So if the path to ground is not the path of least resistance, what does electricity do?
In: Physics
“Electricity” takes every path to ground simultaneously in an amount inversely proportional to the resistance of that path, more or less. It doesn’t prioritize one path, or somehow seek out the path of least resistance. The POLR will take the majority of the current.
Take a circuit with two resistors in parallel. If the original statement was true, the larger resistor would experience no current flow. This is manifestly false.
It doesn’t flow that way, unless the potential difference is too great. And you’ve actually seen this happen – it’s lightning.
Clearly, normal air is not a very good conductor, so it’s certainly not the path of least resistance. But you make the potential difference between the ground and the cloud high enough, and it will find a way.
Of course, put up a metal spike and call it a lightning rod, and now it’ll prefer it over your shiny new building. So it does both. Your two statements are not contradictory.
Perhaps, in the spirit of ELI5, it’s best to say this
Water will always flow from a higher point to a lower point. When it does this flow, it will follow the path of least resistance. Sometimes, when there is a lot of resistance, the water may not flow for a bit, but you build up enough potential difference (pile up an ocean of water), and it will overcome any resistance to flow where it wants to.
They aren’t the laws of electricity. The laws are:
– ∇ · E = ρ/ε₀ (Gauss’s law)
– ∇ · B = 0 (no magnetic monopole)
– ∇ × E = − ∂B/∂t (Faraday’s law)
– ∇ × B = μ₀(ε₀∂E/∂t + J) (Ampère’s law)
All other ideas about electricity stem from these 4 laws, collectively known as Maxwell’s Equations. You absolutely do not need to understand these equations.
So it doesn’t matter that there are contradictions in the resultant ideas, because they are applications of Maxwell’s equations in specific cases, and those results might not extend to other cases.
To answer your question, consider that every point has an electric potential, measured in Volts. Then if there is a difference in potential between two points, charge is going to move from the high energy to low energy. It does this the quickest way.
A good analogy is thinking about bumpy terrain, where higher is more potential and lower is less potential. A ball will roll down the potential difference and end up at the bottom.
Since there is a potential difference between a wire connected to a battery and the earth, this is where charge will flow, even if going elsewhere is easier.
You are confusing the concept of electrical ground with the actual ground.
In many circuits you have a common “ground”. In a car your entire frame is the electrical ground and connected to the negative battery port. The actual ground has nothing to do with this.
For house wiring the actual ground is used for a universal connection for return.
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