All Questions
Tagged with electricity electric-current
97
questions with no upvoted or accepted answers
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Is this the reason why a circuit with no components (except wire) would discharge the battery faster?
I read that if I simply connect two ends of a battery it would discharge really quick and it would last longer if the circuit contained e.g. a light bulb.
I wondered why is this happening and my ...
- 373
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Drift velocity in Silicon wafer
I have been asked the following question in a problem sheet:
A $100mm$ diameter, $0.5mm$ thick silicon wafer at room temperature has a charge carrier
density of $1.5×10^{10} cm^{-3}$. A potential ...
- 349
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256
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How does non-constant conductivity change surface charge on a wire?
Current density is equal to conductivity times electric field. Therefore flux through a cross section of a wire is equal to current over conductivity. Current has to be constant along a wire. This ...
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2
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Why Ampère’s Law holds for infinite currents?
I'm reading Griffiths proof of Ampère’s Law and in that proof he needs to show that :
$$\oint \frac{(x - x^{'})}{\imath ^{3}}\mathbf J \cdot \mathbf {da^{'}} = 0 $$ where $$\imath = \sqrt {(x - x^{'})^...
- 105
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Does all the Energy provided by the battery dissipate into heat?
Before proceeding onwards please note that I am talking about a simple circuit consisting of an ideal battery, a switch and an external resistance.
So I was told that $$ W_\text {ideal battery} = Q_\...
- 93
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34
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Is there electric field inside the conductor in moving charges case?
Is there an electric field inside a conductor when steady current passes through it ?
I have two conflicting notions here : I was watching this Electroboom video and at minute $14:00$ electroboom ...
- 441
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45
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Why current density is defined?
I feel that the reason to define thing like current density is that we want to use the directional nature of the current like a vector quantity and since electric current is not a vector so we define ...
- 131
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57
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Current in a two capacitors system in parrallel
I solved this question and I got the values of charges on capacitors in figure B. But my question is charge on capacitors is getting redistributed,but how is it possible when potential difference ...
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Can you measure different currents at different contact points for a volume of material made of two different metals with different conductivities?
My question is about the variation of conductivity in a volume of material and its effect on measured current. A volume is comprised of two metals joined symmetrically in a cuboid shape as in the ...
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3
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102
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Potential drop against internal resistance of cells in combination
Suppose two cells of emf and internal resistance e1, r1 and e2, r2 respectively are connected in series. The negative electrode of 1st cell is connected to negative electrode of the second cell. Why ...
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36
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Current in a Nonuniform Diameter Wire
According to the text Current depends on Area, but then in problems with a "nonuniform diameter" we say that the Current does not change even though the Area changes.
I think I understand ...
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644
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Why Do Van De Graaff Generators Only Shock When Grounding Someone?
When someone touchs the metal sphere of the Van De Graaff Generators, the charge on them builds up, causing the famous hair raising. However, why is it when a person is rapidly grounded by someone ...
- 101
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210
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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
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19
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Electrostatic attraction between charges in different media
Imagine you have two non-conducting spheres of density a (a < density of water). Therefore the spheres float on the surface of water with a portion of their bodies immersed in water. Now how do you ...
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Is the rheostat in a potentiometer compulsory to have?
I've seen some constructions of potentiometer and all of them had a rheostat. Is it necessary for a potentiometer to have a rheostat? If yes, why?
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