The ability of an object to store electric charge.

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64 views

Intuitive explanation for uniform electric field between capacitor plates

Could anyone explain why the intensity of the electric field between plates of a charged capacitor is constant? Moreover, the varying the distance between plates doesn't change the electric field ...
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1answer
44 views

Why don't charges build up on wires like plates of a capacitor?

Suppose you have a parallel plate capacitor and you want to charge it by using a battery. You will connect the plates with the two terminals of the battery. Now my book says that the charges will get ...
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1answer
22 views

Connecting spheres of different capacitance

If I connect a sphere of capacitance $C_1$ to a charged sphere of capacitance $C_2$, will the charge be distributed evenly on both spheres (is the charge density going to be equal on both spheres?). ...
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0answers
34 views

Capacitance as integral of electric field [duplicate]

My question refers to part of Ex. 1.17 in Jackson, 3rd Ed.: A volume $V$ in vacuum is bounded by a surface $S$ consisting of several separate conducting surfaces $S_i$. One conductor is held at ...
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1answer
24 views

What would occur between the parallel plates of the capacitor?

In capacitors dielectric materials are sometimes inserted between the parallel plates. What would happen if a diamagnetic, or a paramagnetic material is inserted between the parallel plates of a ...
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0answers
26 views

What is meant by short circuit in capacitor?

I can't understand the mechanism of short circuiting in a capacitor. How will it come to know me that the capacitors are short circuited
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0answers
28 views

Capacitors in space [closed]

I'm new here and I have a question for all of you. What happens to a capacitor in open space? There are different kind of them, which one of these is better to use there? And... We know that if we ...
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0answers
36 views

How inversion layer shields electric field?

This question is somewhat relating to electronics but I think it fits better with physics. The leccture here (slide 13) shows that the gate to body capacitance (Cgb) in linear region is 0. However, ...
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2answers
75 views

Discharging a capacitor

Suppose I have a charged capacitor, meaning there's a voltage (electric potential difference), say, $2V$, between its two plates. We don't know the electirc potential of the individual plates, right? ...
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0answers
31 views

Regarding the zero internal electric field in a conductor (electrostatic case)

Let's say we have a homogenous electric field in the $z$-direction. For computational simplicity let's say we have a thin sheet of metal covering entire the $x$-$y$ plane. The answer here is straight ...
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2answers
76 views

Energy changes due increasing plate separation of unconnected charged capacitor

If a capacitor is charged by a source with constant voltage, $V$, the energy, $W$, stored by a capacitor of capacitance $C$ is given by: $$ W = \frac{1}{2} QV = \frac{1}{2} V^{2}C = \frac{Q^{2}}{2C} $...
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18 views

How are the charges on the plates of a capacitor distributed?

Given a specific overall amount of energy a rectangular parallel plate capacitor stores what number of atoms on a specific plate would have any given specific charge?
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1answer
20 views

By which equivalent circuit (RC serie or RL serie) can I substitute the following circuit?

I was trying to solve the following question: "Assuming that ๐‘ = ๐Ÿ๐ค๐›€, ๐‚ = ๐Ÿ๐›๐…, ๐‹๐Ÿ = ๐Ÿ”๐ฆ๐‡, ๐‹๐Ÿ = ๐Ÿ‘๐ฆ๐‡, ๐ž ๐›š = ๐Ÿ๐ŸŽ๐Ÿ’ rad/s, tell if the circuit can be substituted by an equivalent RC ...
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1answer
51 views

What happens when an AC source is connected to a capacitor and a LED?

When a DC source is connected to a capacitor and a LED, and the voltage is removed when capacitor is charged, the capacitor supplies current to it for some time. What happens if this DC source is ...
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1answer
38 views

Principle of mutual capacitive touch screen

I'm curious about how the mutual capacitive touch screen works, so I did some research on internet and found an excellent explanation: youtube video. According to the video, this is how the mutual ...
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0answers
24 views

Circuit with capacitor and battery- why same voltage?

If we connect a capacitor and a battery in the same circuit, what makes the charge move until the voltage on the capacitor is the same as voltage on battery?
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0answers
53 views

Minus sign in analyzing RC with changing emf circuit?

