All Questions
154 questions
0votes
0answers
14views
Direction of Force on an Inserted Dielectric [closed]
In the chapter on Capacitance and Dielectrics, my physics textbook takes great pains to explain why a dielectric being inserted between the plates of a capacitor experiences a force directed into the ...
1vote
0answers
90views
Multi-plate capacitor US physics olympiad 2008 problem A1 [closed]
In the solutions I used a different approach by assuming $\sigma_1, -\sigma_2, \sigma_2, -\sigma_1$(because of symmetry and field outside has to be zero) as in problem 3.21 from E and M Purcell. I ...
- 47
0votes
0answers
44views
Voltage across Capacitor in Series after shorting internal capacitor
I have what appears to be a very simple question, but I have not seen it asked anywhere and would like to verify my solution is correct. Imagine that you have 3 capacitors in series, each with an ...
- 133
1vote
0answers
34views
Exercise (electric field in a dielectric) [closed]
I am trying to solve the following exercise about the electric field generated by a spherical conductor: "A spherical conductor of ray $R=8cm$ and charged with $Q=8\mu C$ is half contained in a ...
- 187
3votes
1answer
138views
Dielectric between capacitor
I encountered the following problem: A parallel plate capacitor has plate area $A$ and plate separation $d$.The space between the plates is filled up to a thickness $x<d$ with a dielectric of ...
- 327
0votes
1answer
51views
How to find the capacitance between two metal sheets [closed]
Let’s say I have two metal sheets in a 2D plane. The first one has area A, the second one is infinitely long, and they are separated from each other by a distance d. How can I find the capacitance ...
5votes
1answer
515views
Theoretical expression for the capacitance of interdigitated electrodes
I am trying to determine the capacitance of interdigitated electrodes, like these: According to the paper, it can be calculated by: $$C=\varepsilon \frac{(2l_0-a+2w_0)t_0}{d_0}(2n-1) \tag{1}$$ Where $...
- 123
1vote
1answer
239views
Electrostatic potential energy of two concentric spherical conductors [closed]
Suppose that a small spherical conductor is placed inside a hollow spherical conductor. The inner conductor has a charge $+q$, which induces a charge $-q$ on the inner surface of the hollow conductor, ...
- 13
2votes
1answer
70views
Electric field becomes non-conservative in electrostatic problem
This question is about what I think was a misinterpretation of the statement of an exercise. But first I have to give some context. The question is at the end. During a class, my professor wrote the ...
- 377
8votes
5answers
1kviews
I am not able to understand what the text is trying to say about the connection of capacitors?
I have added the image of the part of page (the specific statement is highlighted), why does the text says that the capacitors are not connected in series ? And why the text says that they are not in ...
user371106
0votes
2answers
1kviews
Capacitance of a single conducting sphere
we were taught (very recently) in school, that the capacitance of a conducting sphere is $4\pi\epsilon_0R$ where $R$ is the radius of the sphere. we were told that the derivation of this would simply ...
0votes
1answer
161views
Can we use superposition of electric fields to conclude that between plates of capacitor the field is $2\frac{\sigma}{\epsilon_0}$? [duplicate]
Consider a parallel plate capacitor. This is a setup of two very large parallel plates, each a conductor and each with area $A$, and one having positive charge $Q$ and the other negative charge $-Q$. ...
- 321
0votes
1answer
249views
Cylindrical capacitor and charge density per unit area [closed]
I am dealing with the following problem: Assume that a charge has been placed on the inner cylinder, and that the entire charge is distributed on the outer surface of the inner cylinder as shown in ...
1vote
0answers
28views
Problem on capacitors [closed]
Consider a two plate capacitor, with a voltage across them equal to V, that is placed inside a metal box (it is the same as adding another metal plate on each side of a capacitor and connecting them ...
- 49
0votes
1answer
65views
What size capacitor do I need to power a 12v circuit requiring .002A for 1 second? [closed]
I am attempting to make a flashing 12v signal into a constant (ish) 12v signal by smoothing it out. When the flasher is in its "off" phase Im needing to simualate the same as when its on. (...
