ELECTRONS
- Thread starter domnic
- Start date
- Status
xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
If i remember correctly a little bit slower than the speed of light... which is @ 186,000 miles per second. If memory serves correct the actual speed is @ 140,000 miles per sec. Either way, its faster than you can blink, and faster than you can say "I didn't mean to touch that wire"...
K8MHZ
Senior Member
- Occupation
- Electrician
Maybe.
http://www.newton.dep.anl.gov/askasci/phy99/phy99092.htm
More here:
http://en.wikipedia.org/wiki/Drift_velocity
Formula: V = I /(n*Q*A)
Velocity = Current divided by number of electrons times the charge of the electron times the cross sectional area of the conductor.
K8MHZ
Senior Member
- Occupation
- Electrician
If i remember correctly a little bit slower than the speed of light... which is @ 186,000 miles per second. If memory serves correct the actual speed is @ 140,000 miles per sec. Either way, its faster than you can blink, and faster than you can say "I didn't mean to touch that wire"...
Don't confuse the speed of the electron movement with the speed of the effect of the electron movement.
Exactly.
Compare to water through an already water-filled garden hose. The water coming out the end is not the same water entering at the spigot... but the effect of opening the spigot is darn near the speed of light... :happyyes:
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
For those of you who like analogies, think of a 100' long water hose which is completely full of water.
Now turn on the tap and see how soon water starts to come out. Long before the first water that enters the hose from the tap gets to the far end of the hose.
And even this is a pretty limited analogy because the mass of the electrons which are actually moving is extremely small compared to the total mass of the electrons in the wire, let alone the mass of the entire wire.
Now turn on the tap and see how soon water starts to come out. Long before the first water that enters the hose from the tap gets to the far end of the hose.
And even this is a pretty limited analogy because the mass of the electrons which are actually moving is extremely small compared to the total mass of the electrons in the wire, let alone the mass of the entire wire.
K8MHZ
Senior Member
- Occupation
- Electrician
In my apprenticeship class we were taught that the effect of electricity was nearly instantaneous. IOW, the difference of the speed of the effect of electricity and instantaneous is almost too small to measure.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Yes, the speed of light has that effect on most people.
fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
A nanosecond of wire is about 7 inches long.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Whereas a nanosecond in free space (vacuum) is about one foot.
In glass with an index of refraction of 1.5 you are back down to about 8 inches, so fiber optics will not be much, if at all, faster than a wire. Just less attenuation of high frequency signals.
Tapatalk!
Very slowly.
About 0.011579414 inches per second for 10A in 2.5mm^2 wire.
junkhound
Senior Member
- Location
- Renton, WA
- Occupation
- EE, power electronics specialty
re: but the effect of opening the spigot is darn near the speed of light
How about just about the speed of sound in water (shock wavefront), nowhere near speed of light.
How about just about the speed of sound in water (shock wavefront), nowhere near speed of light.
junkhound
Senior Member
- Location
- Renton, WA
- Occupation
- EE, power electronics specialty
I like the 'about' followed by 9 decimal places .......
and just to add in a confusabatorial conundrum for plumbers >G<
Then there is the inductor, it makes the electrons so dizzy doing loop de loops they git slowed down in the molasses of the magnetic field;
And of course the capacitor, where the poor electrons try to get across the dielectric fence but just bounce off and end up just going back and forth, no wonder they cant do any real work at all.
Nope. It's faster than that.
Take an open tank with a vertical pipe out the bottom, completely full of water, and a closed valve at the bottom of the pipe which, when open, dumps water into another open tank. When the valve is opened, water comes out of the valve at the rate of 100 GPM initially. At that same instance, what is the rate of level change in the upper tank? Consider water compression at different elevations insignificant in your reply.
fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
That is actually important in supercomputer design. One of Cray's super computers was shaped like a vertical cylinder to make the wires shorter.
Adm. Grace Hopper, an important figure in Computer Science history used to give lectures at which she would give out nanoseconds made from scraps of 25-pair inside telephone wire.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
It's also important for stock trading. Trading computers have a minimum length of CATx cable they must use to make things "fair". "Fair" in that context is a laughable concept to the rest of us. end rant
xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Thanks.......
Sometimes my humour isn't appreciated.
Kirk: What do you think our chances are of getting out of this alive?
Spock: Approximately 1 in 898.9853.
Kirk: Approximately.
Spock: (Lifting one eyebrow) Yes, captain.
fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
Picard:What do you think our chances are of getting out of this alive?
Data: Approximately 1 in 898.985337438205.
Picard: Approximately.
Data: (Mildly surprised look) Yes, captain.
- Status