Electrostatic Definition and 884 Threads

What is the difference between spin repulsion and electrostatic repulsion of an electron? Is this the same mechanism?

If the electron creates an electric field around itself that can be detected,then the electrostatic field is real? So why was not the "virtual" photon found?

Homework Statement A conductor sphere of radius R without charge is floating half-submerged in a liquid with dielectric constant ##\epsilon_{liquid}=\epsilon## and density ##\rho_l##. The upper air can be considered to have a dielectric constant ##\epsilon_{air}=1##. Now an infinitesimal...

Homework Statement Consider a uniform surface charge density σ on a square of unit area. (a) Compute the electrostatic potential Φ along the line normal to the center of the square. My current attempt at a solution (image attached) is either incomplete or is simply wrong but I am unable to...

Homework Statement A cork ball is suspended at an angle from the vertical of a fixed cork ball below. The mass of the suspended ball is 1.5x10^-4 kg. The length of the suspension thread is .1m. The fixed ball is located .1m directly below the point of suspension of the suspended ball. Assume...

What does it mean ? "the virtual photon's plane wave is seemingly created everywhere in space at once, and destroyed all at once. Therefore, the interaction can happen no matter how far the interacting particles are from each other." As far as I know, the electrostatic force between two...

Homework Statement I have a material placed between parallel plates depleted of free electrons and contain negative ions. What would happen to the charge stored across the plates? Would it still be similar to placing a capacitor with a di-electric constant between them? Homework Equations Q=CV...

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 Consider a charged body of finite size, (\rho=0 outside a bounded region V). \vec{E} is the electric field produced by the body. Suppose \vec{E} \rightarrow 0 at infinity. Show that the total self-force is zero: \int_V \rho \vec{E} dV = \vec{0}, i.e. the charged body does not...

Homework Statement When a point charge is positioned at the origin = 0 in an isotropic material, a separation of charge occurs around it, the Coulomb field of the point charge is screened, and the electrostatic potential takes the form \phi(r) = \frac{A}{r} \exp\left( -\frac{r}{\lambda}...

I am still puzzled by the issue of existence of electrostatic field. According to the classical electromagnetic theory, electrostatic field can be created by an electrically charged particle. The electrostatic field surrounding the electrically charged particle does not stop close to the...

Homework Statement An electrostatic field ## \mathbf{E}## in a particular region is expressed in cylindrical coordinates ## ( r, \theta, z)## as $$ \mathbf{E} = \frac{\sin{\theta}}{r^{2}} \mathbf{e}_{r} - \frac{\cos{\theta}}{r^{2}} \mathbf{e}_{\theta} $$ Where ##\mathbf{e}_{r}##...

Here is the question no1 in image. A charge is in between . We will let it possitive or negative. The answer is 3,1,2 4...But how? Won't the charges in 3 cancel each other out because they are possitive at right and negative at left. One is attracting so the other is repelling.

Hi all Interested in making an electrostatic generator, anyone have experience of building one and also what type would be the most efficient build induction or friction based? Lots of info on the net regarding the principles but and good books for this or websites? Also how best to...

The figure shows a charge q1 exerting a force on a test charge qu. What happens to the electric force when a conductor is placed between q1 and qu (cases 1 and 2)? Does the force still remains the same? I am asking this because I am actually interested in finding what happens to the flux in...

[Note from mentor: this was originally posted in a non-homework forum, so it does not use the homework template.] There is a general relation between the work U required to assemble a charge distribution ρ and the potential φ(r) of that distribution: U = 1/2 ∫ ρ...

I have to increase ion generation in a small ion accelerator but I have troubles to go over 20mA (1.27e17 ions/second). I can modulate up to 40 Mhz at 1kV. What ion generator it is recommended gor large ion flux?, I can work in pulse generation.

Homework Statement My question is more about understanding the task itself, not about calculation. I am supposed to use the poisson equation, to derive the potential inside a semiconductor for a barrier with potential height ##\phi_B## and a donator doping with ##N1 > N2##. Then I should use...

