All Questions
Tagged with electricity electric-current
790
questions
6
votes
2
answers
4k
views
Will I get a shock when I try to use my hair-dryer under water?
Occasionally people get killed in their bathtubs by having an electrical device such as a hair-dryer take the bath with them - in movies.
It seems to be a common belief that this is realistic, even ...
- 462
6
votes
3
answers
652
views
Why can't an excess of electrons or holes by themselves cause current flow?
I am a beginner in electrical engineering. Often times (most cases actually), the underlying physics aren't really explained to us and we are just left to assume that it works "because it works." This ...
- 61
5
votes
6
answers
16k
views
How power lines use high voltages with a low current?
I've read that power lines use high voltages and low currents to reduce power loss due to resistance. Looking at the formula for power -
P = VI
So to increase P, you increase V rather than I for ...
user86680
5
votes
4
answers
988
views
If an electron is repelled by another electron how is it that we get an electric current?
As we know that an electric current is a flow of electric charge in a circuit, and in electric circuits, the charge carriers are often electrons moving through a wire.
Now, since we know that like ...
5
votes
2
answers
135
views
What is the "closed circuit" of a bug swatter racket?
There are bug swatter racket that can kill fruit flies, mosquitos, or flies, if the insect touches the metal mesh.
However, when I look at the construction of the device, the metal mesh is all one ...
- 151
5
votes
4
answers
37k
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Among current and voltage which is responsible for brightness of a bulb?
In a circuit that is fitted with a bulb, which is the factor that affects brightness of that bulb: current in the circuit or the voltage offered by the battery in that circuit?
5
votes
2
answers
696
views
Why do electrons follow the conductors shape?
I'm stuck thinking about this situation. I imagine that there are two oppositely charged objects at short distance $r$, put inside an insulator (Can I say air?). They generate a net elctric field, ...
5
votes
2
answers
4k
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Why can't I connection the anode of a battery to the cathode of an other battery and get a current flowing? [duplicate]
If I touch the anode of a battery or connect the anode the the cathode of an other battery, none (or rather: a very small current) flows between those two. If I instead connect the connect the anode ...
- 797
5
votes
3
answers
458
views
Why would a circuit like this will not work/or work?
In this circuit the two batteries are not connected to each other but I am still assuming that excess electrons from the negative terminal of the cell should flow to the positive terminal of the other ...
- 53
5
votes
1
answer
1k
views
Speakers and Static from Hands
Why is it that when you touch the a bare male end of a speaker feed that the speaker makes hissing noises? Is it just (eddy?) currents running through you?
user24082
5
votes
1
answer
657
views
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 ...
5
votes
1
answer
3k
views
Can conductor be charged?
I have a copper conductor. For a while, I apply a voltage of $12kV$ DC from a source. After removing the source, will the conductor stay charged from the source if is not earthed? Will it discharge ...
- 185
5
votes
3
answers
1k
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Charge signs in current
I've had recently an argument with my friend about different charge carriers in an electric current. Suppose that electrons and holes are moving in the same direction. It effectively means we have ...
- 283
5
votes
2
answers
503
views
How does current flow in a irregularly shaped heterogeneous resistor?
The motivation for my question is understanding how electricity gets through your skin as opposed to running along it, and how the presence of things like water on the skin affect the relative ...
user24082
4
votes
6
answers
2k
views
Electric current definition
I'm trying to understand electric current. Some resources say that it is the flow of charge, and other resources say that it is the quantity of charge that passes through a cross-sectional area over a ...
