All Questions
Tagged with electromagnetic-induction magnetic-fields
513
questions
85
votes
4
answers
16k
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If you are vacuuming your carpet and you wrap the cord around your body do you become a magnet?
If you wrap an active electric cord around your body, do you become an electromagnet?
- 890
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votes
4
answers
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Magnetic field changes induced by vibrating electric guitar string
Here is a picture (from a paper by Feinberg and Yang in the Journal of the Acoustical Society of America) of an electric guitar string vibrating (mostly in the $y$ dimension) near a permanent magnet.
...
- 836
11
votes
3
answers
1k
views
Simple explanation to the induction from the slowly changing $\vec B$ of a solenoid in the region of $0$ magnetic field
I would like to get some elementary intuition into the problem a solenoid fed with a time-dependent current, and the resulting current that such the solenoid field would induce in a loop completely ...
- 46.1k
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votes
7
answers
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I don't understand Ampere's circuital law
Since, magnetic field is a vector quantity, two (or more) magnetic fields (when in close proximity) should influence their fields, according to the laws of vector.
And by that logic, Ampere's ...
- 119
10
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3
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How are the Lorentz force, Maxwell's third law and Faraday's law of induction clasically related?
Faraday's law of induction can be used in any situation where the magnetic flux is changing through a closed conducting loop. While giving the correct answer, it seems to me that for the following ...
- 121
9
votes
6
answers
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Why does a changing magnetic field produce a current?
A changing magnetic field induces a current in a conductor. For example, if we move a bar magnet near a conductor loop, a current gets induced in it.
Faraday's law states that
The E.M.F. $\...
- 1,324
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votes
3
answers
8k
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Can current be induced in a superconductor?
Moving a magnet close to a conductor induces a current. If it consists of a superconducting material with resistance $R=0$, then my textbook says:
Then the induced current will continue to flow ...
- 51.5k
8
votes
3
answers
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Non-conservative electric fields due to changing magnetic flux?
What I read in several places, tells me that, the fact Coulomb's Law follows inverse-square law and gives a force which is radial, implies that a static electric field must be conservative.(In short, ...
- 3,148
8
votes
1
answer
10k
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Why doe we not get a shock on induction cooker?
In induction cooking, eddy currents in cook-pot cause heat to be produced. But why do we not get a shock?
Also, why is it that current is converted to heat while it has a good conductor(say, steel) ...
- 225
8
votes
6
answers
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How does an inductor store magnetic energy?
I am trying to figure out what the potential energy of an inductor with a current really means. In a capacitor, the energy stored works like this: if you let the plates attract each other, before ...
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7
votes
5
answers
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How to generate electric current without a permanent magnet?
The question is pretty simple:
Can we build a device that coverts mechanical work in electric current1 without employing a permanent magnet and without access to any external source of current?
The ...
- 4,577
7
votes
2
answers
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Transformer and magnetic field/flux through the iron core?
I am familiar with how a transformer works.
This is the diagram that I found on the wikipedia page:
The current through the red solenoid varies with time, which creates a time-dependent magnetic ...
- 24.9k
7
votes
2
answers
861
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What is the meaning of Potential Difference in presence of Non-Conservative Induced Electric Field?
Case 1
This is a very commonly discussed case in Electromagnetic Induction. In the case above, we need to find out the potential difference across the rod CD, in the presence of time-varying ...
- 2,517
7
votes
1
answer
2k
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Motion in a time-dependent uniform magnetic field
Suppose you have an infinite solenoid generating an uniform magnetic field inside. The field is oriented along the solenoid axis : unit vector $\vec{\bf n}$. The field intensity varies linearly with ...
- 7,592
6
votes
4
answers
729
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How do Electric and magnetic fields generate each other (mathematically)?
Regarding electromagnetism, a changing magnetic flux$(\phi_B)$ produces emf by-$$EMF= -\frac{d \phi_B}{dt}\tag1$$
This emf creates a current which again creates a magnetic field given by-(bio-savart ...
- 367
6
votes
3
answers
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Suspicious EMF equation
Some context: I am trying to get the equation of motion for a dipole magnet falling through copper pipe. To proceed I need to calculate the EMF. We can do this by using Faraday's law,
$$\oint_{\...
6
votes
1
answer
531
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If a loop is not complete, and magnetic field passing through it is changing; will their be emf induced in the loop?
In a setup like the one show in the figure:
Will there be an induced EMF across the loop(given that the field is increasing)?
(my dilemma is : since the loop is not complete, we cannot define the ...
- 63
6
votes
3
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217
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Ring Magnet with a wire in the middle
I have a very specific question concerning a system with a magnet and a wire.
Consider a ring magnet with a magnetic field directed right through its center. In the center of the magnet is a wire, ...
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6
votes
2
answers
1k
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Direction of Hall current
A Hall current arises when electric currents transverse to a magnetic field exist. In this figure (found online), the Faraday current appears to be going upwards due to a magnetic field pointing into ...
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votes
3
answers
13k
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How to find the direction of an eddy current?
Suppose there is a magnetic field going from left to right. Suppose a thin sheet of metal conductor (e.g. a 1m*1m square) is dropped through the magnetic field such that the plane of the conductor is ...
- 231
5
votes
2
answers
766
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How does electromagnetic induction work on an atomic level?
So far I have come to know that changing magnetic field (or flux) creates current. This is also known as Faraday's law of electromagnetic induction. The direction of the current is opposite to the ...
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votes
2
answers
412
views
Fundamental, intuitive interpretation of the magnetic field $\vec{H}$
In many electrodynamics/magnetism textbooks it is stated that the magnetic induction $\vec{B}$ is related to the magnetic field $\vec{H}$ via $\vec{B}=\mu_0(\vec{H}+\vec{M})$. It is then argued that $\...
- 1,006
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Does changing the electric / magnetic field cause self-reinforcing induction of the other?
I understand that changing electric field produces magnetic field and changing magnetic field produces electric field.
Are these produced magnetic and electric field produced due to one defined to be ...
- 5,481
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1
answer
13k
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Calculate electric field induced by a changing magnetic field
I want to plot the electric field (as a vector field plot) which is induced by a changing magnetic field for some simple cases.
Suppose for example that the magnetic field changes linearly (or ...
- 1,702
5
votes
3
answers
225
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Which is more correct - a changing $B$ field induces a current or an electric field?
I am in an introduction to Electricity and Magnetism class and we are using Griffiths. In example 7.8 on page 318, his solution says that the "changing magnetic field induces an electric field". But I ...
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Do moving charges get affected by the magnetic field they create while moving to constitute current? If not, how can self-induction be possible?
Let a bunch of charge move with a constant velocity $\mathbf v\;.$ Since, the charges are moving, they would create magnetic field $\bf B$ as it is current that produces magnetic field.
Now, would $\...
user36790
5
votes
0
answers
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How to calculate the energy transfer between working coil and working piece and dissipated energy of working piece in induction heating?
For who don't know how does induction heating work, a short description can be found here.
However, my question is about physics. Assume I have a coil inductor calculated carefully 50 uH as below:
...
- 175
5
votes
4
answers
611
views
Induction cooker + superconductive pot [closed]
What will happen if I put a super-conductive object on an induction cooker, and turn the cooker on?
- 359