Eli5- In electrical wiring, does some electricity dissipate into the surrounding material, like water/air/insulation?
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Electricity is really a field induced by flux in conductive material. So it doesn’t “leak” like water, but it does “leak” like light, if you equate conduction with transparency/translucency. So any “black” insulator isn’t going to bleed off any of the force from the electrical field, but any material in the field with a low enough resistance will use some of the energy, usually to generate heat (moving atoms).
It does for AC power because the electricity is constantly changing direction and that means a changing electrical and magnetic field. That’s why high-power undersea cables tend to be DC, to avoid those losses. Air is much less dense so the energy loss is tolerable for above-ground transmission lines. The buried cables in residential areas are relatively short and low power, keeping the losses to acceptable levels.
Technically? yes
As far as normal people care? No
Nothing is a perfect insulator, but they’re pretty close. For some scale here, copper has a resistivity of 10^-8 meaning its a really good conductor (ignore the rest of the units, this is for scale). Air has a resistivity of at least 10^9 making it almost a trillion trillion times more resistive and also that a trillion trillion times less current will flow through the air than the copper. Insulations are even better. Teflon is about 10^23 so that’s a trillion trillion trillion million times more resistive
There is nearly always some absolutely tiny amount of current leakage through insulators but its generally irrelevant because its 9-20 zeros below the rest of the current levels in the circuit
AC also has some capacitive coupling which saps energy from the line. Basically the hot wire and any other conductors nearby each act as the plate in a capacitor and get charged and discharged each cycle and it passes energy through the air to the other side be it the neutral & ground wires(in building wiring) or just the dirt below for transmission lines.
Again, the power losses from this are lower than the rest of your circuit is generally using, the only exception is if you have a 300 kV ultra high voltage line that is traveling thousands of miles and is therefore a really longgggg capacitor plate, then it can be a couple percent of what you’re sending
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