Does electricity have momentum?

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SUMMARY

This discussion clarifies that while charges in electricity possess momentum, the flow of electric current does not behave like water in a pipe. The analogy between water flow and electrical current is flawed; in electrical circuits, the energy flows due to potential differences rather than the movement of individual electrons across the entire circuit. The layout of wires does not affect the voltage or current, provided there is no resistance. Thus, the momentum of charges is largely inconsequential in typical circuit operations.

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  • Understanding of basic electrical concepts, including voltage and current.
  • Familiarity with circuit diagrams and schematic representations.
  • Knowledge of charge movement and its implications in electrical flow.
  • Basic principles of fluid dynamics, particularly incompressible flow.
NEXT STEPS
  • Research the concept of electric potential difference and its role in circuit behavior.
  • Explore the principles of charge movement in conductors and their implications for circuit design.
  • Learn about the effects of resistance in electrical circuits and how it influences current flow.
  • Investigate fluid dynamics in greater detail, particularly laminar versus turbulent flow in pipes.
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Electrical engineers, physics students, and anyone interested in understanding the fundamental differences between electrical and fluid dynamics in circuit design and analysis.

BenChicago
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w = x = y = z ,

If this were a pump system with water, I think the pressure and flow would be much higher at reading #2, because water has momentum? What about electricity, would the current be higher at #2?
 

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If you create a circuit, and then bend the wires around in arbitrary ways, you will not change anything about the voltages and currents.

Charges have momentum, and of course charges have to move for electricity to flow, but it isn't as simple as the case of water (part of the reason the analogy is bad). If current flows from one end of a wire to the other, there is no electron that traveled that whole distance. Energy is flowing in response to potential differences, and (assuming the wire has no resistance) it doesn't matter what the wire does between points A and B, just the potential at the two points. That's why you can draw schematic circuit diagrams without worrying about the actual layout of items in space.
 
BenChicago said:
w = x = y = z ,

If this were a pump system with water, I think the pressure and flow would be much higher at reading #2, because water has momentum? What about electricity, would the current be higher at #2?

How could the water flow be different at different parts of the uniform-diameter pipe? Water is basically incompressible, so the flow rate has to be uniform in that uniform pipe.
 
berkeman said:
How could the water flow be different at different parts of the uniform-diameter pipe? Water is basically incompressible, so the flow rate has to be uniform in that uniform pipe.

I think he's thinking if you bend the pipe, water will have laminar or turbulent flow and all that?
 
Yes, moving charges do have momentum. But it is inconsequential in most circuits.
 

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