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If the electrical energy is outside the wires, how is insulation protecting us?
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madires:
The insulation protects you from closing a circuit (you are a resistor). At the same time there's an electromagnetic field which can impact you (you are an antenna or conductor). In most cases the field strength is too small to have any noticeable impact. But this changes with a very high field strength (frequency plays also a role). Or in other words, if the field strength is large enough you'll sense pain. Most countries defined limits for each field strength. For example, our limit for the electrical field strength at freqencies of 1-50 Hz is 5 kV/m.
TimFox:
In the regulation of MRI, the relevant parameter is "SAR", which is the energy absorbed from the high-frequency magnetic field per kg of body mass.  This energy goes to heating the body tissue which, in extreme cases, can cause burns.
RJSV:
Thanks, timfox, RF can be invisible danger.
   
   I'm wanting to mention, recent a person posted some discussion about a DC Lamp. Uh, OK that could happen, in an RV (12 V automotive), or in uh, a TENT or something. But that is misleading / distraction as we generally are discussing AC transmission of energy.
That's why you get the TWO effects, basic physics.
One effect, the AC current, time varying,  causing field
 fluctuations surrounding the current flow (in wire) and other transmission directly inside the wire. Both will wax and wane, so you can always make the case that one or the other 'goes through zero volts point', on waveform (SINE if it's free of noise etc). OR, you can always say the magnetic field fluctuation goes through zero field strength, too, as it transitions to a (sinusoidal) negative half of waveform. All cyclic.
Yeah, so how, again, does bringing up DC relate, to a pair of sinusoidally vibrating field/ and current (??).
RJSV:
The 'other' faulty / misleading post on my mind right now, states "...it can't be transmitted through wires 'cause they will just 'disapate' it all, in internal resistance.".
   Uh, I ran the numbers, for that (sigh...), it's not that hard to multiply and comes to something like 10 ohms series cable transmission wire resistance added to a 240 ohm  load resistance for a 60 Watt bulb.
That's for a 100 foot length and MY numbers say that the wires have only 4 % while the LOAD at end of cable recieves fully 96 %.
   As the saying goes: Prove me wrong! Please, for the sake of the OP :
   "Publish Your Numbers" ! So we can examine, here.
bsfeechannel:

--- Quote from: typoknig on April 04, 2022, 03:32:33 am ---This response though seems to miss the head scratching aspect of my original question; if the "energy" is outside the wire why doesn't it affect us until we touch the bare wire?
--- End quote ---

It's because you too are a conductor and the electric field inside you must be zero, forcing the energy to circle around you.

When you touch the wire you provide a way for the electric field be in parallel with your skin, effectively pointing the flow of energy into your body, in which case you get barbecued.


--- Quote --- I'm also assuming when you say "outside the wire" you mean really outside (i.e. outside the insulation) and not just on the outside of the wire (i.e. on its surface).
--- End quote ---

Nope. Energy flows through the insulation too, since it can admit the presence of an electric and a magnetic field.
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