Electric field Definition and 1000 Threads

Electric field of opposite charges, cancel out each other, is it right?

I'm looking for a high voltage power supply. I have no experience with such a power supply, nor with all the terms or specifications used for such tools, so I'm looking for general suggestions to what to look for. I want to generate an electric field or potential field between two points a few...

We commonly have E and B defined as: But how can I work in electric field E, instead of vector potential A?

Homework Statement Capacitor has a charge of 0.008C. Capacity is 2 μF. Need to calculate energy of electric field. Answer: 32J Homework Equations E = q2/2*C The Attempt at a Solution This seems right equation, but instead of 32J I get 16J.. any ideas?

1. Homework Statement the a shell is charged Va=120v shell b is grounded, Vb=0V What is the voltage in the center of shells (vo)? The electric field in the center of shells? The potential energy in the center of shells? Homework Equations Vr=Va+(1/r-1/a)/(1/a-1/b)Vab (from integrals) though I...

If a charge is put inside a spherical shell, why is the electric field outside the shell independent of the location of the charge? Gauss's law could find that the net flux is independent, but not each individual field? Is this something about the surface charge density being independent of...

Assuming the point charge lies at the origin, what is the electric field at the origin? Zero or undefined?

Hi. The derivation of the capacity of an ideal parallel-plate capacitor is inconsistent: On the one hand, the plates are assumed to be infinitely large to exploit symmetries to compute an expression for the electric field, on the other the area is finite to get a finite expression for the...

Homework Statement I was working out problem 4, chapter 3 of Introduction to Electrodynamics by Griffiths: a) Show that the average electric field over a spherical surface, due to charges outside the sphere, is the same as the field at the centre. b) What is the average due to charges inside...

A massless spring of spring constant k = 13 Newtons per meter hangs purely vertically. A 20 Newton, 5(10-3) Coulombs charged particle is attached to the spring and released from rest. Besides all this, there is also a constant, external Electric Field of 9000 Newtons per Coulomb pointing...

Homework Statement A charge q1 is at rest at the origin, and a charge q2 moves with speed βc in the x-direction, along the line z = b. For what angle θ shown in the figure will the horizontal component of the force on q1 be maximum? What is θ in the β ≈ 1 and β ≈ 0 limits? (see image) Homework...

I am working on the same problem as a previous post, but he already marked it as answered and did not post a solution. https://www.physicsforums.com/threads/sphere-with-non-uniform-charge-density.938117/ I am curious as to a method of finding the ##k## and substituting into the electric...

Homework Statement An electron is projected with an initial speed v0 = 4.65×106 m/s into the uniform field between the parallel plates in (Figure 1). The direction of the field is vertically downward, and the field is zero except in the space between the two plates. The electron enters the...

Homework Statement A proton located several proton diameters away from a small charged object carrying charge q is subject to an electric field of magnitude E. As the proton moves a distance d along the x-axis away from the object, the electric field magnitude drops to E/4. If the charged...

Homework Statement Find electric field at Point A its an arc with uniform density= lamda https://drive.google.com/file/d/14cBqE2dMe_w0nb9LtPG0h1cUOrzGWt6g/view?usp=sharing the problem Homework Equations E=intergal dq/r^2 The Attempt at a Solution I've tried using wolfram and cosine rule to...

Homework Statement An isolated parallel-plate capacitor of area ##A_1## with an air gap of length ##s_1## is charged up to a potential difference ##\Delta V_1## A second parallel-plate capacitor, initially uncharged, has an area ##A_2## and a gap of length ##s_2## filled with plastic whose...

Homework Statement What is the potential at the center of the sphere relative to infinity? The sphere is dielectric with uniform - charge on the surface of the sphere. Homework Equations ##k=\frac {1}{4\pi\epsilon_0}## ##V=\frac {KQ}{r}## The Attempt at a Solution If the distance r=0 it would...

I have a question what does create a electric filed inside coducting wire? And is it the same field trought the whole wire? Thanx for answers.

Homework Statement A distribution of charge with spherical symmetry has volumetric density given by: $$ \rho(r) = \rho_0 e^{ \frac {-r} {a} }, \left( 0 \leq r < \infty \right); $$ where ##\rho_0## and ##a## is constant. a) Find the total charge b) Find ##\vec E## in an arbitrary point...

