A dielectric-filled parallel-plate capacitor has plate area A =25.0 cm2 , plate separation d = 9.00 mm and dielectric constant k =2.00. The capacitor is connected to a battery that creates aconstant voltage V = 12.5 V . Throughout the problem, use ϵ0 =8.85×10−12 C2/N⋅m2 .
PART A:
U1 was found:
| U1 = | 3.84×10−10 |   J  |
PART B:
The dielectric plate is now slowly pulled out of the capacitor,which remains connected to the battery. Find the energy U2 of thecapacitor at the moment when the capacitor is half-filled with thedielectric.
Express your answer numerically in joules.
PART C:
The capacitor is now disconnected from the battery, and thedielectric plate is slowly removed the rest of the way out of thecapacitor. Find the new energy of the capacitor, U3.
Express your answer numerically in joules.
PART D:
In the process of removing the remaining portion of thedielectric from the disconnected capacitor, how much work W is doneby the external agent acting on the dielectric?
Express your answer numerically in joules.
