Electric forces on materials can pull electrons in one direction and protons in opposite direction {induction, charge} {charge induction}|.
dielectric
Conductors have free charges, so charges move to counter outside electric force, with no net charge. Dielectrics have no free charges, so induction pulls electrons and protons apart to make induced charge and dipoles.
factors
If electric field is more, electric force is more, and system has more dipoles. If atoms are small, smaller mass moves easier, and system has more dipoles.
factors: temperature
In polar materials, if temperature is lower, material has fewer random motions, and material has more dipoles. In non-polar materials, temperature has little effect.
factors: frequency
If electric-field frequency is more than 10^10 Hz, dipole moments cancel, because dipole moments change slower than field changes. If electric-field frequency is above 10^11 Hz, bending and stretching dipole moments cancel, because vibrations are slower than frequency, and only electrons affect polarization.
examples
Sifting sugar or streaming water through electric fields illustrates charge induction.
Physical Sciences>Physics>Electromagnetism>Charge
5-Physics-Electromagnetism-Charge
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Date Modified: 2022.0224