Electric field Definition and 1000 Threads

I am reading the Griffith, Electrodynamics book, 4th edition, Example 4.8. I want to understand some issues more correctly. It's a little bit difficult to understand now. > Example 4.8. Suppose the entire region below the plane ##z=0## in Fig. 4.28 is filled with uniform linear dielectric...

I am reading the Griffith, Electrodynamics book, 4th edition, Example 4.8 and stuck at some statements. It's little bit confused. > Example 4.8. Suppose the entire region below the plane ##z=0## in Fig. 4.28 is filled with uniform linear dielectric material of susceptibility ##\chi_e##...

To make a start. In part (i) we can use Gauss's law to show that inside the smaller cylinder and outside the larger cylinder the field ##\mathbf{E} = 0##. I am not sure how to progress in the remaining case. This is like the last problem I posted in the sense that I find it hard to get off the...

If both S1 and S2 are switched on, then the charge on the leftmost and rightmost surfaces will be zero. Also, we may assume that a charge q would appear on the left surface of Y, and a charge Q-q on the right surface of the same. due to this, there will be a charge q-Q on the left surface of Z...

Hey! I'm a high school student trying to understand electric fields at a deeper, more conceptual level. I had a random thought I wanted to share to get your views on it. So far, I've learnt that electric field lines of a positive charge run outward and that of a negative charge run inward. But...

Any conductor with resistance will develop an electric field. This electric field "leaks" outside the conductor, though its strength falls off with the cube of distance. https://www.physicsforums.com/threads/electric-field-outside-of-a-current-carrying-wire.431870/ So, shouldn't it be possible...

I think the answer to part (i) is given wrong. The flux can't be zero because there is a charge Q/2 enclosed by the shell. So, the flux should be Q/2 divided by permittivity of free space. Now in part (iii), the force on charge at point A is given correct. However, the force on charge at centre...

I'VE SEEN MANY QUESTION WROTE C/m, WHAT IS C? CURRENT? Consider an insulating sphere with 10μC of charge uniformly distributed through its volume. The sphere is surrounded by a conducting spherical shell that has a total charge of −3μC. Outside the conucting shell is an insulating shell with...

Hello! I have a 3 level system with energies ##E_0##, ##E_1## and ##E_2## and 2 time varying electric fields, the first one connects ##E_0## and ##E_1## while the second one connects ##E_0## and ##E_2## with Rabi frequencies ##\Omega_1## and ##\Omega_2## and the frequencies of the electric...

Hello! I do it for definition because Gauss's law not possible. I use cartesian coordinates: $$dq=\lambda dx'\text{because is only in x direction}$$ $$\vec{r'}=(x',0)$$ $$\vec{r}-\vec{r'}=(x-x',y)$$ $$\hat{r}=\frac{(x-x',y)}{\sqrt{(x-x')^{2}+y^{2}}}$$...

Hello, I reasoned by simmetry, the two charges with value 2q not contributed at field because there are equidistant at point and are similar charges. Therefor only survival the field due to Q, using the definition for electric field of the puntual charge...

If I place a conductor between charged plates, spin the conductor or plates and connect the conductor with terminals, would I generate a current?

The volumetric charge density is given as $$\rho(r) = \rho_0 \left(1 - \frac{ar}{R}\right)$$ What shall be the Electric field at any distance ##r## ? My approach was to directly use the coulomb's law and integrate with respect to volume. $$ \mathbf{E}(\mathbf{r}) = \frac{1}{4\pi\epsilon_0}...

Hi I'm trying to solve this So far I have got But me not sure whether it correct or not. Maybe someone knows of a way you can check answer is correct like in math when you plug solution to solve equation? Best wishes to you

In textbooks, are words such as 'metallic', 'metal', etc indicating to the person doing the problem that the material in question is a conductor? This one problem said 'metallic' and the answers were as if it were a conductor with the electric field between 2 concentric hollow spheres being 0...

[ Given that an "electret" can be made, that retains a persistent electric field, most often as a flat slab with a perpendicular field ] Can an electret be made with a permanent circular electric field ? Eg in a slab with the field forming a loop in the plane of the slab ? It would have to be...

