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• Users: Repetit
• In Electromagnetism
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1. ### Light momentum inside a dielectric medium?

Light in a vacuum has momentum \hbar k but when the light enters a dielectric medium, fx. glass, the momentum of the light is increased to \hbar\sqrt{\epsilon} k, where \epsilon is the dielectric constant of the dielectric. Where does the extra momentum come from? How can this be in accordance...
2. ### Light hitting a dielectric, increase of momentum

When light propagates in a dielectric its wavevector is given by: k = \frac{\omega n}{c} where n is the refractive index. If light propagates in vacuum n=1 the momentum is \omega / c but if light propagates in a dielectric of for example n=1.33 the momentum is increased beyond the...
3. ### Electric Charge Vs Electron

I suppose they are the same thing. Electrons are the smallest unit of (negative) electric charge.
4. ### Theory about magnetic monopoles?

You should try to take a look at this article: "Theory of Magnetic Monopoles and Electric-Magnetic Duality" Just do a google search for that title.
5. ### EM wave penetrates?

I believe that high frequency EM radiation penetrates much deeper into matter because it is much more energetic (E=hf). Wouldn't that explain why cell phones work better than FM radios? FM radios are operated at ~80-100 Mhz whereas cell phones are operated at ~1800 Mhz.
6. ### Electric field generated from dipoles

I'm having a little difficulty understanding the electric field generated from electric dipoles. As far as I know electric fields are generated on positive charges and terminated on negative charges. Since a dipole is a positive charge and a negative charge separated by a very small distance...