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For questions that utilize the concept of electric fields (commonly denoted by the letter E), or for questions whose answers likely involve electric fields. More specific than the [tag:electricity], as questions about the phenomenon & theory of electricity do not necessarily involve the discussion ...

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Electric field of an infinite sheet of charge

I am trying to derive the formula for E due to an infinite sheet of charge with a charge density of $ \rho C/m^2$. I assumed the sheet is on $yz$-plane. I used Coulomb's law to get an equation and ...
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2answers
53 views

Proving electric field constant between two charged infinite parallel plates

It is known that the electric field intensity between two infinitely long charged parallel plates is constant. I had read that one explanation is that if a test charge is placed between the plates, ...
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0answers
41 views

Electric field due to a line charge in cylindrical coordinates

We have a straight line charge along the $z$-axis from $-\infty$ to $\infty.$ Now, I understand that by keeping $\rho$ and $z$ constant, we have azimuthal symmetry; and, by keeping $\rho$ and $\theta$...
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0answers
26 views

Capacitor - calculation task (electical field and electrical potential calculations - integration way)

I have a problem with this task: Flat Capacitor with an isolation lamina and an air lamina was charged to $U$ voltage. Calculate and draw the distribution of electrical field $E(x)$ and ...
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1answer
43 views

Electric fields and insulators

Will the electric field of an induced dipole in an insulator match the electric field inducing it but in the opposite direction? I have 2 counter theories: Let's say I place an insulator (and let's ...
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1answer
56 views

Why is the drift velocity directly proportional to the electric field?

If I double the electric field, that should double the acceleration of electrons inside the conductor in the general direction of the electric field. But why does that double the drift velocity, and ...
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0answers
22 views

How would we calculate the magnitude of the electric field of a battery? [on hold]

For a battery with a given voltage, how would we calculate the electric field? Thanks!
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2answers
16 views

Electric field from disc versus point charge

A uniformly charged disc of radius R and net charge Q with an x-axis through the center of the disc will have an electric field in a point $x_0$ on the x-axis $E=kQ(1-\dfrac{x_0}{\sqrt{x_0^2+R^2}})$ ...
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29 views

Grounding a system of (a) parallel (conducting charged) plates (b) coaxial cylindrical shells (c) concentric spherical shells

(a) Find charge on 2 outer surfaces if an inner plate is grounded. (b) Find charge on the outermost surface if an inner cylindrical shell is grounded. (c) Find charge on the outermost surface if an ...
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0answers
34 views

Creating a complete picture of induced current flowing

I'm on the way to understand em waves, but I decided, that I need to completely understand a current flowing. Not basics, not in general, I need to understand every trifle. I think, for a lot of ...
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1answer
49 views

Gausses Law question [on hold]

"A solid copper sphere has a net positive charge. The charge is distributed uniformly over the surface of the sphere, and the electric field inside the sphere is zero. Then a negative point charge ...
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2answers
21 views

Is polarization cause of different permittivity of different substances?

I want to ask is whether polarization of a substance cause of different permittivity of different substances. [If unable to get what I want to ask- Put differently, if a substance is prevented ...
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0answers
33 views

Why do we believe in electric fields [on hold]

This is more of a history related question but what was the motivation behind electric fields? I've read that electric fields help explain 'news' of electric force travelling at light speed but can't ...
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2answers
80 views

Where did the concept of field come from?

What made scientists start to think about what was previously 'forces-exerted-by' (Newtonian view) to fields (e.g. electric fields and magnetic fields)?
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1answer
19 views

Electrical flux through a ring-like surface

I am preparing for a retake exam in electromagnetism, in the exam paper a question asks : "Consider a ring-like surface of internal radius $r_{int} $= 3nm and external radius $r_{ext} $=5nm and an ...
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2answers
52 views

Mathematical proof of electrical field due to a charged ring perpendicular to the axial line [closed]

We know that while calculating electric field due to a charged ring at axial point all the components along axial line sum up to give net electric field while the perpendicular components i.e. cancel ...
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1answer
34 views

Why there is no charge within the conductor even if the charges are static?

