Charged Definition and 1000 Threads

I am dealing with a problem of instability of an infinitely long charged liquid jet. When there is a change is surface profile(which originally is a column with radius R), it surface charge density changes, thus the electric energy change of the liquid jet is E (due to surface charge density...

Homework Statement A line of charge with a uniform density of 34.2 nC/m lies along the line y = -14.9 cm, between the points with coordinates x = 0 and x = 42.8 cm. Calculate the electric field it creates at the origin, entering first the x component then the y component Homework EquationsThe...

Consider empty spacetime containing a charged capacitor. Is there a simple expression for metric for the spacetime between the capacitor plates in terms of Kaluza–Klein theory? We are told that spacetime tells matter how to move; matter tells spacetime how to curve. Is there a Kaluza–Klein...

Consider the Reissner-Nordstrom metric for a black hole: $$ds^{2} = - f(r)dt^{2} + \frac{dr^{2}}{f(r)} + r^{2}d\Omega_{2}^{2},$$ where $$f(r) = 1-\frac{2M}{r}+\frac{Q^{2}}{r^{2}}.$$ We can write $$f(r) = \frac{1}{r^{2}}(r-r_{+})(r-r_{-}), \qquad r_{\pm} = M \pm \sqrt{M^{2}-Q^{2}}.$$ Then...

Homework Statement A charged wire of negligible thickness has length 2L units and has a linear charge density λ. Consider the electric field E⃗ at the point P, a distance d above the midpoint of the wire. What is the magnitude E of the electric field at point P? Throughout this part, express...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] This is a quite a fundamental question in electrostatics and I felt pretty embarrassed getting it wrong .I thought correct option was d) . Could someone help me understand how conductor could acquire charge as charges...

Homework Statement Plot the electric potential ##V(r)## due to a positively charged particle located at the origin of an XY plane. Homework Equations ##V=\frac 1 {4πε_0} \frac q r## The Attempt at a Solution I'm unfamiliar with 3D coordinates at this time, but I like to know how can I plot it...

As shown in figure, we know that at the sharp end E field is strong, and at the other end field is weak. Inside the conductor E=0. that means V=constant. on its surface and throughout the conductor. if we move unit positive charge from B to A or P to Q (as shown in fig.) then different amount...

Homework Statement Two conducting concentric spheres of negligible thickness. The radii of the spheres are R_1 and R_2, respectively, with R_2>R_1. A charge q_2 is placed on the external sphere. A charge q_1 is placed on the internal sphere. Assume that the electric potential is zero...

There is a similar thought experiment I imagined to help me begin to understand the Bell's spaceship paradox: Consider two positively charged spheres, placed side-by-side inside a frame S' with a string stretched to the point where it balances the repulsive electrostatic force between them. For...

Homework Statement I am trying to calculate the theoretical time that it takes for a small piece of aluminium foil on a bottom plate to reach a top plate. The plates have a potential difference created by a 3kV Cockcroft–Walton generator. The plates are short cylinders with a surface area of...

Let some point P on the y-axis and let the disk of radius "a" to lie on the z-x plane perpendicular to y axis. All charge elements in a thin ring shaped segement of the disk lie at same distance from P. If s denotes the radius of such a annular segment and ds is its width, then the area is...

We know that there exists no electric field inside a conductor. But while calculating drift velocity of electrons inside an electric conductor, why do we consider the electrons are present inside the charged conductor?

I've got confused over a topic in my physics textbook (Fundamentals of Physics). The textbook says if a charged particle is enclosed by a shell of uniform charge, there is no electrostatic force on the particle from the shell. I don't firmly get this, as the book uses a confusing reasoning for...

I am researching whether or not there is an equation that calculates energy used by a DC battery to keep a capacitor charged over time in a capacitor circuit. I know a capacitor in a circuit acts as a break when it is fully charged, but does the battery continue using energy to keep the...

Suppose we have two charged particles on the laboratory and two observers A and B. ##A## is inside one of the charges (never mind how) ##B## is sitting at the laboratory In the lab reference frame we accelerate the particles. According to ##A## there will be only electric attraction or...

Homework Statement (Taken from Serway and Jewett Chapter 23, Q44, 9th Edition) A thin rod of length ## l ## and uniform charge per unit length ##λ## lies along the x-axis as shown in the image attached. (a) Show that the electric field at P, a distance d from the rod along its perpendicular...

