You have been given a parallel plate air capacitor having capacitance C, a battery of emf `epsilon` and three dielectric blocks having dielectric constants `K_(1), K_(2) and K_(3)` such that `K_(1) gt K_(2) gt K_(3)`. Describe a sequence of steps such as connecting or disconnecting the capacitor to the battery, inserting or taking out of one of the dielectrics etc -so that the capacitor ends up having maximum possible energy stored in it. [Each dielectric block fills completely the space between the plates]. Write this maximum energy.

Answer

Insert dielectric with constant `k_(1)`, connected the battery, disconnected the battery and remove the dielectric.
`U_(max)=(1)/(2)K_(1)^(2)V^(2)C`