# 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 ...
3answers
94 views

### 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 ...
1answer
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 ...
2answers
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 ...
1answer
474 views

1answer
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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 ...
0answers
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 ...
0answers
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 ...
0answers
10 views

### $C$-$V$ 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 ...
0answers
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 ...
2answers
168 views

### 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 ...
1answer
23 views

### 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 $C$...
0answers
43 views

### 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 (...
3answers
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 ...
1answer
39 views

### 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 ...
2answers
316 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? ...
1answer
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 ...
1answer
45 views

### 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 ...
3answers
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 ...
2answers
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 ...
0answers
67 views

### 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 ...
1answer
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-...
0answers
39 views

### 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 ...
1answer
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 ...
2answers
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 ...
1answer
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 ...
2answers
193 views

### 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 ...
2answers
37 views

### Capacitors connected in parallel with a switch attached [closed]

What does it mean when they say capacitor reaching equilibrium?
2answers
131 views