All Questions
Tagged with electromagnetism inductance
385
questions
2
votes
1
answer
2k
views
How to imagine the first few moments of an LR circuit?
For example, there's a very simple circuit which only contains on resistor. So according to Ohm's law, we have: $\mathrm{emf} = IR$
As we know when time $t = 0$, the current must be $I = 0$. However, ...
- 123
4
votes
4
answers
2k
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What are the practical use of LC oscillations?
I understand how energy is transferred between the capacitor and the inductor in an LC circuit, but I am not sure what are the practical applications. Could someone please help?
- 1,481
2
votes
1
answer
503
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Inductor rise time and inductor wire length
So here is an interesting question about inductors or coils in general.
Suppose you had a inductor which was 12 inch's in diameter and say 12 inch's in length and has 100 turns of wire. The total ...
- 23
3
votes
5
answers
19k
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Transformer: primary side & secondary side current 180 degree out of phase
I am a novice in electrical engineering. I notice that in transformer the secondary side current & current referred to as primary are 180 degree out of phase from each other.
But why it is so, I ...
- 347
2
votes
1
answer
187
views
Circuit Loop Law Doubt
In a circuit with a solenoid/inductor and a resistor and a battery .
Books say that $\Sigma \Delta V=0$ around a closed loop . That means work done by electrostatic field per unit charge is $0$ ...
- 21
4
votes
2
answers
2k
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inductance value of a single turn thin circular coil
the question may seem simple but I haven't found any fitting formula yet. The problem is the following:
consider a single-turn, circular coil made of reasonably thin wire (diameter of the wire much ...
- 506
18
votes
3
answers
11k
views
Faraday's law - does the induced current's magnetic field affect the change in flux?
I've had this conceptual problem with Faraday's law and inductance for a while now.
Take the example of a simple current loop with increasing area in a constant field (as in this answer). So Faraday'...
- 533
2
votes
2
answers
2k
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What is the maximum power available from a magnetic field?
I just want to validate something I inferred from studying Griffiths (1999).
The instantaneous magnetic field $\vec{b}(t)$ at a distance $r$ from a long infinite conductor carrying a current $i(t)$ ...
- 1,483
0
votes
2
answers
148
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Where's the energy in coupled magnetic fields?
Suppose I have two identical current loops superimposed upon one another, but with their currents in opposite directions. The coefficient of coupling $K=1$, and therefore the mutual inductance $M =\...
- 5,318
10
votes
5
answers
10k
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Magnetostatic energy density -- derivation without introducing inductance?
I was looking for a derivation of the expression for the energy density at any point in a static magnetic field. I do know that it is
$$u_B=\dfrac {1}{2 \mu_0}\left|\mathbf{B}\right|^2,$$
I was just ...
- 625
0
votes
1
answer
555
views
Inductively coupled DC circuit
The circuit under consideration has two inductively coupled loops, one with a DC battery, inductor, and resistor in series. The other loop has two inductors, one inductively coupled to the first, the ...
- 33
6
votes
2
answers
7k
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How to calculate required current and specifications for a "wet coil" to generate x Tesla of magnetic field?
A water management project requires a "wet coil" (coil will be submerged in aqueous media) designed to generate a steady-state electromagnetic field of adjustable magnetic magnetic flux density at the ...
- 163
2
votes
1
answer
5k
views
Mutual Inductance and the Dot Convention
Can anyone please explain me, the dot convention in coil systems (Mutual and self inductance) with some related images to understand..?
- 275
1
vote
2
answers
4k
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Ewing's Molecular Theory of Magnetism & Induction Cookers
This question regards Ewing's molecular theory of magnetism.
I.) Ewing's molecular theory of magnetism describes every magnetic substance as being a collection of dipoles that are initially in a state ...
- 383
1
vote
1
answer
784
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Non-conservative Electric Field
I was watching this video from Walter Lewin and while watching these two videos, I noticed there is a "contradiction" in what he is doing. All links direct you exactly to where he begins, so you don't ...
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