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 ...

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29 views

What do we mean by this statement : “some positive charge is put on a metal piece”?

What do we mean by this statement : "some positive charge is put on a metal piece" ? (I know it will be distributed on the surface of the metal piece, if metal is isolated.) Electrons are ...
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0answers
29 views

Half infinite conductor and two charges [closed]

We have a half infinite conductor that fills half the space in the area left of the xz-plane (so $y>0$). We put two charges in the space right of it, one charge $+q$ at $y=d$ and one $+q$ at ...
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1answer
25 views

What happens when a conducting plate is grounded?

(1) When I ground a conducting metal plate, is all the charge on the plate transferred to earth? By this I mean charge on surface of the plate and charge inside the plate. Inside metal plate there ...
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5answers
51 views

If the electrostatic potential is zero, why doesn't the electric field have to be zero?

I thought the relation between the electrostatic field $\vec E$ and the electrostatic potential $V$ is as follows: $$\vec E = - \nabla V$$ Thus, when $V$ is zero, $\vec E$ is also zero.
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4answers
273 views

Surface charge density for an off-centre charge in a spherical shell?

How would I evaluate the surface charge density on the inner and outer surface of a neutral, spherical, conducting shell which has an off-centre charge $q$ inside? I believe that we can not use the ...
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2answers
30 views

Why does the sphere with the smaller radius (r1) have the greater charge density?

Suppose two charged conducting spheres of different radii $r_1$ and $r_2 > r_1$ are very far apart but connected by a conducting wire. Why does the sphere with the smaller radius $(r_1)$ have the ...
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1answer
39 views

Sign of Gaussian surface that encloses negative charge

I can't solve a contradiction that have appeared in my head. Let's assume we have a negative charge, if we enclose it by a spherical surface and $A$ is surface of the sphere, then we will have ...
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0answers
11 views

Calculating the amount of charges for an object that is electrostatically induced

Induction is one of the ways to get an object electrostatically charged. While positive charges accumulate on one side, negative charges accumulate on the other side for an object in an electric ...
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0answers
40 views

is speed of light is the limit [closed]

If an electron is away from a proton about 1 kilometer and the proton is fixed what will be the velocity of electron when they collide? I calculated it its speed was coming out to be more than the ...
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0answers
22 views

Current in discharging capacitor through fixed resistor?

In the textbook I'm using for physics it says that the charge left on the plates of a capacitor after time $t$, that is discharging through a fixed resistor, is $Q=Q_0e^{-t/\tau}$ where $\tau=RC$ is ...
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1answer
39 views

Electrostatic force has longer range than strong nuclear force?

In my revision guide it says that the electrostatic repulsion between protons in a nucleus has a longer (indefinite, actually) range than the strong nuclear force keeping the nucleons together. So I ...
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1answer
53 views

Why is the strong nuclear force > electrostatic repulsion?

In a nucleus there is a gravitational force between the nucleons and also electrostatic repulsion between the protons, and since electrostatic repulson >> gravitational attraction, it follows that ...
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1answer
43 views

Question about particles in electric fields. Homework question

I am currently working on a homework question and I realized that I don't really understand some of the material that we covered so I hoped that you guys can help me clear up some misunderstandings. ...
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0answers
28 views

Uniformly charged sheet and metal rods

A friend of mine asked me a question. Suppose there are two metal rods which are placed in front of a uniformly charged non-conducting plane one after other with their length perpendicular to the ...
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1answer
44 views

Does Earth also move due to some electrostatic forces?

Does the earth experience some electrostatic forces due to other planets...which also make it move? My question is..whether the earth also moves due to electrostatic force of attraction or only due ...
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0answers
18 views

Dipoles and Potential Energy

I was pondering about electrostatics, particularly dipoles. How would one go about calculating the difference in potential energy of a dipole an arbitrary distance away from an arrangement of another ...
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3answers
114 views

Electric field in a conductor

Is it always true that the electric field in a conductor is zero? What would happen if I put a very big charge inside an ungrounded hollow conducting sphere like this image? The charges inside the ...
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1answer
21 views

Understanding the differences and applications of some electrical equations

In preparing for the AP Physics 2 test tomorrow, (the first year this test is being offered, so this material is not easily searchable), I've been doing some reviewing of the equation sheet and trying ...
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1answer
56 views

Calculating the potential of 2 spherical perfect conductors with the image method

I am searching for a way to calculate the potential on the surface of two perfect conductors that are spheres. I am not sure my method is correct. Here is a diagram of what I am studying : They ...
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1answer
56 views

electrostatics and magnetism

Let a square loop be placed in a uniform electric field in a position of stable equilibrium. Then, because of the electric field, if the electric field is in the rightward direction then a positive ...
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1answer
41 views

What is space charge and how to calculate it?

I want to clarify the meaning of space charge. What I know is that the space charge is the total charge in a small region in space. I really confuse this in the ion beam context. Many text book says ...
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1answer
36 views

The definition of mutual capacitance

I am not sure I completely understand the definition of mutual capacitance. Let's say we have two conductors, $A$ and $B$, so that the following holds: Both conductors are isolated. $A$ is isolated ...
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1answer
57 views

Graph of electric potential

In my AP physics guide the graph for electric potential (for a radial field, i.e. point charge) and gravitational potential (for radial field, i.e. point mass) slightly differ from each other and I ...
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1answer
44 views

Graph of energy stored in capacitor?

Question: In an experiment a capacitor is discharged through a constant current. Draw a graph of how the energy stored in the capacitor varies with time. The answer given is: But I seemed to get a ...
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0answers
35 views

How do electric field lines bend?

