Electric current's wavelength

Dear,

I think that the wavelength is very small since the velocity in copper is very less as compared to the velocity in vacuum. So u cannot take the velocity as 3x100000000 m\sec. It is some mm\sec. so wavelength is so small.

DC current has no wave form.

If you live in the UK don't plug your kettle in to a socket in Australia.

Reflected AC wave can be a problem with long transmission lines hence the us of HV DC.

I would like to say the basic concept is wrong here – the velocity of electron is not equal to the velocity of light (3x100000000 m\sec). According to Einstein's theory, any object that reaches its velocity equal to that of light, its mass gets infinity. See this formula.

m_r = m₀ / √(1 - v²/c²)

where, m₀ = is the mass a velocity 0 and m_r = mass as velocity v and c = velocity of light

So, if the millions of tiny electrons flow at the speed of light (3x100000000 m\sec), they all would have their mass infinity – can you imagine what would happen then?

Now, come to the basic concept. The Hertz (either 50 or 60) applies to reciprocating movement of electron within the conductor. In the case of electricity flow, there are two types of velocity: (1) Flow of free electron within the conductor – it is called electron drift velocity, (2) Flow of electricity response within the conductor – called velocity of electricity propagation.

For better understanding, think about this analogy, consider a pipe contains full of small free flow balls and you push the balls from one side of the pipe. The balls may move slowly (drift velocity) within the pipe but the response of the push action goes to the other end of the pipe very quickly (propagation). The same thing happens when current flows through the conductor.

The typical electron drift velocity in copper is in the order of 10^-4 m/sec. (0.0002814 m/s, or very nearly 1.0 m/hour), while the velocity of electricity propagation is close to (nearly 75% - 90%) the speed of the light.

See these links:

http://en.wikipedia.org/wiki/Speed_of_electricity

http://en.wikipedia.org/wiki/Drift_velocity

http://resources.schoolscience.co.uk/cda/16plus/copelech2pg3.html

http://www.ece.unm.edu/summa/notes/SwN/SwN35.pdf

http://www.hnsa.org/doc/neets/mod10.pdf

- MS

There is no need to have a phase shift in the length between the source and the load. The statement that only the positive portion of the wavelength is completed does not have meaning. The source will go through the positive and negative phase 50 times every second. It just so happens that the load will follow nearly exactly in phase. If the sink is connected directly to the source then the phase is the same; so what. There is no need to have a shift.

Is this curiosity or is there something underlying that you would like to know?

Frequency of electric current can be varied and we can select various frequencies using a inverter. That frequency is different from the frequency of electrone when it is travelling. According to your question whenever we changes the frequency of AC, wavelength of electrone varies. How can it possible.

Also, DC have no frequency; but electrones travels with a wavelength through the conductor. So please understand that both frequencies are different.

Yes, the electric current has wave structure and yes it has wavelength. No, the speed of the electrons and the speed of the current are not at all the same, any more than the speed of a wave in the ocean and the speed of the molecules of water in the ocean are the same. You can even have the particles move in one direction and the wave in the opposite direction.

Yes, the wave moves with the speed of light. However, the speed of light, or more properly, the speed of electromagnetic propagation varies according to the nature of the medium through which it is traveling. That change of speed is how glass lenses change the appearance of objects seen through the glass. For an electric current traveling, or conducting, through copper, the "speed of light" is a fraction of the speed through a vacuum, though still very fast ( my memory is that it is about 1/3 the speed in a vacuum). The speed in other conductors than copper, like aluminum, is also slower than light-in-a-vacuum, but different than copper. So to find the wavelength of 50Hz electric AC current, you divide the speed of propagation in the medium being used, by the 50 Hz to get the wavelength. You do have to know the conductor material.

Lets not get into the relativistic gravitational changes in light speed.

For 50HZ the time period is 1/50=20ms.Hence it takes 20ms to complete 1 cycle.If you have a conductor of 3x10^8m how much potential you have to apply inorder to get an output on other end?