All Questions
31
questions
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663
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Magnetic field of coaxial cylindrical capacitor
I have a coaxial cylindrical capacitor as shown, with inner radius a and outer radius b.
The potential difference across both cylinders is V. I need the magnetic field everywhere when the inner ...
CommunityBot
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3
votes
1
answer
2k
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Magnetic field due to a finite-length straight wire carrying a constant current [closed]
My question: I want to find an expression at any point in space for the magnetic field $\mathbf B$ produced by a straight wire of finite length $L$ carrying a constant current $I$.
I think that we can ...
CommunityBot
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0
votes
2
answers
49
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Validating Basic Laws of Magnetostatics [closed]
I am having trouble with the following problem, although with similar problems I run into the same issue when it comes to validation. The example problem below is a problem for Amperes Law.
The ...
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votes
1
answer
593
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Vector potential of a square loop [closed]
I am doing my homework and I'm really stuck on this problem. It asks for the magnetic field due to a square, lying in the $xy$-plane, of side lenght $a$ and with a electric current $I$ running ...
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1
vote
1
answer
302
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Magnetic field in two conducting parallel plates. (stripline) [closed]
Studying Poynting Vector power density I found a geometry that I really can't figure it out and is nowhere to be found on the internet.
I have two conducting parallel plates with opposite surface ...
- 12.1k
1
vote
1
answer
37
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A confusing problem in electro- and/or magnetostatics: two parallel cylinders with opposite currents
I got the following problem as a part of my assignment in physics:
Equal but opposite currents $J$ flow on the surfaces of two cylinders of radii $R_1$ and $R_2$, respectively, with the axes of the ...
- 184
2
votes
1
answer
878
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Why should there be an induced electric field if magnetic field is constant? [closed]
Problem statement:
The curved surface of a very long hollow non conducting cylinder of radius $R$ is uniformly charged with surface charge density $\sigma$. A non conducting small circular ring of ...
1
vote
2
answers
331
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How to find magnetic field as a function of $r$ from axis of solenoid?
I was solving this problem:
Whose answer is given as:
I understand the part for calculating the field outside the cylinder, but for inside, I don't get it. If we apply Ampère's circuital law by ...
- 12.1k
2
votes
2
answers
569
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Find torque due to Lorentz force - Wrong result [closed]
Current I is coming from the Z axis and then it flows out uniformly towards the circumference of this disk. The disk has thickness t and Radius R. There is also a constant B field in the Z direction(...
CommunityBot
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4
votes
1
answer
1k
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Current density $\mathbf{J}$ of particle with magnetic dipole moment $\mathbf{m}$ [closed]
I'm solving some excercises on magnetostatics, and encounterded this on which i'm having some trouble. Given a particle of magnetic dipole moment $\mathbf{m}$, show that its current density is given ...
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-1
votes
1
answer
878
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Cylindrical shell in magnetic field [closed]
Exercise: 'Infinitely long cylindrical shell of inner radius a and outer radius b of material of magnetic susceptibility χ is placed in otherwise uniform magnetic $B_0$ perpendicular to cylinder's ...
- 1,149
1
vote
0
answers
207
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How to calculate the magnetic field of two cylinders when one of them is rotating
Given is the voltage U and the Angular velocity $\omega$. The rotating cylinder is inside the other cylinder and U is measured between them.
To calculate the magnetic field, I tried to solve
$\oint ...
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13
votes
2
answers
5k
views
Deriving Biot-Savart Law from Maxwell's Equations
As an exercise, I've been trying to derive the Biot-Savart law from the second set of Maxwell's equations for steady-state current
$$\begin{align}&\nabla\cdot\mathbf{B}=0&&\nabla\times\...
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1
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3k
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Obtaining the magnetic vector potential inside an infinite cylinder carrying a z directed current:
Suppose we have a nonmagnetic conducting cylinder of radius $ \alpha $ directed in the z direction, with a current density $ J_{0} \hat{a_{z}} $. What is the magnetic vector potential for $\rho < \...
1
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2
answers
4k
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Biot-Savart law and magnetic field of a ring
I have to calculate the magnetic field along the axis of a ring of radius $R$ on which circulates a current $I$ using the Biot-Savart law. The Biot-Savart law as given in my (really bad) course states
...
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