Maxwell fourth equation incorrect?

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In summary, Maxwell's correction to Ampere's law can be derived simply from the conservation of charge.
  • #1
mdn
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Hi all
this question seems to be silly but i want to where i am wrong. Maxwell was made modification in Amperes law curl H=J and he added new quantity displacement current Jd, reason was that Div.J=0 (true in DC current but not in AC charging capacitor).
but if i say Div J=0 in capacitor because the amount of current entering and leaving is exactly equal in Gaussian loop (loop has half part in space between plate) on the same back direction as it is AC currant and can not flow through capacitor plate, where i am wrong?
and second doubt is that current can not added in series because it is same therefore fourth equation should be
Curl H=2J.
 
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  • #2
mdn said:
Hi all
...reason was that Div.J=0 (true in DC current but not in AC charging capacitor).
but if i say Div J=0 in capacitor because the amount of current entering and leaving is exactly equal in Gaussian loop (loop has half part in space between plate) on the same back direction as it is AC currant and can not flow through capacitor plate, where i am wrong?

The reason for adding displacement current term into the right-hand side of the equation

$$
\nabla\times \mathbf B = \mu_0 \mathbf j
$$

was that divergence of the left-hand side is zero everywhere for any field ##\mathbf B##, while divergence of ##\mathbf j## is not always zero.
 
  • #3
The current density between the plates of a capacitor is 0.If you igore dE/dt you get that the curl of B is 0 in this area, and this conflicts with reality.
It's easier to see in integral form, where the curl of B integrated around the boundary of a surface is the same for any surface with the same boundary.
If you take a capacitor you can have one surface going through one of the leads, and another surface going through the gap between the plates. If you integrate only the real current and not the displacement current you won't get the same outcome.
 
  • #4
div of J is zero or not in case of capacitor? if yes then problem in fourth equation
and if no can you prove?
 
  • #5
Maxwell's correction to Ampere's law can be derived simply from the conservation of charge. See: http://arxiv.org/abs/physics/0005084

This thread appears to be personal speculation. It is closed unless you can produce a professional reference supporting the alternative form.
 

1. Why is the fourth equation in Maxwell's equations considered incorrect?

The fourth equation in Maxwell's equations, also known as the Ampere's law, was believed to be incorrect because it did not account for displacement currents. This was later corrected by Maxwell himself through the addition of a term known as the displacement current in the equation.

2. How does the incorrect fourth equation affect our understanding of electromagnetism?

The incorrect fourth equation in Maxwell's equations initially led to a misunderstanding of the behavior of electromagnetic waves. It was not until Maxwell corrected the equation that scientists were able to fully understand the relationship between electric and magnetic fields and how they give rise to electromagnetic waves.

3. What evidence was there for the fourth equation being incorrect?

The evidence for the incorrectness of the fourth equation came from experiments conducted by scientists such as Michael Faraday and James Clerk Maxwell himself. These experiments showed that the behavior of electromagnetic waves could not be fully explained by the existing equations.

4. How was the fourth equation corrected?

Maxwell corrected the fourth equation by adding a term known as the displacement current, which takes into account the changing electric fields that give rise to electromagnetic waves. This correction allowed for a more accurate understanding of electromagnetism and paved the way for advancements in technology such as radio communication.

5. Are there any other equations or laws that have been found to be incorrect?

Yes, there have been other equations and laws in science that were initially believed to be correct but were later found to be incorrect. This is a natural part of the scientific process as new evidence and advancements in technology allow for a deeper understanding of the natural world.

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