The plates of a parallel plate capacitor are, not exactly parallel. The surface charge density therefore :

The plates of a parallel plate capacitor are not exactly parallel. The surface charge density is therefore,

If the plates of a parallel plate capacitor are not equal in area, then

Introduction (parallel plate capacitor)

The separation between the plates of a charged parallel-plate capacitor is increased. The force between the plates

The separation between the plates of a charged parallel-plate capacitor is increased. The force between the plates