How does electricity “know” it has a completed circuit?

766 views

I know that electricity will take the path of least resistance.

Say we have a body of water. This water begins flowing down the path of least resistance and forms a river. However, the water eventually reaches a point where it can no longer flow, and it stops there.

Now in terms of electricity, if I touch an electrical source and also am grounded, it will flow through me and hurt. However, if I touch a source, but I am insulated from the ground, it will not flow & not hurt me.

I would like to think electricity is like water in terms of meandering through and finding the best path, but if electricity flows through and cannot complete a circuit, nothing happens. Or if electricity does not flow like the water would (in search of that path), how would it know that path/circuit is complete?

In: Physics

3 Answers

Anonymous 0 Comments

> I would like to think electricity is like water in terms of meandering through and finding the best path, but if electricity flows through and cannot complete a circuit, nothing happens. Or if electricity does not flow like the water would (in search of that path), how would it know that path/circuit is complete?

And what happens in a water circuit when you have a pipe that is capped off? Water flows in, but eventually the pipe is full, and no more water can enter. That is fundamentally what happens with a wire that is not in a circuit – a full water pipe that is connected to a high-pressure pipe on one side, but not connected to a low-pressure pipe on the other, but just capped off. The water in there simply has nowhere to go, and you cannot just let water flow into a pipe that is already full – there is no space for the extra water to go. Hence no current.

With a river, you have a lake that would form at the end, where the water level would rise until evaporation matches the flow of the river. But electrons do not just evaporate, so such open systems are not really a good analogy for common circuits.

You are viewing 1 out of 3 answers, click here to view all answers.