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dEdt
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To be concrete, consider two parallel conducting plates, one positively charged and the other negatively charged. Why doesn't the electric field between the two plates pull the charges off the surface of the two plates?
Matterwave said:But if the voltage is not strong enough, the insulating material between the plates will prevent the electrons from moving from one plate to the other.
Matterwave said:An electron microscope usually only has the electron jumping very very short distances though right? For a macroscopic separation of the capacitor plates, I would think a ridiculously strong electric field might be needed.
Matterwave said:An electron microscope usually only has the electron jumping very very short distances though right? For a macroscopic separation of the capacitor plates, I would think a ridiculously strong electric field might be needed.
Charges stay on a conductor because of the repulsion between like charges and the attraction between opposite charges. In a conductor, the free electrons are able to move freely and distribute themselves evenly, resulting in an overall neutral charge on the surface.
A conductor is able to prevent charges from flying off because the free electrons are constantly moving and balancing out any excess charges. This is known as electrostatic equilibrium.
Yes, charges can fly off a conductor if there is a strong enough external force or if the conductor is not in a state of electrostatic equilibrium. This can happen, for example, when a conductor is connected to a source of high voltage.
The size and shape of a conductor do not affect the movement of charges as long as the conductor is in a state of electrostatic equilibrium. However, the distribution of charges on the surface may vary depending on the shape of the conductor.
Charges on a conductor only move along the surface because the electric field inside a conductor is always zero. Therefore, there is no force acting on the charges to move through the interior. The free electrons are able to move freely on the surface, but they cannot move through the interior of the conductor.