All Questions
Tagged with capacitance forces
16
questions
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Can dielectric slab be used to move an object?
Could a dielectric slab, as in http://www.physicsbootcamp.org/Forces-on-Dielectrics.html:
be placed in a "box" together with a battery and solar panel (for example) where the slab is fixed ...
- 11
1
vote
1
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781
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Trying to understand how to apply Maxwell stress tensor to calculate forces
I'm struggling to understand how to use Maxwell's stress tensor to compute electromagnetic forces acting on surfaces. I'll take problem 8.7 from Griffths Introduction to Electrodynamics as an example.
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- 171
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66
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Where does the factor $\frac{1}{2}$ come from in the force equation $\vec{F}=\frac{1}{2}Q\vec{E}$?
Generally, I have seen equations like $\vec{F}=Q\vec{E}$ which obviously makes sense. However, in the case of a capacitor where the force experienced by each of the plates (having charges $\pm Q$ and ...
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51
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Enhanced capacitance by magnetism?
Consider the first picture.
This is much like a parallel plate capacitor charged by a battery. But instead of parallel plates we are using parallel rings. The rings are attracting each other because ...
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115
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Why does changing the permittivity of the dielectric within a capacitor not have any effect on the electric field opposite the plate?
Utilizing FEMM 4.2, I built a pair of simple parallel plate capacitors, however I oriented them so that the anodes of these capacitors faced each other. As expected, the electric fields of the two ...
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98
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Force on dielectric
I have been taught that the magnitude of the force on a dielectric is $$F=\frac{bε_0V^{2}}{2d}\left(K-1\right)$$ where:
b is the width of the plate.
$V$ is the EMF of the cell to which the capacitor ...
- 292
7
votes
5
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427
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'Simple' capacitor problem
I posted this question because I have a problem in grasping the connection between force on a charge and voltage potential equilibrium. So the problem is the following: we have a charged capacitor ...
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Fringing Field Effect on 2D Capacitor
I am running a relatively «simple» (or so I thought) 2D electrostatic simulation of a parallel plate capacitor where I would like to see the effects of the fringing fields.
Case 1: air exclusively ...
- 111
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206
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Relation between the energy of a capacitor and the force it applies [closed]
I have a capacitor with stored energy $U$. I do not understand the relation $\vec{F}=-\vec\nabla U$, where $\vec{F}$ is the force that the capacitor applies on the charge inside it.
- 555
2
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1
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943
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Force on dielectric slab
My Doubt is regarding the procedure of calculating force on dielectric while it is being inserted between the capacitor plates (with or without battery).
This is the theory behind it.
Consider a ...
- 127
1
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93
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The force needed to move air for electrostatic speakers/headphones
I am trying to determine what force is needed for the membrane of an electrostatic speaker (headphones, etc) to move the air at a particular frequency. I know that the formula for the force acting on ...
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4
answers
1k
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Mechanical Energy Analog to Capacitance
For starters I am a complete physics noob. I've been trying to understand basic fundamental ideas at a conceptual level I was drawn to the fact that work $(J) = FxD = CxV.$ I started trying to find ...
- 161
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211
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Seperating force between the plates of a capacitor
Imagine a capacitor with capacitance $C$, plate distance $d$ and voltage $U$. Now we decrease the distance between the plates with connected power-source ($U = const.$). For the energy $W$ of the ...
- 103
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94
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Can a statically charged object flying in an airplane float?
Lets say you are flying in a plane headed due west at 1000 km/h (278 m/s) with an altitude of 10km.
According to http://www.ngdc.noaa.gov/geomag-web/#igrfwmm, at 10km altitude, Earth's magnetic field ...
- 652
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The force acting on a plate of a parallel capacitor [duplicate]
How can you prove (using high-school-knowledge) that the force which acts on one plate of a parallel capacitor is equal
$F = \frac{E \cdot Q}{2}$
Where $E = \frac{U}{d}$ is the magnitude of the ...
- 567