All Questions
91
questions
3
votes
6
answers
2k
views
Is electric current actually the flow of electrical charge?
In my high school, the definition of electrical current is "the flow of charges" but I have seen a video about how electricity actually works and it seems to me that electrical current is ...
0
votes
2
answers
93
views
What is actually electric current? [closed]
Electric current is the rate of flow of charges (electrons) or the rate of flow of positive charge. Okay, I get it. But here's my question. The electron flows in the wire and then the current flows in ...
2
votes
2
answers
57
views
Electric current density definition
I'm just wondering why the current density $J$ is always defined as the amount of electric current traveling per unit cross-section area $J = \frac{I}{S}$, and not per volume unit $J = \frac{I}{V}$ so ...
- 21
2
votes
1
answer
80
views
(A10) If light is an EM wave, can it interfere with electrons in a live wire, leading to a change in the wire's current?
Here's my question: If light is an electro-magnetic wave, with oscillating magnetic and electric fields, wouldn't light interfere with the free electrons flowing (slowly) in a wire, as the electric ...
- 23
1
vote
3
answers
1k
views
Does current make the full return trip?
In an AC system, the neutral wire is said to provide a return path for the current back to it's source. Given that the current is said to be alternating back and forth, how does this work, does the ...
- 13
0
votes
2
answers
210
views
Flow of Electrons in Potential divider circuit
Take the above circuit. I'm trying to understand how current flows through this potential divider circuit. I used the following simulation to help me visualize this.
In the simulation the electrons ...
- 69
0
votes
1
answer
53
views
Potential Energy of an Electron inside a circuit [closed]
Why doesn't the electric potential energy of an electron decrease while moving in a circuit away from the negative terminal? This question is concerned with the drop in the potential energy of ...
- 53
3
votes
1
answer
650
views
Is charge carrier density an intrinsic property of a material and is thus constant?
I was studying the equation $$I = nAvq$$
where $n$ = the charge carrier density, $A$ = cross-sectional area of the conductor, $v$ = mean drift velocity of the
charge carriers, and $q$ = the charge on ...
- 31
0
votes
2
answers
68
views
What is a current?
I am confused. One GCSE video on YouTube says it is a flow of electrons around a circuit; while, my textbook says it is a flow of charge around a circuit, carried by electrons. Since charge can be ...
0
votes
2
answers
156
views
Can we make electron drift velocity faster than light by reducing area of resistor?
We know that $I= nqAV_d$.
Can we send high current ($I$) through a "fat wire" (more $A$) then reduce $A$ at the resistor so much that $V_d$ becomes faster than light in order to maintain $I$?...
0
votes
1
answer
191
views
Motion of the electrons in a electric conductor when connected to a potential difference?
(I am a beginner in physics, so please forgive me if this is stupid.) Normally, under static electric state there is no resultant electric field existing inside a conducting material. But, when a ...
- 201
3
votes
2
answers
299
views
What makes a lightbulb glow?
I am self-studying electricity and magnetism, and I am confused about a point.
I have learnt that the drift speed of an electron is extremely small. However, according to Drude's model, the electron ...
- 268
0
votes
1
answer
141
views
Why were electrons chosen to be negatively charged? [duplicate]
Wouldn't it make more sense to call electrons positively charged because when they move they make electricity?
- 1
0
votes
1
answer
32
views
How are the electrons able to overcome the significant force of attraction of the ions?
The cause of electrical resistance(in a metal) is electrons colliding with themselves and the positive ions. So if the electrons collide with the positive ions, how are they able to overcome the ...
1
vote
2
answers
259
views
Does a higher voltage always mean a higher electric field strength?
In a step-up transformer, the output voltage is higher than the input voltage, while the output current is lower than the input current. Basically, since P = VI is conserved, the current has to ...
- 337
0
votes
1
answer
455
views
Why is this incandescent light bulb working under water?
The bulb is directly connected to 220V supply and is put into this glass container containing normal tap water.
Why is this bulb working under the water?
What about the ionisation of water molecules ...
- 11
1
vote
0
answers
23
views
In AC, do Electrons move in perfect Sync with Generator Rotation across the whole distance?
While i'm self studying electricity, one interesting topic seemed counterintuitive to me, which is:
When an AC generator connects to a long XX KM length cables; each cycle, the electrons in the cables ...
- 11
2
votes
1
answer
270
views
Is the electron flow restricted by filament of a bulb?
Suppose that the electrons move with a speed of 0.0005 mm/sec in the copper wires. Do the electrons move with the same speed in the tungsten filament as well? This has to be true if current is same in ...
- 41
3
votes
3
answers
2k
views
Why is flow of current considered opposite to flow of electrons even by "convention" [duplicate]
This question is a very basic one,
We are told that that current is produced because of flow of electrons but it is stated that the flow of current is opposite to the direction of the flow of ...
- 341
0
votes
3
answers
345
views
Safety devices like fuses should be connected with the live wire rather than the neutral wire?
So, I was told in my class that Safety devices like fuses should be connected on the live wire. But isn't the conventional current opposite to the direction of the flow of electrons? And what actually ...
- 3
38
votes
8
answers
20k
views
Is electricity really the flow of electrons or is it more involved?
I am new to the physics category of the Stack Exchange site. I apologize if my question is wrong, too broad, simple, or worded incorrectly. I am just trying to figure out what is true and false when ...
- 499
0
votes
1
answer
1k
views
Is the path of an electron between successive collisions (with positive ions of the metal)a straight line in the presence of electric field?
I feel that the answer should be yes. While the entire journey isn't straight, the journey between successive collisions is straight. But the internet and my book says the opposite (the path is curved)...
- 7
0
votes
1
answer
307
views
Free electrons in materials with high resisitivity
I want to understand why exactly resistors or materials with high resistivity difficult the flow of current. If I'm not mistaken, there are not many free electrons in this materials to move and ...
2
votes
1
answer
446
views
How does electric field propogate in a wire? [duplicate]
When I say electric field, I'm referring to the electric field that causes the movement of charge in the wire.
I have learnt about currents and resistances, but I have never really had an ...
- 669
0
votes
1
answer
55
views
What is the actual physical movement of the electron from the copper atom that produces electric current?
What is the actual physical movement of the electron from the copper atom that produces electric current? Is the electron given a higher energy level and this releases the electron from the copper ...
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
4
answers
196
views
Electrons in an electric circuit , its movement and power delivered
Does an electrical appliance convert electrons into its respective work , I mean is electron being consumed by appliance (say bulb ) and then this mass gives us energy.
or the same number of electron ...
- 784
0
votes
1
answer
767
views
How do electrons actually move in an alternating current?
Here's what I think the motion of electrons would be like.
Let's say the electrons were initially at rest. Now, when the voltage starts increasing, the electrons start accelerating faster till the ...
0
votes
1
answer
566
views
Would a flow of current (of positrons) zap us?
I have read this question:
Will Positron Cause flow of electricity?
To your question, yes, positrons are just as good as electrons for carrying a charge. There is no difference between "...
- 29k
1
vote
4
answers
870
views
Confusion about electron flow and current
So, I learned in class that current is defined as positive charges moving from south to north. However, in all reality, the negative charges are moving, but the convention of positive to negative wors ...
- 11