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meteorologist1
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Hi, I have trouble on the following problem:
Given a parallel plate capacitor, fixed area A, and fixed separation d. Find the energy stored, before and after insertion of a slab of dielectric, which completely fills the space between plates, for each of the two cases:
a) Plates are connected to a battery which maintains constant potential difference
b) Plates are charged with fixed charges +Q and -Q, and battery disconnected.
Explain differences in the two cases.
For part a, I think the answers would be just:
Before insertion of dielectric: U = (1/2)CV^2 where C = A(epsilon)/d and
after insertion of dielectric: U = (1/2)KCV^2 where C = A(epsilon)/d and K is the dielectric constant.
But I'm not sure about part b. Thanks.
Given a parallel plate capacitor, fixed area A, and fixed separation d. Find the energy stored, before and after insertion of a slab of dielectric, which completely fills the space between plates, for each of the two cases:
a) Plates are connected to a battery which maintains constant potential difference
b) Plates are charged with fixed charges +Q and -Q, and battery disconnected.
Explain differences in the two cases.
For part a, I think the answers would be just:
Before insertion of dielectric: U = (1/2)CV^2 where C = A(epsilon)/d and
after insertion of dielectric: U = (1/2)KCV^2 where C = A(epsilon)/d and K is the dielectric constant.
But I'm not sure about part b. Thanks.