It many places one can read that electric field inside a conductor is zero (steady state) and there are plenty of explanations. I guess this is due to the fact that number of electrons is so great in the conductor that their movement can nullify almost any field. However, what if external electric field is very strong and it pulls all free to move electrons, then area left without free electrons will have none zero electric field. Is this argument accurate? I guess with such a strong external electric field we will run into other problems with other fundamental forces.
Electric Field Inside Conductor – Practical vs. Theoretical Aspects
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Related Solutions
Conductors are defined by the freedom of some of the charges inside to move with little resistance.
So, if there were a non-zero field, what would happen? Answer: some of the free charges move until the field is again zero.
You might be wondering if there are limits to this claim, but a introductory book of that sort is not worrying about extreme situations. In any case, try choosing a simple geometry, make an estimate of the fraction of charges that are free to move and calculate the saturation field.
Take a metal block and place it in a uniform electric field which points from left to right, since the metal block has free electrons they will move opposite to the field, that is, to the left side of the conductor.Since the block is electrically neutral if a charge of -q appears on left side an equal positive charge +q must appear on right side. This will create another field inside the block from right to left.The movement of electrons will continue till the electric field inside the conductor is equal and opposite to the electric field outside the conductor after that the movement will cease as the field inside the conductor will become zero. The field produced inside is the net field of negative and positive charges induced in the conductor(here metal block).
Best Answer
The principle that Electric fields inside conductors are 0 (Thomson's Theorem of Electrostatics) follows necessarily from the fact that free charges inside the conductor will rearrange themselves to make it so (in the same way that molecules in water will rearrange themselves to make a level surface).
If you don't have free charges for any reason - whether because the material is insulating or you're simply "out of" free charges, this principle will no longer be true and you now effectively have a dielectric - polarized to partially attenuate the electric field.