PopularFX
Home Help Search Login Register
Welcome,Guest. Please login or register.
2022-11-29, 07:31:20
News: Forum TIP:
The SHOUT BOX deletes messages after 3 hours. It is NOT meant to have lengthy conversations in. Use the Chat feature instead.

Pages: 1 2 3 4 5 6 7 8 9 [10]
Author Topic: Displacement Current - Does it Exist?  (Read 96035 times)
Group: Experimentalist
Hero Member
*****

Posts: 1550
Putting capacitors in series will never prove that the magnetic field comes from a displacement current.

Either the capacitors have connecting wires, and then the ordinary currents in these wires will produce the magnetic field, or they are just plates, and even if they are infinitely thin and the current through them can be neglected, they are only equipotential and will therefore be of no use between the first and the last plate, so that we will no longer be in the approximation of the plane capacitor.


---------------------------
"Open your mind, but not like a trash bin"
   

Group: Tinkerer
Hero Member
*****

Posts: 3798
tExB=qr
Paper: physical interpretation of displacement current

   
Group: Experimentalist
Hero Member
*****

Posts: 1550
"There is no way now that the electron can move, so there is no electron conduction current through the capacitor. Here something very primitive happens. These electrons induce a positive charge onto the other side of the capacitor or they push the electrons on the other side of the capacitor plates away from them and pull the positive charges towards them such that opposite chargers are induced on either side of electron."

I agree. You don't need anything between the two plates for the charges of one plate to influence the other.

The coulombic influence does pass between plates as if it were the field of moving electrons, so we do have, in a way, coulomb/s crossing the gap between plates, which is called displacement current.



---------------------------
"Open your mind, but not like a trash bin"
   
Hero Member
*****

Posts: 2318
Quote
"There is no way now that the electron can move, so there is no electron conduction current through the capacitor. Here something very primitive happens. These electrons induce a positive charge onto the other side of the capacitor or they push the electrons on the other side of the capacitor plates away from them and pull the positive charges towards them such that opposite chargers are induced on either side of electron."

I think this shows how little most understand about electricity and electric fields.

First, in a metal conductor only the negatively charged free electrons are mobile. The positive charges cannot move only the negative free electrons can move in a conductor. Conventional flow notation was proven wrong decades ago and it's complete nonsense. In Canada all children are taught electron flow notation in grade school and nobody believes (+) charges are flowing in a conductor.

Here is a better model of how charges and electricity actually work in reality.
http://amasci.com/redgreen.html
http://amasci.com/miscon/whatis.html

As well it boggles the mind that in this day and age so many still don't understand basic electricity, capacitors and what a displacement current is. I mean, it's so simple even a child could understand it.

1)Mobile free electrons with a (-) charge are forced onto the (-) capacitor plate. Only the (-) electrons can move not the (+) protons.

2)The (-) electric field from the excess of (-) electrons on the (-) plate repel any like (-) charges in the dielectric and opposite plate.

3)The opposite plate acquires a (+) charge because the (-) free electrons have been repelled from the plate by the (-) electric field of the (-) plate. No (+) charges moved into the opposite plate because they cannot move, they were already present and stationary in the metal. The opposite plate became (+) because some of the (-) free electrons were removed from it. See amasci red/green link above.

4)The (-) free electrons in the dielectric cannot flow as an electron current but they can be displaced a small amount towards the opposite plate. Any time we have many (-) charges displaced even a small amount the combined (-) electric field can repel any other nearby (-) electrons. The process of electric field induction is taught in every Canadian grade school. I find the fact that so many adults still don't understand electric field induction while most children do a little disturbing.

We could also talk about the actual forces present. One example which stuck in my mind was by A.D.Moore in his book on electrostatics. Moore calculated that if we separated all the (-) electrons and (+) protons or "charges" in a 1 cm cube of aluminum by a distance of 1 meter. The forces pulling the opposite charges together would be 32 million million million pounds. Roughly equivalent to the weight of a steel cube 76 miles x 76 miles x 76 miles in size. I memorized this example because it shows that electric fields can produce unimaginable forces in the right context.

AC


---------------------------
Comprehend and Copy Nature... Viktor Schauberger

“Progress is impossible without change, and those who cannot change their minds cannot change anything.” George Bernard Shaw
   
Pages: 1 2 3 4 5 6 7 8 9 [10]
« previous next »


 

Home Help Search Login Register
Theme © PopularFX | Based on PFX Ideas! | Scripts from iScript4u 2022-11-29, 07:31:20