Force between capacitor plates

AI Thread Summary
Introducing a dielectric between capacitor plates affects the electric field and the force between them. While some sources suggest the force remains constant, others argue it decreases due to the reduction in the electric field strength caused by the dielectric. The surface charge density and the relationship between the electric displacement field and electric field indicate that the force should decrease when a dielectric is present. The context of the capacitor's connection to a voltage source or its charge state is crucial for understanding the force dynamics. Clarifying these conditions can resolve discrepancies in the interpretations of the force's behavior.
Prateek Kumar Jain
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What will happen to the force between the capacitor plates (Will increase or decrease or remain constant) if we introduce a dielectric between them?

As per the answer given the physics textbook , the force will remain same? But as per my understanding the force should decrease since electrical field between the plates reduces.
 
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The surface charge on a plate is given by the normal ##D=\epsilon E## field. The force is the charge times the ##E## field. For the same amount of charge, the ##E## field is reduced since ##\epsilon>1## so the force will go down.
 
Prateek Kumar Jain said:
As per the answer given the physics textbook , the force will remain same?
I can suggest that either the answer you have found is 'in the back of the book' and is wrong due to a simple typo or, if there is a worked example, there may be more to the question than you have stated.
For instance, what is the actual circuit? Is the Capacitor attached to a voltage source or was it charged and then disconnected?
 
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