Any deep cause of magnetic field

In summary, when a potential difference is applied to a conductor, it creates an electric field that exerts force on charged particles and sets up a moving current. This moving current also produces an electric field that contributes to the magnetic field. The relationship between magnetic and electric fields is deeply intertwined and is best understood through special relativity. The presence of a displacement current term in the equations for Curl E and Curl H accounts for the symmetry between the two fields. Additionally, a transverse electric field in one reference frame can be transformed into a transverse magnetic field in another reference frame, further demonstrating the close connection between the two fields.
  • #1
Nikaro
4
0
when we apply potential difference across any conductor the electric field set up in the conductor which apply force on charged particles and set up moving current.While the current is moving the charge which is at the outer surface of conductor also make elecricfield which is moving along the conductor.
Is this moving electric field is the cause of magnetic field ?
If it is not than please please tell me the reason of magnetic field?
And is there is any deep relation between magnetic and electric field.
 
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  • #2
Not sure what you mean by a moving electrical field. Moving charges produce a magnetic field, but also an electrical field that changes with time produces a magnetic field.

I think one of the nicest and deepest understanding of magnetic fields arise from special relativity. Where a magnetic and electric field are part of the same phenomenon. Different observers will see different type of fields.
 
  • #3
One reason is that curl H = J, meaning that currents are the cause of magnetic fields. Another reason (which you point out) is that a Lorentz transformation on an electric field creates a magnetic field. A time-dependent magnetic field does create electric fields (curl E = - dB/dt), but a time dependent electric field (=dE/dt) cannot create a magnetic field.
 
  • #4
Bob S said:
A time-dependent magnetic field does create electric fields (curl E = - dB/dt), but a time dependent electric field (=dE/dt) cannot create a magnetic field.

Could you elaborate on this seeing as

[tex]
\nabla \times \vec{B}=\mu_0 \vec{J}+\mu_0 \epsilon_0 \frac{\partial \vec{E}}{\partial t}
[/tex].
 
  • #5
Cyosis said:
Could you elaborate on this seeing as

[tex]
\nabla \times \vec{B}=\mu_0 \vec{J}+\mu_0 \epsilon_0 \frac{\partial \vec{E}}{\partial t}
[/tex].
Mea culpa. I should have included the displacement current term, which makes the Curl E and Curl H equations more symmetric, and is very important in electromagnetic radiation, especially when there are no conductors around.
 
  • #6
E & H are mutually inclusive under dynamic conditions, i.e. one cannot exist w/o the other. If one is time-changing, the other must be non-zero. Einstein in his 1905 paper, described that neither one is the "seat" ("seat" meaning basis or primary).

Claude
 
  • #7
There is another source of a magnetic field. A transverse electric field in one reference frame can be converted into a transverse magnetic field in another reference frame by a Lorentz transformation:

BT' = γBT - (γ/c2) v x ET

α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ ς σ τ υ φ χ ψ ω . . . . . Γ Δ Θ Λ Ξ Π Σ Φ Ψ Ω
 

FAQ: Any deep cause of magnetic field

What is the origin of Earth's magnetic field?

Earth's magnetic field is generated by the movement of molten iron and nickel in its outer core. This movement creates electric currents, which in turn produce a magnetic field.

How does the magnetic field protect Earth?

The magnetic field acts as a shield, deflecting harmful solar radiation and cosmic rays away from Earth's surface. This protection is crucial for the survival of life on our planet.

Can the magnetic field reverse its polarity?

Yes, the Earth's magnetic field has reversed its polarity many times in the past. This means that the north and south magnetic poles switch places. The last reversal occurred about 780,000 years ago.

How does the magnetic field affect navigation?

The magnetic field is used by animals such as birds and bees to navigate, and it also plays a crucial role in human navigation. Compasses work by aligning with the magnetic field, allowing us to determine direction.

Can changes in the magnetic field affect our climate?

Yes, changes in the Earth's magnetic field can have an impact on our climate. The magnetic field helps protect Earth from solar wind, and any weakening or reversal of the field can lead to increased solar radiation and potential climate changes.

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