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Electrostatics is concerned with the electrical fields and scalar potentials of stationary electrical charges and charge distributions. Use this for questions about electromagnetic situations in which currents and magnetic fields are absent, otherwise use [tag:electromagnetism] and/or [tag:magnetic-...

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Using Aluminum Cabinet to make Faraday Cage

I am planning on using a solid (solid walls, doors, floor, and top) aluminum cabinet to make a Faraday cage in order to protect electronics against the effects of a possible EMP. I have thought of ...
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10 views

Will total capacitance change if the dielectric slab inside it is kept at an angle w.r.t the plates of the capacitor?

Suppose I have a capacitor, inside of which there is a dielectric slab that does not have the same thickness as the separation between plates of the capacitor and the slab is kept right in the middle ...
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11 views

Dielectric movement in between Capacitor plates

A rectangular piece of dielectric material is inserted partially into the (air) gap between the plates of a parallel plate capacitor. Then what will happen with the dielectric slab?
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1answer
21 views

Meaning of a sentence concerning the electric field inside its source charge

Could someone please explain to me the meaning of this sentence in bold type ? : " In the neighborhood of a true point charge the electric field grows infinite like $\frac{1}{r^2}$ as we approach ...
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23 views

3 identical charges suspended on a string

Three identical styrofoam balls (m=0.00200kg) are suspended on a point by 3 non conductive strings, each with a length of 0.50m. When in equilibrium the balls form an equilateral triangle with sides ...
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1answer
45 views

Question on capacitor and springs

The question is as follows: One of the plates of a charged parallel plate capacitor is connected to a non conducting spring of stiffness K while the other plate is fixed. The other end of the ...
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2answers
38 views

Electric field between 2 coaxial cylindrical charged tubes

Griffith's book on electrodynamics says the electric field between 2 coaxial metal tubes of charge $+q$ and $-q$ is found by using Gauss's law, where the gaussian surface is a cylinder with radius ...
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2answers
76 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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1answer
37 views

How is water a worse electric insulator than air?

I know I must be missing something here. Water has a much higher permittivity than air, which means it has higher (distributed) capitance. That means it can more effectively convert an electric field ...
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1answer
46 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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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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31 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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20 views

Electric field for uniformly charged axisymmetric surface

I am considering an axisymmetric surface, in cylindrical polar co-ordinates (r, θ, z), defined by r= r(z) between say z_1 and z_2. Can Gauss's law (or any other method) be used to calculate the ...
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3answers
42 views

Negative electrostatic potential energy interpretation

While going through an introductory text in electricity and magnetism , in a section dealing with the electrostatic potential energy (EPE) , the author gave an example of the EPE in an ionic crystal , ...
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0answers
15 views

A charge A situated outside hollow conductor experiences a force of another charge B is placed inside the cavity of the conductor

A charge A situated outside hollow conductor experiences a force of another charge B is placed inside the cavity of the conductor,but B does not experience any force.What may be the reason.Does it ...
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0answers
38 views

Creating a complete picture of induced current flowing [on hold]

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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33 views

Why do we believe in electric fields [closed]

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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22 views

What happens to electrons on accelerated charged plate?

If I charge an aluminum circular plate with 10 000 V and rotate it will the electrons stay in place or rotate with plate? Will it behave the same if instead of one single plate I have a pattern of ...
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3answers
61 views

Electric shielding skin depth

I read that lower the frequency,the deeper is the skin depth in conductor.If we are using piece of thin conductor,like aluminum foil for example to shield something from electric fields,it would ...
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1answer
20 views

Cavendish's experiment on concentric conducting shells

In a paper were there was a section addressing Cavendish's experiment on concentric conducting shells which was basically the following : Two conducting spherical shells were put together (like the ...
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1answer
22 views

Lost potential energy?

