Electric Definition and 1000 Threads

Hi, I was reading the capacitor and its operation and it is written there that when the DC is applied to the capacitor it becomes open circuit. The main mechanism behind this phenomena is explained as below:- "When DC voltage is applied the charge started accumulating on the plates of the...

Homework Statement Hello to everyone who's reading. :) I hope I posted this in the right place; while this is not exactly a homework problem, I am trying to improve my understanding of the background information before proceeding with course-style problems. This post is because I'm trying to...

Let's say we have a basic electric circuit consisting of a battery with some potential difference, and a loop of wire. The wire loop also has some segment with a higher resistance. Now since there is a potential difference, the free electrons will move to make the circuit equipotential. The...

The Faraday's law and Lenz's law together give you, $$\xi = -\frac{\partial\phi_B}{\phi t}$$ or put another way,$$\vec{\nabla} \times \vec{E} = -\frac{\partial \vec{B}}{\partial t}$$. My question, I am just asking to make sure, the spatial dependence of ##\vec \nabla \times \vec E## will be the...

Homework Statement A long, thin, straight wire of length 1.3 m has a positive charge 4.1 × 10-8 C distributed uniformly along it. The electric field created by this wire at a radial distance 3.2 cm has a magnitude of ε= 8.85E-12 Homework Equations I think I need to use E= q/(4πr^2ε) but I...

I have some understanding, but I'm not sure about how accurate it is: Electrostatic force is given by F = qE, where F and E are both vector quantities. If the dot product of either side and the displacement vector Δs along an equipotential line is taken, the equation becomes F⋅Δs = qE⋅Δs. F...

According to an inertial observer the electric field of a charged ball sitting on the floor of an accelerating elevator is contracted more than the elevator is contracted. So the inertial observer concludes that an observer inside the elevator will measure that the Coulomb-force from the ball is...

Hello! I am reading Griffiths derivation for the electric dipole radiation (actually my question would fit for the magnetic dipole radiation too). He considers 2 charged balls connected by a wire with charge going back and forth between them. Now, when he calculates the vector potential he uses...

[Mentor's note: two threads on the same topic have been merged] I live here in Stephenville, TX and currently going to Tarleton for Civil engineering. A bit rusty and new to electrical components. But anyways, here in town lawnmower racing is kind of a big event. Many of us have 600cc crotch...

Good day all, This is my first post here, hope you all are able to help me out here. I am thinking about converting an old Suzuki GS500E from an internal combustion engine to an electric motor. At the moment I am having some difficulties with the physics side of things, I would like to...

Hi everyone, I often work on a SEM, a type of microscope which is based on electron acceleration between an electron source and the sample you are working on. For this reason and since a few weeks I was wondering how an electron (in term of speed) behaves in a constant and linear electric field...

Hi I need help to understand how electric potential could be zero at the center of two equal but opposite charges. It seems, there is a no field free region anywhere inside the space between the charges. If I move a test charge from negative to positive charge or otherwise, there seems to be no...

How works a "NOS" of a electric car?

I would very much appreciate a clarification on what is meant by a changing electric field in the context of statements such as 'a changing electric field creates a changing magnetic field'. My question is does the electric field actually need to reverse as a lot of examples show where two...

I need a little help here when calculating the work done in a uniform electric field on a positive charge to move it from point a at higher potential to point b at lower potential that means the charge is going towards the negative plate we first use V = - ED and then we have a...

An electric current in a wire occurs when... A. electrons move in the wire as a result of getting pushed along from a neighboring electron. B. electrons move in the wire as a result of the repelling force from the negative battery terminal and the attractive force from the positive battery...

If I try to calculate the electric field in the x-y plane of a ring of charge resting at the origin on the x-y plane, I keep getting zero. I start with Coulomb's Law. $$ dE(r) = \frac{1}{4\pi\epsilon}\frac{dq}{r^2} = \frac{\lambda R}{4\pi\epsilon}\frac{d\theta}{r^2},$$ in which ##\vec R## is...