Homework Statement https://www.physicsforums.com/threads/find-the-electric-field-in-the-point-p-of-a-right-triangle.965285/#post-6125768 knowing that the three charges are equal and that the angles of the triangle are 90°, 45°, 45°. Homework Equations The Attempt at a Solution I tried...

Homework Statement A charge q is placed at one corner of a cube. What is the value of the flux of the charge's electric field through one of its faces? Homework Equations The flux surface integral of an electric field is equal to the value of the charge enclosed divided by the epsilon_naught...

Homework Statement A rod of charged -Q is curved from the x-axis to angle ##\alpha##. The rod is a distance R from the origin (I will have a picture uploaded). What is the electric field of the charge in terms of it's x and y components at the origin? k is ##\frac {1} {4\pi \epsilon_0}##...

Homework Statement In the figure above, charge A is -5.00 nC, charge B is 10.0 nC, and charge C is 5.00 nC. If x = 2.10 cm and y = 4.20 cm, what is the electric field at the dot? Homework Equations E = kq/r^2 The Attempt at a Solution r = distance from A to point = sqrt(x^2+y^2) Ea = kq/r^2...

I am doing some research into atmospheric energy harvesting. To design a proper feasibility experiment, I need to establish some theoretical baselines. I see a lot of values for the field strength for example, tossed about from various papers. However, there does not seem to be a standard...

Homework Statement Find the electric field of a point outside sphere without using Gauss's law. (Do not evaluate the integral) Homework Equations Coulomb's Law Spherical Co-ordinate System The Attempt at a Solution I have attached my attempt as a picture but now I am stuck, I don't know how I...

Having come experimentally to an interesting electrostatic effect, I have returned, aged 47, to my old books in physics. It turns out that my books delight in using Gauss theorem etc. in rather ideal geometrical surface charge distribution, but never gave me the tools to answer to this simple...

Homework Statement A point charge of 6 × 10−9 C is located at the origin. The magnitude magnitude at ##\langle 0.6,0,0\rangle## m is 150 N/C Next, a short, straight, thin copper wire 5 mm long is placed along the x axis with its center at location ##\langle 0.3,0,0 \rangle## m. What is the...

Homework Statement Show that the magnitude of the net force exerted on one dipole by the other dipole is given approximately by:$$F_{net}≈\frac {6q^2s^2k} {r^4}$$ for ##r\gg s##, where r is the distance from one dipole to the other dipole, s is the distance across one dipole. (Both dipoles are...

Hi! Could you please help me with the queries below? Thanks a lot. Question 1: My question is about the field outside the plates of parallel plate capacitor. It is said that the field(s) between positively and negatively charged plates gets added up but the field(s) outside the plates gets...

Homework Statement You make repeated measurements of the electric field ##\vec E## due to a distant charge, and you find it is constant in magnitude and direction. At time ##t=0## your partner moves the charge. The electric field doesn't change for a while, but at time ##t=24## ns you observe a...

Homework Statement A dipole is located at the origin, and is composed of charged particles with charge +e and -e, separated by a distance 2x10-10m along the x-axis. Calculate the magnitude of the electric field due to the dipole at location ##\langle 0.2\times 10^{-8}, 0, 0\rangle##m Homework...

Homework Statement A charged particle has an electric field at ##\langle -0.13, 0.14, 0 \rangle## m is ##\langle 6.48\times10^3, -8.64\times10^3, 0 \rangle## N/C. The charged particle is -3nC. Where is the particle located? Homework Equations ##\vec E=\frac 1 {4π\varepsilon_0} \frac q {|\vec...

Hello there, I'd like to model a simplified version of a "Magic Eye" tube (e.g. without the amplification triode, and for a start, 2 dimensions only), or the visible display behavior. What I'm talking about: https://en.wikipedia.org/wiki/Magic_eye_tube#Operation Here is a nicer depiction of...

Homework Statement Two charges, one of 3.2 x 10 ^ -9 C, the other one of -6.4x10^-9 C are 42 cm apart. Calculate the net electric field at point P, 15 cm from the postie charge, on the line connecting the charges (+) -------------(Point)---------------------- (-) 15cm...

