^PPC with a dielectric slab in plates

PPC with a dielectric slab in plates

If a dielectric slab of dielectric constant K, thickness t < d is placed between the plates of a PPC then due to the electric field between the capacitor plates the dielectric gets polarized & an electric is induced in it, as a consequence net electric field in dielectric is found to be .

Due to this field electric field net potential difference across the capacitor plates becomes .

Using C = q/V, capacitance of capacitor becomes .

1. If the entire space between the capacitor plates is occupied by air or vacuum, then .       [using K = 1 and t = 0]

2. If the entire space between the capacitor plates is occupied by dielectric, then            [using t = d]