All Questions
Tagged with capacitance potential-energy
61
questions
0
votes
2
answers
174
views
How Do Dielectrics Affect Electric Potential Energy in Capcitors?
I am currently learning about dielectrics and capacitors in my physics class and part of what I have learned is conflicting.
For starters the book says that capacitors do not interrupt current flow, ...
12
votes
5
answers
4k
views
Why do we say that electric potential energy is stored in the electric field?
I have been learning electrostatics and came across capacitors. I don't really get why do we say energy is stored in electric field rather than in the charges upon which we or the battery does work. I ...
- 129
0
votes
1
answer
184
views
What happens to the potential energy stored in a capacitor when the plates are pushed closer together?
A capacitor is charged up with a battery and then removed from the battery. What will happen to the stored potential energy when the plates are pushed closer together?
My attempt:
Let the subscript $1$...
- 100
0
votes
4
answers
208
views
What happens to the kinetic energy of an electron in a current?
When a capacitor is charged, electrons flow from the battery terminal to the plate of the capacitor, as the electrons flow through the wire, they must be having some kinetic energy?
So, when the ...
2
votes
1
answer
284
views
Energy stored in a space with electric field is $\tfrac12 \varepsilon E^2$ per unit volume. Why?
I'm a high school student and my book says that once it has been established that a region containing electric field $E$ has energy $\tfrac12 \varepsilon E^2$ per unit volume, the result can be used ...
- 21
0
votes
2
answers
99
views
Energy stored in a capacitor filled with dielectric
while calculating the energy stored in a capacitor of capacitance C to charge up to a voltage $V_{0}$ we say that the work done is move a infinitesimally small amount of charge $dQ$ from the negative ...
- 169
1
vote
1
answer
70
views
Why was $U=\frac{1}{2}QV$ not listed in my book as the potential energy of a capacitor?
$$U=\frac{Q^2}{2C}\tag{1}$$
$$U=\frac{1}{2}CV^2\tag{2}$$
$$U=\frac{1}{2}QV\tag{3}$$
$(1)$ and $(2)$ were listed in my book. However, I think $(3)$ is also a valid formula. Is there any particular ...
- 1,018
0
votes
1
answer
117
views
Can a grounded capacitor, which was charged originally, store infinite charge?
Let us consider the following arrangement. Two infinitely long parallel plates separated by $d$. Let their cross-sectional area be A. Energy stored in a 2 two plate system upon calculation can be ...
- 1,161
2
votes
2
answers
92
views
Energy to assemble a capacitor [closed]
Consider a body $\Omega$, inside of which a dielectric is present. We have a conductor on $\partial \Omega$.
I am trying to understand the computation of the energy required to assemble the entire ...
- 133
2
votes
1
answer
193
views
Alternate derivation for energy stored by a capacitor [duplicate]
The usual derivation of energy stored in a capacitor is as follows
$$dU=Vdq\\dU=\frac QCdq$$$$U=\frac12\frac {Q^2}C\equiv\frac12QV\tag1$$
Where $V$ is the final potential. Explicitly
$$V=-\int\vec E\...
3
votes
1
answer
214
views
How does a capacitor 'transfer' voltage/charge from one plate to the other when the circuit is open?
I am new to electrical engineering, electronics and capacitors specially.
I am having trouble understanding why in the following circuit, the voltage is the same in both plates, acting as a wire, when ...
user355227
0
votes
1
answer
25
views
How different material capacitors can develop different charges?
I learned in a video tutorial that same battery could produce different charges based upon different capacitance of the materials used.
Also A capacitor fully charged has the same voltage as the ...
1
vote
2
answers
185
views
How is the total energy conserved when an electron moves through a plate capacitor and gets accelerated?
We assume that the electron enters the plate capacitor with a constant velocity. If we also assume that the electric field is homogeneous and edge effects can be neglected, a force along the y-axis ...
- 47
0
votes
1
answer
74
views
Electrostatic energy of capacitors and point charges
A number of questions have previously been asked about electrostatic energy for a system of conductors. But I am still confused about this topic.
Suppose we have an ideal capacitor consisting of two ...
- 13
0
votes
3
answers
512
views
What is the correct derivation of energy stored in parallel plates capacitor?
I am little confuse in deriving the energy stored in the capacitor. I read two different derivation in totally different way but yet getting the same value.
Here they have calculated work done by ...
- 121