The electric-field tag has no wiki summary.
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Charge Distribution on a Parallel Plate Capacitor
If a parallel plate capacitor is formed by placing two infinite grounded conducting sheets, one at potential $V_1$ and another at $V_2$, a distance $d$ away from each other, then the charge on either ...
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Electric Field and Electric Potential [closed]
How can electric field and electric potential function for charged conducting and uniformly charged non-conducting spheres?
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2answers
107 views
Estimation of the internal electric field strength in the pn-junction
I would like to compare my result in an order of magnitude. So, How can I estimate the strength of the electric field in a typical Si PN-junction?
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1answer
276 views
Electric field and insulator or dielectric
I have a uniform electric field $E$ projected from left to right and I placed an insulator or dielectric right in the middle of it. To the left of the insulator, the $E$ is the original $E$. Inside ...
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1answer
37 views
The potentiality of the electric field
Could you, please, explain me using just words why electric the field is potentially? I know the proof using integral: $A = \int_{12}q\overrightarrow{E}\overrightarrow{dr} = ...
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1answer
207 views
Electric field due to nonconducting sphere
For calculating electric field outside a nonconducting sphere with a hollow spherical cavity. When I use the rule (Charge density= $dQ/dV$), I don't know exactly what is $dV$, is the volume here ...
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“Find the net force the southern hemisphere of a uniformly charged sphere exerts on the northern hemisphere”
This is Griffiths, Introduction to Electrodynamics, 2.43, if you have the book.
The problem states Find the net force that the southern hemisphere of a uniformly charged sphere exerts on the ...
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1answer
67 views
Difference between electromagnetic radiation (EMR) and Electromagnetic Field?
I'm a freshly graduated electrical engineer. One course that I really struggled with was Field Theory, because it was a lovely assortment of vector calculus and things that were explained to me well ...
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0answers
67 views
The electric field inside a uniformly polarized cylinder
Given a uniformly polarized cylinder with some polarization $P\vec{z}$ which has radius $R \gg d$ where $d$ is the height and $R$ is the radius. The cylinder's center is on $\vec{z}$ and it's on the ...
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Horizontal $E$-field for a charged conducting disk
For part of a simulation I am writing, I need to know the electric field emitted from a charged conducting disk. If the disk was laid out in the $x$-$y$ plane, I am interested in the field in that ...
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40 views
Work required to pull capacitor plates apart when connected to battery [closed]
For (a), I just use $F = k \frac{Q_1 Q_2}{r^2}$, then (b) $W = - \Delta U = - qE \Delta d$, correct so far? But how do I do (c)?
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Energy content after moving point charge [closed]
I have the following exercise:
In point A there is a charge with $Q_1 = 3.3\times10^{-5} C$
In point B charge $Q_2 = 8.5\times10^{-6} C$
In point C charge $Q_3 = -6\times10^{-6} C$
This happens ...
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2answers
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Energy stored in space/frequency electric field
I've come across a problem with finding the energy stored in time/frequency electric field. In space/time we have (taking $\epsilon = 1$)
$$ Energy = \frac{1}{2} \int_V |\mathbf{E}(\mathbf{x},t)|^2 ...
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1answer
51 views
Maximum separation when 2 unlike charges shot apart
I want to compute the maximum separation when 2 unlike charges are shot apart from each other
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2answers
297 views
Does a current carrying wire produce electric field outside?
In the modern texts of electromagnetism in the presence of stationary currents the electric field is assumed conservative $\nabla \times E =0 $. Using this we get $E_{||}^{out}=E_{||}^{in}$ which ...
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2answers
90 views
Difference between electrostatic and magnetic field [closed]
In this, F (the force set by the field) is perpendicular to the speed of the particle. In which case does F change the absolute value of V? Why or why not?
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1answer
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Why electric field outside the sphere that carries polarization is 0?
There is a sphere with radius $R$ that carries a polarization
$$\vec P(\vec{r})=k\vec r$$
$\vec r$ is the vector from the center.
I found electric field the outside generated by the sphere is $\vec ...
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0answers
37 views
Spherical charge in two different dielectric materials
I am trying to freshen up my memory about electrical fields and I came across this exercise from school.
A sphere with a constantly distributed charge is located in between two different dielectrics ...
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1answer
91 views
Electric field around charged cylinder
This is a homework question, so please don't give me the answer outright. I just need help conceptually.
"A cylindrical shell of length 190 m and radius 4 cm carries a uniform surface charge density ...
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5answers
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Paradox with Gauss' law when space is uniformly charged everywhere
Consider that space is uniformly charged everywhere, i.e., filled with a uniform charge distribution, $\rho$, everywhere.
By symmetry, the electric field is zero everywhere. (If I take any point in ...
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0answers
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Static electrical attraction [closed]
Coulomb's law is used to calculate the electrical attraction between 2 charged particles, what formula do I use to calculate an electrical attraction magnitude between 2 plates? Let's assume the first ...
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1answer
33 views
Gaussian surface in a charged infinite plance sheet
The following question arises on the use of Gauss law. In the charged finite sheet problem, we consider a Gaussian surface on only one side of the sheet. But, In the case of an infinite sheet, we ...
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0answers
265 views
What is a boundary condition for capacitors/dielectrics?
I am extremely confused about what boundary conditions are. One minute ago I was solving easy capacitor questions and the next minute I am being asked boundary condition questions and there is no such ...
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1answer
53 views
Electric field and potential [closed]
An oil drop of radius 0.70mm containing a charge of -4.8 x 10-19 C is placed in an electric field if the drop remain stationary at the point find the magnitude and direction of electric field ...
