How Do Electric Fields Differ Between Aluminum and Glass Plates?

AI Thread Summary
The electric field generated by a charged aluminum plate is calculated using the formula E = σ/2ε0, where σ is the surface charge density. In contrast, the glass plate, being an insulator, does not allow for the same distribution of charge and requires a different approach. The electric field for the glass plate is E = σ/ε0, reflecting its inability to conduct electricity like aluminum. This distinction leads to a stronger electric field for the glass plate compared to the aluminum plate when both have the same charge. Understanding these differences is crucial for analyzing electric fields in various materials.
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Homework Statement


A very large flat aluminum plate of area A has a total charge Q over its surface. The same charge is placed over the upper surface of a glass plate. Compare the electric fields.


Homework Equations





The Attempt at a Solution


I know how to get the electric field of the aluminum plate.
\sigma = Q/A
2EA = \sigmaA/e0
E = \sigma/2e0

For the glass plate, I'm not so sure... Initially I would think E = \sigma/e0, but it isn't...
 
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Realize that the aluminum plate is a conductor.
 
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