Hello, I'm wondering how you would go about drawing a Feynman diagram for a weak charged current scattering interaction of a positron and a proton. I have attached a diagram of what I have tried but it doesn't conserve lepton number (I think this is a problem, from what I gather...

Superconductors can be used to store energy in the form of magnetic fields, because the current in a superconductor can persist indefinitely. In fact, some large power grids are already using this as a way to regulate power flow in the grid. My question is how are the coils "charged"? How do we...

I was thinking about the title but after searching Arxiv, PF and the internet in general, my confusion has only increased. I have a few questions: 1. Often I see units where ##G=c=\hbar=1##, but what is the charge of an electron in these units? Everyone says M=Q as if it was somehow obvious how...

Hello! So I've been working on proving to myself different parts of https://ocw.mit.edu/courses/nuclear-engineering/22-611j-introduction-to-plasma-physics-i-fall-2003/lecture-notes/chap2.pdf packet for several weeks. Under 2.1 Uniform B field, E=0, for the Larmor Radius, I need to know...

Homework Statement Can't really find out b, probably due to a mistake in a. Was wondering what I did wrong. Homework Equations Kinematic equations of motion, w/ constant a ##F=qE## The Attempt at a Solution [/B] (a) ##E=\frac {\Delta V} {\Delta d}= \frac {V_R-V_L} {L} = \frac {V_0}{L} ##...

I'm doing some special relativity exercises. I have to find $$x(t), v(t)$$ of a charged particle left at rest in $t=0$ in an external constant uniform electric field $$\vec{E}=E_{0} \hat{i}$$, then with that velocity I should find the Liénard–Wiechert radiated power. I will show you what I did...

Homework Statement Homework Equations potential energy = -kQq/r potenial = kQ/rThe Attempt at a Solution i am not quite sure how does l play a part in this experiment since it is far away l is insignificant and the only initial energy is kinetic energy and final is kinetic and electric...

Homework Statement Homework EquationsThe Attempt at a Solution I have the complete solutions for this problem, I just don't understand them: This is the first part. I don't understand what r' is, or how we found it. Otherwise I understand the concept of the problem just not the details...

Hi folks, this is not an actual HW question, but rather one of personal interest. I'm basically trying to understand your classic idealized parallel plate capacitor, but moving face-on through a plasma. 1. Homework Statement We have a diffuse neutral plasma made of free protons and electrons...

Homework Statement [/B] Consider two charged particles 1 and 2, each of them able to translate (move from place to place) and to spin.Homework Equations I can not completely think of relevant equations at the moment. The Attempt at a Solution [/B] I am a bit confused on how charged particles...

Homework Statement The cylinder has a radius a and is perpendicular to the electric field, E(r)=E(x_hat). It also carries charge Q. The potential is of the form V(r,φ)=A0+A0'ln(r)+∑(n=1 to ∞)((Ancos(nφ)+Bnsin(nφ))rn+(An'cos(nφ)+Bn'sin(nφ))r-n) Homework Equations V=-∫E⋅dl The Attempt at a...

Homework Statement So this was a problem worked in class by the professor in class. Find the net electric field at the origin due to the arcs Homework Equations L=2πr/4 λ=q/L E=kQ/r2 The Attempt at a Solution So the professor gave the answer using the fromula...

I have a very weak understanding of the particle modelling of electrical phenomena.1: Electric field =\frac{Force}{Magnitude of charge} 1 is The definition of electric field on a particle (?) 2: Force = \frac{Q1*Q2*K}{R^2}\\ 2 is Coulombs law, to find force between two particles. 3...

Homework Statement At our university we were given this problem: charged ball with mass of ##m = 0.0001 kg## and charge ##Q = -10^{-5} C## is placed on geometric axis of thin torus with inner radius of ##r_{inner} = 0.05 m##, outer radius of ##r_{outer} = 0.1 m## and surface charge density...

Dear all, I'm curious to know how to calculate an interaction. I'm a chemist and I'm not really used to practice Maxwell equations, so I don't have the complete background for that, but I think it may be trivial even for a physicist student. Let's say we have two surfaces, one has a total...

Homework Statement Figure (a) shows charged particles 1 and 2 that are fixed in place on an x axis. Particle 1 has a charge with a magnitude of |q1| = 19e. Particle 3 of charge q3 = +16e is initially on the x axis near particle 2.Then particle 3 is gradually moved in the positive direction of...

Does a charged particle need to experience a momentum changing force to emit light? Or is it sufficient for an observer to accelerate relative to the particle?

