Questions tagged [gauss-law]

A law in classical electromagnetism and Newtonian gravity which relates (charge) density to the divergence of a field, or alternatively the charge in a volume to the flux through the bounding surface.

Filter by
Sorted by
Tagged with
0
votes
1answer
41 views

How to mathematically find the flux through side of cube or simiar cases?

We have a $+q$ charge kept $a/2$ distance from the centre of a surface of dimensions $a\times a\,\,m^2$. Now we usually find flux by imagining a cube of $a\times a\times a$ dimensions around the ...
0
votes
1answer
80 views

I am not able to convince myself with the gauss law, explain why the situation below shouldn't have non-zero flux?

I have drawn an image of a spherical surface and positive charge outside it. As the positive charge is outside the sphere the electric field incident at every small surface is different from the other ...
0
votes
1answer
22 views

Electric field inside a non-uniformly charged conductor

With Gauss's Law, if we take a uniformly charged hollow sphere for instance, the electric field inside the hollow sphere is 0 because there is no charge inside. However, what if this sphere is not ...
1
vote
1answer
145 views

Electric field $\propto \frac{1}{r^3}$ [closed]

If some charge is given to a solid metallic sphere, the field inside remains zero and by Gauss’s law all the charge resides on the surface. Suppose now that Coulomb’s force between two charges varies ...
1
vote
0answers
46 views

Gauss's Law for Electric Dipole [closed]

Hello, in this question i tried applying Gauss's law for electric fields since on its Left-hand Side I will have the electric flux. My question is why is the enclosed charge not equal to zero at first ...
1
vote
5answers
80 views

Using gauss law to determine field

Let us consider a $+q$ charge and we are trying to find out electric intensity $E$ at a distance $r$ from $+q$.The conventional way is this: We take a gaussian sphere of radius $r$. We know the ...
0
votes
3answers
103 views

Is it possible to find the proportionality constant in Gauss's law for an electric field without knowing Coulomb's law?

Using the definition of electric flux, and knowing that the electric flux through a closed surface is proportional to the charge enclosed (that proportionality constant being $ \frac{1}{\epsilon_0} $)....
0
votes
2answers
50 views

Is momentum flux scalar or vector?

I'm trying to derive Navier Stokes equation and stacked the linear momentum equation below. The second term is momentum flux, but it seems scalar value for me because it is vector times vector. How ...
1
vote
1answer
75 views

How is charge locally conserved?

I am aware of how to use both Gauss's and Ampere's Law but I am really interested in knowing and understanding how charge is conserved as a consequence of these laws, especially using these forms of ...
0
votes
1answer
32 views

How to solve for the electric potential inside a metal sphere without the gauss law?

I was wondering how it would be possible to solve for the electric potential inside of a metal sphere that has a total charge Q without using Gauss's Law? I completely understand the problem with ...
2
votes
0answers
31 views

Spherically symmetrical surfaces in gauss law [closed]

Note: This is not a check my work question, this is merely an example that came to my mind while solving the following question. Charge distribution on a rod bent as a semicircular arc is given by L=...
-2
votes
2answers
91 views

Flux due to charge placed ON a sphere [duplicate]

Question If we place a charge, say Q, ON the surface of a sphere, will there be a flux through the sphere? My Understanding of the Concept I'm studying high school physics, so I have learnt Gauss's ...
0
votes
2answers
45 views

Why can we assume electric field to be uniform to calculate flux?

In this video https://youtu.be/jYMSdBUhrDo at 3:25 in the side view of the ring, why we consider the $E$ value which they have calculated at axis to be same for whole area of blue shaded part? And ...
1
vote
1answer
33 views

Gauss' Law Application

I was reading about the electric field at a radial distance $r$ from an infinitely long, thin wire having a linear charge density $\lambda$. Although I understood how it's derived using Gauss' Law, I ...
0
votes
3answers
69 views

Net flux through surface [closed]

if equal number of electric field enters and equal leaves. Then why isnt net flux zero?
0
votes
1answer
15 views

Blackbody emission from $N$ parallel & infinite 2D planes

This is something that's been bothering me. A solid object will emit radiation with a flux surface of $\sigma T^4$, but what about a plane? Here is a thought experiment I came up with to help me make ...
0
votes
1answer
30 views

Why does the the electric field intensity is 0 inside a charged conducting spherical shell? [duplicate]

Given a conducting spherical shell with infinitesimal thickness and the radius of $R$. The shell is uniformly charged with surface density $σ$. Find the electric field intensity vector $\bf E$ at the ...
2
votes
0answers
47 views

A conceptual and condractictory question about Gauss law

Suppose we have a charge q which is placed at some distance from the center inside a conducting spherical shell of equal and opposite charge. Now according to gauss law the charge of the outer shell ...
0
votes
5answers
91 views

Is electric flux dependent on geometry of gaussian surface?

