Propagation of Light from Maxwell's 3rd & 4th Eqns

In summary, to show that a plane polarized electromagnetic wave follows the generalized wave equation, the third and fourth of Maxwell's equations in integral form were used. By evaluating over a rectangle and manipulating the equations, the general form of the wave equation was obtained, with the velocity of light being determined as 1/(mu*epsilon)^(1/2) in terms of the permeability and permittivity constants.
  • #1
Schr0d1ng3r
59
0

Homework Statement



Using the third and fourth of Maxwell’s equation in integral form, show that a plane polarized electromagnetic waves propagates in accordance with the generalized wave equation. Determine the velocity of light in terms of the permeability and permittivity constants.

Homework Equations



Faraday's Law

Maxwell-Ampere Equation
 
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  • #2
I'm pretty sure that they are supposed to form some sort of differential equation, but I'm lost as to where I'm supposed to start.
 
  • #3
Schr0d1ng3r said:

Homework Statement



Using the third and fourth of Maxwell’s equation in integral form, show that a plane polarized electromagnetic waves propagates in accordance with the generalized wave equation. Determine the velocity of light in terms of the permeability and permittivity constants.

Homework Equations



Faraday's Law

Maxwell-Ampere Equation

It's been a while since I did this problem, but start with the form of the Wave equation. What is the general form of the Wave equation? And can you post the two Maxwell's equations that they want you to use? What variables are involved?
 
  • #4
In order to satisfy the general wave equation, I'm pretty sure that means that it must fit the form x=(c1)cos(wt) + (c2)sin(wt), but I'm not sure

Faraday's Law:

[tex]\oint[/tex] E dot [tex]\partial[/tex]L = -[tex]\partial[/tex][tex]\Phi[/tex]B/[tex]\partial[/tex]t

Maxwell-Ampere Equation

[tex]\oint[/tex] B dot [tex]\partial[/tex]L = [tex]\mu[/tex][tex]\epsilon[/tex][tex]\partial[/tex][tex]\Phi[/tex]E/[tex]\partial[/tex]t

Sorry if the eqns are hard to read, I'm not great at putting them into script
 
  • #5
Never mind, I got it. I just had to evaluate over a rectangle Ldx and then do some differential manipulations and substitute the equations into each other. The general equation of the wave, by the way, was (d^2y/dx^2) = (1/(v^2))*(d^2y/dt^2), and the speed of light was, 1/(mu*epsilon)^(1/2), as expected.
 

Related to Propagation of Light from Maxwell's 3rd & 4th Eqns

1. What are Maxwell's 3rd and 4th equations?

Maxwell's 3rd and 4th equations, also known as the Gauss' law for electricity and the Gauss' law for magnetism, respectively, are two of the four fundamental equations that describe the behavior of electric and magnetic fields. They were developed by James Clerk Maxwell in the 19th century and are a cornerstone of the theory of electromagnetism.

2. How do Maxwell's 3rd and 4th equations relate to the propagation of light?

Maxwell's 3rd and 4th equations are essential in understanding the propagation of light. These equations describe how electric and magnetic fields are generated and how they interact with each other. Light is an electromagnetic wave that consists of oscillating electric and magnetic fields, and Maxwell's equations explain how these fields propagate through space.

3. What is the role of Maxwell's 3rd and 4th equations in explaining the speed of light?

Maxwell's 3rd and 4th equations, along with the other two equations, explain the behavior of electromagnetic waves, including light. These equations show that the speed of light is a fundamental constant, and it is determined by the properties of electric and magnetic fields. Without these equations, we would not be able to accurately predict the speed of light.

4. Can Maxwell's 3rd and 4th equations be used to study the behavior of light in different mediums?

Yes, Maxwell's 3rd and 4th equations can be used to study the behavior of light in different mediums. These equations can be modified to include the effects of different materials on the propagation of light. This allows scientists to study how light behaves in different mediums, such as air, water, or glass.

5. Are Maxwell's 3rd and 4th equations still relevant in modern science?

Yes, Maxwell's 3rd and 4th equations are still relevant in modern science. These equations are a fundamental part of the theory of electromagnetism, which is essential in understanding many phenomena in the universe, including light, electricity, and magnetism. They are still used to make predictions and explain various phenomena in the fields of physics, engineering, and technology.

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