All Questions
129
questions
1
vote
1
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57
views
Determine the charge distribution and the total charge of the system [closed]
Suppose we have a spherical symmetrically distributed charge in vaccuum which yields us a spherically and symmetrical potential $V(r)$ according to:
$$V(r) = V_0(1-(r/a)^2)$$
for $r\leq a$ and $0$ ...
- 344
-1
votes
1
answer
92
views
No limits of integration for electric field integral?
For this problem,
The solution is,
However, why have they not included limits of integration? I think this is because all the small charge elements dq across the ring add up to Q.
However, how would ...
- 49
0
votes
1
answer
563
views
Electric field in a center of a tiny hole cut out in a hollow sphere [closed]
Suppose we have a hollow sphere charged uniformly with
a surface charge density σ. A circular hole is cut out,
small compared to the radius R of the sphere. Find the electric field
in the center of ...
- 3
1
vote
1
answer
742
views
Force between two dipoles [closed]
I am extremelly confused with this question: Basically suppose we have two electric dipoles, parallel to each other, as follows in the figure:
I am supposed to show that the force is attractive and ...
- 980
1
vote
2
answers
272
views
Electrostatics Boundary condition for 2D problems [closed]
The 4 conditions above are what I am being taught, and I am aware of the usual boundary conditions of electric field and potential, but that links to surface charge density, and I was wondering how do ...
- 11
0
votes
2
answers
53
views
Electric field of a configuration of five parallel infinite slabs of dieletric materials [closed]
I am having a hard time trying to figure out how to proceed in order to calculate the electric field of a configuration of five slabs of dieletric (insulating) material (actually one of those is ...
0
votes
1
answer
28
views
What is the distribution of surface charge of the inner conductor of this system? [closed]
Given the following system, where the conductors (marked as yellow in the picture) have spherical symmetry. The inner conductor has $\textit{+Q}$ charge and the outer conductor has $\textit{-Q}$ ...
- 177
1
vote
1
answer
37
views
A confusing problem in electro- and/or magnetostatics: two parallel cylinders with opposite currents
I got the following problem as a part of my assignment in physics:
Equal but opposite currents $J$ flow on the surfaces of two cylinders of radii $R_1$ and $R_2$, respectively, with the axes of the ...
- 43
1
vote
2
answers
312
views
Conversion of 1D charge density to 2D charge density via integration
I'm self-studying EM (using the third edition of Griffiths) and have a quick question. Problem 2.41 states:
Find the electric field at a height $z$ above the center of a square sheet (side a) ...
- 684
0
votes
1
answer
239
views
Potential energy of two point charges of opposite sign (exercise)
I'm trying to do this exercise, but I don't understand how the textbook does it:
I don't understand, how they get a positive $27V$ and a got a few more doubts:
First thing, you can only measure ...
- 299
0
votes
3
answers
850
views
Right Hand Rule Help: Part 2
I’m confused about this problem with the right hand rule.
According the book:
My thumb should point up (as expected)
My fingers should point into the page (I don’t know how that would work)
My palm ...
- 113
3
votes
1
answer
94
views
Potential near a charged cylinder? [closed]
A non-conductive electrically charged cylinder of length $L$ and radius $R_o$ has a uniform charge distribution $q$.
What is the potential $V$ at the cap and bottom ($z=-L/2, z=+L/2$)? And at the ...
- 35.4k
2
votes
0
answers
61
views
Work required to bring point charge towards conducting planes [closed]
Consider the following configuration: A point charge sits in the upper right $(x>0,y>0,z)$ space. The other quadrants are separated by two conducting planes in the $(x=0,y,z)$ & $(x,y=0,z)$ ...
- 329
-1
votes
1
answer
38
views
Eletrical Field created by a charge surface on a point [closed]
I was answering this question and even tho i know intuitively that the radial component of the eletric field will cancel out by simmetry, i could not get that in the integral calculation. I´m asking ...
2
votes
1
answer
262
views
Conducting sphere in uniform field held at zero potential [closed]
The set up is "A conducting sphere of radius $r_0$ is placed in an originally uniform electric field E, and maintained at zero potential. Show that the potential outside the sphere is:
$$\Phi(r,\...
- 21