Electronic – A question about electrons, charges and current


Let's talk about DC, a very simple circuit: a light bulb and a battery.

Some authors say that electrons move from negative to positive and current from positive from negative.

I always thought electrons moved in a wire at the light speed, but this video says that charges move very slow in a wire, about 5 centimeter per hour (2 inches per hour).

If electrons are charge carriers, is this video saying that electrons move at 5 cm/hour????

If electrons are that slow how can circuits work?

The video says that electric fields move at light speed.

So, I am not understanding anything.

I aways thought the whole magic were dome by electrons…

What is the correct explanation for this?

Charges, electrons and current?

Is the effect similar to a newton cradle, where one ball knocks the first one and the force is transmitted through the chain?

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Best Answer

In a metallic wire, electricity propagates as a field, effectively. Electrons move quickly and literally bump into other atoms which (usually) dislodges another electron. This continues down the conductor so the effects of electrical current are seen very quickly.

This is not how electric currents propagate in a superconductor, though.

In that sense, the velocity of electrical propagation is very fast (in a wire it is typically about 63% of the speed of light for reasons I won't go into here. It is known as the velocity factor).

Electric fields (or more accurately electromagnetic fields) propagate at the speed of light in free space.

Any given electron does not travel very far in each of these short hops, but they do move, and a specific electron will move quite slowly. This is known as drift velocity.