Whats the speed of an electron during conduction?

It's called drift velocity and at 1 amp of current the electrons are drifting at an amazingly slow 23 μm/s assuming a 2mm thick pure copper wire. 2mm is a super thick cable mind. Source: wikipedia

Another source (school science) puts the drift velocity of the electrons that are part of a glowing hot 5 amps of current squirting down a tiny little wire of 0.5mm diameter at the much faster but still real slow:  7.35 × 10-4 m s  or 0.7 milimeters per second.

They travel slower in thick cables and faster in thin!

Inspired by this stack exchange question that asks: Is voltage the speed of electrons? Up until now I figured it was but voltage is more like the pressure of electrons. In a big thick wire they will be moving slowly because still waters run deep... as the wire thins, like white water rapids, they'll accelerate to relativistic speeds (waterfall) unless they hit something (impedance) and get warm maybe turn into steam (radio). Just like water in a hose with your finger at the end pinching the output and causing the water to spray out at high speed, so maybe do the electrons grinding to a halt as a fuse blows and breaks the chain of quantum custody.

A resistor is a device that can slow the waters without evaporating or over heating. A power grid uses high voltage a cable that is so much thicker than it needs to be, in order also to keep cool and organised.

According to a webpage I just read, the average distance an electron travels between collisions is 2.0 μm.

According to the wisdom of these Quora answerers in 1 amp at 1 volt there is 6.25 E18 unit charges. That's 6,250,000,000,000,000,000 unit positive charges.

Now assume long distance transmission line running at 625 KV but only 1 amp. Now it's only 10,000,000,000,000 electrons per second because they are travelling faster.

Hence, 1 Coulomb contains 1/(1.6 E-19)=


Posted by tomachi on February 10th, 2018 filed in Science

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