Let's assume that we have a finite plate which is at the center of a cartesian coordinate system. Now let's define a point ##r## with coordinates ##(0, 0, z)##. My question is, can we use Gauss's law to find the electric field at this point? The direction of the electric field is going to be up...

Consider a scenario in the picture where one half of space consists of a material with permittivity ϵ1 and the other half consists of a material with permittivity ϵ2, where ϵ1 > ϵ2. A unit positive charge is fixed at the interface between the two materials. Path1 is entirely within the material...

We are given a conducting solid sphere, and it is cut by a plane which has a minimum height r/2 from the centre of the sphere, which has radius r. A charge Q is given to the smaller part of the conductor, and it is required to find the induced charge on the curved and flat surfaces of the other...

Hello, I need some help regarding how to calculate the needed radius to achieve 1 x 10/6 v/m on the surface of a spherical inner grid, inside a conductive vacuum chamber. I have used various equations, however I don’t know if they are very good and would like to know other methods. Thanks!

We know that E is conservative so the integral of E around a closed loop is zero. I know this helps us (in some way, that's why i'm asking) to calculate the total voltage drop around the complete circuit (which is zero). What exactly is "E" in the integral? For example, internet says "electric...

Hi, I found this interesting video about How electricity actually works. The point he makes (see for example the video at minute 7:23) is that the energy in a light bulb connected to a battery is actually transferred by the electromagnetic field and not by electrons flowing through it. The...

My solution is this: $$q = \varepsilon_0 \int E.dA$$ Based on gauss's law. Taking the derivative of both sides with respect to $$A$$ we get: $$\frac{dq}{dA} = \varepsilon_0 E$$ From chain rule: $$\frac{dq}{dA} = \frac{\frac{dq}{dr}}{\frac{dA}{dr}}$$ On the other hand: $$q = \int \rho dv = \int...

If a charged particle moves with velocity V over a perpendicular margnetid feild B then the particle experiences lorentz force F = q(V x B). This force eventually results in what is called circular motion where the magnetic force becomes centripetal. However if the Lorentz force results in...

To some of these questions I can't find answers on the internet and to some I assume what the answer is but I'd still like to get a confirmation. When I am not given the thickness of the plate, does that mean that the plate is intinitely thin? What is the area of the sheet of charge when the...

I’ve been trying to get the proper understanding of electric field. Fine I get the definition: any charge changes space around itself and thus generates electric field that acts with force on any object that’s relatively close to the charge. But first from the first, how can the FIELD act with...

If a battery is in a closed circuit, we have an electrostatic field ##\vec{E}## from the positive terminal to the negative terminal of the battery through the circuit outside the battery. This field generates current. Inside the battery, the electrostatic field lines go from positive to...

Question 1: The sphere is at the electric potential of the top plate. As the sphere is small with respect to the capacitor, one can consider the bottom plate to be at infinity and therefore we can use the capacitance formula as C = 4 ∏ε0 R. The charge Q is therefore Q = C (V -0) = C V...

I have the video linked with the time stamp. . Isn't Electric Field anywhere inside the conductor zero. So there will be no electric field inside the thickness of the conductor. But he managed to integrate it somehow? he considered electric field to be changing inside the conductor that has...

I am trying to wrap my head around something and would be grateful for some insight. Specifically, why the different electric fields along different paths to different areas of an irregularly shaped conductor don't impart different energies to inflowing particles. Say we have a negatively...

In many homework problems I've encountered, they all seem to assume the electric field = 0 point is along the axis of the two charges. Intuitively it kind of makes sense, but I'm looking for a solid justification for it. In other words, why can't it be off the axis of the two charges? When...

We know Gauss's law for an infinite sheet yields ##\textbf{E}=\frac{\sigma}{2\varepsilon_{0}}##. This is relatively elementary and I completely understand the derivation. This is also valid when looking at a parallel plate capacitor (the electric field is additive between the plates yielding...

