Movement speed of electricity in cable, is same as speed of light in space? In other words, electricity moves in usual electro cable aproximatelly 300 000 km/second ?
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Sorry for a low-tech explanation.
It is like a metal pipe filled with water. If you put more water in one end, it (almost) immediately comes out the other end, because the pipe cannot expand, so some water has to come out to make room for the water that goes in.
When I say (almost) immediately, it depends on the speed of sound in water. It requires a pressure wave to convey the information from input to output.
Is the water moving at that speed? Of course not. It is moving slowly, at a speed that depends on the diameter of the pipe.
It's basically the same with electric charge carriers. The information travels from one end of the wire at a speed close to the speed of light, but not equal, because it is traveling in the conductor.
Mike Dunlavey
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There are two velocities to consider here. Firstly there is the velocity of propagation of the electromagnetic wave. As soon as you get a force on the first row of electrons on the cable, their displacement will create a force on the second row and so on. This chain reaction travels at the speed comparable with the speed of light (between 0.42c and 0.72c) and it's responsible for the time it takes between you flipping the switch and having electricity flowing on the light bulb.Wikipedia about velocity factor
There is also the drifting speed of the electrons themselves, which is very very slow. As an illustrative example, consider the case of copper with a current of 5A and a cross section of 0.5 mm^2 that results in each electron moving at a speed around 0.75mm/s.
SlySherZ
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It depends on voltage, material; etc. But as an example, for a 12-gauge copper wire carrying a 10-ampere DC current, the speed of electric current (average electron drift velocity) is about 80 centimeters per hour or about 0.0002 meters per second.