Intensity of Electromagnetic Wave

In summary, the conversation discusses how to show that the intensity of radiation (EM wave) decreases with depth z using the equation I(z)= Ie^(-2niwz/c), where I is the initial intensity and ni is the complex part of refractive index. The person has been trying to solve the problem using the Poynting vector and has been struggling for two days. They ask for help in determining the electric field, assuming normal incidence of an EM wave on the surface.
  • #1
iontail
24
0

Homework Statement



Show that intensity of radiation(EM wave) falls off with depth z
as
I(z)= Ie^(-2niwz/c)

where I = initial intensity
and ni=complex paert of refractive index

Homework Equations


I have tried the solving the solution using poynting vector.


I have been pondering over the question over the last two days without any success. I think i am making it more complicated than it needs. to be. I would appreciate it if you point me in the right direction .
 
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  • #2
Determine the electric field. You are probably supposed to assume that an EM wave is normally incident on the surface.
 

1. What is the intensity of an electromagnetic wave?

The intensity of an electromagnetic wave is the rate at which energy is transferred through a given area. It is measured in watts per square meter (W/m²).

2. How is the intensity of an electromagnetic wave related to its amplitude?

The intensity of an electromagnetic wave is directly proportional to the square of its amplitude. This means that as the amplitude increases, the intensity also increases.

3. Can the intensity of an electromagnetic wave be changed?

Yes, the intensity of an electromagnetic wave can be changed by altering its amplitude or by changing the distance from the source of the wave. Intensity can also be affected by the properties of the medium through which the wave is traveling.

4. What is the relationship between intensity and frequency of an electromagnetic wave?

There is an inverse relationship between intensity and frequency of an electromagnetic wave. This means that as the frequency increases, the intensity decreases, and vice versa.

5. How does the intensity of an electromagnetic wave affect its potential to cause harm?

The intensity of an electromagnetic wave is directly related to its potential to cause harm. High intensity waves, such as x-rays and gamma rays, have the ability to cause damage to living cells and tissues. However, low intensity waves, such as radio waves, are generally considered safe for human exposure.

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