Electric field lines arise perpendicular to the surface of a conductor and travel away from + charges towards - charges. Is there a more complex and specified definition for these lines? Also why do ...
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1answer
33 views

Charging a capacitor (terminals)

When a battery is connected to a conductor electrons are repelled from the end of the conductor connected to the negative terminal of the battery and flow to the end of the conductor connected to the ...
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0answers
12 views

Why the Amount of electric field generate from any small surface of a body is equal to the electric field generated from remaining surface left out?

Recently I just read one property of electrostatics which states that: The amount of electric field generate from any small surface is equal to the electric field generate from remaining surface ...
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15 views

Integrating Charged Bodies

Why is it possible to integrate charged bodies by first taking a small charge and adding more small charges around it? Wouldn't the similarly charged particles exert an immense amount of force on ...
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3answers
92 views

Electric field or static electric field around a plugged-in lamp cord (when lamp is not turned on)?

When an electrical cord from, say, a lamp, is plugged into an AC wall socket, I'm aware that an electric field forms around the entire length of the cord and even before the lamp switch is flipped on. ...
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1answer
33 views

Electric potential at midpoint?

I understand that if you assume the field is uniform between R and S then you can use E=V/d to get E=(30-20)/(0.5)=20Vm^(-1), so the answer is C (which is correct according to the mark scheme). But ...
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0answers
29 views

Potential Energy of a Molecule

A generic problem asks that we find the total potential energy of a water molecule. Potential energy is given by $\Sigma \ kQ_{1}Q_{2}/r$ where $Q_{1}$ and $Q_{2}$ are the charges of any one bond ...
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1answer
41 views

Calculation & derivation of de-Broglie wavelength [duplicate]

How to calculate the de Broglie wavelength of an $\alpha$ particle that is accelerated through a potential difference of $V$ from rest.
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2answers
58 views

Need help on electric potential definition

I'm having trouble understanding electric potential. In my book it says "an electric force acts on a charge situated in an electric field." I understand this part. Then it goes on to say "If a charge ...
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0answers
34 views

Why does Hauksbee orb or a similar device produce light?

This essentially fits well to the question asked earlier but had to placed as a separate question... An interesting and detailed answer was provided. However, there are few points, originating from my ...
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2answers
69 views

Electric field and flux through a spherical surface inside an uneven hollow charge distribution

Consider a uniformly charged shell and two concentric spherical Gaussian surfaces $S_1$ and $S_2$. ($S_1$ radius is greater than charged shell and $S_2$ radius is less than that of charged shell.) We ...
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1answer
244 views

Is there a difference between Electric and Electrostatic Field?

Is there a difference between Electric and Electrostatic Field? All I know is that they both represented with same law suppose we have a Charge placed at the Origin: ...
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3answers
52 views

Electrostatic field in a vacuum

Can an electrostatic field, the direction of which is constant in space, but the magnitude varies in space, exist in a vacuum?
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1answer
37 views

Electric Field and Neutral Objects

Due to electrostatic induction, when a charged object gets closer to a neutral object, sides of the neutral object can get charged. Thus, a charged object can attract a neutral object. However, is ...
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3answers
33 views

Path followed by a free test charge in an electric field region represent the electric lines of forces?

As we know that if we put any free test charge in an electric field which is moving horizontally then it will experience an repulsive force and move in that direction so by that we can say that for ...
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2answers
183 views

Why do electric field lines start and end at 90 degree at the surface of a conductor? [duplicate]

There is one property of electric lines of forces which states that: Electric field lines start and end at 90 degree at the surface of the conductor. But why is that so? Is there any proof for ...
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2answers
54 views

Electric field due to a finite line charge [closed]

I was wondering what would happen if we were to calculate electric field due to a finite line charge. Most books have this for an infinite line charge. In the given figure if I remove the portion of ...
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1answer
54 views

Where should five charges be placed inside a hollow sphere so as the system has the lowest potential energy? [duplicate]

I want to know the configuration where the system would be most stable.I only know basic Physics & Maths and cannot start solving the problem.I can understand it for 4 charges and 6 charges as a ...
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0answers
30 views

Charged particle inside a hole in a charged layer

The layer $-a\le x \le a$ is homogeneously charged with a electric charge density $\rho \gt 0$ and on the x-axis a thin hole is made. A particle with mass $m$ and charge $q \gt 0$ move on the ...
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2answers
37 views

How does friction product heat?

Suppose there are two similar particle-like objects attempting to "bump" against each other to create friction, they are prevented from colliding against one another due to either electrostatic ...
0
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1answer
24 views

Electric Flux through a lamina

I was wondering what the electric flux would be through a square (or any planar lamina for that matter) if I placed a charge at the centre of the square. I think that it will be 0 since none of the ...
0
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1answer
38 views

The influence of electric potential of a planet to a spaceship

How does the electric potential of a planet influence a spaceship? If a distant planet is at very high potential compared to Earth. A spaceship is sent from Earth to land on the planet. Is the mission ...
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2answers
58 views

Induction in Electrostatics

While solving some problems on electrostatics, I came across this question : Two balls carrying charges of +3 $\mu C$ and -3$\mu C$ attract each other with a force $F$. If a charge of +3$\mu C$ is ...
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1answer
93 views

Physical intuition for quadrupole source

In his Theory of Vortex Sound M. S. Howe defines sources "mathematically" (i.e. dipole is a source that could be described as a vector and than there is proved that it's equivalent to a two point ...
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2answers
32 views

How can plants rooted on the ground become charged?

According to a quote on the physics forum "Plants are usually charged negatively and emit weak electric fields." Reference However this seems to contradict the fact that plants are grounded and any ...
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0answers
50 views

Calculating the electric charge of two spheres knowing their potential

I have a system of two spheres, the first one is at a potential of $ V_1 = 1 V $ and the second one is at a potential of $ V_2 = 0 V $ The distance between them is $d$ and the radius are respectively ...