All Questions
Tagged with electromagnetic-induction magnetic-fields
513
questions
4
votes
3
answers
3k
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Where is the energy stored in an inductor?
In an inductor,
Most text books say that the $(1/2)Li^2$ is stored in the magnetic field.
But is there another way to explain this?
In a capacitor I understand that all the energy that the battery ...
- 43
4
votes
2
answers
136
views
Faraday's law and a moving charge
Suppose we have a moving point charge with respect to some conductor which has a shape of a closed loop (e.g. a loop of wire). From the conductor's point of view the moving charge has a magnetic field ...
- 267
3
votes
3
answers
1k
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Why is there a current in a changing magnetic field?
If there is a circular metal loop and a changing magnetic field perpendicular to the loop, there is an induced electric field that causes the electrons to move and cause a current. But my question is ...
- 169
3
votes
3
answers
311
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Motional EMF and Faraday's law in this case
My textbook states that when a straight conductor with a velocity perpendicular to itself and the magnetic field (see image), an emf will be induced between the two ends of a conductor. This means ...
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3
votes
2
answers
5k
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EMF induced due to moving rod in magnetic field
When a conducting rod moves in a uniform magnetic field as shown.
By Lorentz force it is easy to explain that EMF induced is BvL and upper end is positive and lower end is negative.
But in books, ...
- 293
3
votes
2
answers
958
views
Induced electric field due to a long wire
Given an infinitely long wire, carrying a linearly increasing current, what is the shape and direction of the electric field induced by the magnetic field?
Given increasing magnetic flux in a ...
- 220
3
votes
3
answers
5k
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Zero current induced in a loop
Consider the following two cases,
Case 1 – A coil moving through a constant magnetic field
Case 2 – A conductor moving through a constant magnetic field
Now, in Case 1 (a coil moving through a ...
- 195
3
votes
2
answers
200
views
Maxwell equations and electric and magnetic fields produced repeatedly
Consider the two Maxwell equations (in the case of no conduction currents):
$$\mathrm{rot}\bf{E}=-\frac{\partial \bf{B}}{\partial t}\tag{1}$$
$$\mathrm{rot}\bf{B}=\mu_0 \epsilon_0\frac{\partial \bf{E}}...
- 2,617
3
votes
1
answer
424
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Does Motional EMF depend on the shape of path taken or depends on the shortest distance between given two points?
A semi-circular conducting wire of radius 2m is rotated in a uniform magnetic field $B=0.1\text{ T}$ ($\vec k$) about point $O$ with angular speed $\omega=10\text{ rad/s}$ as shown in the figure. The ...
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3
votes
1
answer
2k
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Why is the electric field induced due to a Time varying magnetic field non-conservative?
As the title states, Why is the Electric Field which is induced due to a time varying Magnetic Field Non Conservative in nature ?
Everywhere I read the answer that the line integral over a closed ...
3
votes
1
answer
4k
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Spinning a bar magnet above a disc
I'm preparing for a physics exam and this scenario was in one of the past papers:
If I have a horizontal bar magnet connected to a motor, and directly underneath there is a horizontal copper disc ...
- 91
3
votes
2
answers
1k
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Faraday's law and "infinite induction"
I may have confused after thinking too much about Faraday's law. If an emf is induced in a circuit due to some changing magnetic field, the induced current will be in a direction such that the "...
- 213
3
votes
1
answer
39
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Can paramagnetics materials like iron be levitated by a spinning halbech array like aluminium, copper etc?
I know diamagnetic conductors like aluminium or copper can be levitated using a spinning Halbech array as in this video. But can the same work using paramagmetic conductors, specifically iron?
Or will ...
- 169
3
votes
1
answer
740
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Explaining how a magnetic field affects currents in a conductor, in the limit of high conductance
Recently, I gave an answer to this question,
explaining my intuition on how much electric field impinges into
a good conductor under certain conditions, in order to reason about the limit of
perfect ...
- 1,379
3
votes
1
answer
539
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Can $F=qvB$ be applied to a solenoid and a parallel moving magnet?
If you take a scenario like this,
Charge gathers at either end, and if you could somehow form a complete circuit without there being a canceling effect, there would be a current flowing. This makes ...
- 347