Hi! I need help with this problem. I tried to solve it by saying that it would be the same as the field of a the spherical shell alone plus the field of a point charge -q at A or B. For the field of the spherical shell I got ##E_1=\frac{q}{a\pi\epsilon_0 R^2}=\frac{\sigma}{\epsilon_0}## and for...
V(ρ) = V_o*ln(ρ/0.0018)/ln(45/180)
(Attached picture is where the unit vector of r is really ρ.)
In cylindrical coordinates
∇V = ρ*dV/dρ + 0 + 0
∇V =derivative[V_o*ln(ρ/0.0018)/1.386]dρ
∇V = V_o*0.0018/(1.386*ρ)
E = V_o*0.0012987/ρ
Work = 0.5∫∫∫εE•E dv
Bounds: 0.0018 to 0.00045 m
D = εE =...
Hi! My main problem is that I don't understand what the problem is telling me. What does it mean that the surface is a flast disc bounded by the circle? Is the Gauss surface the disc? Does that mean that inside the circle in the figure, there is a disc?
Can you give me some guidance on how to...
So I figured out the potential is: dV = (1/(4*Pi*Epsilon_0))*[λ dl/sqrt(z^2+a^2)]
.
From that expression: We can figure out that since its half a ring we have to integrate from 0 to pi*a, so we would get:
V = (1/(4*Pi*Epsilon_0))*[λ {pi*a]/sqrt(z^2+a^2)]
In that expression: a = sqrt(x^2+y^2)...
I tried to work out both a) and b), but I am not sure if I am correct. I drew a picture with a sphere around q first with radius r and then with radius 3r.
For a) ##E.A=\frac {q}{ε_°}## (when using Gauss' Law)
Since ##A=4πr^2##, I substituted this in the equation and solved for E giving me...
Hi, so I was able to solve this problem by just equating the forces (Tension, mg, and EQ).
But I thought I could also solve this problem with Conservation of Energy.
However, I calculated it several times, and I never get the right answer this way.
Doesn't the Electric Field do the work to put...
I read Wikipedia's description of how a plasma ball works. Question: What kind of energy is the "radio-frequency energy from the transformer"? Is in the form of electric field energy, magnetic field energy, or both? Thank you!
(from Wikipedia)...
Although many variations exist, a plasma lamp is...
Hi,
A solution contains some ions (charged particles). We are only interested in my exemple to positive ions.
It is assumed that these ions acquired some mobility under a concentration gradient. Their direction is A to B.
Then these ions encounter/cross an electric field which is oriented from B...
The electric field due to a dipole distribution in volume ##V'## can be viewed as electric field due to a volume charge distribution in ##V'## plus electric field due to a surface charge distribution in boundary of ##V'##.
##\displaystyle\mathbf{E}=\int_{V'} \dfrac{\rho...
Hi,
I've a question about electricity in the following scenario: consider an accumulator (e.g. a 9V battery) and an analog/digital voltmeter having a probe connected to the accumulator + clamp and the other to the ground (for instance connecting it to a metal rod stuck in the ground).
Do you...
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...
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...
1. 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)
2...
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...
1. 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...
1. 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.
2. Homework Equations
##k=\frac {1}{4\pi\epsilon_0}##
##V=\frac {KQ}{r}##
3. The Attempt at a Solution
If the distance...
1. 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
2...
1. 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?
2. Homework Equations
The flux surface integral of an electric field is equal to the value of the charge enclosed divided by the...
1. 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}##
2...
1. Homework Statement
Find the electric field of a point outside sphere without using Gauss's law. (Do not evaluate the integral)
2. Homework Equations
Coulomb's Law
Spherical Co-ordinate System
3. The Attempt at a Solution
I have attached my attempt as a picture but now I am stuck, I don't...
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...
1. 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...
1. 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...
1. 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...
1. 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
2...
1. 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?
2. Homework Equations
##\vec E=\frac 1 {4π\varepsilon_0} \frac q...
1. 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.
2. Homework...
1. 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?
2. Homework Equations
Gauss's Law: ∫EdA=Qencl / ε0...
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...