Electric fields Definition and 483 Threads

"Three charges are placed at 100-m intervals along a horizontal line: a charge of –3.0 C on the left, 2.0 C in the middle, and 1.0 C on the right. What is the electric field E on the horizontal line halfway between the –3.0 C and 2.0 C charges?" When I do the calculation E = E1 - E2...

Homework Statement The potential difference between the accelerating plates of a TV set is about 20 kV. If the distance between the plates is 1.0 cm, find the magnitude of the uniform electric field in the region between the plates. Homework Equations V=ED so E=V/D where E is the...

Homework Statement Two concentric plastic spherical shells carry uniformly distributed charges, Q on the inner shell and -Q on the outer shell. Find the electric field (a)Inside the smaller shell, (b)between the shells, and (c) outside the larger shell Homework Equations integration(E *...

Two large flat metal sheets are a distance L apart. The separation L is small compared to the lateral dimensions of the sheets. Each sheet has a total surface area A, which includes both top and bottom surfaces of the sheet. The thickness of each sheet is very small compared to its lateral...

Homework Statement A thin circular sheet of glass of diameter 6 meters is rubbed with a cloth on one surface, and becomes charged uniformly. A chloride ion (a chlorine atom which has gained one extra electron) passes near the glass sheet. When the chloride ion is near the center of the sheet...

Homework Statement A rod of length 2L lies on the x axis, centered at the origen, and carries a line charge density given by t=T(x/L), where T is a constant. (a) Find an expression for the electric field strength at points on the x axis, for x>L (b) Show that for x>>L, your result has...

In a rectangular coordinate system, a positive point charge q = 9.00 nC is placed at the point x= 0.250 m, y = 0, and an identical point charge is placed at x= -0.250 m, y = 0. Find the x and y components and the magnitude and direction of the electric field at the following points. (a) Find...

Two 10cm-diameter charged disks face each other, 18 cm apart. Both disks are charged to - 30 nC. What is the electric field strength a point on the axis 5.0 cm from one disk between them? \eta/2\epsilon0 * [1-1/\sqrt{1+ R^2/z^2}] with \eta = -4.0 X 10^(-6) C/m^2 R=.05m z=.05cm for the left...

electron one is moving directly toward stationary electron two. the field at electron one due to electron one is proportional to 1/d^2. but the field at electron two due to electron one is less because electron ones field is compressed. it would seem from this that the forces on the 2...

I'm a little stuck on the theory behind this question: (in relation to a line of infinite charge: a wire) A hollow cylindrical metal tube with inner radius 2.5mm is now placed around the wire, to form a coaxil cable. What will be the charge per unit length on the inner surface of the tube...

I really just want to know if I'm doing this correctly, as I don't have access to the answer to check. Homework Statement A cylindrical shell of radius 7.00 cm and length 240 cm has its charge uniformly distributed on its curved surface. The magnitude of the electric field at a point 19.0 cm...

A long non-conducting cylinder has a charge density ρ = α*r, where α = 4.95 C/m4 and r is in meters. Concentric around it is a hollow metallic cylindrical shell. https://www.physicsforums.com/attachment.php?attachmentid=14741&d=1216404841 1. What is the electric field at 2 cm from the...

Homework Statement A point exists a distance D away from a rod of length L ( (point) |-----d-----| (ROD) ) So the point is in allignment with the rod, charged with a uniform charge density of -6.5uC/m Homework Equations E= Integral(k(dq/r^2) The Attempt at a Solution Im not...

Hi, I'm having a bit of trouble with the following problem. Any insight as to what I'm doing wrong? Homework Statement A solid metal sphere with radius 0.900 m carries a net charge of 0.130 nC. Find the magnitude of the electric field at at a point inside the sphere, 0.100 m below the...

[SOLVED] more electric fields Homework Statement four particles form a square of edge length a = 5.20 cm and have charges q1 = 10.8 nC, q2 = -8.87 nC, q3 = 11.6 nC, and q4 = -10.4 nC. What is the magnitude of the net electric field produced by the particles at the square's center? q1 is in...

I have a few questions about electric potential and electric fields. If two points have the same electric potential, is it true that no work is required to move a test charge from one point to the other? Does that mean that no force is required as well? Also, How much work is required to...