We say, Electric Flux, $\phi_E = ES \cos (\theta)$ where $\theta$ is the angle between E and S. However, there is another definition for the same given by Gauss Law - ${Q_{enclosed} \over \epsilon _o}$...
0
votes
1answer
29 views

Some question in flux which is produced by magnetic field

I was trying to solving the problem. I know that total flux (which produced by magnetic field) of any system is $0$. Even flux in a closed surface is $0$ also. But flux in a non-closed surface isn't ...
0
votes
1answer
42 views

About applicability of Gauss’ law in electrostatics

While reading about Gauss’ law in electrostatics, I saw that we do not apply this law to evaluate the fields generated by dipoles, quadrupoles etc. It is only applicable to cases where the fields fall ...
0
votes
0answers
50 views

Question on Dirac delta and Gauss's law

Suppose you have something that looks like an inverse square law, i.e. $\textbf{v} = \frac{1}{r^2}\textbf{1}_r$. We know that it's divergence is 0 except in the origin. We also know that for any ...
0
votes
3answers
62 views

Gauss law apparent violation

If we assume to place a dipole or a quadrupole inside a Gaussian surface, then the Gauss law will give zero electric field outside Gaussian surface at any point since enclosed change is zero. However,...
0
votes
2answers
48 views

Increasing capacitance of a capacitor [duplicate]

In my book, it's given that: ”Principle of Capacitor: In the capacitor arrangement, the increase in capacitance of a conductor is due to the decrease in potential V (charge Q remains constant) when ...
0
votes
4answers
26 views

When I need to calculate the electric field due to a charged infinite plate, does the intensity of the field not drop with distance from the plate?

As opposed to calculating electric field due to a cylindrical wire or sphere where there is a dependence of the field to the distance between the point chosen and the charged body in itself. But in ...
0
votes
2answers
61 views

How to apply Gauss' law in this case?

Suppose I have 3 charges $-4e, -6e$ and $+10e$ and these 3 charges are placed on the corners of an asymmetric triangle (which means all the sides have different lengths and the angles between them are ...
0
votes
0answers
17 views

What is the electric field at point P due to the charged dielectric and +Q?

$+Q$ is $D$" /> We are given a a uniformly charged dielectric sphere of radius $R$. The dielectric contains a cavity of radius $r$. The distance between the centre of the sphere and that of the cavity ...
0
votes
0answers
32 views

How does change in electric flux leads to production of charge?

I was doing questions related to Gauss Theorem and then I came across a question which was as follows: If the amount of electric flux entering and leaving an enclosed surface respectively are $\phi_1$ ...
0
votes
0answers
42 views

Lines of force or electrostatic field: Faraday's criterion

This question is related for students of an high school. The that force lines can be used to represent an electric field. Lines of force have three fundamental properties: 1. Lines of force always ...
-1
votes
3answers
79 views

Variables in the first Maxwell equation

The first Maxwell equation: $$\vec\nabla \vec E(\vec r)=\frac {\rho(\vec r)}{\epsilon_0} .$$ But why both variables in the electric field and in the charge density are of the same letter, in this case ...
0
votes
4answers
82 views

Is the field used in the Gauss Law affected by the outer charge configuration?

Following is the Gauss Law: $$\oint E\cdot\mathrm dA = \frac {q_\text{enc}}{\epsilon_0}$$ Now consider the following scenario: The electric field in the following case, at the sphere, is due to $q_1+...
0
votes
2answers
62 views

Field lines of two charges whose algebraic sum is not zero

I know that field lines are directly proportional to the value of electric charge. Assuming that $8$ lines of force, or of field, of the come out of the charge $+q$, then $16$ lines of force will come ...
0
votes
1answer
19 views

Closed surface present in a electric field, no charge inside then net flux is zero. So what does that tell?

