What is Vector potential: Definition and 183 Discussions
In vector calculus, a vector potential is a vector field whose curl is a given vector field. This is analogous to a scalar potential, which is a scalar field whose gradient is a given vector field.
Formally, given a vector field v, a vector potential is a vector field A such that
In David Bohm's "Quantum Theory" (an intro topic building up to the Rayleigh-Jeans law), he states:
"We now show that in empty space the choice div a = 0 also leads to \phi = 0 ...
But since div a = 0, we obtain
\nabla^2\phi = 0
This is, however, simply Laplace's equation. It is...
Homework Statement
Consider a finite wire which lies on the z-axis and extends from the point z=-Λ to the point z=+Λ. The vector potential in the xy plane a distance s from the wire is:
Λ->∞
A=(µₒI/2π) ln (2Λ/s) k̂
An equally good vector potential is given by A'=A+∆λ, where λ is any...
Homework Statement
A finite wire lies on the z axis and extends from the point z=-V to z=+V. the equation from griffiths introduction to electrodynamics (equation 5.62) can be used to determine the vector potential at a point in the xy plane a distance s from the wire to be A=mu(naught)I/4pi...
Homework Statement
There is a disc with radius R which has a uniformly-distributed total charge Q, rotating with a constant angular velocity w.
(a) in a coordinate system arranged so that the disc lies in the xy plane with its center at the origin, and so that the angular momentum point in...
http://en.wikipedia.org/wiki/Vector_potential
The Wikipedia article is mentioning an interesting formula for defining vector potentials. Isn't that the same thing as a formula
\nabla\times\int d^3y\;(V(y)\times\nabla)\frac{1}{\|x-y\|} = -4\pi V(x),
where V:\mathbb{R}^3\to\mathbb{R}^3 is...
Hello all. I am hoping someone could lend a hand. I need to determine the vector potential of a long wire. I am given the B-field = (\muI)/(2\pir) and I know at some point I will need to use \nabla X A. Thanks in advance.
Prove that 4 vector potential does really a 4 vector? Most of the textbooks I found only mention that divergence of 4 vector potential equals to zero and the d'Alembertian of it is a four vector current and therefore it 'should be' a four vector. However I do not see there is any tensor theorem...
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Homework Statement
In a certain region, the magnetic field as a linear function of time is given by
B = Bo \frac{t}{/tau} z hat
Bo and tau constants.
A)FInd a simple expression for the vector potential which will yield this field.
B)Assuming the scalar potential is a constant, find E...
I'm trying to get from the magnetic vector potential
\vec{A}(\vec{x},t) = \frac{1}{\sqrt{\mathcal{V}}}\sum_{\vec{k},\alpha=1,2}(c_{\vec{k}\alpha}(t) \vec{u}_{\vec{k}\alpha}(\vec{x}) + c.c.)
where
c_{\vec{k}\alpha}(t) = c_{\vec{k}\alpha}(0) e^{-i\omega_{\vec{k}\alpha}t}...
Homework Statement
Compute the vector potentials for the following two-dimensional fields:
\vec{F} = \frac{xy\vec{i}}{1} - \frac{y^{2}\vec{j}}{2}
Homework Equations
(1)\int^{1}_{0} t \vec{F}\times \frac{d\vec{r}}{dt} dt
The Attempt at a Solution
I solved this problem a...
Homework Statement
Compute vector potential for the following field:
\vec{F} = <xy, y^2/2 >
Homework Equations
^{0}_{1}\int t\vec{F} x \frac{d\vec{r}}{dt}dt
The Attempt at a Solution
I set r = tR, where R = <x,y,z>. Taking the crossproduct F x R, I get <0,0,xy^{2} +...
Homework Statement
It's problem 2.b) on this page:
http://www.phys.washington.edu/users/schick/322A/322-08ps3.pdf
The Attempt at a Solution
So, what it looks like to me, since the only terms in the actual vector potential are all multiplied, Lambda would have to be a constant, so...
Homework Statement
A current I flows counter-clockwise in a thin wire bent around a square form of side 2a. Calculate the vector potential A and the magnetic induction B along an axis passing through the center of the square parallel to one of the sides. for definiteness, assume the loop...
