Chapter 8, Problem 8.8CYU

Check Your Understanding Continuing with Example 8.12, show that when the battery is connected across the plates the energy stored in dielectric-filled capacitor is $U{=}_k{U}_0$ (larger than the energy $U_0$ of an empty capacitor kept at the same voltage). Compare this result with the result $U=U_0{}_{/K}$ found previously for an isolated, charged capacitor.