Quick Question: Electromagnetic Waves

[BrooklynBees]

What happens to the amplitude of an electromagnetic wave when it crosss from a less dense to a more dense medium?

I couldn't find it anywhere on the net.

 

[lzkelley]

Less dense to more dense isn't specific enough for EM waves. If the material is close enough to electrically neutral (even in the presence of strong EM fields), then the waves wil continue unchanged.
If your talking about light, it gets even more complicated.

 

[Moetasim]

The amplitude of an electromagnetic wave does not change when it crosses from a less dense to a more dense medium. The amplitude of an electromagnetic wave is determined by the source of the wave and is not affected by the medium it travels through. However, the speed of the wave may change as it enters a more dense medium, which can result in a change in the wavelength of the wave. This phenomenon is known as refraction and is governed by Snell's law.