A 1 uF parallel-plate capacitor is charged to 12 V and then disconnected from the voltage supply. The plate separation distance is doubled and the dielectric is replaced by a material with another that has one quarter of the former relative permittivity. Find the final charge on the capacitor's positive plate and the final voltage difference between its terminals. 2. A parallel-plate capacitor consists of two equally thick layers of dielectric sandwiched between 1 cm X 2 cm rectangular plates that are separated by 200 um. One layer of dielectric has permittivity of 5 uF/m. The other has twice that value. Find the energy stored in the capacitor when its leads are connected to a 60 V supply.
