Electromagnetic wave in a conductor

In summary, when an electromagnetic wave hits a conductor, the transmitted part of the wave is significantly weakened. This is due to the fact that the electrons in the conductor, while free to roam, are not completely free and can be affected by the electric field. As a result, the electric field inside the conductor is attenuated, but not completely eliminated. This can be observed in the heating of a conductor when a current is passed through it.
  • #1
aaaa202
1,169
2
When an electromagnetic wave hits a conductor the transmitted part of the wave is damped considerably. I want to know if anyone can explain physically why the field is attentuated inside the conductor - i.e. what happens.
I know the basic properties of a conductor:
- Electrons free to roam
- E-field 0 inside it
- Net charge resides on surface
But can't really combine this to a clear understanding.
 
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  • #2
aaaa202 said:
When an electromagnetic wave hits a conductor the transmitted part of the wave is damped considerably. I want to know if anyone can explain physically why the field is attentuated inside the conductor - i.e. what happens.
I know the basic properties of a conductor:
- Electrons free to roam
- E-field 0 inside it
- Net charge resides on surface
But can't really combine this to a clear understanding.

The electrons are not completely free in most conductors (except super conductors ). If the electrons were completely free in metals incandescent electric lights would not work. A current that is passed through a conductor heats it.

The electric field dies off rapidly inside a conductor but the change is not infinite, dE/dx ≠ ∞
 

What is an electromagnetic wave?

An electromagnetic wave is a type of energy that is created when an electric field and a magnetic field interact with each other. These waves can travel through space and are responsible for phenomena such as light, radio waves, and X-rays.

How does an electromagnetic wave behave in a conductor?

When an electromagnetic wave encounters a conductor, it can induce an electric current in the conductor. This is because the electric field in the wave causes the electrons in the conductor to move, creating a current. The magnetic field in the wave also interacts with the conductor's magnetic properties, resulting in a resistance to the flow of current.

What is skin effect?

Skin effect is a phenomenon that occurs in conductors when high frequency electromagnetic waves are passing through them. The current tends to flow more towards the surface of the conductor, rather than through the entire cross-section. This is due to the electric and magnetic fields in the wave interacting with the conductivity and permeability of the material, causing the current to concentrate near the surface.

How does the conductivity of a conductor affect the propagation of electromagnetic waves?

The conductivity of a conductor plays a significant role in the propagation of electromagnetic waves. Higher conductivity allows for more efficient transmission of the wave, as there is less resistance to the flow of current. This is why highly conductive materials, such as copper, are commonly used in electrical wiring and transmission lines.

Can electromagnetic waves be completely blocked by a conductor?

While conductors can reflect and absorb electromagnetic waves, they cannot completely block them. This is because the electric and magnetic fields in the wave can induce a current in the conductor, leading to some energy being transmitted through the material. However, the amount of energy that is transmitted depends on the conductivity and thickness of the conductor.

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