All Questions
38
questions
1
vote
1
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140
views
Do transformers return current to source when magnetic field collapse at primary coil?
When we close the circut containing an inductor and a battery, the current starts flowing, which builds magnetic field around inductor, changing magnetic field produces its own current in opposite ...
2
votes
1
answer
290
views
Mutual inductance - induced magnetic flux in the primary
Let there be two coils, L1 (with self inductance L1), and L2, with self inductance L2.
The first coil is connected to a sinusoidal supply, and the second one is connected to a resistor load, as shown ...
CommunityBot
- 1
0
votes
0
answers
12
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Self-induction in a permanent magnet
when a permanent magnet is moved in a coil, an emf is induced in the coil. so is an emf also induced in the magnet itself? and if not then why not. and if I replace this permanent magnet with a ...
- 207k
0
votes
0
answers
50
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What logic is being used in Bleaney & Bleaney to prove the reciprocity theorem for mutual inductance?
I'm currently reading Bleaney & Bleaney 3rd Ed. On pg 136 they discuss the case of 2 coils. Their logic is as follows:
If a second coil is brought near to a coil carrying a current $I_1$, there ...
- 126
0
votes
3
answers
69
views
Are there losses in an ideal transformer?
In a circuit with an AV power source $V$ and a zero-resistance ideal coil, the power from the source. $P_{in} = IV$ is equal to the rate of change in the magnetic energy $U_B$ stored in the coil. The ...
- 4,896
0
votes
1
answer
24
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How different is the induced magnetic field of a coil with a solid rod core and a sheet-wrapped one? (Assuming both use the same material)
I'm doing research for a university project and looking for commercial references for Mu metal, I found out that in my country at P2B (particular to business) level, sheets are significantly easier to ...
- 95.5k
1
vote
2
answers
149
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Intuition behind self-inductance
I'm having a little bit of a hard time understanding some concepts to do with self-inductance in class.
I understand mutual inductance. That's when a loop has some time-dependent current going through ...
- 13.1k
2
votes
0
answers
65
views
Variation of Permeability with DC magnetising Field
For any Powder core, as DC magnetising field increases, the initial permeability decreases known as "permeability roll off".
For example for an MPP core-
For MPP cores the initial ...
- 21
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0
answers
22
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How does proximity of a grounded conductor effect an electric / inductive field (and practical application)
My apologies - I'm missing a couple years of learning to be able to ask this question well, to know the right terminology.
Suppose a grounded conductor, such as a 12mm copper water pipe.
The grounded ...
1
vote
0
answers
42
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Please clear up the following confusion about Faraday's law, electromotive force, magnetic inductance, and current
As the magnet moves from the outside, the magnetic flux that is linked to the circuit is [pi_0 sin(wt)].
We have listed a series of processes related to electromotive force, self-inductance L, and ...
1
vote
0
answers
45
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What is the flux linkage or inductance or induced voltage per unit length of the hollow tube conductor surrounding the inner conductor?
What is the flux linkage or inductance or induced voltage per unit length of the hollow tube conductor surrounding the inner conductor in some section due to the current in the inner thin conductor?
...
1
vote
2
answers
315
views
Magnetic Field Produced by Solenoid
I was reading about solenoids and came to know that the magnetic field strength of a solenoid is greatly increased by
Increasing the number of turns in the solenoid coil (directly proportional to ...
- 24.2k
1
vote
1
answer
164
views
Calculating Induced EMF in Wireless LED Circuit
I have built the following circuit to power a wireless LED and my calculations and measurements do not give the same values. I am measuring a voltage nearly 6 times larger than I would expect in my ...
- 3,075
1
vote
2
answers
224
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Doubling the length of a solenoid doubles its inductance. Two identical solenoids in series have up to four times the inductance due to M. Why?
The inductance of a long solenoid with $N_o$ turns and a length $l_o$ is
$$L_o=\pi r^2 \mu_0\frac{N_o^2}{l_o}$$
If I now make a new solenoid, $L_{new}$, with double the length of the original ($l_{new}...
- 21.8k
0
votes
1
answer
557
views
Electromagnetic induction in varying current
I know about Faraday's Law and how it states that an electric field will be produced if it will sense a change in magnetic flux that there are other sources of electric field except for an electric ...
CommunityBot
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