All Questions
141
questions
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132
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Why is current density assumed to be uniform in following scenario
This was homework question, and i got it right. But i still don't understand why.
Assume that we have some glass rod, which is heated. At the ends of the glass rod potential difference $\Delta V$ is ...
-1
votes
3
answers
93
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Current and voltage - Incompatibility between Ohm's Law and Power Law! [duplicate]
Ohm's Law: I $=\frac{V}{R}$: Increasing voltage increases current.
Power Law: P $={V}*{I}$: Increasing voltage decreases current.
Am I missing something?
- 340
0
votes
1
answer
252
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Electromagnetic induction - How is the polarity of an uncoiled wire determined? [closed]
Using the right-hand rule, we can determine the solenoid's polarity. So when we move a magnet towards a solenoid devoid of a current, the current flows so as to make the nearest side of the solenoid ...
- 340
5
votes
1
answer
657
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How are electric and magnetic fields able to travel through space and wires, and how are they more than mathematical constructs?
Once I was taught that light is physically made up of in-phase E and B fields oscillating perpendicularly, it was a little baffling because I always thought fields were just analysis tools (or even ...
0
votes
2
answers
843
views
Can current be induced in a spinning wire due to Earth's field
I came across a scenario where two people are spinning a wire with no specific magnetic field:
In such a scenario, can any current be induced due to the change in magnetic flux (where the magnetic ...
- 15
1
vote
2
answers
564
views
During the negative cycle, how the inductor returns the power?
The following is related to AC circuits:
When an inductor(or a capacitor) is connected to an AC source it consumes some power in the form of some field during first T/4 time interval and returns the ...
- 315
-1
votes
2
answers
71
views
Could you transmit electricity wirelessly?
Since you can wiggle an electron to get a radio wave And if you 'wiggle' it fast enough you get higher and higher frequency right? So couldn't you just broadcast an electromagnetic beam or whatever ...
- 33
0
votes
2
answers
1k
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Skin depth; EM wave and AC
When I google skin depth, I get the following definition,
Skin effect is the tendency of an alternating electric current (AC) to
become distributed within a conductor such that the current ...
- 455
0
votes
0
answers
52
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Do charges move on the surface of conductors for steady direct currents?
The answers in this post suggest charges move through the bulk of conductors, not only their surface, when dealing with direct currents.
However, suppose we have a steady direct current, this steady ...
- 1,292
0
votes
1
answer
55
views
The currect density in materials of uniform resistivity
Inside an infinitely large piece of material that fills the whole $\mathbb R^3$ space with uniform resistivity $\lambda$ (which letter should I use, when $\rho$ has been used for charge density?), ...
- 1,335
2
votes
1
answer
2k
views
Skin Effect Explanation
I do not understand some things about the Skin Effect.
Its Wikipedia definition is:
Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor ...
- 1,319
0
votes
2
answers
204
views
Do surfaces charge distribution in a wire move?
Upon reading matter and interactions ,In the chapter "electric field in a circuit" and surface charge distributions in a steady current, The book dosen't explain why doesn't the surface charges move ...
- 323
2
votes
1
answer
1k
views
What forces are acting on electron in a circuit? Do electrons act on each other in a current?
What forces are acting on electron in a circuit?
What is the source of such kind of forces?
Do electrons act on each other in electric current?
If i have an ordinary electric circuit with only one ...
- 47
2
votes
2
answers
500
views
Direction of magnetic field around a straight current carrying wire
I am currently studying for O Level and I have been learning about electromagnetism for the past year. The topic has never clicked for me because I've never been taught the true relationship between ...
- 123
1
vote
4
answers
159
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Basics of electric current
I am a mathematician who never took a physics class besides classical mechanics. Recently I have been looking at biophysics for a small project and I have a hard time understanding the basics of ...
- 113