"When excess charge is placed on a solid conductor and is at rest, it resides entirely on the surface, not in the interior of the material. �" Source: University physics 13th edition p(736). ...
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2answers
34 views

Electric field around a infinite plate with voltage $V$ [duplicate]

Say that you have an infinite plate uniformly charged with voltage V, and you want to calculate the electric field strength at some distance z away from the surface. I know that you can calculate the ...
3
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3answers
139 views

Electric field at the focus of a parabolic line

Today my physics teacher was teaching me magnetism and application Biot–Savart law ;I came to realisation that Biot–Savart law is some what similar to coloumbs law. While teaching us application of ...
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0answers
23 views

Speed of electron and proton in electric field

Speed of electron and proton in electric field. In a uniform electric field E, the acceleration of an electron in vacuum is 1836 times that of a proton (proton/electron mass ratio is 1836). I'll like ...
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0answers
20 views

Finding the magnitude of the electric field vector and the charge

So our teacher has given us this question: In the below form, if $F$ is the net electric field at point $C$, and it bisects the angle $ACD$, find the magnitude of $F$ and the charge $A$ (amount and ...
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1answer
52 views

Moving a conductor with the presence of both E & B fields?

If a conductor is charged from an exterior electric field, moved in a magnetic field perpendicular to the E-Field, the velocity's direction is also perpendicular to both the B-field and E-field. How ...
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0answers
22 views

How do I calculate an electrostatically induced potential in a conductor of a arbitrary form?

Let's suppose we have an electric field $\vec{E_0}$ generated be a point charge $q>0$ placed at the origin of coordinate system. Now, we put a non-charged conductor of a fancy form anywhere to this ...
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2answers
24 views

Confusion about surface charge density and electric field intensity of an infinite plate

consider a plate with some thickness. If both surface of the plate have a total of q charge and the area of each surface is A then would the charge density be q/A or q/2A ? And what would be the ...
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2answers
72 views

Does potential at a point in circuit allows the flow of charge?

Suppose I have the following circuit with lamp connected and there's also a really long neutral ( total charge zero ) conducting wire under the circuit as follows : Then , from the theory of ...
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1answer
70 views

Which of my understanding of electric field as a quantum object is correct? [closed]

Yeah, there are a lot of text, but, please correct my statements below, if I wrong Let's consider an electron in two-dimensional space: Rest It always emits\creates\propagates an electric field, ...
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0answers
16 views

the effect of electric potential on the threshold frequency in the Lenard's photoelectric experiment

I have been taught that electrons can ejected from the atom by applying strong electric field(field emission), and according to photoelectric effect even light of certain frequency for certain atom ...
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0answers
59 views

Why use potential functions to solve Maxwell's equations?

I'm reading "Antennas and Wave Propagation" by Harish and Sachidananda. They introduce the phasor form of Maxwell's equations: $$\nabla\times E=-j\omega\mu H$$ $$\nabla\times H = j\omega\epsilon E + ...
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1answer
25 views

How can electric field be uniform in a conductor with charge separation when calculating the motional emf in it?

We say the charges stop moving when $B×v=E$, but how we are saying it's uniform when we are considering that all the charges are at the ends (consider a rod for example)? Conductor is straight and $B$...
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1answer
43 views

Electric field due to a line charge

From the image you can see that i've attemted to calculate electric field due to a straight conductor at a point P ,to which the perpendicular distance is r, in three ways . 1) I'm integrating with ...
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0answers
42 views

Computing the radial component of an electric field in spherical coordinates

I have the $\vec{\phi}$ and $\vec{\theta}$ components of a electric field in spherical coordinates. I also know the location of the vector $(r,\theta,\phi)$. I want to compute the $\vec{r}$ component. ...
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4answers
195 views

Why does an atom in an oscillating electric field behave like an electric dipole?

