All Questions
129
questions
3
votes
2
answers
5k
views
The electric field of a conductive sphere containing a charge - grounded vs not grounded
Let's suppose we have a sphere but unlike theoretical ones it'll have some thickness say $\Delta r$ and inner radius $R$. What I was wondering about is how will it behave if we place some charge $q$ ...
3
votes
3
answers
3k
views
Maxwell Stress Tensor in the absence of a magnetic field
I'm having some trouble calculating the stress tensor in the case of a static electric field without a magnetic field. Following the derivation on Wikipedia,
Start with Lorentz force:
$$\mathbf{F} = ...
- 133
0
votes
1
answer
4k
views
Finding the electric field
The charge per unit length on a long, straight filament is -91.9 µC/m.
(a) Find the electric field 10.0 cm from the filament, where distances are measured perpendicular to the length of the ...
- 453
0
votes
2
answers
2k
views
Calculate force of electric charges "suspended" by strings [closed]
In a question:
Two small plastic balls hang from threads of negligible mass. Each
ball has a mass of 0.110g and a charge of magnitude q. The balls are
attracted to each other, and the ...
- 495
3
votes
1
answer
1k
views
Electric Field due to a charged sphere
Suppose we have a spherical surface with a surface charge density varying as $cos(\theta)$. Apparently one can find the electric field both outside and inside such a spherical surface by superposing ...
- 33
1
vote
1
answer
108
views
Potential at a point
What is the electric dipole moment of the charge distribution with $q$ at $(0,0,1)$, $q$ at $(0,0,-1)$ and $-2q$ at $(0,0,0)$? I would think that it is $\vec{0}$ by the definition $\vec{p}=\sum\...
- 23
3
votes
1
answer
2k
views
Given charge distribution find electric field
Given a charge distribution $\rho(\vec{r})$ where $\vec{r}$ is the position vector and that $\rho$ is a function of only $|x|$, Why is it that the corresponding electric field $E$ is necessarily of ...
- 33
-2
votes
1
answer
18k
views
Electric field due to nonconducting plastic sheets [closed]
Two very large, nonconducting plastic sheets, each 10.0 cm thick, carry uniform charge densities $\sigma_1, \sigma_2, \sigma_3$ and $\sigma_4$ on their surfaces (the four surfaces are in the following ...
- 11
2
votes
2
answers
910
views
Gauss' law giving zero field where field is not zero?
Two plastic sheets with charged densities as shown:
I'm trying to find the field at $B$. I obtained the correct answer by adding up the fields created by each charge density. But I realized that ...
- 163