All Questions
Tagged with electricity electric-current
791
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The temperature of a metal wire rises when an electric current passes through it because- [closed]
The options given were-
A)Collison of conduction electrons with each other releases heat energy
B)When the conduction electrons fall from higher energy to lower energy level heat energy is released.
C)...
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1
answer
69
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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
1
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1
answer
40
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Confusion about EM waves in a conductor, AC in wires, and skin effect
I am trying to get my head around these different points:
From Maxwell's equations we find that an electromagnetic wave in a conductor decays in amplitude with a characteristic length of about 1 cm in ...
- 197
1
vote
1
answer
110
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Derivation and theory for $I = kV^n$ [closed]
I performed an experiment in college to study the nature of a filament of a lamp, determine $k$ and $n$ in the relation mentioned, and study the variation of wattage of a lamp. I assume ohm's law is ...
- 33
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1
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53
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Why is current through the short circuited wire not zero? [duplicate]
Why does current flow in a short circuited wire? I understand that it offers negligible resistance to the flow of charges, but two points on the short circuited wire will have the same potential, so ...
0
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2
answers
78
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Why doesn't charge accumulate in a loop?
When learning about electromagnetism at my university, electricity flow is generally shown as a conductor with a high potential at one end and a low potential at the other and thus charges flowing ...
- 3
3
votes
6
answers
2k
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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
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2
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92
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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 ...
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1
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50
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Why should the heating coil of a heater have high resistance?
In my book, it is given:
The resistivity of an alloy is generally higher than that of its constituent metals. Alloys do not oxidise (burn) readily at high temperatures. For this reason, they are ...
- 1,066
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1
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38
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Force on charge carriers in a simple circuit
Is it true that in a simple circuit where a simple conducting wire is connected to a battery, the force on each charge carrier is same in magnitude ? If yes, then can you explain how? I know that if ...
1
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2
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119
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Why does the power loss in transmission cable increase when resistance is increased?
In transmission cables, why does power loss increase when length of conductor is increased? According to the formulas V=IR and P=I²R, When we increase the length, the resistance increases, while the ...
3
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3
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124
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Current density of moving charge distribution - mobile charge density vs. "ordinary" charge density of the distribution?
in Introduction to Electrodynamics by David J. Griffiths I have latched upon this definition of current density vector $\mathbf{J}$ (Chapter 5, section 5.1.3, p. 220 in 4th edition) and I would ...
- 85
2
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2
answers
52
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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
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1
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41
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Do electrons move faster towards the end of a circuit?
As 1 coulomb electrons go through 1 volt of potential difference, they gain 1 joule of energy. So in s series circuit, do electrons move faster towards the end of the circuit where they went though a ...
5
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2
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135
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What is the "closed circuit" of a bug swatter racket?
There are bug swatter racket that can kill fruit flies, mosquitos, or flies, if the insect touches the metal mesh.
However, when I look at the construction of the device, the metal mesh is all one ...
- 151