How can I understand that an atom subjected to an oscillating electric field (e.g., $\vec{E}=\hat{i} E_0\cos\omega t$) behaves like an oscillating electric dipole? What is the underlying picture that ...
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1answer
18 views

Electric charge and net force

Consider two point charges $+Q$ and $-Q$, which are fixed a distance $d$ apart. Can you find a location where a third positive charge $Q$ could be placed so that the net electric force on this third ...
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3answers
38 views

Fixed charge inside a conductor (Finding electric field)

This is a charge q (unknown sign) fixed inside a conductor so it cannot move, the goal is to find the electric field at A and to find the electric field at B My attempt at solution: I drew a ...
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0answers
35 views

Quaternion Electric/Magnetic field reception

I always wondered: why people think of EM field in terms of real numbers, since it exists in 3D space and is described by both direction and strength at some point? Is not it more natural to threat it ...
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1answer
38 views

What does it mean for a battery to be 1.5 Volt? [duplicate]

What does it mean by a battery is of 1.5 Volt ? Does it mean that it would take 1.5 Joules of energy to transfer -1 columb of charge from the negative end to the positive end of the battery ? What is ...
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0answers
11 views

Electric field in a spherical shell [duplicate]

Question mentioned like this find out the electric field inside and outside a spherical shell of radius r which carries a uniform surface charge density sigma. In the above question it is not ...
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2answers
33 views

Electric field generated by an infinite plane paradoxon

Every element of the distribution generates weaker electric field at a larger distancce. Although other arguments involving gauss' law or taking the limit of the field result it's constancy. How could ...
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1answer
30 views

Field inside a hollow sphere uniformly charged [duplicate]

How to prove that field inside a hollow sphere is zero anywhere inside that sphere using solid angle concept?
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1answer
586 views

Problem verifying Gauss's law

I am trying to verify Gauss's law, differential form, SI units, non-special relativity regime, ignoring time retardation, by performing the differentiation on the left-side of the equations to see if ...
3
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1answer
91 views

How does the electric field produced by a simple circuit look?

I have not seen anywhere a description of how the electric field looks inside and around a simple circuit. For example let's say we have the circuit shown below. One DC voltage source, two resistors, ...
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1answer
46 views

Discontinuity of electric potential in parallel plate capacitor

Using Gauss' law, an idealisation of infinitely large plates and symmetry arguments one can show that the electric field of a parallel plate capacitor vanishes outside the plates and is constant ...
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2answers
58 views

About fundamental physics (static fields, forces, and energy)

Disclaimer, so that you can provide a more informative answers: I have a degree in mathematics but I am quite ignorant in physics. I was reflecting about the ability of a charged particle (any ...
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0answers
10 views

can a capacitator have an anode but more than one cathode (vice versa)

since a capacitaor's electric field can be seen as a displacement current, can there be a capacitator that has one anode but more than one cathodes?
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5answers
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Can a magnetic field exist without an electric field present?

I know an electric field can exist without a magnetic field as in the case where you have a stationary point charge. But, magnetic fields are created by moving charges so wouldn't you always need an ...
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5answers
150 views

Why is electrostatic force a function of the product of charges, not the sum?

When you have two forces , you ADD them to get the total. If both of us push on a car, the total force on the car is the sum of our forces. But, If we have an electron approaching another electron, ...
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1answer
79 views

Does electric and magnetic field interact?

Can electric field or magnetic field interact with an Electromagnetic radiation? And can 2 electromagnetic radiations interact with each other? Rather than the interference effect.
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0answers
37 views

How to calculate electric potential distribution of nodes in subgrid using FDM?

Boundary: the potential of the upper electrode is 7 V, and lower is 0. Potential of two edges is shown in the following figure. It is easy to calculate the potential distribution of nodes using ...
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2answers
61 views

Voltage and electric field between Live and Neutral conductors

As far as I understood, conductors connected to some DC voltage source terminals will try to "gain" corresponding terminal potential (though capacitance of typical conductor is pretty low, so amount ...
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0answers
74 views

Is the electrostatic condition $\vec{E} = \vec{0}$ in a conductor something to be accepted?

The usual explanation goes as follows. Charge flows until the applied electric field is canceled by the induced field, giving a total field $\vec{E} = \vec{0}$. This is reasonable if one gives as an ...