Why is the magnetic vector potential of a point inside a infinite soleniod azimuthal assuming the axis of solenoid is the z axis.
Problem is the formulae A(\vec r)=\int_{v} \frac {\vec J(\vec r^{'})}{r} d\tau doesn't hold any more due to the infinite extent of the current
Homework Statement
A particle of charge q in a vector potential
\vec{A} = (B/2) (-y\vec{i} + x\vec{j} )
show that a classical particle in this potential will move in circles at an angular frequency \omega_0 = qB/ \mu c, \mu is the mass of the particle.
Homework Equations
The Attempt...
i am having trouble visualiszing what vector potential A means physically. I understand that if you take the curl of it it give you the magnetic field B. I was wondering if anybody could also direct me to a website or show me a proof of how the electric field E is equal to the partial derivative...
Homework Statement
Find the vector potential and magnetic field everyehere of a cylinder of radius R and length L which carries a magnetization \vec{M} = ks^2 \hat{\phi} where k is a constant and s is the distance from the axis of the cylinder. Homework Equations
A(r) =...
Homework Statement
What current density would produce the vector potential, A = k \hat{\phi} where k is a constant, in cylindrical coordinates?
Homework Equations
\nabla^2 A = -\mu_{0} J
In cylindrical coordinates for radial and z symmetry
\nabla^2 t = \frac{1}{s^2}...
Is it at all ethical to prove divA=0 here A is the magnetic vector potential?
That is, curlA=B?
Griffiths goes through a systematic development to show that we may make sure that div A=0 to make life easy.But in our exam the question appeared assuming the vector potential's form:[1/4 pi]int{J...
We know in all ordinary cases the direction of vector potential will be mimic to the direction of current.As it is evident from the expression of A=(mu/4*pi) int{J /(r-r')}dV which is valid only for finite current distributions.
But in example 5.12 and in exercise 5.25 Griffiths has given...
Homework Statement
I have to find the magnetic vector potential in a round coaxial cable. The internal conductor has a finite (known) conductivity. The external conductor is a perfect electrical conductor. Both the radius of the internal and the external conductors are known.
I have to assume...
I don't know if this thread belongs in Introductory Physics or here, so please feel free to move it if you wish.
The question is
Find the vector potential a distance r from an infinite straight wire carrying a current I
I know that the vector potential can be given by
\frac{\mu_0}{4 \pi}...
Vector V=x^2i+3xz^2j-2xzk
The divergence of this vector is zero. So it can be expressed as the curl of a vector. I have to find that vector, which is also called the vector potential.
But I don't know how to find it. When I have to find the scalar potential, then it is easier to equate...
\mathbf{F}(x,y,z)=(x^2+yz,y^2+zx,-2z(x+y)) Find the vector potential.
A vector potential \mathbf{V} would have to satisfy
\mathbf{V}_x=x^2+yz
\mathbf{V}_y=y^2+zx
\mathbf{V}_z=-2z(x+y)
So,
\mathbf{V}=\frac{x^3}{3}+xyz+M(y)+N(z)
\Rightarrow \mathbf{V}_y=zx+M_y(y)
\Rightarrow M_y(y)=y^2...
How to find the Vector Potential of an infinite solenoid with n turns per unit length,radius R and current I.
since here current extends to infinty..
How will it be done
Pls Help
The vector potential (A) in a certain region is given by A = xj-yi where i and j are unit vectors.
How will the lines of force look like?
What is the direction of magnetic induction B in the given region of space?
vector potential of magnetic field
Hi everyone.
I have a question about the vector potential of magnetic field, A:
we just set the divergance(A)=0 inorder to define the potential. I just wanted to know why we are allowed to do this.
Thanks a lot.
Somy :smile:
How do you get the B field from the magnetic potential?
I tried converting the curl into matrix format, but the corresponding matrix can't be inverted.
How do you get the B field from the magnetic potential?
I tried converting the curl into matrix format, but the corresponding matrix can't be inverted.
Hi All,
I've just looked at an example for calculating the vector potential for a point in the vicinity of a long straight wire.
I've now got to calculate the vector potential for a point between 2 parallel straight wires carrying currents in opposite directions. How does the vector...