1. Homework Statement An infinite line of charge with linear density λ1 = 6.8 μC/m is positioned along the axis of a thick insulating shell of inner radius a = 2.5 cm and outer radius b = 4.8 cm. The insulating shell is uniformly charged with a volume density of ρ = -667 μC/m3. 1) What is λ2...

Homework Statement I got an alpha particle (charge 2+) fixed at x=0 and an electron fixed at x=2. I then add a fluor ion (charge 1-) to the right of the electron and we note his position xeq. The question is to find the constant spring (k) relative to the harmonic oscillation made by the fluor...

Homework Statement Two parallel plates 1.40 cm apart are equally and oppositely charged. An electron is released from rest at the surface of the negative plate and simultaneously a proton is released from rest at the surface of the positive plate. How far from the negative plate is the point at...

According to Cosmic Sensorship Conjecture, naked singularities are prohibited in General Relativity. To my knowledge, naked singularity means light from the singularity can escape to infinity. In Reissner-Nordström metric, references say naked singularity appears only if ##GM^2<P^2+Q^2##...

Please delete if not allowed. The teacher charged a 1 square foot sheet of mylar sheet up to approx DC 20 kv one day long ago in school via an modified EHT output of a TV. I had one of my mates hold it by the corners in line with my hands, I then judged and guessed and clapped it with both...

I am looking to find a combination of electric and magnetic fields that create something similar to the (d) crests Currently, I have the cracks flipped clockwise 90deg, so that the crests are concave up. And each crest can be defined by a parabolic function (which are uniform with each new...

Homework Statement Basically having a problem when trying to theoretically calculate the mass of alpha particle in a charged field. r is the unknown radius of curvature m = mass of an alpha particle (6.646 *10^-27 kg) v = velocity of an alpha particle immediatly after decay (1.381 *10^7 m/s)...

Hi I am confused about rotating magnet. Feynman lectures on physics 13–6 The relativity of magnetic and electric fields, http://www.feynmanlectures.caltech.edu/II_13.html , deals with two inertial frames. Wire is charged in some inertial frame. Can we apply it to tangential parts of curved...

Homework Statement Let me just put this here: http://i.imgur.com/dgcWAC3.png . Homework Equations E_flux=EA=(q_encl)/(permittivity) Area=4pir^2 The Attempt at a Solution Whenever I manipulate the above equations, I get a term of the form R/r, which implies, R being 5 cm, and r being the...

1. Homework Statement A flat ring, with radii ##b>a## like on the picture is charged with a surface charge density ##ρ_s=ρ_0\frac{b}{r}## where ##ρ_0=const.## Calculate the potential of the ring on the ##z-axis## by taking the reference point to be in the infinity. Picture below. 2. Homework...

Homework Statement We are given a disk with negligible thickness, a radius of 1m, and a surface charge density of σ(x,y) = 1 + cos(π√x2+y2). The disk is centered at the origin of the xy plane. We are also given the location of a point charge in Cartesian coordinates, for example [0.5,0.5,2]. We...

Can anyone help me find any mistake in this expansion ? (I've asked it also in other places but I got no answer)) Pα= e Fαβ Uβ c = speed of light m = "rest" mass e = charge a = sqr(1 - v2/c2) v2 = vx2 + vy2 + vz2 dτ = dt a (proper time) momentum 4 vector : Pα = [mc/a , mvx/a , mvy/a ...

Homework Statement Ions having equal charges but masses of M and 2M experience a constant electric field while they travel a fixed distance d and then enter a uniform magnetic field perpendicular to their path. If the heavier ions follow a circular arc of radius R, what is the radius of the arc...

Homework Statement Homework Equations F= q v x B The Attempt at a Solution [/B] I tried using the right hand rule to find the direction of the force and seeing if the particle curves that way or not but obviously that's wrong

If there are 3 positive charges of +1, +3, +5 coulombs equidistant from a negative charge of 1 coulomb what positive charge will this negative charge be attracted to ? Is the result different if the charges exist in a “bound” state (resulting in electrovalent compounds) where a positive charge...

I know that, in the presence of a magnetic field, the momentum of a charge particle changes from ##p_{i}## to ##\pi_{i}\equiv p_{i}+eA_{i}##, where ##e## is the charge of the particle. I was wondering if this definition of momentum is gauge-invariant? How about ##\tilde{\pi}_{i}=p_{i}-eA_{i}##?