Questions tagged [capacitance]

The ability of an object to store electric charge.

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Capacitance and energy transfer [duplicate]

Capacitors: Using direct current I apply a voltage, $~V_o~$, to a capacitor of capacitance $~C~$. It acquire a charge of $~Q_o~$. I remove the charging source and I connect both sides of the ...
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Why don't capacitors hold charges on the outer walls of the plates? [on hold]

Suppose I have two metal plates in a vacuum and I give this system some electric charge,the charge would distribute itself according to Gauss law on both the inner and outer walls of both plates...but ...
981 views

Maximum current in LC Circuits [on hold]

Two capacitors of capacitance $C$ and $3C$ are charged to potential difference $V_o$ and $2V_o$ respectively and connected to an inductor, all three in series. Now the switch S is closed. Find the ...
500 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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Why is the electric field of a conducting sheet of charge double the electric field of just a sheet of charge?

I was reading Feynman's Lecture on the Application of Gauss' Law and I came across this: Source This really confused me. What are the "other" charges he talks about? How does the additional field ...
45 views

A Simple RC Circuit [closed]

This is the most simple Rc circuit (i have just started learning) .My questions regarding this is- (This is a dc voltage supply) Will capacitor get charged by the potential drop of resistor or ...
11 views

Engineering physics capacitor [closed]

A long cylindrical conductor has length 1m and is surrounded by a coaxial cylindrical conducting shell with inner radius double that of long cylindrical conductor. Calculate capacitance for this ...
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$C$-$V$ characteristics of MOS capacitors for different material [closed]

For C-V curve below for 3 different materials, (Si, InAs, InSb). What material will be corresponding to curve A/B/C? My understanding is that C is inversely proportional to the dielectric constant in ...
18 views

Force of attraction in capacitor [duplicate]

In a question, it was asked the force of attraction between the plates of a parallel plate capacitor. and it was solved as $$\frac{(1)(C)(V^2)}{2}=(F)(d)$$ $$F=\frac{(1)(C)(V^2)}{(2)(d)}$$ and I ...
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Influence of an external electric field on an uncharged capacitor

Influence of an external electric field on an uncharged capacitor. Fig A shows an uncharged capacitor with no external electrical field. There is no net charge on each of the plates. Since the ...
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Why are the times at which max rate occurs different for the energy of a capacitor and the battery

When charging a capacitor the rate at which the battery provides energy is maximum at $t=0$ but the time at which the rate of increase in the energy of a capacitor is maximum is $t=CR\ln(2)$ (where $C$...
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I got the answer but I suppose I did not understand the question very well [duplicate]

See as per the question, The Inductor pretty much will induce emf due to magnetic field and not due to other coil/current nearby. Thus I used $E= - d(phi(t))/dt$ as the induced emf. Then using (...
345 views

What happens when electrons reach the battery?

We have a capacitor which is connected to a voltage source. The top plate of the capacitor is connected to the positive terminal of the source. Therefore, electrons go from the top plate to the ...
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Doubt in the derivation of Gauss's law in dielectrics

so in the 2nd page,when the dielectric material is introduced the gauss's law becomes $$\oint _ { S } \vec { E } \cdot \vec { d S } = \frac { ( q - q _ { i } ) } { \epsilon _ { 0 } }$$.But my ...
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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? ...
455 views

Differential Equation Of Capacitor Energy In RC and RL Circuits?

I'm having a hard time finding the differential equation for enregy in a capacitor for an RC basic circuit which contains a resistor and a capacitor + the source . I have to start using the ...
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Force in an isolated capacitor when a dielectric slab is introduced [closed]

my question is about capacitance: a dielectric slab is inserted between the plates of an isolated capacitor. The force between the plates will remain unchanged. how? I mean the knowledge I had gained ...
293 views

Potential difference across a capacitor

Look at the above circuit, I didn't get anything of it. Firstly i tried it using Kirchoff's voltage rule, I failed. I'm confused with those batteries. Can someone please explain me the role of those ...
579 views

Charged dieletric/conductor in capacitor

It is a standard problem to consider a dielectric or a conductor between the parallel plates of a capacitor. But what happens to capacity, voltage, charge, inserting between the plates of an ideal ...
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Voltage propagation along a wire [closed]

Let's say you have a wire connected to a device that you can switch between high-voltage and ground voltage. The wire is not connected to anything on the other end. You're observing the voltage in two ...
677 views

Diode-Resistor-Capacitor Circuit Equations

So I took the time to measure the current dependency on voltage of a diode I have. I applied an exponential fit to it, and have a pretty reliable equation (within 1%). I'm interested in how a diode-...
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Why am I getting two different expressions for capacitance? [duplicate]

The question is: A capacitor of capacitance C1 is connected to a battery of potential V0. The battery is then disconnected and a second capacitor of capacitance C2 is connected to the first ...
414 views

What is capacitance, in general?

In circuit analysis software capacitance can be measured between any two nodes of a circuit or of a multiterminal device. In practical terms we take $C_{ij}$, the capacitance between $i$ and $j$ as ...
876 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 ...
748 views

Principle of capacitor

It is said that second conductor reduces the potential of fist conductor and hence increases charge taking ability of first conductor My confusion... As per my limited knowledge it is electric field ...
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One terminal of an ideal voltage source connected to earth->Massive current will flow?

Assume we have a "somewhat" ideal voltage source like a DC power supply powered by mains. Take just one terminal and form a conductive path between it and earth ground. Assuming that no conductive ...