Deriving Poynting Vector from EM Waves: A Guide

In summary, the speaker is looking for help in deriving the Poynting vector and average value from the energy density of electromagnetic waves. They are specifically looking for resources on the internet, such as Jackson's book, to avoid typing out the formulas themselves. They also mention needing resources for optics formulas, electric dipole moment, and the creation of electromagnetic waves in antennas. They are open to any helpful websites and express that finding the right resources takes up a lot of their time.
  • #1
tmoan
39
0
can anyone help me derive the poynting vector from energy density of electromagnetic waves?
and how we obtain average value <S>
thanks
 
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  • #2
The standard derivation is available in many places, such as Jackson's book. What have you tried so far?
 
  • #3
i need the way to derive poynting vector and the average value from energy density of electromagnetic waves on the internet so i can copy it on power point
coz i don want to type them one by one on word and then copy paste
also any site that has all those optics formulas derived on stuff like radiation
electric dipole moment and creation of electromagnetic waves in antennas
you see my problem is wikipedia and sites like that has everything in them.
i didn't use to browse a lot of sites before. so i could use some help thanks
 
  • #4
btw i have books where i can read the derivations i don't need explanations i understand the concept of all this very clearly
but as i mentioned before just finding the proper site to browse takes a lot of my time
 

1. What is the Poynting vector and why is it important in understanding electromagnetic waves?

The Poynting vector is a mathematical representation of the directional energy flow of an electromagnetic wave. It is important because it helps us understand how energy is transferred through space by these waves and is a key concept in the study of electromagnetism.

2. How is the Poynting vector derived from electromagnetic waves?

The Poynting vector is derived using Maxwell's equations, which describe the relationship between electric and magnetic fields and their behavior in space. By combining these equations, the Poynting vector can be calculated as the cross product of the electric and magnetic fields.

3. Can the Poynting vector be negative?

Yes, the Poynting vector can have a negative value. This indicates that the energy flow is in the opposite direction of the vector's direction. This can happen in regions where the wave is being absorbed or reflected.

4. How is the magnitude of the Poynting vector related to the intensity of the electromagnetic wave?

The magnitude of the Poynting vector is directly proportional to the intensity of the electromagnetic wave. This means that as the Poynting vector increases, so does the intensity of the wave, and vice versa.

5. Are there any practical applications of the Poynting vector?

Yes, the Poynting vector has many practical applications. It is used in the design and analysis of antennas, as well as in the study of electromagnetic radiation and its effects on various materials. It is also used in the development of technologies such as wireless power transfer and solar energy harvesting.

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