All Questions
Tagged with conservation-laws electrical-resistance
10
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Charge conservation in ohmic material - Apparent paradox
Consider an ohmic material with constant conductivity, which obeys the relation:
$$\vec J = \sigma \vec E$$
where $\vec J$ is the current density and $\sigma$ is the conductivity. Applying the first ...
- 1,616
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Continuity Equation on a Non-Ideal System
I recently watched a video on the diffusion equation for neutrons in a fissile material, and at about 2:30 minutes into the video, the author points out that the right hand side of the continuity ...
- 11
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Why does current not decrease in/after a resistor if electrons are impeded/lose energy? [duplicate]
I was told that current is uniform across a series circuit. Yet I was also told that a resistor works by impeding the flow of free electrons, which should mean slowing them down. Does this mean that ...
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1
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Does $J = \sigma E $ hold when a charged mass is subjected to an external force?
Let's say that I have a charged mass that is moved by some non-electromagnetic means such as gravity or fluid flow.
I expect Maxwell's equations to hold in this case. However, I am confused as to ...
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Prove that electric current in any arbitrary cross section is the same
Consider a conductor with variable cross sections there is an electric current in it. Now prove that electric current in any arbitrary cross section is the same.
- 125
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Is electricity perpetual in a superconductor system?
I wonder if electricity consumption happen according to the Law of conservation of energy and Joule effect, in a regular circuit certain amount of energy is transformed into heat by components ...
- 171
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2
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Is Ohm's law valid for all frequencies?
From continuity equation and Ohm's law it it's possible to say that:
$$ \nabla \cdot (\sigma \mathbf{E}) = -\frac{\partial \rho}{\partial t} \Rightarrow -\frac{\partial \rho}{\partial t} \frac{1}{\...
- 275
5
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3
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Why doesn't current decrease in series combination?
I know that the question is quite stupid but I want to get an insight of this case. consider 3 resistors connected in series with a battery, after the current passes through resistor 1 it loses some ...
- 103
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Why current in series circuit is the same?
I have read in the internet that the charges do not have any other path to go and they must go through the same in a series circuit,hence the current is same.
It was quite convincing but what ...
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Why does current density changes but not current? [closed]
let us assume that we have a conductor with a specified resistance ( case 1 ) and a normal conductor ( case 2 ) as shown in the figure , and now we apply an external electric field with a battery on ...
