Charge Definition and 1000 Threads

Till now, all I have found out, is that for option P, it matches with ## C_0 /3 ##. not able to understand, how to find the capacitance, if two plates are "shorted". My attempt (to solve Q): I mentally connected ## S_2 to S_3 ## with a connecting wire, to ensure that the two plates are at the...

How to calculate the field due to a uniformly charged ring at a point not on the perpendicular axis of the plane of the ring I have tried using coulomb's law and divergennce of the electric potential but I always stumble with a complicated integeral

For this question, I get that $$\mathbf{p} = \int \mathbf{r}\,\rho(\mathbf{r})\,d^3r$$ but for the bounds, does r go from 0 to ##r_0## or from 0 to ##\infty##? I would think infinity, but then how do I use the "hint"? I also don't get the significance of shifting the electron charge density...

$$Q=\int_{0}^{R} \left(\frac{a}{x} \times 2\pi x \right)dx$$ $$=2\pi aR$$ But the answer key is ##4\pi aR##. Where is my mistake? Thanks

Hello people, super confused here. In electrostatics we define the work done on a point charge Q to move it from A to B as $$W = Q \cdot \int_A^B \vec{E} \cdot d\vec{s}$$ . Where exactly does the energy go here? For instance when a positive charge Q is moved in the direction of the electric...

I did a forum search and couldn't find this, so forgive me if my search skills were insufficient to find a previous explanation of this. But, I'm a bit confused as to why merely having the same mass but opposite charge would cause, for example, an electron and positron to annihilate each other...

I'm not asking for a solution, but for one of my homework problems, it is asking about a circular surface and a positive charge to the right of the surface. I just wanted to check if the net electric flux through the loop would be zero, as the charge is not enclosed by the loop. Is there...

This is the description of the thought experiment. There are two plates forming a parallel plate capacitor. Both plates are rectangular but one is large and long and the other is much smaller. Both are "charged up", the difference is that the smaller plate has surface charge across it's full...

Can the polarization bound charge density be expressed in vacuum by a wave function?

Under normal circumstances both plates of a parallel plate capacitor develop a charge imbalance in each plate as the capacitor gets charged, the charges redistribute with one plate lacking electrons and the other plate having an excess of electrons, both plates together still can be though of as...

Hi, I have some trouble understanding the charge transfer process in photodetectors that are built from two different semiconductors, creating depletion region. To my knowledge, to make an effective detector, there needs to be effective charge separation, in order to avoid recombination...

I thought by "charge separation" the question is asking about distance between H and H so I was thinking of using cosine rule to find the distance. It turns out the answer stated by answer key is 0.328e (which I don't know what that is) Dipole moment has direction from negative to positive...

It's simply a theoretical question.

Suppose a charge is moving towards another charge at rest. At a given instant of time, The electrostatic force applied by either charge on the other is same, but only one is applying magnetic force on the other. Doesn't this violate Newton's third law?

Can someone prove that outside of two infinite planes with opposite charge, the E-field got cancelled? But the between are not.

Let the charge density be $\rho$, radius be $R$, total charge be $Q = \rho \frac{4}{3} \pi R^3$. We know from Gauss's law, $E (r) = \frac{Q r}{4 \pi \epsilon_0 R^3}$. We also know from Maxwell stress tensor $\sigma(r) = \half \epsilon_0 E^2$. We can compute the pressure due to the electric...

I tried to solve the question using two different approaches to gain a better understanding of the subject. However, I reached two different results with each approach. I believe I used Gauss's law to find the electric charge distribution and the electric field inside the cavity incorrectly...

I am reading Purcell's Electricity and Magnetism and am getting confused on equation 5.22. It seems to me they are using relativistic velocity addition for u' which is u'=(u-v)/(1-uv/c^2), but aren't we solving for the velocity of the electrons in the test charge's frame of reference, so should...

It is common lore that bosonic fields of odd spin, such as electromagnetism, cause equal charges to repel, while bosonic fields of even spin, as pions or gravitons, cause equal charges to attract. Has anyone seen this argument in a textbook? And its proof? Or is it just internet lore, or...

Q 1) In electric currents, in a battery, the positive charge starts at the negative terminal and gains energy through emf which forces the charge to go to the positive terminal of the battery, with plenty of energy. This voltage is the energy difference between the terminals. For the charges to...

I'm talking about a situation like this. Ive been told that charge distribution on the inner side of the conducting material is non uniform and equal to -q. This makes perfect sense But ive also been told that the charge distribution on the outer part of the conducting material is ##uniform##...

I'm only confused about one part of this problem and that is setting up the conservation of energy equation. In the solution, they just wrote this: $$\frac{mv_o^2}{2} = - k \frac{q_1 q}{r} + k \frac{q_2 q}{l + r}$$ where ##r## represents the distance at which the force created by the negative...

On Problem 3.11 for Griffiths' Electrodynamics, there is a question that asks for the critical value between a point charge and a conducting shell, but I don't quite know what they mean by 'critical value' in this context and how I'm supposed to approach this question, the rest of the problem is...

I took a point P on the conductor with charge Q. We know that the field inside a conductor is zero in electrostatic equilibrium Therefore I took induced charge on the neutral conductor to be x and gave the respective charges to the others. On the side facing conductor with charge Q the neutral...