I'm learning electromagnetism from Purcell's book. He say that if we have the following circuit: $$-\frac QC + RI = \mathcal E_0\cos\omega t~,\quad I = -\frac{\mathrm dQ}{\mathrm dt} $$ The ...
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1answer
37 views

main cause of self charging of unshorted capacitors?

In the lab, we keep all of the high voltage capacitors shorted when not in use, and rightfully so. They tend to spontaneously charge when left for some time and become extremely dangerous. while the ...
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2answers
46 views

How do charges accumulate even though current flows through a capacitor?

I don't understand why do charge accumulate on each plate of capacitor.I learned about displacement current which flows through the gap of the capacitor and this makes the circuit continuous.But why ...
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1answer
31 views

Self-Capacitance of Disc [duplicate]

I was reading a paper today modeling capacitances, and came across self-capacitance of a disc. After skimming google, it looks like this is defined as "the capacitance between the object itself, and ...
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1answer
33 views

Does the charge leakage of capacitors lead to photon emission?

Capacitors will leak charge over time. This charge is basically electrical current leaking through insulating layer of the capacitor. I am wondering, if there is some emission of photons as there is ...
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1answer
29 views

Force between plates of a capacitor with dielectric a battery

My teacher told me that the force will increase $k^2$ times, where $k$ is the dielectric constant, but I don't see how. To start with, with no dielectric, the force between the plates is given by $\...
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3answers
26 views

How do you find the charge and potential difference of a single capacitor? [closed]

Here is what the diagram of the capacitors look like: 5.00 ยตF 6.00 ยตF ---| |--------| |--- ---| |--------| |---- 2.00 ยตF 4.00 ยตF NOTE: The system ...
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2answers
29 views

Potential difference between two assymetrically charged plates

What is the potential diff between two plates of charges $q_1$ and $q_2$ ($q_1$ $>$ $q_2$)? I know the equation is $V = \frac{q_1-q_2}{2C}$ where $C$ is the capacitance of the system but how has ...
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0answers
15 views

Electrostatic energy of the system

Problem : $(A)$ There are two thin concentric metallic shells of radius $a$ and $b$ $(b>a)$. Inner shell carries a total charge $Q$ and the outer shell carried a total charge $โ€“Q$. Calculate the ...
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1answer
55 views

Why can't we use a capacitor to detect electrons in the electron double slit experiment?

So, basically I have been learning Quantum Mechanics online and I leant about the double slit experiment with electrons, wherein if you try to detect an electron with a light source having wavelength ...
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1answer
37 views

Force between the plates of a capacitor

As we know that the electric field between two parallel plates of a capacitor is $$E=\frac{\sigma}{\epsilon_0}$$, so the magnitude of force exerted by one plate on the other should have been $$F=QE$$. ...
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1answer
27 views

why potential becomes equal when capacitor are connected

If we have a circuit as shown in which two capacitor are connected of unequal potential. Now if we close the switch the charge will flow till potential becomes equal. But as we know $Q=CV$, $V=Ed$...
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1answer
24 views

Final potential difference between plates of capacitor [closed]

If the plates of a parallel plate capacitor are given charges 4Q and -2Q . The capacitor is then connected across an uncharged capacitor of the same capacitance as first one (=C) . Now we have to find ...
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2answers
96 views

What moves the charges between capacitors?

Suppose I charged two capacitors to charges Q1 and Q2. By charging a capacitor to charge +Q , I mean that one plate acquires a net charge +Q and another plate acquires a net charge -Q.The capacitors ...
2
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2answers
60 views

Are these capacitors parallel or in series?

