All Questions
22
questions
2
votes
1
answer
29
views
Energy in Dielectric Medium as a Sea of Dipoles
Simply, why is the energy density in a dielectric medium = $\frac{1}{2}K\epsilon_oE^2$ where K is the dielectric constant of the dielectric medium?
Working proof
Consider a capacitor that is charged ...
- 35
0
votes
2
answers
34
views
For a plane isolated capacitor with a dielectric slab partially introduced inside it, what's indpendent of the medium? $\mathbf E$ or $\mathbf D$?
Say we have an isolated capacitor with charge $Q$ and a dielectric slab, $\varepsilon_r$, partially introduced between the capacitor's plates, then, I'd say the displacement vector should be the same ...
- 296
1
vote
1
answer
29
views
Charging capacitor moving with respect to the dielectric
Suppose I am charging a capacitor, so that a magnetic field is generated. This capacitor is placed inside a dielectric material with permittivity $\epsilon$ and then it is moved parallel to it's ...
- 49
1
vote
1
answer
91
views
Does the current inside a capacitor with dielectric becomes zero, if a DC (constant)voltage is applied?
Imagine a capacitor with dielectric with conductivity $\sigma$ and constant voltage source with voltage applied say $V$ is applied to it's ends, now using Ohm's Law we have $ \vec{J} = \sigma \vec{E}$....
0
votes
1
answer
27
views
Finding potential difference for one side of a parallel plate capacitor with dielectrics in parallel [duplicate]
I'm doing some homework problems and there's a question that asks for the potential difference of the left side of a parallel plate capacitor that looks like this:
...
- 1
0
votes
1
answer
155
views
Is an electrical capacitor ever possible to exist in a perfect vacuum space?
Fig.1 Magnetic field outside the plates of a charging capacitor
This question could be rephrased as:
Does a non-ideal capacitor have a magnetic field outside its plates after it is fully charged?
It ...
- 4,170
1
vote
2
answers
109
views
For capacitors, why does the dielectric need to be inserted at a small constant speed?
Likely a very silly question.
I am aware that there is an attractive force from a charged parallel-plate capacitor in an open circuit without battery pulling the dielectric in, and that a decrease in ...
- 13
0
votes
2
answers
895
views
Surface charge on dielectric interface
What I have in mind is a system that consists of a capacitor filled with two dielectric materials, one of them with dielectric constant $\kappa_1$ and the other with $\kappa_2$. The capacitor is ...
- 11.9k
0
votes
1
answer
202
views
Does the dielectric constant changes as the voltage is applied in every dielectric material?
As the voltage is applied at both sides of the dielectric material(ex. front surface +5V and rear surface 0V), the energy is stored in the material, right?
I heard it's because the dielectric ...
0
votes
1
answer
152
views
$E$-field between dielectric and plate in parallel plate capacitor and Feynman's claim
Feynman says about $E_{0}$ below
Note that the field $E_{0}$ between the metal plate and the surface of the dielectric is higher than the field $E$; it corresponds to $\sigma _{free}$ alone.
$\...
- 1,292
0
votes
0
answers
539
views
Fringe fields do not explain the origin of the force pushing dielectric slab inside a capacitor?
In the problem of a dielectric slab being inserted between the plates of a parallel plate capacitor, it is usually argued that the origin of the inward force acting on the slab is the fringing ...
- 50
0
votes
2
answers
1k
views
Effects of Dielectric on the Electrostatic Potential Inside a Capacitor
Let's consider two identical capacitors (same geometry) with the same applied DC voltage, but with different dielectrics.
Is the electrostatic potential function V (y) (with y = distance with ...
- 1,319
1
vote
2
answers
502
views
Force on dielectric on pulling it out from capacitor
This is the text from Griffiths Electrodynamics for calculating force on dielectric on pulling it out from capacitor when the capacitor is connected to Battery so that voltage of capacitor is fixed:
...
- 129
0
votes
1
answer
391
views
Is it possible to create and control a magnetic field in a dielectric material?
A capacitor is usually formed by an insulater between two conductive plates. By applying voltage difference between the plates we create an electric field within the insulator in one direction. If you ...
- 175
0
votes
2
answers
218
views
What happens to a system of capacitors when a dielectric is inserted into one of them?
sorry for my English.
While doing some homework I've stumbled upon this "circuit":
the system is connected to the same potential difference through a generator that is connected to points A ...
- 55