So in my textbook (Introduction to Electrodynamics by Griffiths) it said that inside a conductor, the electric field E would have to zero, since if it wasn't the free charges would move accordingly and create a electric field that cancels the original field. But in a question that soon followed...

Homework Statement The following figure represent the traversal cut of a system with two cylindrical equal conductors of radius r0 length l at a distance d from one another and at the same distance h of a plane conductor (conductor zero). The dielectric that surrounds the conductors is the air...

Homework Statement Given an E field, determine if it's a possible electrostatic field. If so, determine a potential Homework Equations ∇⋅E ∇×E The Attempt at a Solution [/B] Just more of a clarification, since my friend and I both attempted this question differently. I took the...

So I'm studying electrostatics and I came across to two different definitions of potential difference/voltage (because we're in stationary regimes) and I'm having trouble understanding how the expressions are equivalent. They are for a voltage between point A and point B $$U=V_a - V_b...

Could one make a negatively-charged insulator with the extra electrons trapped all the way through its volume by building it up layer by layer with electrons "sprayed" onto each layer as it was constructed? I guess the electrons would be trapped in empty atomic orbitals within the material - is...

Hi, I have a wirmhurst electrostatic generator and I want to use it to create a corona discharge. My common sense tells me that the metal "shaft", which connects to the metal spheres should lead to significant (electron) leak, since it has a much smaller radius of curvature than said spheres. If...

Hi! I would like solve this kind of relation: \phi = \int_0^r \phi (r') 4 \pi r'dr' But I don't know how to proceed... Can you advise me ? Thank's in advance !

Homework Statement A cylindrical conductor of length L and radius R, L » R, carries a charge Q. 1. Neglecting boundary effects; evaluate the potential difference between a point at distance r from the center of the cylinder, and the center. Assume r to be of the same order of magnitude as R but...

If a person with long thin hair touches a Van de Graaff generator, his hair will begin to levitate by electrostatic repulsion. The body is a conductor. Hair is an isolator, so the charge cannot flow through the shaft from root to end. To me it is unclear whether the hair is charged...

I have a plate capacitor connected to a battery with a known potential difference. Now the plates are moved apart by dx and I must figure out the change in energy stored in the battery. Question 1: When a plate capacitor is connected to a battery charges must flow until the potential difference...

EDIT: Problem is FIXED. Hello, I'm trying to understand Ewald Summation and finally found a great link (http://micro.stanford.edu/mediawiki/images/4/46/Ewald_notes.pdf) that I could follow in the five first pages. But then I'm blocked by a rather odd formulation p. 5, after eq. (25): "where...

In classical physics electrostatic potential energy is: ##U=k_e\frac{q_1q_2}{r}## So amount of potential energy is not limited as ##r\rightarrow 0## But obviously potential energy (= binding energy) is limited by masses of charge carrying particles. Say when electron and positron annihilates...

Homework Statement Suppose we have a regular n-gon with identical charges at each vertex. What force would a charge ##Q## at the centre feel? What would the force on the charge ##Q## be if one of the charges at the vertices were removed? [/B]Homework Equations Principle of Superposition, the...

So there was a question in a textbook that went as so: 'Two point charges (30 cm apart in air) are charged by transferring electrons from one point to another. Calculate how many electrons must be transferred so that an attractive force of 1 N exists.' It is assumed that both point charges...

Homework Statement A plane z=0 is charged with density, changing periodically according to the law: σ = σ° sin(αx) sin (βy) where, σ°, α and β are constants. We have to find the potential of this system of charges. Homework EquationsThe Attempt at a Solution [/B] I...

Homework Statement Assume a conducting sphere has a radius of 3400km with an electric field of 100 V/m at it's surface. a) Calculate total charge of sphere. b)Calculate potential at the surface using infinity at reference point c) Calculate capacitance of the sphere using the result of a or b...