It means like water entering and whole water coming out so net flux is zero, I know that but so what? Isn't that obvious? and even if it is not what does that tell about electric field and it's ...
1
vote
1answer
59 views

Invalid structure of atoms on a classical scale and wrong assumption for the time of publication

(Actual question at the very bottom) In his 1911 paper "The scattering of α and β particles by matter and the structure of the atom" Rutherford starts with this assumption: Consider an atom ...
0
votes
1answer
21 views

What is the electric field in a cavity of a charged non-conductive sphere?

How can we solve this problem attached below, without using the trick that considers superposition of a negative cavity and positive filled sphere. I have started to consider to use Gauss's law, but i ...
0
votes
0answers
11 views

How to calculate electron flux from recorded dose in oncology calibration tests?

For the purpose of testing a diode response to electron and gamma irradiation, we have used a linear electron accelerator at an oncology facility. The 6 MeV beam with dimensions 40 by 40 cm was ...
1
vote
1answer
75 views

Question about cancellation of electric field

Why can't I cancel the two opposite electric field shown below? I already searched about this and saw the article that says "It can't cancel each other because they aren't in the same region.&...
0
votes
1answer
17 views

Feasibility of the Diffusion Equation to Model Electric Charges in a Conductor

Background: Given that equilibrium solutions of charges in a spherical shell formed from a conductor satisfy the Poisson problem $\nabla^2 \Phi = - \frac{\rho}{\epsilon_0}$ as a corollary of the ...
1
vote
1answer
83 views

Is the divergence of electric field in a solid cube of uniform charge density position dependent?

Within a solid, uniformly charged non-conducting cube, the electric field is clearly position dependent, does that make the divergence of the electric field position dependent as well? If that is the ...
0
votes
1answer
46 views

Why Gauss's law for gravity can be applied to this problem?

Consider a spherical and homogeneous celestial body with mass $ M $ and radius $ R $ crossed from pole to pole by a straight cylindrical tunnel of negligible diameter. At one of these poles a point ...
1
vote
3answers
88 views

Why does Gauss' Law apply to any shape given that it's a closed surface?

I've read some answers on stack exchange for this question, but I don't find them particularly clear. I am convinced of the case for a sphere, since the area of a sphere is used in the derivation for ...
2
votes
1answer
32 views

Why does the charge distribution on the surface of a conducting sphere remain uniform even if there is a perturbation in the inner electric field?

In a conducting sphere, the net charge is evenly distributed at the surface because of repulsion while the inner electric field remains zero as charges cancel inside. Here is an example, where the net ...
0
votes
1answer
39 views

Electric flux through a infinite strip

We have to find flux due to a point charge at $(0,l,0)$ on an infinite strip lying in region $(0,0,0)$, $(l,0,l)$ and extending to infinity along $+x$ direction. I am aware that a general case has ...
3
votes
1answer
68 views

Joule effect in Poynting theorem

I came across two different statements of the Poynting theorem. In one of them the power dissipated through Joule effect is made explicit. The one without explicit Joule effect is: $\frac{dW}{dt} = \...
3
votes
4answers
233 views

Using symmetry in Gauss' Law

I have to find electric field at any inside point due to a uniformly charged solid sphere I do it in following steps $\to$ First I choose a spherical gaussian surface passing through required point ...
0
votes
2answers
51 views

Can Gauss' Law apply to an irregular 3D region?

Let's say I have this configuration: The figure above is a cube with a charge not in the center. Can I calculate the flux through the surfaces using Gauss' Law, or does it only apply when the charge ...
0
votes
0answers
52 views

Besides the curl is there any other difference between an electric flux line and a magnetic flux line?

As far as I know, both types of flux mediating the electromagnetic phenomenon and related forces consist of coherent streams of virtual photons according to the known theory. Besides the total non-...
-2
votes
1answer
89 views

In the statement $\text dV = 4\pi x^2\text dx$ , how is the radius $x^2\text dx$?

I was recently studying a question based on Electrostatics. Here is the link to the question (along with the answer below). I haven't learned integration yet. But my question here is how did we get $x^...
0
votes
0answers
41 views

Does GR gravity obey a form of Gauss' law? [duplicate]

In Newtonian mechanics, Gauss' law is the assertion that, for any volume $V$ enclosed within a regular surface $\partial V$, the flux of the acceleration produced by gravity through $\partial V$ is ...
0
votes
0answers
41 views

Electric displacement - why are field lines continuous?

I recently attempted problem 4.17 in Griffiths's "Introduction to Electrodynamics" 3rd edition in which you are asked to make a sketch of the electric displacement vector D in and around a ...

1
2 3 4 5
26