I was watching The Fox and the Hound, and I was wondering why in this scene the bird gets electrocuted when he taps the insulator?
I know that current needs a complete circuit in order to flow, and that it always takes the path of least resistance. But glass has high resistance. I’m not sure why electricity would flow through the bird instead of just continuing through the path of the metal wire?
Your understanding is correct.
Same as the way the caterpillar ends up flashing like an LED - it’s a cartoon and doesn’t necessarily make any sense.
But I suppose if you want to fanwank it, you could suppose that when the bird pecks through the insulator, there is a path to ground through the bird from its feet on the wire through its beak, to the pole once the glass insulator is smashed.
It’s hard to tell, but it looks like he broke the top of the insulator with his beak. If so, I can see how he would receive a shock… he is at a very high potential relative to earth ground, and the wood post (that the insulator is sitting on) is at ground potential. The breakdown voltage for air is much less than the breakdown voltage of glass. Once the insulator is broken or even cracked, an arc would form between his beak and the top of the wood post.
This is how I see it. The woodpecker breaks the insulator, there is a ground path through the pole. Not a good path, but a path none-the-less.
My understanding is that electricity doesn’t just take the path of least resistance, it takes all paths. But the amount that flows through each path is proportional to the inverse of the resisitance. So in the normal situation there, almost all the electricity is flowing through the low resistance wire and very little is flowing through the glass insulator. So little that it can safely be ignored.
When a new path is formed that has lower resistance than the glass, some electricity will flow through it, more than what flowed through the insulator. Most of the electricity will still flow through the wire, though.
Agree. And at 7200 V, you don’t need a “good” path for an appreciable magnitude of current to flow through you. A total resistance (wood + body + etc.) of 102 kΩ would create a peak current of 100 mA, which is more than enough to kill you.