Two positive point charges with a charge of 10nC each are 10cm apart. What is the electric field strength at point A? How is it directed? Which force acts on a charge of 100nC at point A? F = k * q1 * q2 / r^2 E = F/q r^2 = (l1/2)^2 + (l2)^2 => r = 0,707m Electric field strength : E1 = E2 =...

Homework Statement Homework Equations The Attempt at a Solution Is my answer correct ?

I've been reading the Feynman lectures in physics. In volume 2 chapter 7: http://www.feynmanlectures.caltech.edu/II_07.html he shows how to mathematically model a 2D electrostatic field. Is it possible to create an experiment that behaves the same way even with the complex variables? Thank you...

Homework Statement An oil droplet is suspended between two horizontal parallel plates with a separation of 0.4 cm. If the potential difference of 320V is applied to the plates, determine the number of electrons transferred to/from the droplet. Given/Known Values mdroplet = 5.2×10-6 kg d = 0.4...

Homework Statement fig 1 : Area of each plate is S, separated by 2d, charge Q in the capacitors fig 2 : uncharged conductors of area S, thickness d, inserted parallel between plates What is the ratio of electrostatic energy in fig 2 to electrostatic energy in fig 1? Homework Equations Q =...

Find the electric field strength at point B between two charges shown below: Given/Known Values q1 = 4.0×10-6 C r1 = 40 cm = 0.4 m (Distance from q1 to point B) q2 = -1.0×10-6 C r2 = 30 cm = 0.3 m (Distance from q2 to point B) k = 9.0×109 Nm2/C2 Equations Electric Force: FE = (k⋅q1⋅q2)/r2...

Homework Statement https://imgur.com/3H3pCkD R is the resistance of each resistor, determine total resistance in the circuit. (see the image in the link above) Homework Equations R=1/R₁+1/R₂+1/R₃+... (in parralel circuit) R=R₁+R₂+R₃... (in series circuit)The Attempt at a Solution I'm...

I know little about QED, QCD, and whatever the corresponding theory for the weak force is, and of course virtually nothing about the quantized theory of the gravitational force, which mostly doesn’t exist, so the following arguments and questions may be somewhat wrongly based where they refer...

Homework Statement (This is not a HW problem, but HW-type problem.) A half cylinder of radius R and length L>>R is formed by cutting a cylindrical pipe made of an insulating material along a plane containing its axis. The rectangular base of the half cylinder is closed by a dielectric plate of...

A solid sphere has surface charge density, Rho (r) Rho(r) = k 1 ( 0 < r < a) k2 x ( a < r < R) 2) Find the electric field in all region i.e 1) r < a and 2) a < r < R and 3 ) R < The attempted solution and the question with the diagram is attached below Could the answer be verified...

Can an electrostatic field be used to create an oxide layer that has a permanent electric field? For a specific example; an aluminium domed van de graaff generator with no oxide layer. If it is turned on and allowed to contact oxygen, would the oxide layer store a permanent electric field?

A point charge +Q is located 1 m below the x-y plane. What is the total electric flux passing through the x-y plane? I know the answer should be Q/2 but how?

Hello PF community, I am currently self-studying electrodynamics from Griffiths textbook, and I'm at a point where the book discusses electrostatic boundary conditions. If someone can please check if my reasoning is right. So, as I am approaching an infinite, uniformly charged plane (let the...

If the coulomb's law instead of following an inverse square relationship, follows an inverse cube relationship, How would it affect an isolated charged conducting sphere? How would it's field vary within the volume and how would the volumetric charge density be affected? Please give in some...

Homework Statement Homework EquationsThe Attempt at a Solution Option (a), because the potential is 0 on the surface, and potential due to point charge is positive so there must be negative charge on the surface. Since opposite charges attract each other, there is an attractive force...

Homework Statement The electric field in an xy plane produced by a positively chatged particle is 7.2(4x+3y)N/C at the point (3, 3)cm and 100x N/C at the poiint (2, 0)cm. Note, x and y used here are unit vectors. find the x and y co-ordinate of the charged particle what is the charge of the...