All Questions
259
questions
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Force acting on an infinite wire with current inside a magnetic medium
I've recently stumbled on an electromagnetics problem that I don't quite understand.
There is an infinite wire carrying current I that is placed inside a medium with magnetic permittivity μ1. At a ...
0
votes
1
answer
27
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General Form of the Biot-Savart Law for anywhere on the $x$-Axis [closed]
This question is beyond me, and I have very little direction for solving it. I understand that the component of $\ B $ perpendicular to the $x$-axis is 0, and that the component parallel along the $x$-...
- 3
1
vote
1
answer
48
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How can I estimate the force of an electromagnet?
I am doing an experiment on electromagnetism, basically I am just testing the pulling force of an electromagnet using a newton meter with a magnetic hook and seeing how the pulling force changes as i ...
- 11
-2
votes
1
answer
75
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Where is this circular loop attracted? [closed]
A circular loop carrying current "I" in anti-clockwise direction is placed between two straight and parallel wires each carrying current I. Ignoring the force of the straight wires on each ...
- 119
1
vote
1
answer
94
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Magnetic Scalar Potential of Infinite Wire
While working on a question about magnetic scalar potential, I encountered a challenge. The question posits that the magnetic scalar potential, denoted as $\phi$, takes the form $\phi = -\frac{I}{2\pi}...
3
votes
3
answers
113
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Finding the vector potential
$$\nabla\times\mathbf{B}=\nabla\times\left(\nabla\times\mathbf{A}\right)=\nabla\left(\nabla\cdot\mathbf{A}\right)-\nabla^2\mathbf{A}=\mu_0\mathbf{J}\tag{5.62}$$
Whenever I try to work this out and ...
- 220
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1
answer
49
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Why can the current in this region be represented as this formula?$I_{in}=I-I\frac{r^2-b^2}{c^2-b^2}$ [closed]
An air coaxial transmission line has a solid inner conductor of radius a and an outer conductor of inner radius b and outer radius c. Find $\vec B$ as a functions of radial distance r.
The region in $...
- 51
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2
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481
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Should a wire loop moving through a constant rectangular magnetic field directed perpendicular to it's motion have zero induced current in the middle?
Suppose we have a loop of copper wire moving perpendicularly through a constant finite rectangular magnetic field directed into the screen .
When the loop enters the field, the induced current would ...
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1
vote
1
answer
216
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Magnetic field in the left focus of an ellipse current loop
given a 2D ellipse in 3D space parametrized as $x(t)=a\cos{t}$, $y(t)=b\sin{t}$, I would like to find the magnetic field at point $(-c,0,0)$, $c=\sqrt{a^2-b^2}$. (The current $I$ is running counter-...
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42
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Calculating Magnetic Vector&Scalar Potential
I want to calculate the magnetic scalar and vector potentials for an infinite axial current density given as
\begin{equation}
J(r,\varphi) = \frac{I}{R} \delta(r-R) \sin\varphi \cos\varphi \bf{\hat{k}...
- 125
1
vote
1
answer
54
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Why does $\vec v \times \vec B$ change to $\vec a \cdot \vec B$? [closed]
I was doing a question where the solution said this:
$$\vec F = q (\vec v \times \vec B)$$
$$m \vec a= q (\vec v \times \vec B)$$
$$ \therefore \vec a \cdot \vec B = 0 $$
$$(x\hat i + 7 \hat j) \...
- 29
0
votes
1
answer
174
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How to derive the magnetic field at a point a distance $x$ from the center of the axis of a circular loop of radius $R$ carrying current $I$? [closed]
Question: What is the magnetic field at a point a distance $x$ from the center of the axis of a circular loop of radius $R$ carrying current $I$?
I was given the answer $\frac{\mu_0}2 \frac{IR^2}{(x^...
- 103
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1
answer
123
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In The question given below, why the length for calculating reluctance is taken by those dotted lines?
The question is as follows:
For the core shown in Fig. 3.20, it is required to produce a flux of 2 mWb in the limb CD. The entire core has a rectangular cross section of 2cm × 2cm. The magnetizing ...
- 31
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2
answers
202
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How to determine the electric and magnetic fields from $*F=q\sin \theta d\theta \wedge d\phi$?
I have the 2-form $*F=q\sin \theta d\theta \wedge d\phi$, how can I determine the eletric and magnetic fields from that?
I have tried wrtting F in the vector potential form for them finding the ...
- 346
1
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30
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Can I find the maximum magnetic flux of my magnet knowing the magnetic flux density? (and also for multiple stacked together) [closed]
I'm working on an extended essay in physics for IB with my experiment relating to the magnet down a copper tube experiment. I'm trying to find the terminal velocity with my independent variable being ...
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