I don't know if i'm exactly right. But I started with x(time) = V cos θ t which = (6810 m/s) cos (69.1°) (11.4 * 10^-3 s) is ... 27.69 m & since Electric field due to uniformly charge surface is represented by... E = (q * σ)/(2 * ε_0 * m), and since acceleration (a) can be expressed as F/m...

E1= 9.0 x 10^9 * 10 x 10^-9 / (0.045)^2 = 45000. x cos(153.43)= E2= 9.0 x 10^9 * 10 x 10^-9 / (0.02)^2= 22500 x cos(180)= E3= 9.0 x 10^9 * 5.0 x 10^-9 / (0.04)^2= 28125 x cos(90)= ? Enet= ?

Hello. I was wondering why do we not multiply cos(alpha) by 2. I believe we should do this since the y-components of the electric field cancel out, meaning there would be 2 x-components of the electric field(at least I think so). Currently, this derivation/answer only considers one horizontal...

I have attached an image of what *I think* the electric field looks like. Would this be correct? I am convinced about everything here, apart from the ones on the far right. All the other ones loop from the +ve charge to the -ve charge, but where do the grey lines on the right loop to (the ones...

My first attempt at solving: I divided up the point charges based on the radius away from point A. 1 charge was s*sqrt(3) away, 3 charges were s*sqrt(2) away, and 3 charges were s away from point A. q remained constant. Therefore, my F_total was: F_total = k * [(q^2 /...

I want to derive the electric and magnetic field at a point around an infinitely long wire which carries a sinusoidal alternating current. And I want the answer includes the phase delay according to the limited speed of propagation of the wave. Surely the answer must satisfy the Maxwell's...

We have $$\vec{E}(\vec{r})=\frac{1}{4\pi\epsilon_0}\int_V\frac{\rho(\vec{r}')}{\eta^2}\hat{\eta}d\tau'\tag{1}$$ A few initial observations 1) I am using notation from the book Introduction to Electrodynamics by Griffiths. When considering point charges, this notation uses position vectors...

Suppose there is an electric charge of 350 micro coulombs in space. The electric field at a distance of less than one meter will be more than 3,000,000 volts/meter considering that this field is greater than the electric breakdown of air and the charge has no place to discharge, what happens...

I have been reading about Magnetohydrodynamics and would like a bit of insight from anyone who has any knowledge on the subject. If I understand correctly when a conductive fluid is in motion it produces an electric field, and motion can be generated using a few methods one of which is a...

Consider infinite charged sheet in xy plane and suppose that charge is gradually and uniformly removed from the sheet. Electric field outside the sheet obviously do not depend on x and y variables, thus the Maxwell equation divE=0 reduces to the simpler form ∂Ez/∂z=0, this means that z component...

and Can someone explain how they made these equations like this? How did the radius become that equation? What formulas from algebra did they applied? I'm looking at these formulas and I don't understand how r=z+1/2*d

Hello. Sorry. I am not a physicist and I have very superficial knowledge of the subject. I would like to ask a question about the practical field. I only have a device that measures the electric field. When I measure the signal coming from a cell phone tower before it is reflected from a metal...

Question : I have tried to solve but I struggle with this part: Any help would be appreciated.

I would like to consult with you about something. Mobile phone towers transmit at relatively high frequencies. From a health perspective, on the internet :) all measurement values are interpreted in microteslas. However, with the Wavecontrol probe (WPF8) I have, only the electric field (E) can...

In a simple circuit consisted of a battery and a resistor, how is potential difference actually established on the resistor? My understanding is that battery creates the electric field which propagates through space at the speed of light. Resistor is put inside this field and therefore...

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Hello, I am stuck on a problem that I don't quite understand, which looks like this: "Given a nonmagnetic material with the magnetic field H = 50⋅exp(−100⋅x)⋅cos(2π⋅10⁹⋅t − 200⋅x)⋅ŷ determine the electric field strength E" I don't understand how I am supposed to find the solution for this...

As accelerated charges produces time varying electric field which produces time varying magnetic fields and so on. I know there is something wrong with my argument, I can't point it out. Please be kind to help.