If I understand correctly, Gauss's law is for a surface off which someone walking could never fall. Like the Earth for example.
Whereas Faraday's Law is for surfaces like when we thought the Earth was flat.
Is that correct?
I was reading here https://www.physicsforums.com/library.php?do=view_item&itemid=294
gauss law's for magnetism says
∮B⋅dA = 0
but then faraday's law has d/dt ∮B⋅dA in it. Well if its 0 then d/dt of 0 is 0.
Homework Statement
http://img805.imageshack.us/img805/6030/82154948.png
Find Vemf (between points 1 and 2) and it's polarity at t = 0.
I have omitted details because my question is specifically on the polarity.Homework Equations
Lenz's law:
An induced electromotive force (emf) always gives...
If i use the fact that a X b = |a| |b| sin(theta) then I understand where the sine comes from, it this case it would also mean that z X R is in the φ direction if d\vec{l}\times \hat{R}=\hat{\phi}\sin \left (\theta \right )dz is correct.
but when I compute z X R using the 3x3 matrix
R φ z
0 0...
In my physics textbook we have
d\vec{l}=\hat{z}dz
and then it says
d\vec{l}\times \hat{R}=\hat{\phi}\sin \left (\theta \right )dz
How so? What is \hat{z}\times\hat{R}? If it is \hat{\phi} then where does the sine come from?
I found that d\overrightarrow{l}=dR\overrightarrow{R}+Rd\phi \overrightarrow{\phi}+dz\overrightarrow{z}
so
V_{B}-V_{A}-\int_{A}^{B}\overrightarrow{E}\cdot d\overrightarrow{l}=-\int_{R_{A}}^{R_{B}}\frac{18}{R^{2}}dR=\frac{18}{R_{B}}-\frac{18}{R_{A}}
is that correct? in that case it seems my...
Some questions...
I'm trying to compute V between two general points for the given E field, just to see what it will give and also for the sake of it.
We know that
Vb-Va = -\int_{A}^{B}\overrightarrow{E}\cdot d\overrightarrow{l}
any idea how I could express d\overrightarrow{l}...
Homework Statement
Given the E field
E = 18/R2 R, R is the radial direction.
Find the electric potential between A and B where A is at +2m and B at -4m, both on the z axis.
The Attempt at a Solution
My question is, since E field depends only on R, the distance between the point and the...
Homework Statement
We have a sheet of charge, which is infinite in the x direction and has width d in the y direction.
Find E field at a height h above the center line of the sheet. The sheet has λs surface charge density.
My attempt:
We know that the E field for an infinite wire is λl / 2πrε...
I am trying to compute
-dx i CROSS -x i -y j
i,j,k are the unit vectors
x is from -∞ to ∞ and y can only be negative.
Right hand rule tells me that the cross should be in the negative k direction but computing the cross product gives me y dx k.
What's wrong?
Whenever I argue with people and they resort to logical fallacies, I get extremely frustrated and even violent. I have no problem accepting different opinions as long as they are defended in a logical way. What ticks me off specifically is logical errors, fallacies. I can't stand when logic...
We know that ∇.D = ρV
My question is, if D is due to a linear or a surface charge distribution, can we apply this equation and get a surface or linear charge density?
Thank you very much
Hello, please take a look at the first 2 minutes of this video:
He says that we compute the E field, so when we put a charge anywhere, we can know what will happen to the charge because we know the E field due to the other charges.
But wouldn't the added charge disrupt the force...