I am a bit confused. The authors say these conductors are parallel when the switch is on. But to me it looks like they are in series since the handle is insulating. How can you explain that they are ...
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1answer
23 views

Different charges of plates of parallel plate capacitor

Suppose the plates of a parallel plate capacitor have charges +2Q and -Q initially. Then if they are connected with a battery of emf V what will be the charge distribution on the plates of capacitor? ...
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0answers
27 views

AP Physics 1/2- Electrostatics Capacitor [closed]

I recently took a physics exam over Electrostatics Capacitor and was unsure about a couple of questions. the test was free response and I had to explain. Please tell me if my answer and reasoning ...
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1answer
15 views

Relyance of plate distance on the capacitor equation

I am studying capacitors and i cannot seem to understand why the increase/ decrease in voltage and distance between the plates would affect the capacitor's abillity to store charge. Can anyone help??
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33 views

Dynamic energy of capacitors in circuit

If I have 3 capacitors and 1 battery in a circuit how should I connect them in order to have maximum dynamic energy, when I connect them with the battery? Parallel or in series?
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0answers
27 views

Is it possible to get an analytic expression of the capacitance for this geometry?

Here is the geometry I'm talking about: Assume the red rectangle is at some constant potential V, like 10 Volts, and the blue is at ground. We can assume that the rectangles extend infinitely (to ...
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3answers
58 views

Finding equivalent capacitance between A and B, [closed]

Following is the question, asked is to find equivalent capacitance between A and B. I've tried couple of times and getting 7/3 micro farad as the answer while the correct answer is 8/3 micro farads. ...
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0answers
14 views

Charges on outer faces of parallel plate capcitor

Can there be charges on outer charges of a parallel plate capacitor if both the plates are initially charged by different amount and then connected with a battery.
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21 views

Where will the charge be stored in this capacitor?

A capacitor whose charged plate is hemispherical,concave side is facing each other then will the charge be stored on concave surface like all other capacitors(i.e. parallel plate,cylindrical etc.) or ...
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1answer
29 views

Mechanism by which a capacitor is charged, using surface charges

I want to gain a deeper understanding as to how a capacitor actually gets charged. Consider a situation in which an uncharged parallel plate capacitor is connected to a battery using two wires. I ...
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4answers
81 views

Current in inductor just after switch is closed

I have read that the current in an inductor resistor circuit just after closing the switch is zero. This is derived by finding the differential equation in terms of current by using KVL. Is this true ...
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0answers
38 views

Grounding system of conducting plates

So, I always make mistakes on problems such as this (the grounding part), so I'm hoping someone could really explain to me how the process works . There are n large parallel plate conductors carrying ...
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1answer
72 views

Can we “use” a capacitor while simultaneously charging it?

I know that capacitors can be charged to work like a battery . But I wanted to know whether we can charge a capacitor while it is in use ( given that the current supplied to it is more than what it ...
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1answer
33 views

Charging capacity and capacitance of a conductor

I know that charging capacity of a conductor is the maximum charge a conductor can hold And capacitance is the ability of a conductor to hold charge in a given potential . But how are these two ...
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0answers
41 views

What is space charge Capacitance of diode?

Most of the books say that $p$-type and $n$-type materials of diode act as parallel plates of space charge capacitance were as the depletion charges (uncovered) act as dielectric. Then why do these ...
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1answer
30 views

How to obtain $2\pi\epsilon_0$ when computing capacitance per unit length of a system?

To make my question more clear, I will use an example to illustrate it. Consider an infinite conducting plane, with a long conducting cylinder of radius $R$ at a distance $h$ away from it, with the ...
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1answer
47 views

Is the $C$ rating of a battery a measure of Capicitance or Charge?

I have become confused as to the meaning of what a C rating of a battery means. My understanding is that because a C rating is measured in milli-ampere hours the units should cancel to be a unit of ...
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2answers
28 views

AC circuit having a capacitor

Consider a parallel plate capacitor connected to an AC. The current in the circuit leads the emf by $\pi /2$. My question is, what does it mean that the current lead the emf by $\pi/2$? Does it ...
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1answer
48 views

capacity of the capacitor in two states

what is the difference between the capacity of the capacitor when we ignore the effect of the sides and in reality?(with regarding side effcts) this question is from"fundamental of physics by 'rex ...
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24 views

May the total charge in a supercapacitor be different using unipolar and bipolar voltage power supply?

Consider a supercapacitor where a Helmoltz double layer is formed at each of the 2 electrodes, which is like having 2 capacitors mounted in series, but with different polarities. The total charge at ...