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2answers
135 views
Energy of particle in electric field
I'm taking a physics class and the professor teaches us really basic things in lecture and then gives homework way beyond what he taught in lecture. Obviously I need to find some resource other than ...
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1answer
151 views
Minimizing potential energy of a dipole in an electric field
My test paper asked me which way a dipole should be orientated in an electric field to minimize its potential energy. My answer was that the dipole should lie parallel to the electric field with the ...
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3answers
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In electrostatics, why the electric field inside a conductor is zero?
In electromagnetism books, such as Griffiths or the like, when they talk about the properties of conductors in case of electrostatics they say that the electric field inside a conductor is zero.
I ...
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1answer
109 views
Does the electric field inside a sphere change if point charge isn't in center?
As i understood , if you have a point charge in the center of a hollow conducting sphere then the electric field inside it, is zero because the charge distribution is spherically symmetric.
But ...
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1answer
228 views
Non conducting charged planes
I have two parallel non conducting charged planes with opposite charges $6\mu C/m^2$, area $A = 3m^2$ and distance between the planes $d = 0.004 m$. I know the potential between these two planes is ...
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2answers
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Electric vs. Gravitational shielding [duplicate]
There are great similarities between electric and gravitational fields and, furthermore, a room can be electrically shielded so that there are no electric fields simply by surrounding it with a ...
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1answer
234 views
What's the electric field with a point charge not in the center of the sphere? [closed]
That's a hollow conducting sphere link
My charge is at P (10uC). R = 0.15m. PS = 0.05m. DS = 0.35m. What's the electric field at point D?
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1answer
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Possible to generate an electromagnetic field from moving an object through a magnetic field?
Is it possible to generate an electromagnetic field from a stationary rare earth magnet with a hole in it by passing an object through the hole?
By definition, a Lorentz Force is the force on a ...
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0answers
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Microscopic fields inside a conductor
In a neutral conductor if we assume electrons as point charges, the electric field in the space between them cannot be identically zero. This microscopic field may be very weak. What if we were very ...
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1answer
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Electric field of a negative charge
Displacing something against the gravitational field, gains it potential energy. Moving something against the nature requires work. If the electric field of a negative source charge 'Q' points inward, ...
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2answers
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Electric field of a negative charge
How was it discovered that the electric field of a negative charge points towards the charge itself? Is it true?
(Courtesy of wikipedia)
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Electric field outside nonconducting sphere [duplicate]
An electric charge $Q$ is distributed through out a nonconducting sphere of radius $r_ 0$ and has a spherical cavity of radius $r_1$ centered at the sphere's centre. Assume the charge $Q$ is ...
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1answer
52 views
Why do fields decrease with distance? [duplicate]
For example, electric, gravitational field decreases with $1/r^2$. Is it like decrease of energy of an object when goes it is moving with friction/air drag etc?
Does it mean that field's strength is ...
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1answer
72 views
Should the electric potential of a positively charged sphere be negative?
Because the indefinite integral of the electric field results in a negative value? (As the function is proportional to $r^{-2}$?
I've got to be missing something... Help please!! Thanks!
Also, I ...
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Charges and Fields [closed]
Three charged particles lie along the x axis of a Cartesian coordinate system. q1 is located at x = 0,
q2 lies at x and q3 lies at x = r. All three charges are positive, but only q2 is free to move. ...
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2answers
156 views
Influence of charged particle's own electric field on itself
I read this in my textbook: A charged particle or object is not affected by its own electric field.
Since I find this completely unintuitive and my mind is yelling "wrong! wrong! how could a particle ...
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1answer
154 views
What do physical properties of materials trigger the capacitive touch screen?
I have watched some youtube videos about capacitive touch screen
http://www.youtube.com/watch?v=ZHzaVzYEZbw
http://www.youtube.com/watch?v=GmCE18RMEeQ
The videos show that a conductor(finger), in ...
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2answers
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How does lightning “know” where to go?
If lightning comes down in, say, a large flat field with a lightning rod sticking out of the middle, the lightning will strike the rod.
How does it "know" the rod is there?
Will it always strike the ...
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1answer
235 views
Electric field strength between 2 positive charges [closed]
I'm having a lot of trouble trying to solve this problem:
Three identical point charges of magnitude $+1.0$ $mC$ are located at the corners of a square that is $1.0$ $m$ on a side. A point charge of ...
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1answer
491 views
Gradient of the electric potential
I was wondering if for a point-like charged object, does the gradient of the electric potential point in the direction of maximum increase or maximum decrease of the function $V$?
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2answers
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Electric lines of force
Why cant electric lines of force pass through the charged sphere? Well, basically that's how a Faraday cage works, but how can it be so?
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3answers
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Explanation on the resulting forces of two positive point charges
Why will the resulting force lines of two positive point charges be like this:
I would expect this:
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1answer
105 views
Electric Field inside a hollow ball, excentred of a homogeneous charged ball
Q:
We have a homogeneous charged ball with radius R which contains a ball-shaped hollow (with radius := r and distance from center of the bigger ball (M) to the center of the hollow (N) := b).
...
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3answers
194 views
Why can we use Gauss' law to compute electric field?
For simplicity I'm considering only the sphere case.
In the Gauss' Law formulation we have some field E introduced by charges $Q$ inside some sphere, then we compute flux and integrate, and we get ...
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1answer
165 views
Electric field caused by magnetic field
Does electric field caused by time varying magnetic field form closed loops(electric field starts from a positive charge and ends at a negative charge)? and are they conservative or non-conservative ...
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65 views
Electric field singularity
What's a general proof for the log-singularity of electric field near the edge of a uniformly charged surface?
