All Questions
30
questions
1
vote
1
answer
105
views
If a downed powerline contacts the metal chassis of my car, can I touch any metal parts of my car while sitting inside of it?
consider the following situation. I parked my car underneath some high-voltage lines – let’s say 380 kV-lines. Suddenly, one of the lines breaks in the middle due to a storm and one end of the (still ...
- 11
0
votes
2
answers
1k
views
Why can't we use a slip ring instead of a split ring in a dc motor?
I've been taught that in a dc electric motor a split ring is used to connect the two ends of the rotating coil to two carbon brushes so that
The wire does not get twisted and
The current passing ...
- 252
0
votes
4
answers
71
views
Do you "lose" electricity when you course it through subpar conductors?
Imagine I had a basic circuit - say the classic 9V battery on one end, a couple of wires, and a little light bulb on the other.
Of course, in a real world example those wires would probably be ...
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 ...
1
vote
2
answers
766
views
What force moves electrons through a conductor that is rotating in a magnetic field [closed]
Is it the magnetic force ( F= qv +B ) or the electromagnetic force (F= q(E+vxB) that acts on the electrons of a conductor that is moving in a magnetic field?
Thanks.
user232620
3
votes
1
answer
698
views
Does the shape of a wire affect the electric current in it in any way?
Say we have a straight wire connected across two terminals carrying electricity between them. If everything is kept the same (voltage across the two terminals, resistance of the wire, etc.) will there ...
- 195
5
votes
4
answers
987
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 ...
0
votes
1
answer
63
views
GENERATION OF CURRENT DUE TO ELECTRON FLOW
Why do flow of electrons generate current? whenever an electrons flows through a wire it generates electricity why does it actually happen?
- 31
1
vote
1
answer
94
views
Does the electron in wire too move because of voltage difference?
When we talk about electricity through a circuit because of a battery it is said that the electrons from negative terminal travel to positive terminal of the battery.
I can't help but imagine about ...
- 300
0
votes
1
answer
121
views
When AC electricity is generated, how does the current flow? [duplicate]
I have read multiple different versions of how AC current flows in our power lines. How does the current flow? Is the energy just photonics waves passing through electrons that vibrate or are ...
- 1
0
votes
2
answers
148
views
Resistance in special cases
I am curious-
I know that resistance doubles when length does, and that resistance would be halved if cross sectional area was doubled -
But is there such a case of special conditions where It ...
- 3
2
votes
1
answer
362
views
How does electricity work exactly? [closed]
So it just isn't popping for me how electricity actually works.
AC at 60 Hz can swap directions 60 times a second and drift at roughly 1 m/s while they kind of ping pong forward with constant push ...
0
votes
2
answers
465
views
How does the current become homogeneous within a circuit?
I have two questions:
In a given circuit with resistances of different values connected in parallel, there is a different build up of electrons when the power source is turned on. Then, how is the ...
- 1,235
1
vote
2
answers
924
views
Does electric current create positive ions while flowing through a conductor?
As the conduction electrons are free to move randomly, i.e they are not restricted to a particular atom, then why don't these atoms get positive charge due to loss of these conduction electrons?
- 41
0
votes
1
answer
66
views
Mechanism of electricity in conductors
In mechanism of electricity in conductors my teacher said the free electrons collide with positive lattice and this positive lattice is oscillating about its mean position. Ok for producing current ...
- 35
1
vote
1
answer
167
views
Capacitance due to accumulation of charge on the interface between resistors
It is well known that the continuity condition for current density necessitates that at a steady state:
$$\frac{\rho}{\epsilon_0}=-\frac{E\cdot \nabla \sigma}{\sigma}$$
Where $\sigma$ is the ...
- 234
0
votes
1
answer
89
views
Is the speed at which electrons move through a conducting wire binary?
If a voltage differential causes electrons to move through a conducting wire, and no other forces are acting against them, will they always move at the highest possible speed through that material?
...
0
votes
1
answer
75
views
Point resistance
The resistance of a given object is expressed through:
$$R=\rho\frac{l}{A}$$
I'm wondering if there is any quantity like resistance at a specific point. For example, $R$ for a copper wire with l=...
- 3
1
vote
2
answers
954
views
Does an electron physically flow? [duplicate]
In a DC current in a conductive wire, is it more accurate to think of one electron wiggling its way through a sea of electrons... or to think of one electron bumping into another, which bumps into ...
- 445
1
vote
2
answers
206
views
Resistance Being Proportional to Length And Its Relation to Magnitude of Current
"Resistance of an electrical conductor is proportional to it length"
The intuitive explanation I found in many articles was that the greater the length of the conductor, such as a wire, the greater ...
- 1,387
5
votes
4
answers
2k
views
Temperature distribution in a current carrying conductor
A rod of uniform cross section and composition is connected across a battery. Let the middle part of the rod(when divided into three equal parts) is heated uniformly.
A book says that the temperature ...
- 71
0
votes
3
answers
1k
views
Heating of an non-ohmic conductor
So I know that if you increase the voltage across a wire then the current will increase. But an increase in current leads to a increase in heat production though $P=I^2R$, but as the temperature ...
- 273
5
votes
2
answers
695
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, ...
0
votes
1
answer
583
views
Why are spheres supposed to become discharged?
Source of image: Fundamentals of Physics extended fifth edition by Halliday, Resnick and Walker. Concerned to First Paragraph.
Why in the rejected scheme, Spheres are supposed to go neutral (or ...
user104909
-3
votes
1
answer
362
views
How electricity works acutally?
I've been told that electricity is due to flow of charges(-ve charge=electron) that are provided by the battery. And no. of charges that leave battery at one end are equal to no. of charges that re-...
-3
votes
3
answers
1k
views
How can the copper wire in an electricity generator provide an infinite number of electrons? [closed]
How can copper wire in an electricity generator produce an infinite number of electrons when the is a finite number orbiting each copper nucleus?
1
vote
2
answers
1k
views
Some questions related to circuits and flow of electrons
I have some doubts related to electric fields and flow of current. So, let us assume an electric circuit, which contains a battery and a wire connecting positive and negative terminal of the battery. ...
- 972
4
votes
1
answer
23k
views
Why don't you get electrocuted when you jump and touch an electric fence?
I've read that you won't get electrocuted if you jump and touch an electric fence because you aren't closing the circuit with the ground. Which is also why birds don't get electrocuted when they're ...
29
votes
5
answers
29k
views
Why is there an electric field in a wire even though it is a conductor?
If you take a perfect conductor, there cannot be a field across it since if there were, the particles would arrange themselves in a way to cancel out the field right?
Yet, why does the same not hold ...
- 1,585
1
vote
2
answers
926
views
How is electric field instantaneously generated inside a conductor connected across two terminals of a battery? [duplicate]
I have learnt that the electric field that is responsible for current flow is generated inside a conductor as soon as the two ends of the conductor are connected or brought in contact with the two ...
- 115