Solving Problem on Capacitor - India IIT Prep

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The discussion revolves around the effect of introducing a dielectric into an isolated, charged parallel plate capacitor. The original poster questions why the force between the plates remains the same despite the presence of induced charges on the dielectric. Responses clarify that the electric field created by the charge on one plate remains unchanged outside the dielectric, as the induced charges cancel each other out. Thus, the force between the plates does not decrease. Understanding this principle is crucial for IIT preparation.
ambuj123
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Hello
i am new to this forum from India and preparing for IIT
:eek:
well i have question
"If a dielectric is placed between two plates of parallel plate capacitor which is isolated and charged the force between plates decrease or remain same . well i found answer in my book that it remains same but i don't know why?
i think it should be reduced becuase induced charges appear on the edges of dieelectric and due to these charges two electric field nullify some of the effect?"
Please help
 
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Welcome to PF!

Consider first the capacitor without a dielectric. The charge on one plate creates an electric field which exerts a force on the other plate. That field is proportional to the surface charge density, and is independent of distance. When the dielectric is introduced, induced surface charges do appear on each side of the dielectric, but they cancel. (They effect the field within the dielectric, but not outside it.)
 
Thanks

THANX for help
:smile:
 
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