Hello! I am reading about image charges for an infinite plane and a charge above the plane. In the book I am reading (Griffiths) the author says (and uses this results several times) that the field below the plane is 0. How do we know this? The method of the mirror charges gives the V above the...

1. Problem Statement: Find positions on the x-axis for the charges Q1 = -1 C and Q2 = +3 C so that the electric field is zero at x = 0. Homework Equations :[/B] I'm thinking I need to use Coulomb's law for this one. I'm just having trouble figuring out where to start. Coulomb's states E=kQ/r^2...

Homework Statement Griffiths' Introduction to Electrodynamics problem 2.10, Homework Equations Gauss' Law, ##\int_{S} \textbf{E}\cdot \textbf{dS} = \frac{Q_{\text{enc}}}{\epsilon_0}##[/B]The Attempt at a Solution It seems reasonable that the flux through the shaded surface and the front...

Say you have a hollow cylinder, whose one side is open. Now, you pace a positive charge ##Q## at the centre of this open end (such that it is just inside the cylinder). How much should be the flux coming out from the closed end? I just thought of this problem. In order to use Gauss' Law, we...

Hi there Only known variables include the solar flux on the Earths atmosphere at the equator is 1.5 kWm^ -2. I've calculated the total energy from the Sun as 4 x 10^26 W, but can't seem to get to a calc of the mag of electric field at equator (measured in kVm^-2).

How work triboelectricity in QFT? Materialists exchange electrons as well as in classical theory?

Can anyone know please know how can i impose the electrode surface potential to vary lineary and periodically with time as: E(t)= phimin+v*t for 0<=t<t0 phimax-v*(t-t0) for t0<=t<2*t0 with t0=(phimax-phimin)/v v=scan rate in V/s

In Griffith's electrodynamics chapter 2 example 7 he calculates potential due to a spherical shell outside it. Here E is radially outward while dr is radially inward as we are going towards the sphere hence E.dr should be negative but it is taken positive?

Homework Statement In a TV tube, an electric potential difference accelerates electrons from a rest position towards a screen. Just before striking the screen, the electrons have a wavelength of 1.0 x10-11m. Find the electric potential difference.[/B] Homework Equations λ = h/mv Ek = qΔV The...

Homework Statement Two charges, A (-3 C) and B (+4 C), are placed 2.40 m apart. Point X is 30 cm from A, and Point Y is 30 cm from B. What is the electrical potential difference going from X to Y? Homework Equations W = △Vq The Attempt at a Solution Teacher gave answer as 6.9 x 10^4 V I am...

recently i saw a thread where skin depth was mentioned (I guess in one of my own threads) and then it got me thinking, well imagine we have a rather thick wire thick enough so that for a given frequency there is almost no current running in the middle of the wire due to skin effect. let's take...

Hello, I'm struggling to understand how the electric potential difference is measure especially when a distance is not given. For instance in Serway, on the explanation of the Van de Graaff Generator the authora write, "Van de Graaff generators can produce potential differences as large as 20...

Homework Statement An electric field is created by an uniform linear charge with a linear charge density is 40 nC/m. Find the potential difference between the two points, one of which is situated 5 cm from the line charge and the second at 10cm. Two charges, q and -3q, are situated at a...

Homework Statement A solid insulating sphere of radius a = 3.6 cm is fixed at the origin of a co-ordinate system as shown. The sphere is uniformly charged with a charge density ρ = -215 μC/m3. Concentric with the sphere is an uncharged spherical conducting shell of inner radius b = 11 cm, and...

Homework Statement Two charged balls are placed in point A and B and the distance between them is 9,54cm. Each of the balls are charged with 8,0 x 10^-8 C. Find the scalar value and direction of the electric field in point C placed 5 cm from A and 6 cm from B. Homework Equations Cosine Rule...

Hello, I have a question on electric potential, potential energy and work. ##\Delta V = \frac{\Delta U}{q_o}## ##W = q_o\Delta V## ##W = -\Delta U## Example: A point A that is closer to the source charge than point B, then the electric potential difference is negative (##\Delta V = V_B -...

