What is traveling across the neutral wire in your typical household wiring if the load is using the electrons?


I understand basic electricity in that electrons are flowing to energize whatever is on the line, say a light bulb, but in order for it to work you need to complete the circuit, why? What is traveling from the light bulb back to the source over the neutral wire?

In: Engineering

The electrons don’t disappear, they move from a high energy place to a low energy place, like water at the top of a hydroelectric dam vs water at the exit. The water at the top has more energy, and extracting that energy doesn’t make the water disappear.

The electrons flow “through” the object being powered. In the case of the lightbulb, resistance to the flow of electrons through the light filament makes the filament heat up and shine as electrons move through it.

Imagine a stream that powers a waterwheel. The water pushes the wheel and then moves along on its way, while the wheel turns and performs some kind of work.

An electrical load is powered by moving electricity (current flow). Think of it as something that is pressurized (with voltage). If you had a pump that was powered by water it would need water constantly flowing to perform the mechanical energy needed to perform work. A light bulb is burning a filament, an LED is a diode which lets off light when current flows through it. An electric motor uses electromagnets that turn in order to follow changing polarity which only changes because current is flowing through it. Work can’t be performed if there is no movement/ kinetic energy.

Think of electricity as the wind moving through a field of wind turbines. It only performs work as it passes through. In order to keep moving through the field, it needs some place to go. It can’t just stop and stay in the field. When it stops moving, it stops being wind.

Electrons = Air, Electricity = Wind

You’re thinking electrons are like the gas in a gas stove: Some kind of fuel that’s used up as the device operates.

Electrons aren’t like that. They’re more like the chain links on a bicycle chain. They can transfer energy into making things happen as long as they’re connected to a mechanism that forces them to move. The chain links travel from pedal to wheel and back, and cause the wheel to spin, but they aren’t used up in the process of the bicycle’s operation.

This is a great explanation. Thank you.