If there are two electrons and a positron are in an closed system (not being influenced by gravity) all these have electromagnetic potential energy amongst them . if one of the electron then touches ...
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19 views

Electric field between two parallel conducting plates [closed]

Can someone please explain What is the strength of electric field between two sufficiently large parallel conducting plates? Will it be double in strength compared to a configuration of non-...
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0answers
21 views

Electrostatics boundary discontinuities

Can someone explain this: The interface between two dielectric has a discontinuity in the electric displacement vector by a negative amount of free charge. Under curl of polarisation being zero and ...
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0answers
46 views

Density of ionised air

Is ionised air less dense than ordinary air, if so, by how much?
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0answers
23 views

Electrostatics:Discontinuity of displacement vector field

Could anyone please explain about the discontinuity at the boundary of a spherical dielectric and free space. It's a homogenous linear dielectric medium The problem which I'm working on has ...
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4answers
2k views

Can Newton’s law of gravitation be derived from Coulomb’s law? [duplicate]

I’m casually learning physics and have noticed that Newton’s law of gravitation and the electrostatic force formulas look similar. I’ve asked this question before but would really appreciate another ...
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2answers
23 views

Different forms of electric displacement vector D

In Irodov's Basic Laws of Electromagnetism, D is derived as D=ε°E+P. Later substituting the polarization vector for an isotropic dielectric as P=Χε°E, the result reached is D=ε°εD where ε is ...
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4answers
79 views

What does electrical potential at a point mean?

From my understanding, potential difference (or voltage) between point A and point B is the difference in electrical potential at the two points. The potential difference is also, the work done per ...
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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
36 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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4answers
61 views

Capacitor connected to battery at one end

I was recently solving a problem that involved a circuit with a capacitor that was connected to a battery at one end(the second plate just had a wire which didnt lead anywhere).  In the solutions it ...
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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 ...
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1answer
88 views

Why is the constant of proportionality in Gauss's law exactly $1/\epsilon_0$

$\epsilon_0$ is epsilon naught, or permittivity of free space. Let me preface this by saying that I've just started to learn about electromagnetism. When I first saw Coulomb's law, I was incredibly ...
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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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1answer
46 views

Magnetic field from displacement currents in a capacitor, and an applied exterior magnetic field

If an exterior magnetic field ($B$) is applied to oppose or support the magnetic field produced by the displacement currents ($B_D$), what would happen to the electric field within the gap? And the ...
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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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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
48 views

Internal energy of dielectric

I have a plate capacitor with a given charge. It is then dipped in a dielectric fluid and I must determine which height the fluid reaches (all the necessary parameters are given). I can solve this ...
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0answers
27 views

Can charge and potential be related via an integral equation?

The potential at $x_0$ generated via a point charge $q$ at $x$ is (proportional to) $-\frac q{\lVert x_0-x\rVert}$. Now suppose we have a charge density function $f$ and want to work out the ...
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33 views

Electric flux through each of the sides of the cube at point a

Charge q is very close to vertex a, so I'm treating it as if it were on vertex a, and I'm trying to get the flux going through the 3 surfaces intersected at g, and the answer my book gives me is 1/8 q/...
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0answers
26 views

Can Newton’s law of gravitation and electrostatic force be related? [duplicate]

I’m very new to physics and have noticed that Newton’s law of gravitation and the electrostatic force formulas look similar. Is it possible they are related? Can the charge of particles be interpreted ...
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2answers
112 views
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1answer
20 views

From where energy comes for the heat released when direction of electric field is changed with a dipole placed in the field

This is an example problem in my book. Forget about the values. Initial anf final(after heat is released) conditions in this problem are same, ie, dipole moment and electric field are in same ...
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0answers
53 views

Eletric potential outside a conductor sphere [closed]

During my chemistry graduation, my Physics III professor gave to us an exercise that would worth an adition in the final mean. Well, I've finished the graduation, and the exercise was forgoten until ...
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1answer
23 views

Electric Potential-Electric Field Relationship

In my book its given-At point A(closer to electric field) the potential is v but at point B(farther from electric field) potential is v+dv.How is it possible as we know that potential decreases if we ...
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1answer
73 views

Can charge move without accelerating?

According to Wikipedia : "An electric potential (also called the electric field potential, potential drop or the electrostatic potential) is the amount of work needed to move a unit positive charge ...
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1answer
54 views

Electromagnetic Wave (Without Magnetic and Electric Field)

As I know, every electromagnetic wave has magnetic and electric field component (perpendicular to the direction of wave). I have a doubt about this, as a hot iron bar also emits EM waves, and as ...
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2answers
59 views

Potential inside a uniformly charged spherical shell [closed]

If electric field inside the uniformly charged spherical shell is zero then how potential will be a non-zero constant equal to potential of shell, since there is no need to do work in moving a charge ...