All Questions
Tagged with electricity electric-current
790
questions
7
votes
4
answers
49k
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Why don't we get a shock touching neutral wire?
Neutral wire has a V same as ground i.e almost 0. Also it carries some current. So if we touch the wire don't we to become a part of the circuit? Even if we are on the ground and current should flow ...
- 103
7
votes
5
answers
3k
views
How does a resistor "know" to increase the potential difference across its ends?
My book says that current has to be constant throughout a simple series electrical circuit consisting of wires, a cell and few resistors, and hence resistors have higher potential difference across ...
- 1,168
7
votes
5
answers
2k
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How to generate electric current without a permanent magnet?
The question is pretty simple:
Can we build a device that coverts mechanical work in electric current1 without employing a permanent magnet and without access to any external source of current?
The ...
- 4,577
7
votes
3
answers
21k
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Questions about voltage
For some reason, I feel like the concept of voltage is escaping my grasp. I've done much research on these forums and through texts, and come across answers that seem quite well thought out, but still ...
- 909
7
votes
2
answers
22k
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How do stun guns not kill people?
Now, I've seen a lot of answers to this sort of question, but most of them provide answers that don't actually make sense from a physics perspective.
As an example of such an answer, I've commonly ...
- 73
7
votes
2
answers
64k
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Capacitor circuits with light bulb
Let's say we have a normal circuit with a light bulb, with wires and a battery.
When one places a capacitor in this circuit, how is the light bulb able to light up, even when the capacitor prevents ...
- 561
7
votes
1
answer
95
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Why would a steel tube vibrate under high voltage?
Can anyone explain why a vertical steel tube, standing with one end in contact with the ground under a $230 \space kV$ electric transmission tower, would physically vibrate at high frequency? I'm not ...
- 71
6
votes
10
answers
5k
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How do resistors work?
Why is the current before and after a resistor exactly the same? I understand the same amount of charge that enters the resistor leaves, but current is defined to be charge per time. The way I ...
6
votes
3
answers
2k
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Why don't stationary charge feel force from a current carrying wire?
The current carrying wire doesn't apply any magnetic force on nearby charge $q$( positive stationary charge) because it has 0 velocity in lab frame. We found that there is no force on q by wire. But ...
- 79
6
votes
4
answers
6k
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How can there be a current and an electric field in an idealized wire with no voltage drop?
In an ideal circuit, How can there be a current b/w points a & b, when there is no potential difference and thus no electric field between a & b? If there is no current, then where does ...
- 1,578
6
votes
7
answers
937
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Is a charged particle in motion an electric current?
Do a moving charge let's say electron linearly with constant velocity constitue an electric current? If yes what would be it's magnitude?
- 63
6
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2
answers
7k
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Why does welding produce UV light?
Looking directly at a welder is dangerous because large amounts of UV light is produced. What makes this light? Is it electrons from the current that excites metal atoms, and these atoms sends out UV ...
- 495
6
votes
3
answers
40k
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How exactly does a resistance reduce current?
I've heard that resistors are used to decrease current to a particular appliance, such as in the regulator of a fan. However, I've also heard that the total current in a circuit is always the same- in ...
- 219
6
votes
2
answers
2k
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Earthing, neutral and Earth's conductivity
Ok so this is gonna be a lot of mini-questions.
What exactly is the neutral wire?
How does earth conduct electricity for a live AC mains even though its just dirt and stones (it should be an ...
- 838
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