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
55
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
78
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
208
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
643
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
187
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
296
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