I just want to know if I'm even given enough information in this question to generate an answer. I don't need an actual answer. Thanks. "An electron is fired from a negative plate towards a hole in a positive plate. It then passes between two parallel plates that are 5 cm long and 3 cm...

Homework Statement A metal ring 4.50 cm in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. These magnets produce an initial uniform field of 1.12 T between them but are gradually pulled apart, causing this...

[SOLVED] Capacitance and electric fields Homework Statement I want to find the capacitance of a parallel-plate capacitor consisting of two metal surfaces og area A held a distance d apart. First I find the electric field, which I know is \frac{\sigma }{{2\varepsilon }}. Then I use that the...

If an electric field wave oscillates north and south, and the wave is traveling straight up, then what direction does the magnetic field wave oscillate? east and west north and south up and down It does not oscillate; this situation is impossible. I know that magnetic...

Ok, this may borderline a homework problem, but I'm not quite grasping the concept of induced electric fields. So let's say that they exist a wire loop and solenoid. The switch in the circuit containing the solenoid is originally open and then closed. At this instant, we induce an emf in the...

Another question on electric fields. :( I have another problem I don't understand on electric fields. I thought I understood these after my last post, but I guess not. I'm guessing it has something to do with the signs of the forces, but I am not sure. Homework Statement Particles of charge...

What is the field near a square metal plate (with infinitesimal thickness) The answer is E = \sigma / \epsilon where \sigma = Charge per unit area \epsilon = relative permeabily Please help me to derive this result. using coulombs and then gauss' law

A small object carrying a charge of -5.50 nC is acted upon by a downward force of 24.0 nN when placed at a certain point in an electric field. What would be the magnitude and direction of the force acting on a proton placed at this same point in the electric field? Magnitude & Direction of the...

Homework Statement I need to solve the following wave equation: [\nabla^2 + \frac{\omega_a^2}{c^2}\epsilon]\mathbf{E_a} = -\frac{4\pi\omega_a^2}{c^2}\mathbf{P}^{(3)} Homework Equations \mathbf{P}^{(3)}=\chi^{(3)}:\mathbf{E_1E_1E_2^*} E_1 and E_2 are two electric fields with...

[SOLVED] Electric Fields- point charges Homework Statement Two point charges of charge 7.40 μC and -1.60 μC are placed along the x-axis at x = 0.000 m and x = 0.360 m respectively. Where must a third charge, q, be placed along the x-axis so that it does not experience any net force because...

Hello Sir , i am new to the site and so is not familar of that but i have question and i found u online so wish u to help me with that. Electric forces are used to accelerate small particles (like ink particles in a printers) but consider electrostatic action on macroscopic objects .Suppose...

Greetings everyone, I have a question about determining electric fields when given parallel planes of charge. In particular, I need some help getting the sign conventions straight in my head. I've attached 2 quick problems with solutions in a Word document so that perhaps you can help me to...

the electric field produced due to a time varying magnetic field is non-conservative in nature. does it follow gauss law?

Hi all, I am having a hard time understanding the following scenario (I'm quoting from page 305 of the "Electricity & Magnetism" textbook which you can access via Google Books): "Assume a simple model for an atom which consists of a point nucleus (+q) surrounded by a uniformly charged...

Homework Statement More of a general question: I have a situation where I have a conductor at eight volts and a conductor with zero volts. Just because there is an electric field, does that mean there is an electric current present in the system? And what is the direction? Homework...

Homework Statement The electric fields created by a point charge, a conducting sphere and insulator sphere are identical, if they all have the same amount of charge and the field is measured outside the spheres. Homework Equations The Attempt at a Solution I think its...

Homework Statement What are the magnitude and direction (in degrees counterclockwise from the horizontal) of the electric field at the center of the square of Fig. 23-31 if q = 0.9*10^-8 C and a = 5.1 cm? http://personalpages.tds.net/~locowise/23-30.gif Homework Equations E=kq/r^2...

i just need to get this question over with i tried and tried but i couldn't get the right answer plss anyone u.u 1. Homework Statement point charges q1 = -6q and q2 = +3q are separated by distance d. Locate the point (measured from the origin at q1) at which the electric field due to...

http://s253.photobucket.com/albums/hh64/physics_god/?action=view&current=physicsquiz3.jpg http://s253.photobucket.com/albums/hh64/physics_god/?action=view&current=physicsquiz2.jpg http://s253.photobucket.com/albums/hh64/physics_god/?action=view&current=physicsquestion.jpg Sorry its sort of in...