Homework Statement A block of mass m having charge q placed on smooth horizontal table and is connected to a wall thorough an unstretched spring of constant k . A horizontal electric field E parallel to spring is switched on. Find the ampliture of the shm by the block. Homework Equations kx=...

Homework Statement An electron enters the lower left side of a parallel plate capacitor and exits precisely at the upper right side (just clearing the upper plate). The initial velocity of the electron is 7*10^6m/s parallel to the plates. The capacitor is 2cm long and its plates are separated...

Homework Statement A solid non-conducting sphere of radius R carries a uniform charge density. At a radial distance r1= R/4 the electric field has a magnitude Eo. What is the magnitude of the electric field at a radial distance r2=2R? Homework Equations Gauss's Law: ∫EdA=Qencl / ε0 Charge...

Hello, I am trying to measure the time-varying electric field of a parallel plate capacitor using short dipole antenna, but my numbers are off by almost 100 times. I have a parallel plate capacitor, A=23cmx11cm, d=10cm. I apply 10sin(2pi*1KHz) and 10sin((2pi*1KHz)+180deg) to each plate. I am...

Metals are highly effective at screening electric fields. If we place two contacts reasonably far away from each other on a piece of metal and apply a voltage bias, the charge carriers in the section that is far enough from both the contacts should be unaffected by the electric field. Why then...

I am currently in grade 12, and for a physics project (a huge project, which gets assigned to you at the start of the semester and needs to be completed just before exams. You think up your project, make a proposal for it and you prove your hypothesis to be right after a presentation and lab...

I was studying Feynman Lectures on Physics Volume 1 chapter 29. In there he proves that electric field propagates like a wave. Here is my attempt (in image), please tell me my mistake. Thank you

1. We've been given a spherical capacitor with radius of 1 cm for inside electrode and 2 cm for outside electrode. Voltage between electrodes is 360 V and the task is to find largest and smalles electric field strength in capacitor.2. I'm not sure how voltage given in capacitor works and how to...

Homework Statement We have an uncharged, conducting wire with radius a. We surround it by a linear dielectric material, εr, which goes out to radius b. We place this in an external electric field, Eo. Homework Equations We have electric potential inside (a < s < b) Vinbetween=Acosφ +...

Homework Statement The question is exactly the same as this question https://physics.stackexchange.com/questions/250297/metal-sphere-in-a-uniform-electric-field However, it says "Then by symmetry the entire xy plane is at potential zero" in the book. I don't understand this. Homework...

Homework Statement Hi guys, my exam is in four days and my tutor for the electromagnetic module is neither very active nor very competent, so I would like you guys to check my solution for this question. I am afraid I might have messed up some signs or some linear algebra. Homework Equations...

Dear all. I would like to know the general expression of the ratio of the electric field strength E to the magnetic flux density B. I know E/B = c, where c is the speed of light, for a vacuum, but I want to know if this is stil valid for any material where the electric and magnetic fields are...

There are infinite number of charges each with charge q along a straight line at a distance of 1,2,4,8,16,… … … unit from a point. What is the electric field at this point? No idea about it.Please help me out.

Homework Statement There is a 3nC charge at (-3,0), -6nC at (0,2) and 5nC at (1,0). What is the electric field at the origin (0,0)? Homework Equations ##E = \frac{Q}{4 \pi \epsilon_0 r^2}## The Attempt at a Solution i think its ##(\frac{1}{4 \pi \epsilon_0})(-\frac{14}{3} i - \frac{3}{2} j)##...

Dipole problem (which is solved through mirror imaging) has been troubling me with its solution. I understand everything except how the dipole moment's coordinates came to be, since when converted into x-y axis, its doesn't make sense. (problem 4.6) The screenshot contains the solution which...

Homework Statement A charged sheet with charge density ##\sigma## is described by ##-\infty<x<0,-\infty<y<\infty, z = 0##. Find the electric field at ##(0,0,z)##. Homework Equations Electric field of continuous density charged body from the Coulomb law: $$E = \frac{1}{4\pi...