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

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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

Think of electricity like a river.

A wide and deep river will run slow. That is high current (volume) but low voltage (speed).

A shallow narrow river will run fast. That is low current (volume) but high voltage (speed).

The same river can can fast and slow areas. This is the equivalent of transformers stepping the voltage up or down.

Current and voltage are related to each other. You can trade them back and forth, which is what transformers do.

The big transmission lines run high voltage but low current. The speed of the electricity is very slow in those lines. This reduces losses due to heat, which happens in high current (speed) applications.

To be useful, that electricity needs to be stepped down in voltage from 12,500V to 120V, which increases the current (speed) of the electricity. This allows high current machines such as an electric dryer to function.

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