Skip to main content

All Questions

0 votes
0 answers
17 views

if divergence of a vector is zero, how to find the spherical coordinate of the vector?

The perturbed part of magnetic field is $\mathbf{\delta B}$ where $\mathbf{\delta B} = \delta B_x(x,y), \delta B_y(x,y)$ and $\nabla \cdot \mathbf{\delta B} = 0$. To prove $\mathbf{\delta B} = \delta ...
Mon's user avatar
  • 37
-1 votes
1 answer
116 views

Polar coordinates: What unit vectors span the $(r,\theta)$ space? [closed]

Polar coordinates: What unit vectors span the $(r,\theta)$ space? I am thoroughly confused. If in the Cartesian system, the associated orthonormal polar vectors at different points on a circle keep ...
S_M's user avatar
  • 419
1 vote
2 answers
176 views

Book Recommendation: One that has a lot of problems and theory associated with polar coordinates and spherical polar coordinates

I would like to "master" polar coordinates and spherical polar coordinates. In the sense, I would like to become as well versed with them as I am with cartesian coordinates. I have gone ...
S_M's user avatar
  • 419
1 vote
1 answer
93 views

Distance becoming equal to displacement

Consider a charged particle of charge q and mass m being projected from the origin with a velocity u in a region of uniform magnetic field $\mathbf{B} = - B \hat{\mathbf{k}} $ with a resistive force ...
Srish Dutta's user avatar
0 votes
0 answers
46 views

How do scalars like currrent or amplitude add vectorially and give correct results?

I have seen in alternating current that values of current and potential difference in different circuits like LR, CR or LCR circuits are found by adding them like vectors. It also happens with ...
Aurelius's user avatar
  • 471
2 votes
2 answers
1k views

Finding the distance from a point a distance $z$ above the center of a square to any point on the edge

I was working on an electrostatics problem that I thought I was doing correctly. However, upon reading the solution I see I was not. I will post my attempt and the solution below and then ask a few (...
Numerical Disintegration's user avatar
3 votes
1 answer
79 views

vector calculus directions

Consider a current density: $$\vec{j}=j_0(1-\frac{r^2}{R^2})\vec{e_3}$$ if $r\le R$ and $j=0$ if $r\ge R$ where $r$ is the distance from the $x_3$ axis. I need to use Biot-Savart law to find the ...
Tomy's user avatar
  • 429
3 votes
1 answer
223 views

Calculation of a vector by taking the gradient of the integral of its divergence

I have encountered several times of a special way of calculating a vector from the divergence of the vector. It has at least appeared in the theories of elasticity and electrodynamics. If I define the ...
ranger's user avatar
  • 67
0 votes
0 answers
165 views

Irrotational implies conservative without using the path-connection

Let's consider a simply-connected domain $V$ in $\mathbb{R}^{3}$ and a smooth vector field $\mathbf{F}$ in $V$ (please don't answer considering other scenarios). Under this assumption, let's consider ...
Simo's user avatar
  • 41
1 vote
1 answer
102 views

Can we have vectors with vectors as components?

I was working on my course on Electrodynamics earlier today, when I was tasked with computing the eletric field of a non-trivial charge distribution, and it struck me that I had a field with ...
DerpyMcDerp's user avatar
1 vote
1 answer
132 views

A laplacian working on an equation containing a laplacian and a gradient

I have an equation as follows: $$a \Delta \mathbf{u} + \mathbf{\nabla}(\mathbf{\nabla} \cdot \mathbf{u}) = 0$$ in which $a$ is a constant, $\mathbf{u}$ is a vector, $\Delta$ is the Laplacian operator, ...
ranger's user avatar
  • 67
1 vote
1 answer
73 views

Volume Integral : $\int \mathrm d^3\mathbf{r}' \frac{\nabla \cdot \mathbf{M}(\mathbf{r'})}{|\mathbf{r'}-\mathbf{r'}|}$

I am trying to understand the following claims. I would appreciate if you could help me, as I am still unable to understand it. The problem asks us to find the following integral: $$I = \int \mathrm d^...
Junjiro's user avatar
  • 187
3 votes
1 answer
537 views

Proof that the vector area is the same for all surfaces sharing the same boundary

In the book, Introduction to Electrodynamics by Griffiths (4th edition) in question 1.62 part c, we are asked to prove that the vector area is the same for all surfaces sharing the same boundary. The ...
Ali Pedram's user avatar
2 votes
1 answer
58 views

Where does this matrix, $\begin{pmatrix}0 & \mathcal{B}_{z} \\-\mathcal{B}_{z} & 0\end{pmatrix}$ come from in the Lorentz force law?

The anisotropic conductivity of the Hall configuration. We will only explore the case of perpendicular electric and magnetic fields, throughout the course, with the convention that: $\boldsymbol{\...
Electra's user avatar
  • 324
0 votes
1 answer
83 views

Vector Analysis cross product and dot product

Three vectors $\vec A,\vec B,\vec C$ Compare the value of these 4 questions.(use the parallelepiped) a) $(\vec A\times \vec C)\cdot\vec B$ b) $\vec A\cdot(\vec C\times\vec B)$ c) $(\vec A\times\vec B)\...
eeeventually's user avatar

15 30 50 per page