Tagged Questions
1
vote
1answer
26 views
Capacitance of a conducting disk
I'm reading this(PDF) derivation of the capacitance of a thin conducting disk. The surface charge density of such a disk can be shown to be:
$\sigma(r) = \frac{Q}{4\pi a\sqrt{a^2 - r^2}}$ (in ...
0
votes
1answer
19 views
Work due to introducing a dieletric in a capacitor
I have a doubt about a couple of exercises tha asks to find the work done on introducing a dieletric between the plates of a capacitor. Yes, this question is in the general case, how do we procede? I ...
0
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0answers
34 views
Can you find the potential between capacitor plates with liquid dielectric in the capacitor's frame? [closed]
A magnetic field B is applied perpendicular to the plates of a capacitor whose parallel plates are separated by d. An electrically neutral liquid of relative dielectric constant k flows between the ...
0
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2answers
242 views
Capacitors and resistor in series and in parallel [closed]
In this circuit, are $R_1$ and $C_1$ in parallel and $C_2$ and $R_2$ in series?
I have think that the currents that flows trought $R_1$ isn't the same that flows trought $C_1$ so, $R_1$ and $C_1$ ...
8
votes
3answers
321 views
Where's the energy in a boosted capacitor?
Suppose I look at a parallel plate capacitor in its rest frame and calculate the electrostatic energy, $E$.
Next, I look at the same capacitor in a primed frame boosted in the direction perpendicular ...
1
vote
1answer
72 views
Magnetic force on capacitor
I have this problem: I have a capacitor formed by two parallel square-shaped plates, of side $a$, and with distance $d$ between them. They're asking me out of other things, the magnetic force as a ...
0
votes
1answer
88 views
Is it possible to charge a capacitor to any potential? Does it depend on the dielectric placed between them?
Is it possible to charge a capacitor to any potential? Does it depend on the dielectric placed between them? Or, are there other factors affecting it?
0
votes
1answer
250 views
Capacitance per unit area and CMOS case
In a modern 0.35μm CMOS processor, the gate oxide thickness is around 80Å = 8nm. This gives us a capacitance per unit area of $430nF/cm^2$
I am not getting how one gets this capacitance per unit ...
0
votes
1answer
93 views
Will I recieve a shock if I charged a capacitor then i touch the 2 poles in same time?
What happens if I charged a capacitor then i touch the 2 poles in same time?
0
votes
1answer
46 views
Can we transfer the charge on a plate of a capacitor elsewhere?
I know it is hard , but can we transfer the charge on a capacitor plate elsewhere?
1
vote
2answers
400 views
Poynting vector of a wire between capacitors
A capacitor made of two circular plates of radius $L$ separated by $d$, initially the plates carry $\pm$ Q charge.
Then a wire of resistance R is placed between them, how do I go about deriving a ...
1
vote
0answers
227 views
Calculating capacitance of integral PCB components
I posted this question originally with Electrical Engineering Stack Exchange but nobody seems to know the answer. So I thought a physicist might find the question more approachable.
Formulas for ...
1
vote
2answers
345 views
Parallel-plate capacitor
I'm trying to grasp parallel-plate capacitors in a class of electromagnetic field theory. My book leaves out a lot and I couldn't figure it out from what I found on Google.
The book's procedure is ...
14
votes
3answers
549 views
Distorted colors of Google StreetView photographs near electric power lines
This is a followup to my question:
Cyclist's electrical tingling under power lines
Some users presented a convincing picture that the electric shocks under power lines are primarily from the ...
1
vote
3answers
2k views
How is calculated the potential between two capacitors in series?
Suppose to have two capacitors in series:
The voltage in the middle point will be:
$$
V_X = V_1 \frac{C_1}{C_1+C_2}
$$
How can this be explained? It's been asked in electronics, and explained in ...
0
votes
1answer
305 views
Potential difference between conductors
Reading some books there is something that i don't understand. Is the capacitors topics when they name a potential difference between conductors.
As i know, Potential difference is the difference in ...
0
votes
2answers
117 views
Is it true that capacitors closer to a power source charges quicker and gets priority?
Let's say I hook two capacitor in a parallel circuit with a voltage source. Would the capacitor closer to the battery be charged up first? Because when the voltage excites and draws electrons from the ...
1
vote
0answers
217 views
Dielectric in Parallel Plate Capacitor
Given a parallel plate capacitor of width $w$, length $l$, with a dielectric moving along the length $l$. Let the dielectric be from $x$ onwards.
The capacitance will be $\frac{w \epsilon_0}{d} ...
1
vote
1answer
339 views
How do home-made capacitator bottles affect a tesla coil?
In the tutorial I'm following, the guy uses 6 snapple bottles to make capaciter (by covering them with foil and filling them with salt water) for a 9kV 30mA input. I have a stronger transformer (15kV ...
0
votes
3answers
1k views
Electric field at a point inside a capacitor
Let's say I have a parallel plate capacitor.
How would I find the electric field at a certain point INSIDE the capacitor (inside the dielectric let's say). From what I understand, the flux of the ...
2
votes
2answers
124 views
Determining the capacitance of a system with a non-homogenous dielectric
In an experiment we were given non-homogenous dielectric substances described by functions of coordinate. How can capacitance be determined from this?
1
vote
2answers
491 views
how can I find the potential created by spherical capacitor with dielectric material
If we have a spherical capacitor with inner radius or r1 and outer radius of r2, with charges (+/-)q on them and there is a dielectric material (with constant e) in between them with.
What kind of a ...
