How can electric fences have a high voltage and low current when current is proportional to voltage?

452 viewsOtherPhysics

As I understand it, voltage is the difference in charge between two points. The greater that difference, the greater the current because more electrons will flow between the two points.

I thought a high resistance might explain this, but apparently the metal in electric fences have very low resistance.

In: Physics

10 Answers

Anonymous 0 Comments

More voltage only means more current if the current source is capable of supplying that amount of current. On an electric fence or some other high voltage / low power source, the voltage will not stay that high once current actually starts flowing, so only a little current will actually flow. That’s in contrast to something like an power line, which has enough juice at the source to keep the voltage (and therefore current) high even when a bunch of current is actually flowing.

It’s kind of like how the tiny sparks thrown up by campfires can’t burn you, because although they’re hot, they’re so tiny that they’ll use up all their heat before they can heat your skin up enough for you to notice. A big block of metal at the same temperature as that spark, however, could burn you and keep on burning you for a long time, because it has more total heat.

You are viewing 1 out of 10 answers, click here to view all answers.