

37 views

### Refraction of the electric field lines, at the interface of separation between two conductive media

Suppose we have 2 media with electrical parameters ${\varepsilon _1},\,{\sigma _1}$, respectively ${\varepsilon _2},\,{\sigma _2}$, separated by the plane surface $\Sigma$; electrical charge surface ...
43 views

### Why does the polarization vector P depend on the net electric field and not the original one?

P= χε0E, where E is the net electric field from the effects of both free and bound charges. But E=(σfree-P)/ε0 So E itself depends on P. My concern is, isn't this circular? ...
66 views

### Work to assemble charge distributions in the presence of a dielectric

I am asked by a problem to: Find the potential energy of a point charge in vacuum a distance $x$ away from a semi-infinite dielectric medium whose dielectric constant is $K$. I wish to approach ...
53 views

### what is the physical significance of dielectric constant and loss tangent?

I want to know that the significance of dielectric constant and loss tangent behaviour. How it characterises the materials. and possible relation between the dielectric constant and polarisation ?
27 views

### Does the sign of imaginary part of complex permittivity have any physical meaning?

I have noticed some papers having written complex permittivity as $e' + je''$ and others as $e' - je''$. The data in literature does not specify the sign. What should I use and does the sign of $e''$ ...
52 views

### Why doesn't the gravitational force have a permittivity in its formula? [duplicate]

We know that the electrostatic force between two charges depends on the medium between the charges and its permittivity. Why, then, doesn't the gravitational force depend on the medium?
16 views

### How can I know the induced charge density in a dielectric?

There's an infinite conduciting plane lying over the XY plane, conected to a battery that keeps it at a constant potential $\phi_0$. At a distance $D$ from the plane there is a point charge $q$ that ...
33 views

### Charging capacity and capacitance of a conductor

I know that charging capacity of a conductor is the maximum charge a conductor can hold And capacitance is the ability of a conductor to hold charge in a given potential . But how are these two ...
23 views

### Dielectric permittivity tensor of rank 2

In special relativity, one knows the Euclidean and Minkowski metric to raise or lower the index of a covector or vector. The Euclidean metric is a (1,1) tensor and is represented by a 3x3 identity ...
12 views

### Electric displacement and Field

Given a problem with dielectric constant value in a region and asked me to find Electric Field and Electric Displacement inside the medium, Should I calculate E first or D first?
44 views

### Difference between dielectric and insulators

AS per my knowledge - dielectric are insulators which can be polarized in presence of external electric field. Does that mean all Insulators are not dielectrics ? If yes then kindly share example of ...
27 views

### The effect of an electric field on capacitance

Decreasing the distance between the two parallel plates of a capacitor increases the amount of charge that can be held on each plate. If this is because the charges are attracted to each other and ...
15 views

### Constructing a chriped dielectric mirror for negative dispersion for ultrashort laser pulses resulting in group velocity delays

I'm currently looking at designing a chirped mirror for a project but I am confused over several aspects. I understand the principle of a chirped mirror in terms of how a laser pulse has a broad set ...
108 views

### What happens to the electric field at the boundary of a dielectric?

The question in the title is a broader one, but for now, I want to confine myself to the following problem. I have the task to find the potential difference between points A and B shown in the ...
55 views

### Electric field inside a material

I was thinking about the polarisation, and how the electric field behaves inside the material of permittivity greater than one. I think to have understood what happens to D and P, but is not clear ...
46 views

### Electric Field Vector on an insulating solid ball

An insulating solid ball with radius $R$ has a uniform charge density $ρ$. Find the electric field vector inside and outside of the ball if it has dielectric constant $K$. Normally, I'd treat this ...
24 views

### Why is the direction of E field inside a Linear Dielectric same as an external field?

If an uncharged linear dielectric is exposed in a uniform external field, an e field inside is induced that points in the same direction as the External field, Why is this so? Isnt the field be ...
36 views

### What exactly is Breakdown Voltage of Air?

Most of the online sources say that the breakdown voltage of air is 30kV/cm. I've made a Cockcroft Walton multiplier and I can see the air breaking in between 17-18kV/cm. Only in a discussion at one ...
42 views

### Gauss law in dielectrics

How shall we apply Gauss's law for a space such that the volume enclosed by the Gaussian surface have 2 or more mediums with different dielectric constants, such that equal or more than two ...
51 views

### Capacitor and Dielectric [closed]

Here's a homework problem: A $12 \mu F$ capacitor $C_{1}$ consists of plates $A$ and $B$. An $18 \mu F$ capacitor $C_{2}$ consists of plates $C$ and $D$. (a) Each are charged up by a $10 V$ battery ...
26 views

### I want to use the complex susceptibility to prove that E dot J is independent of the real part

As stated above, I want to use $\chi$=$\chi'$-i$\chi''$ to prove that E$\cdot$J is related to $\chi''$ and independent of $\chi'$. I need to do this using a monochromatic field E(t)=E($\omega$)*exp(...
76 views

### Inserting dielectric slab into a capacitor

I studied that inserting the slab into a capacitor which is connected to a battery is difficult and we have to do the work, and inserting the slab into a disconnected capacitor is easy and we don't ...