A few hours ago, I tried solving this problem and I'm still not quite sure if I've made a mistake somewhere or perhaps the guy in the video is wrong? Anyway, here's my solution: In the problem we're given that the total kinetic energy of of these 2 charges at this instant(look at the picture)...

$$I=\frac{q}{t}$$ $$=\frac{4Q}{T}$$ $$=4Qf$$ My answer is (a). Is that correct? Thanks

The most common explanation I know is that anomaly cancelation implies the sum of electric charges of each particle must cancel generation-wise, so 3 Q(Up) + 3 Q(Down) + Q(electron) = 0, and electroweak doublets imply Q(Up) - Q(Down) = Q(neutrino) - Q(electron), so with Q(neutrino) = 0 it solves...

Color charge is not scalar. Still, do their components have dimensions (in metrological terms)?

Is there only one type of elementary charge? The type of elemental charge that appears on particles such as electron, proton, etc. It is well known. Could there be another different type that we don't know yet?

If there is no field inside the conductor, how can there be electric potential? I think of potential very similar to gravity, as how much energy would be required to move a particle of mass/charge against the gravitational/electric field. If there is no field at all, how would there still be...

This paper aims to resolve the inconsistency between different transformation equations by expressing the electric current created by a moving electric dipole as the sum of polarization and magnetization currents and calculating the resulting magnetic field. Here they take charge density to be...

I know that the formula qqk/r applies to a system (two charges), but where is the flaw in my derivation? Thanks!

Conservation of charge: The sum of the charges on all the particles before and after a reaction are the same I was considering this reaction: n + 3 He → 3 H + p + 0,764 MeV Making the charge balance I have: 0 + 0 (2protons + 2 electrons) → 0 (1proton + 1electron) + 1 (proton) There is...

I originally thought that this problem was simple, and it still seems like it is, but there are conflicting solutions and I don't know which is correct. So I first solved for R1 and R2 using V=kQ/r where R1 is 0.514 and R2 is 0.54. My original thought was volume is conserved so V1 + V2 = V3 and...

I had two trains of thought. One is that the capacitor will fully charge when t = infinity, so when you plug t = infinity into the equation of charge as a function of time you get 1.68E-4, which you also could've gotten from Q = CΔV where ΔV = 42V. My other train of thought was that when t =...

I solved using the formulae listed in the relevant equations and got the right answer. However, I noticed something strange to me. The electric potential due to the inner semi-circle was equal to that due to the outer semi-circle. But based on the formula for calculating V, we notice that there...

Apparently the answer is not 2.9 cm or 7.4mm. I've looked at similar questions in this thread and solving the exact same way gives me the same answers. I set it up as (3.5/x^2)=(10/(.02+x)^2). What am I doing wrong?

My first attempt at solving: I divided up the point charges based on the radius away from point A. 1 charge was s*sqrt(3) away, 3 charges were s*sqrt(2) away, and 3 charges were s away from point A. q remained constant. Therefore, my F_total was: F_total = k * [(q^2 /...

(1) https://www.youtube.com/results?search_query=relativity+and+electromagnetism (2) If I understand this correctly, then, well, shouldn't all current-carrying wires exhibit a small amount of positive charge?

Consider a metal sphere connected to one end of the battery and the other end of the battery to be connected to the ground. Does the metal sphere become electrically charged with this method?

There appears to be a conservation of charge momentum (qv) analogous to that for mass (mv) although in the case of charge it is more potential in nature. A change in the flow of charge (or current) produces changing magnetic and electrics fields according to Maxwell's equations. These in...

Suppose there is an electric charge of 350 micro coulombs in space. The electric field at a distance of less than one meter will be more than 3,000,000 volts/meter considering that this field is greater than the electric breakdown of air and the charge has no place to discharge, what happens...

Our car battery is past its warranted life by 1.5 years (it's 5 years old). It's been discharged a few times due to lights being left on overnight. We're not currently using the car because of engine issues, so it just sits in the driveway for the last few months. Last week, it was found...

My thought: First of all, I find the upper hemisphere (with a total charge +Q): ##ρ(\vec r)=\frac {V} {Q}## where V is the volume of the upper hemisphere = ## \frac {2} {3} \pi R^3##. Secondly, find the lower hemisphere (with a total charge −Q): ##ρ(\vec r)=\frac {V} {Q}## where V is the volume...

I'm confused in the calculation for R/2. The author took in account that the charge will change by a factor 1/8. But how does it show that the coloumbic force will become 1/8th. The distance will also reduce by half shouldn't that also be taken into account? Or am I missing something here?

suppose I should evaluate $$Qa_{p1}^{r \dagger}a_{p2}^{s \dagger} b_{p3}^{t \dagger}$$ I get lost in the commutator relation. Any help?

why test charge is always positive ?

Would it still work in a similar manner as an actual electroscope where you would charge it either positively or negatively and then observe attractive or repulsive forces or is there an easier and more efficient method?

Fg = Fc Fg = 2.3g*9.8m/s^2*cos(28)=19.90N 19.90 = (8.99*10^9)*(4*10^-6)*(6*10^-6)/(r^2) 1/(r^2) = 92.23 r = 0.104m However, it's not one of the option...

I am doing the Millikan Oil Drop experiment to determine the charge of a single electron. I have been following the lab manual provided by the manufacturer, https://hepweb.ucsd.edu/2dl/pasco/Millikans%20Oil%20Drop%20Manual%20(AP-8210).pdf. The manual defines a simple method to calculate for...