The discussion revolves around the behavior of a parallel plate capacitor when it is disconnected from a battery. Participants are exploring the relationship between charge, voltage, and the effects of inserting a dielectric after disconnection.
The discussion is active, with participants sharing their reasoning and questioning the assumptions about charge retention and voltage presence in the capacitor after disconnection. Some guidance has been offered regarding the relationship between charge, capacitance, and voltage.
Participants are considering the implications of inserting a dielectric into the capacitor and how it affects the voltage and charge, while also noting the absence of an external voltage source after disconnection.
xchococatx said:If there is a parallel plate capacitor, connected to a battery, which is then disconnected, there is NO voltage now, but "Q" (charge) on the capacitor remains the same. YES OR NO? I think yes.
xchococatx said:Well basically I'm thinking that a capacitor stores charges (or energy) so, onces its all charged up by a battery, I don't see how it could lose those charges...even when the battery is disconnected. (immediately anyways, it wouldn't be all gone I don't think) Why I was thinking about this was because if the battery is now disconnected, and you wanted to calculate the work needed to insert a dielectric, fitting perfectly between the 2 plates, since there is no voltage, I don't see how you could calculate the work unless you used the original charge of the capacitor (without dielectric). (By means of E=Q^2/2C) So in order to use the original charge of the capacitor, I figured charge has to stay in the capacitor even if the battery is disconnected.