The capacitance tag has no wiki summary.
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Capacitance of a conducting disk
I'm reading this(PDF) derivation of the capacitance of a thin conducting disk. The surface charge density of such a disk can be shown to be:
$\sigma(r) = \frac{Q}{4\pi a\sqrt{a^2 - r^2}}$ (in ...
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152 views
Charge on capacitor plates in series combination?
Suppose 2 capacitors are connected in series, the plates connected to the battery terminals receive charges $+q$ and $-q$, and the isolated plates in the combination receive equal and opposite charges ...
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78 views
Capacitor Charging and Discharging when connected to the ground
When we charge a capacitor using a battery and then remove the battery, the plates of capacitor becomes charged. One holds positive charge and the other one gets equal negative charge. o. k. ?
Now ...
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150 views
Effect of charges near a parallel plate capacitor
If I charged a parallel plate capacitor. And then, I insert a charged body near one of the plates.
Will there be any interactions like attraction or repulsion?
What if I disconnected the battery?
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533 views
Capacitor charging and discharging
I have a conceptual question.
The circuit is shown below. Let us assume that the capacitor shown in the figure is of 2.2 micro-farads having rated level of 5 volts and we decide to charge it up to 2 ...
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246 views
Capacitors and resistor in series and in parallel [closed]
In this circuit, are $R_1$ and $C_1$ in parallel and $C_2$ and $R_2$ in series?
I have think that the currents that flows trought $R_1$ isn't the same that flows trought $C_1$ so, $R_1$ and $C_1$ ...
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456 views
If we charge a capacitor can we discharge it into a battery?
I have read that we can charge a capacitor using a battery, but can the vice versa happen? My project needs to show a battery being charged through a fully charged capacitor.
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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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What's the right way to calculate charge on a capacitor?
How much charge is on each plate of a 4.00-F capacitor
when it is connected to a 12.0-V battery?
I said 2.4 x 10^-5 C because there are two plates of a parallel plate capacitor. But the key said only ...
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3answers
455 views
When I connect two charged capacitors side by side, what will be the voltage across them?
Say, I have two charged capacitors, one 3mF and one 2mF. The voltage across them are 20V and 30V respectively. Now if I connect the two capacitors side by side as shown below, what will be the voltage ...
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57 views
Capacitors discharging in series [duplicate]
If you connect positive plate of a charged capacitor to ground, it doesn't get discharged. Now consider $4$ capacitors of equal capacitance connected in series to a $10\, \mathrm{V}$ battery. Connect ...
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How we approach RLC circult from RLGC model?
In the text, it introduces a practical model to investigate a transmission line (like BNC cable), it considers the transmission line has resistive $R$, inductance $L$, conductance $G$ and capacitance ...
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57 views
Why does the area of the plates affect the capacitance?
Why does the area of the plates affect the capacitance? Lets say I have a parallel plate capacitor with a charge of 10C and a potential difference of 5V. By the definition $C=Q/V$, the capacitance is ...
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4answers
103 views
Capacitance of a capacitor
Why does the capacitance of a capacitor increase if the distance between the two plates of a parallel plate capacitor is decreased? I think, with decreasing distance between the two plates, the force ...
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1answer
310 views
how to calculate electric relative permittivity of fluid or medium
I am confusing in calculating permittivity of the fluid. Permittivity differs from one fluid to another.
$$\varepsilon=\varepsilon_r\varepsilon_0$$
Since it is an electrical property combined with ...
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1answer
27 views
Finding the Steady State Charges
Here the problem states to find the steady state charges on the condensers.
But here the capacitor have a resistance in parallel connection , so how can we distribute the potential drop across ...
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1answer
19 views
Work due to introducing a dieletric in a capacitor
I have a doubt about a couple of exercises tha asks to find the work done on introducing a dieletric between the plates of a capacitor. Yes, this question is in the general case, how do we procede? I ...
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Experiments related to Capacitor and Prism [closed]
I want my students to learn experiments on prism and capacitor. Can you provide me different experiments related to prism and capacitor (except charging and discharging). The experiments will be given ...
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Capacitance of this unusual capacitor
This capacitor is composed of two half spherical shelled conductors both with radius $r$. There is a very small space between the two parts seeing to that no charge will exchange between them.
...
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2answers
59 views
Inserting metal into parallel plate capacitor
The plates of an isolated parallel plate capacitor with a
capacitance C carry a charge Q. The plate separation is d.
Initially, the space between the plates contains only air.
Then, an ...
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2answers
69 views
Flashlights and Capacitors
Why capacitors are used in flashlights of cameras instead of attaching the light directly to the battery? How this leads more light?
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4answers
191 views
Energy Gain with capacitor?
I have a question about energy gain in capacitors. Assume the following system:
As the electron gets accelerated inside the capacitor, it will have more kinetic energy coming out than going in. But ...
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3answers
805 views
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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What is the principle of active voltage balancing/equalizing device?
I am wondering about active voltage sharing devices. Their purpose is to equally divide voltages on slightly unequal super-capacitors. I found some papers like this, but it is too scientific.
I want ...
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1answer
48 views
Where are exactly the charges of charged capacitor?
a capacitor is connected to a battery and is charged, are there charges inside the wires or they just accumulate on the surfaces of capacitor?
