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2006-07-27 20:38:33 · 26 answers · asked by stingmyflesh 4 in Science & Mathematics Physics

26 answers

The speed of electricity through a wire is a bit of a complex question. It
depends on whether you are considering the rate at which electrons
themselves flow along a wire or whether you are considering the rate at
which an electrical signal passes along a wire.

In the first case, electrons themselves move quite slowly - about 100
micrometres per second (or, from another perspective, 1 metre in about 2.8
hours!) Clearly, this is not what we observe when we turn on a light switch.

Ideally, electricity moves at the speed of light. Imagine a tube full of
marbles. If you push a marble in at one end of the tube, another marble pops
out the other end almost instantaneously. Even if the individual marbles are
moving very slowly, the marble "wavefront" is travelling at a very high
velocity.

In the real world, things are not quite so tidy. Electricity flowing through
a gas, or having to work its way through electronic components such as
resistors or capacitors, can be slowed to speeds of 60 to 80 percent of
light speed. However, that's still fast enough that you can safely expect
the light to come on as soon as you flick the switch.

2006-07-27 20:42:25 · answer #1 · answered by pyr0maniac 3 · 0 0

There is some confusion here:

What is measured in Amperes is NOT the speed of electricity but the intensity of the current, proportional to the number of electrons per second . If a four-lane highway allows twice as many cars per minute to enter the city than a two-lane highway would, this means twice as many "Amperes", yet the cars don't run faster. Also, an electromagnetic wave is NOT the same as electricity.

While the speed of an electrical signal is generally close to the speed of light, the speed of individual electrons depends on the medium but also on the strength of electrical field, which is proportional to the force that the field exites on each electron. Imagine an astronaut on the moon (or Earth) that lets a metal ball fall in a glass of honey (or water). The thickness of the honey slows the ball, but also the Earth's strong gravitational field makes the balls fall faster on Earth.

To compute the strength of the field, divide the voltage with the length of the wire. If the cable for your desktop lamp is two meters and the voltage is 110 Volt, the field strength is 110/2=55 Volts per meter. A Volt per meter is 0.00000000000000000016 Newton per electron.

2006-07-28 04:04:29 · answer #2 · answered by helene_thygesen 4 · 0 0

Interesting question. The electrons move quite slowly -- order of feet per second. But the electrical signal moves rapidly -- not as fast as the speed of light, but not very much less. If you are moving electricity through a coaxial cable, you can learn the propagation speed from the cable characteristics. But this is seldom done, because in the vast majority of cases it does not matter. (However, I know of a radar facility where it does matter -- the antenna is a phased array, and the time delays to the antenna elements are very significant.)

2006-07-28 03:44:32 · answer #3 · answered by Anonymous · 0 0

It depends on what it is moving through. Some metals conduct electricity, or energy, easier than others.
Have you ever used a speed controller for a slot car, or something like that? The metal that is used in that controller make electricity move very slowly. The longer the piece of metal, the slower it moves.

2006-07-28 03:43:57 · answer #4 · answered by my_alias_id 6 · 0 0

Here's a hint about travel speed of electricity.. pull some wires out of a socket, wet the end of your fingers.... touch the bare red wire.. betya within nanoseconds you feel rahter uncomfortable...

ONLY JOKING..FOR THOSE IDIOTS OUT THERE IN PC WORLD.. DO NOT TRY THIS AT HOME!! IT WAS A JOKE!!

Speed of electricity is measured in amps.. the higher the amperage, the faster the flow of electricity.. so the answer can be varied upon voltage and amperage!!

2006-07-28 03:42:56 · answer #5 · answered by bikeranimal69 2 · 0 0

In a vacuum, it moves at the speed of light: approximately 186,000 mph, or 300,000,000 m/s. In a gas or a conducting medium it moves more slowly, but in a good conductor it is "close" to light speed, in the sense that for most purposes the slight reduction doesn't make much practical difference.

2006-07-28 03:55:27 · answer #6 · answered by Graham I 6 · 0 0

It depends on the medium. For instance, in a vacuum (such as that in a cathode ray tube), electric currents flow at near the speed of light. In a solid conductor (such as a cable), its much slower. Also, the conductivity (conversely, the resistance) of such a medium also affects the speed at which electricity flows.

2006-07-28 03:42:18 · answer #7 · answered by 6 · 0 0

Speed of light my backside.

Electricity is the flow of electrons.

Electrons have mass and therefore can not move at the speed of light. E=mc²

The time taken to get a response in a signal cable at point B, when a switch is thrown at point A, is dependant on the signal cable, and the ability of teh electrons to flow along it.

2006-07-28 04:12:16 · answer #8 · answered by Anonymous · 0 0

Electricity travels at the speed of light.

The electrons themselves move slowly, but the disturbance (caused by closing the circuit) itself travels with the speed of light.

2006-07-28 05:54:37 · answer #9 · answered by swami060 3 · 0 0

Speed of Light

2006-07-28 03:42:53 · answer #10 · answered by LocoFF 1 · 0 0

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