All Questions
Tagged with electromagnetism inductance
385
questions
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2
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137
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Why does electrical impedance have as many parameters as it has?
The impedance of a circuit is written:
$$ Z(R,L,C,f) = R + j ( 2 \pi f L - \frac{1}{2 \pi f C} ). $$
What is the line of thinking that frequency, resistance, capacitance, and inductance are the only ...
- 161
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1
answer
5k
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Why does the inductance of a coaxial cable not depend on the number $N$ of coils?
Suppose we have a long coaxial cable like in the following figure:
I want to compute the self-inductance $L$ of the cable. As I understand, given a coil with $N$ closely winded turns, through which a ...
- 47
2
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1
answer
2k
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Force on permanent magnet solenoid core
I was wondering, since a coil/solenoid will pull any ferromagnetic material inside it, does the initial magnetization of the object in question affect the magnitude or direction of the force? I know ...
- 123
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What is the magnetic flux density "outside" the solenoid when AC current is passing through it?
I know that there are well defined equations explaining the magnetic flux density in the solenoid.
However what about magnetic field outside the solenoid?
How is the magnetic flux density related ...
- 111
0
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2
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299
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Calculating potential difference for fraction of loop with induced current
Given a circular wire loop of radius r, resistance R enclosing a magnetic field perpendicular to the plane of the loop that increases with time ($B=\alpha t$), I have calculated the induced current $I=...
user44816
4
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2
answers
6k
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Magnetic moment of an iron-core solenoid
I'm currently developing a Simulink model for the attitude control system (ACS) of an undergrad-developed CubeSat. The ACS uses magnetorquers for attitude actuation.
The magnetorquers are iron-nickel ...
- 93
2
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1k
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Why is the electric field inside a solenoid tangential?
I have been looking at some derivations for the electric field inside a solenoid. I know how to find it, but I don't get the symmetry argument used. This is often of the form:
Since if we choose a ...
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Why must the deviations from equilibrium be small for zero difference in energy in this solenoid?
A long solenoid with a square cross-section is partially immersed in a magnetic, non-conductive liquid of permeability $\mu$. The solenoid's axis is parallel to the liquid's surface.
Task: determine ...
- 567
1
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1
answer
947
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Arcing through an inductor
When a current is passed through an inductor coil, potential difference across it is given as $$V=L\frac{dI}{dt} \, .$$
Now, if we suddenly disconnect the coil from the circuit, the current will ...
2
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1
answer
3k
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Does the direction of the magnetic field inside a solenoid depends on the direction which it is turned?
Today trying to explain some magnetic stuff, just came across with a simple (at least seems) question.
My question is brief: does the direction of the magnetic field inside a solenoid depends on the ...
2
votes
2
answers
11k
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Calculating magnetic field strength for a very small electromagnet
I am trying to calculate the magnetic field (in tesla/gauss) of an electromagnet that is very small and has very few windings. For example 12 windings over 0.003 meters. I know this is not going to ...
- 301
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1
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842
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Explanation of force amplification inside a solenoid
For a system being actuated by a motor, the force can be amplified by gearing. The energy is being used for force instead of distance, so it produces more torque but moves slower.
For a system being ...
- 301
2
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2
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5k
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How to get the magnetic field strength in space near a solenoid
I am trying to find the magnetic field strength along the axis of a solenoid.
If I know the strength of the field at the center of the solenoid, and I know the distance from the center of the ...
- 1,340
1
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1
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214
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What does an induced emf do to a loop of varying current?
I know that the magnetic flux through a loop in space is proportional to the current such that $\Phi=LI$. Therefore a change in magnetic flux will produce an emf, so $\mathscr{E}=-L\dfrac{dI}{dt}$. ...
- 518
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2
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891
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Why can't mutual inductance create perpetual electricity?
Consider the following image.
When the battery is connected then current starts flowing through the primary cicuit and magnetic flux changes through the coil, this causes electricity to be induced in ...
- 378