When a Na ion and a CI ion are placed in air a force F acts between them when they are separated by a distance of 1 cm from each other the permittivity of air and the dielectric constant of water are ε0 and K respectively When a piece of salt is placed in water then the force between Na+ and CI- ions separated by a distance of 1 cm will be
Two point charges placed at distance of 20 cm in air repel each other with a certain force.When a dielectric slab of thickness 8 cm and dielectric constant K is introduced between these point charges force of interaction becomes half of its previous value Then K is approximately.