All Questions
141
questions
2
votes
1
answer
135
views
How does the magnetic force exerted to moving electrons in a current-carrying wire, actually transmit to the wire itself?
From my physics book I understand that the magnitude of the magnetic force is $F=qvB\sin(\phi)$. It is posteriously derived that the total magnetic force exerted to all electrons in a current-carrying ...
user336281
0
votes
1
answer
585
views
Conventional Current
Recently I learnt about conventional current as well as electron flow, and although electron flow is in the opposite direction to conventional current, we still use conventional current because it ...
2
votes
4
answers
1k
views
Why is current density in a conductor of uniform cross sectional area constant at all points?
According to what I was taught, if current was dispersed “uniformly,” current density would remain constant.
So, in a conductor, the 'current density should be the same at all points.' But, given that ...
- 444
0
votes
1
answer
175
views
How is Lorentz Force $BQv=BIl$?
The formula for Lorentz Force on moving charge is $$F=BQv$$ which for current carrying wire is modified to $$F=BQv$$$$=BQ\frac lt$$$$=BIl$$
Where $l$ is the length of the wire inside the magnetic ...
- 1,168
2
votes
3
answers
66
views
How does the actual power of the device depend on the angular frequency of the voltage? [closed]
The voltage source produces a sinusoidal AC voltage. An electrical device with resistance and inductance is connected to the source. How does the actual power of the device depend on the angular ...
user331916
1
vote
1
answer
225
views
High voltage in transmission line [closed]
I'm trying to understand why high voltage is used in transmission but I seem really confused by the explanations I read.
Here's what I could make out:
$$P_\text{loss} = \dfrac{ΔV^2}{R_t} = \dfrac{(...
- 349
6
votes
3
answers
2k
views
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
1
vote
3
answers
124
views
$I$ proportional to $V$ or vice versa?
I am confused whether Voltage depends on current or the vice versa. I always thought that the vice versa was correct. I tried to find the answers of some of my other conceptual doubts on the web but I ...
0
votes
1
answer
89
views
How Electric field is generated inside wire when a voltage source is connected to it? [closed]
I have found by my searches that the electric field inside wire is generated by the positive or negative charges accumulated at the surface of wire.
My question is, Why do charge get accumulated on ...
user316791
-1
votes
3
answers
131
views
What exactly is AC Amperes
In the case of AC, electrons don't go anywhere. So what exactly are amperes in the case of AC current? It is supposed to be the measure of AC current, But obviously, I would argue that since electrons ...
- 73
-2
votes
3
answers
312
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What is meant by Electrical resistance and Electrical resistivity? Some different thoughts needed
The Electrical resistance is defined as the oppose of flow of charge by a material(wire for example). Also $R = \rho l/A$
What i think is that "charge" here actually means the magnitude of ...
0
votes
3
answers
100
views
What is the definition of direction of current?
Wikipedia defines the direction of current as:
The direction of conventional current is arbitrarily defined as the direction in which positive charges flow.
But suppose a region where there is a non-...
- 480
1
vote
2
answers
84
views
What will happen if both electrons and positive charges got ability to move inside the conductor?
Let's consider a conductor which has a potential difference across its ends.
And let's say that the electrons which already have tendency to move inside the conductor, by all of a sudden if positive ...
- 962
1
vote
1
answer
281
views
Does the number of electrons colliding in wire get double as the length of wire gets doubled?
Does the number of electrons colliding in a wire get doubled when length of wire is made twice with its area of cross-section remain constant.
My calculations for this are:-
For wire of length $L$ and ...
0
votes
1
answer
183
views
EMF of source depends on the charge and the path then what do we mean when we say EMF of a source is $\epsilon$?
EMF of an EMF source (a battery for example) is defined as the work done by the non-conservative force(s) on charged particles as it passes through the terminals of the source divided by the charge of ...
- 480