I was watching this video on Hall effect, and to demonstrate that it is not electric fields that are bending the electron beam, the presenter puts a metal plate between the magnet and the beam.
So, my question is, say there was a charge instead of the magnet. How will the metal plate shield the electric field produced by a charge?
My reasoning till now was, say, you put a positive charge in front of the metal. Since the electric field inside the metal is zero, negative charges will develop on the face near the charge, and to maintain charge conservation, a positive charge will develop on the other face of the metal. So, in effect, the plate has done nothing. There are still positive charges pointing toward the beam, and the beam will still perceive a force from the charge.
So, how is the metal plate acting as a shield? ( If I assume that the plate is grounded, then I can say that the plate will serve as a shield. But in the video, it is not grounded.)
