- #1
allister
- 1
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Hello forum,
I have a few doubts on EM.
1. The skin depth formula for constant current(DC) shows that there can be current uniformly distributed through the cross-section of a conductor.However as there can be no electric field within a conductor(as per Maxwell's equations) there can be no force on the electrons within a conductor and the electrons do not move inside the conductor and so there is no current inside a conductor.These two facts seem contradictory.
2. Also,if it is so that current flows inside a conductor,the drift velocity of electrons is too slow.Is it the EM wave on the periphery of the conductor that causes a bulb to light as soon as it is switched on?
3. I am a bit confused about the working principle of wire grid polarizers. Maxwell's equations says that there shall be a non zero magnetic field on the surface of a conductor as an EM wave is incident on it.That means there shall be a varying surface current density(i.e. motion of electrons).As those grids which have their grids parallel to the E vector allow that and thus satisfy Maxwell can reflect EM waves.Please correct me if I am wrong.
thanks
I have a few doubts on EM.
1. The skin depth formula for constant current(DC) shows that there can be current uniformly distributed through the cross-section of a conductor.However as there can be no electric field within a conductor(as per Maxwell's equations) there can be no force on the electrons within a conductor and the electrons do not move inside the conductor and so there is no current inside a conductor.These two facts seem contradictory.
2. Also,if it is so that current flows inside a conductor,the drift velocity of electrons is too slow.Is it the EM wave on the periphery of the conductor that causes a bulb to light as soon as it is switched on?
3. I am a bit confused about the working principle of wire grid polarizers. Maxwell's equations says that there shall be a non zero magnetic field on the surface of a conductor as an EM wave is incident on it.That means there shall be a varying surface current density(i.e. motion of electrons).As those grids which have their grids parallel to the E vector allow that and thus satisfy Maxwell can reflect EM waves.Please correct me if I am wrong.
thanks