All Questions
37
questions
3
votes
1
answer
740
views
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
0
votes
1
answer
119
views
What equation should I use to calculate inductance of a wire coil?
I've been working on a project recently which requires me to build an inductor, however in my research I found many different equations (with a range of variables used and giving very different ...
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 ...
- 21
0
votes
1
answer
245
views
What is the area $A$ in the magnetic flux for AC generator and a coil?
I am getting confused with what area do you use in AC generators and coils.
Let me explain:
in an AC generator, there are two coils that rotate. When using the equation - magnetic flux $= BA\cos(x)$, ...
- 220
0
votes
1
answer
940
views
Is emf equal to or proportional to the rate of change of magnetic flux?
I'm slightly confused about Faraday's law. Is it directly proportional or is it equal to the rate of change flux? If it is proportional, what's the proportionality constant? It might seem like a ...
- 195
2
votes
2
answers
483
views
Energy Conservation: How is Heat generated in a loop with Time Varying Magnetic Field through it?
Consider a circular loop kept in a time-changing magnetic field. We know, via Faraday Law, that EMF is induced across the loop and hence a current appears in the loop. Let there be some Resistance ...
- 1,568
0
votes
2
answers
64
views
What are the basic rules governing the workings of an Inductor? [closed]
To explain my question, I wish to use the case as shown above. I am able to solve the numerical based on the above and similar cases, but still, I have a conceptual doubt regarding the workings of an ...
- 2,517
7
votes
2
answers
860
views
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
1
vote
2
answers
353
views
Infinite EMF produced in transformer
If I have an ideal lossless transformer, where the ratio of voltages is proportional to the ratio of turns of wire, what, theoretically would stop infinite amplification of the EMF in one coil, and ...
2
votes
0
answers
84
views
How do you apply "flux-rule" in free space?
Faraday's law of induction states that, the tangential component of the force per unit charge$^*$; EMF produced in a loop of wire, is equal to change in the magnetic flux through the loop,
$$\int_C \...
- 455
0
votes
1
answer
512
views
Potential drop across inductors in DC circuits
The potential drop across an inductor is equal to $L(di/dt)$ where $L$ is inductance coefficient. But according to this in a DC circuit there should be no potential drop across the inductor (because $...
0
votes
2
answers
6k
views
Magnetizing inductance in transformer
I asked this question in electronics stack exchange as well but I thought it would also be applicable here as my question revolves largely around Maxwell's equations.
I am learning about transformers ...
- 191
2
votes
2
answers
3k
views
What is total magnetic flux through a coil?
According to Gauss's law of magnetism, the total magnetic flux through a closed surface is zero. But during induction, we study that the magnetic field lines passing through a coil change, as does ...
- 329
1
vote
1
answer
165
views
Don't understand step-down transformer
I think I understand how a step-up transformer works, but don't understand how a step-down transformer converts high voltage AC to low voltage AC. Following the ratio $\frac{V_1}{V_2}=\frac{N_1}{N_2}$...
- 165
2
votes
2
answers
17k
views
How doI find the average induced emf in a coil given the rate of change of flux density, and the area of the coil?
The magnetic flux density changes from +10 T to -10T in 5 seconds. The area of the coil is 2.5 m^2. What is the average emf induced?
By Faraday's law, this will be equal to the change in magnetic ...
- 254