Homework Statement [IMG]http://[url=https://ibb.co/dgUy6T]https://preview.ibb.co/iyqS0o/20180525_213806.jpg Since i only know the field direction, increasing go into page. Why the answer is C? Why the answer "a" ? The R and r on the pic is respected to what? Homework EquationsThe Attempt...

Homework Statement Homework EquationsThe Attempt at a Solution I know the units for V is J/C so #3 and #4 are wrong. But how do I determine the signs?

Homework Statement A charged polystyrene ball of mass 0.14g is suspended by a nylon thread from a fine glass spring. In the absence of any electric field the spring extends by 30mm. The polystyrene ball is then placed in an electric field that acts vertically upwards, of strength 200kV m^-1...

Outside the battery, in the conductor it is in the direction of conventional current. But what about inside? Since magnetism and electricity are related, and magnetic field inside a magnet is from South to North (outside it is North to South), i doubted for any correspondence.

Homework Statement Sorry, the post isn't about a single homework problem but rather something that I keep getting confused on. It's about calculating the electric potential of a spherical shell of uniform charge in two different ways. Homework Equations ##\Delta V=\int_a^b -\vec E\cdot d\vec...

Homework Statement Q1: There are two concentric spherical shells with radii ##R_1## and ##R_2## and charges ##q_1## and ##q_2## uniformly distributed across their surfaces. What is the electric potential at the center of the shells? Q2: There is an infinitely long hollow cylinder of linear...

Do the SM and Lambda-CDM lepton-era models predict that the electron’s isolated electric charge be equal in magnitude (to 12 significant figures) to that of the proton which is a composite particle? What makes that this identity in electric charge magnitude is so exquisitely ‘fine-tuned’? What...

Homework Statement Calculate the electric field given by a voltage drop of 1 V across an insulator with thickness 20 nm. 2. The attempt at a solution I am not sure which formula to use in order to obtain the electric field. I think one should use the formula E=U/d, where E denotes the...

I would like to share some information related to electric design. Electrical design includes planning, creating, testing and supervising the development and installation of electrical equipment, including lighting equipment, power systems, power distribution, fire and life safety systems...

Why does my laptop's screen refresh every time I bring a metal object (any size) to my electric lighter? -Happens when I am 1 foot away from the laptop -1 foot away from the external monitor's wires (HDMI & power) 1. Video footage (MUST WATCH) NOTE: the laptop screen also flickers a bit NOTE...

Homework Statement Give two reasons why transformers are an important part of the power distribution grid My lessons don't have any information regarding this topic. I have read everything in my lesson and can't find anything to answer this question. please help. thank you

I don't really know how to fit what i want to this template, but i'll try. The thing is that i wonder if anyone can explain to me step-by-step what happened in this solution, because i don't really understand it. Homework Statement There are two balls. Upper one(mass m, charge Q) hung on a...

In basic electrostatics any charged particle will produce an electric field at every point in space, and will have electric filed lines spreading out radially. E = kQ/r^2 The Standard model of particle physics says that the Photon is the force carrier for the Electromagnetic force, just like...

Homework Statement Homework Equations gauss law q=charge on sphere Q=total charge enclosed by gaussian surface Q=alpha/r x (4/3 pi r^3-4/3 pi R^3) + q The Attempt at a Solution EA=Q/ε[/B] E=Q/(Aε) now for E to be independent of r, alpha/r x 4/3 pi r^3 + q = 1/(4)(pi)(r^2) alpha x 4/3...

Homework Statement So I have got the question below. I am asked to find the phase difference between the electric field and magnetic field of electromagnetic waves traveling in a plasma, using the electrical conductivity expression. Now I have found the frequency of the waves and I know that...

Homework Statement In the diagram, two small objects, each with a charge of -4.0nC, are held together by a 0.020 m length of insulating string. The objects are initially at rest on a horizontal, non conducting frictionless table & the effects of gravity on each other are negligible. (b)...

The electric field inside a conductor is zero. Or: the internal electric field is equal in magnitude but opposite in direction to the external electric field, so that the net electric field inside the conductor is zero. Why is this? The part where I am confused is why the magnitude is equal...