Electric Fields is being taught in my A-level physics course but I don't really get it. Firstly, we are given the equation Force= (Q1*Q2)/4*pie*permittivity*r^2 . But I don't know how it is derived. What area of Electric Fields should I research into to begin with?

Homework Statement Two equal charges (Q = +0.80 nC) are situated at the diagonal corners A and B of a square of side x = 1.2 m as shown in the diagram. What is the magnitude of the electric field at point D? Homework Equations E=kQ/r^2 The Attempt at a Solution First I converted...

hey guys i was wondering if anyone could help me with this question, kinda got stuck Homework Statement Figure 24-31 shows a section of a long, thin-walled metal tube of radius R = 5.56 cm, with a charge per unit length λ = 7.34 x 10-8 C/m. What is the magnitude E of the electric field at...

Homework Statement http://session.masteringphysics.com/problemAsset/1001949/13/knight_Figure_25_69.jpg An electric field 1.00×10^5 N/C causes the ball in the figure to hang at an angle. What is theta? Homework Equations E = F/q F = mg The Attempt at a Solution The ball isn't...

Homework Statement A small object A, electrically charged, creates an electric field. At a point P located 0.250m directly north of A, the field has a value of 40.0N/C directed to the south. A) 1.11×10^−9C B) −1.11×10^−9C C) 2.78×10^−10C D) −2.78×10^−10C E) 5.75×10^12C F)...

Homework Statement Use Coulomb's law to determine the magnitude and direction of the electric field at points A and B in Fig. 16-57 due to the two positive charges (Q = 8.0 µC) shown. Is your result consistent with Fig. 16-31b? Figure 16-57 Figure 16-31b A)Find the magnitude of...

Homework Statement 1. Four charged particles are held fixed at the corners of a square of side s. All the charges have the same magnitude Q, but two are positive and two are negative. In Arrangement 1, shown below, charges of the same sign are at opposite corners. Express your answers to...

Hey, just wanted to check my method. 1)What is the distance between 2 protons experiencing a mutually repelling force of magnitude 4*10-11? so for this, we have to use the formula for coulombs law--F=kq1q2/r^2 we know F and k. And q1=q2= 1.602*10-19. hence we can find r. 2)Two point...

suppose there is a region S through which the magnetic field changes with time then is the electric field induced there only or everywhere in space . if everywhere what equations does it satisfy

Homework Statement Charge of a uniform density (8.0 nC/m2) is distributed over the entire xy plane. A charge of uniform density (5.0 nC/m2) is distributed over the parallel plane defined by z = 2.0 m. Determine the magnitude of the electric field for any point with z = 1.0 m. Homework...

Homework Statement A hollow metal sphere has 6 cm and 10 cm inner and outer radii, respectively. The surface charge density on the inside surface is -100 nC/m^2. The surface charge density on the exterior surface is + 100 nC/m^2 . What is the strength of the electric field at point 4 cm from...

E&M Electric Fields (Harmonic Motion?) This problem comes out of "Physics (for scientists and engineers w/ modern physics) Volume 2 7th Edition" by Serway/Jewett Review Problem Two identical particles, each having charge +q, are fixed in space and separated by a distance d. A third particle...

All atoms have magnetic moments but does Quantum theory require magnetic fields at all? Does Quantum theory require electric fields?

Homework Statement Hi, my question isn't actually over a particular homework problem, I've attached a file of my notes on electric field, electric dipoles, i don't quite understand why the equation of the electric field is setup that way for the negative charge. Homework Equations...

Here is a question, which may seem dumb: Consider an electron and a positron that annihilate, both of which are non-relativistic (taking the observer's frame of reference to be the center of mass frame of the electron-positron pair) so that we only consider their electric fields for simplicity...