Solve EM Wave Vacuum Homework: Prove Relation, Find B, Reflect Wave Form

In summary, the conversation discusses the propagation of EM waves through vacuum towards a conducting surface at x=0. The boundary conditions for E and B are found for a surface with charge density σ and current density s. The reflected wave is shown to have a perpendicular E-field of 0 and a parallel E-field equal to the negative of the incoming E-field. There is some confusion regarding the presence of free charge and currents in a perfect conductor.
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unscientific
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Homework Statement


EM Waves propagating through vacuum towards the x-direction approaches a conducting surface at x = 0.

Part (a): Prove the following relations. Find the boundary conditions for [tex]E [/tex] and [tex]B[/tex] if charge density [tex]σ[/tex] and current density [tex]s[/tex] exists on the surface.

Part (b): Find [tex]B[/tex] in terms of [tex]E_0[/tex]

Part (c): Show the reflected wave has the following form:

Part (d) Find magnetic field of reflected wave and [tex]s[/tex]

Homework Equations


The Attempt at a Solution



Part(a)
33xbj9w.png


Part(b)
migps3.png


Part(c)

This is the part that disturbs me. I assumed the free current s = 0 and σ = 0. Usually [tex]k[/tex] would be perpendicular to the surface, making derivations easier.

I actually got perpendicular reflected E-field = 0, which is wrong..
But, I got parallel reflected E-field = - incoming parallel E-field, which is right

rms6rn.png


I'm confused - If it's a perfect conductor it should have no free charge or currents, but the question says it does. Then again, in order to derive the reflected e-field, we need to assume they are 0.
 
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Edit: Question here
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1. How do I prove the relation between EM waves and vacuum?

The relation between EM waves and vacuum is determined by Maxwell's equations, which describe the behavior of electromagnetic fields in a vacuum. These equations show that EM waves can propagate through a vacuum, and their properties such as wavelength and frequency are determined by the properties of the vacuum.

2. What is the value of B in the equation for EM wave propagation in a vacuum?

The value of B in the equation for EM wave propagation in a vacuum is the magnetic field. It is one of the components of the electromagnetic field and is perpendicular to the electric field. The value of B can be calculated using the equation B = μ0E/c, where μ0 is the permeability of free space, E is the electric field, and c is the speed of light.

3. How do I reflect an EM wave in a vacuum?

An EM wave can be reflected in a vacuum by encountering a boundary between two different media, such as air and a solid object. The reflection of an EM wave is governed by the law of reflection, which states that the angle of incidence is equal to the angle of reflection. This means that the wave will bounce off the boundary at the same angle at which it approached.

4. How do I find the form of an EM wave in a vacuum?

The form of an EM wave in a vacuum can be described by its electric and magnetic fields, which are perpendicular to each other and vary sinusoidally with time and distance. In a vacuum, these fields propagate at the speed of light and are related by the equation E = cB, where c is the speed of light.

5. What is the significance of solving EM wave problems in a vacuum?

Solving EM wave problems in a vacuum is crucial for understanding the fundamental principles of electromagnetism and for practical applications such as wireless communication and radar technology. Vacuum is the medium through which EM waves travel at their maximum speed, making it an important reference point for studying their behavior. Additionally, solving problems in a vacuum allows for simpler calculations and provides a baseline for comparison with other media.

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