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Can you find the potential between capacitor plates with liquid dielectric in the capacitor's frame? [closed]
A magnetic field B is applied perpendicular to the plates of a capacitor whose parallel plates are separated by d. An electrically neutral liquid of relative dielectric constant k flows between the ...
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The heat dissipated in the resistance in a C-R circuit [closed]
If an uncharged capacitor (of capacitance $C$) is charged by connecting it with an ideal battery and a resistance R (The capacitor and resistor are in series combination ), then the heat generated in ...
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A problem of missing energy when charging a second capacitor
A capacitor is charged. It is then connected to an identical uncharged capacitor using superconducting wires. Each capacitor has 1/2 the charge as the original, so 1/4 the energy - so we only have 1/2 ...
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50 views
Energy lost when charging a capacitor: where does it go? [duplicate]
I've been wondering for a while where half the energy goes when charging a capacitor... Most textbooks say that it is dissipated through resistance in the wires, but what happens if, say, the wires ...
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262 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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2answers
59 views
Why isn't this capacitor charging?
Let's say you have a parallel plate capacitor and you connect one plate to the positive terminal of a battery and the other plate to the negative end. So this is like a static situation, you have a ...
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3answers
134 views
Can I charge a capacitor using 2 batteries?
1 capacitor, 2 separate batteries (Battery A and Battery B).
Connect A+ to one side of the capacitor and B- to the other side of the capacitor.
A and B are not connected, there is no closed circuit.
...
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0answers
121 views
Energy stored in charge capacitor [closed]
Two identical parallel-plate capacitors, each with capacitance $C$, are charged to potential difference $V$ and connected in parallel. Then the plate separation in one of the capacitors is doubled.
...
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2answers
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Why does a capacitor discharge?
Suppose a charged capacitor (parallel plates), the negative and positive charges on two plates attract each other. Which force cause the negative charge carriers (electrons) move through the circuit ...
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What defines the maximum charge a capacitor can store?
The formula for a capacitor discharging is $Q=Q_0e^{-\frac{t}{RC}}$
Where $Q_0$ is the maximum charge. But what property defines the maximum charge a capacitor can store?
If it depends on ...
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1answer
96 views
Calculate Capacitance in Series AC Circuits?
I'm supposed to calculate the capacitance of an unknown capacitor in series, but I'm not sure exactly which equation to use.
I know the voltage across the resistor (Vr), voltage across the capacitor ...
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1answer
136 views
Parallel capacitors without battery. Does charge flowing after a dielectric input?
If I charge two capacitors which are connected parallel $[$the minus (-) of the one opposite to the minus (-) of the other and the plus(+) of the one opposite to the plus (+) of the other.$]$, will I ...
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221 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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Two capacitors sharing charge
My two capacitors:
I have these two capacitors ($C_1 = 3\mu F, C_2 = 4\mu F$) both initially under 19 volts. Then, I added a dielectric with $k=4$ at $C_1$ and entire ...
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1answer
42 views
What happens to this energy of the capacitor?
Let's say you have a charged, isolated parallel plate capacitor with a certain voltage. My book says that if you insert a dielectric, the voltage drops. However, that would require the energy between ...
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88 views
Is it possible to charge a capacitor to any potential? Does it depend on the dielectric placed between them?
Is it possible to charge a capacitor to any potential? Does it depend on the dielectric placed between them? Or, are there other factors affecting it?
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Is there a deep reason why springs combine like capacitors?
I was solving a practice Physics GRE and there was a question about springs connected in series and parallel. I was too lazy to derive the way the spring constants add in each case. But I knew how ...
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1answer
57 views
Capacitor and hydraulic analogy
Would anyone kindly explain me the hydraulic analogy for the working of a capacitor w.r.t the article of wikipedia http://en.wikipedia.org/wiki/Capacitor... Help!!
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390 views
Capacitor circuits with light bulb
Let's say we have a normal circuit with a light bulb, with wires and a battery.
When one places a capacitor in this circuit, how is the light bulb able to light up, even when the capacitor prevents ...
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1answer
148 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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322 views
Where's the energy in a boosted capacitor?
Suppose I look at a parallel plate capacitor in its rest frame and calculate the electrostatic energy, $E$.
Next, I look at the same capacitor in a primed frame boosted in the direction perpendicular ...
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2answers
90 views
How can you calculate (or convert) the Wh of a capacitor whose energy is given in Farads
When trying to compare the energy in a battery to the energy in a capacitor, the units don't match up. How can one compare a battery whose Ah are 10 and Voltage is 3 (for a total of 30 Wh) to a ...
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What happens to capacitor’s charge when the plates are moved further apart?
In my physics textbook there is an example of using capacitor switches in computer keyboard:
Pressing the key pushes two capacitor plates closer together, increasing their capacitance. A larger ...
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Is this really how a capacitor works? Why doesn't it behave like a resistor?
My book says a capacitor is two conducts being connected by an insulator. Now let's take a parallel plate capacitor to simplify the problem I have.
Suppose I got two parallel plate capacitor in ...
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How would I explain a farad being a second per ohm?
The farad has many alternative representations in SI. I can comprehend some of them. For example, a capacitance of 1 farad means that it will take a single coulomb to create a single volt between the ...
