Why do we need two wires for electricity?

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Discussion Overview

The discussion revolves around the necessity of using two wires in electrical circuits, particularly in the context of how electrons move and the role of potential energy. Participants explore analogies and explanations related to electrical energy, circuit completion, and the behavior of electrons in a circuit.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that a complete circuit is necessary for devices to function, questioning whether electrons are lost or simply lose kinetic energy when returning to the positive end.
  • Another participant provides an analogy comparing electrons in a wire to a bike chain, explaining that electrons move from high potential (positive terminal) to low potential (negative terminal) and require conductors to facilitate this movement.
  • It is noted that current is driven by an electric field, and if the circuit is not closed, charge accumulation occurs, which reduces the field strength in the wire to zero.
  • Some participants emphasize the distinction between electron flow (from negative to positive) and conventional current flow (from positive to negative), with one participant humorously attributing confusion to Benjamin Franklin.
  • There are repeated assertions about the direction of electron movement and current flow, with some participants expressing frustration over misconceptions regarding these concepts.

Areas of Agreement / Disagreement

Participants express differing views on the implications of electron flow versus conventional current flow, and there is no consensus on the broader implications of these distinctions. The discussion remains unresolved regarding the understanding of these concepts.

Contextual Notes

Some statements rely on specific definitions of potential energy and charge movement, which may not be universally agreed upon. There are also unresolved nuances regarding the implications of conventional versus electron flow in practical applications.

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I know the circuit must be complete in order for devices to work. I want to understand this with an analogy in reference of a battery. Let there be a bulb in the circuit connected to a battery. Now if circuit is closed then what happens in the circuit? Electrical energy lights up the bulb so is there any loss of electrons in numbers or is it electrons lose kinetic energy when they are returned to the positive end.
 
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Think of the electrons in the wire like a bike chain and the power source is like the pedals. When you do work on the pedals, you pull the chain, and the work is done on the rear wheel.

The electrons, like the chain, let the power source do work on the load (in your case, a light bulb).

Now, the reason we need two wires is that to make those electrons move they need to use up potential energy. The positive terminal is high potential (has more potential energy) and the negative is low (or ground, which may or may not literally be the ground) potential. The electrons want to go to from the high potential to the low potential, but to do that they need a conductor. Work is done by a system when it uses up potential energy, so the electrons do work when they use up potential energy in moving from high potential to low potential.
 
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Current is driven through a wire by an electric field. If the circuit is not closed charge will accumulate which produces an opposing field reducing the field strength in the wire to zero.
http://www.phy-astr.gsu.edu/cymbalyuk/Lecture16.pdf
http://www.astrophysik.uni-kiel.de/~hhaertel/PUB/voltage_IRL.pdf
 
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jack476 said:
Now, the reason we need two wires is that to make those electrons move they need to use up potential energy. The positive terminal is high potential (has more potential energy) and the negative is low (or ground, which may or may not literally be the ground) potential. The electrons want to go to from the high potential to the low potential, but to do that they need a conductor. Work is done by a system when it uses up potential energy, so the electrons do work when they use up potential energy in moving from high potential to low potential.
except the electrons move from negative to positive ;)

be careful with your conventional and electron flow directions :)

Dave
 
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davenn said:
except the electrons move from negative to positive ;)

be careful with your conventional and electron flow directions :)

Dave

The electrons move from negative to positive, the current flows from positive to negative. Damn you Benjamin Franklin!
 
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analogdesign said:
The electrons move from negative to positive, the current flows from positive to negative. Damn you Benjamin Franklin!

We now know the true mission of "Interstellar".
urgent_mission.png
 
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haha that's awesome. Never saw that one.
 
analogdesign said:
The electrons move from negative to positive, the current flows from positive to negative. Damn you Benjamin Franklin!
If that presents a problem for anyone then they can't claim to have a proper grasp of electricity. It's irrelevant (could be African or Indian :D).
 

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