[Physics] Does force between two charges depend on medium

Question

I know that net force on a charge decreases by a factor of K(dielectric constant of medium ) but I wanna know that whether

The force on one charge due to other charge has changed

Or

This decrease of force is due to force exerted by the medium and force between the two charges still remain the same. ( I mean that forces on one charge remain due to the other remains unchanged but the net decrease is due to the medium applying force on the opposite direction ) .

Thanks.

Answer 1

I wouldn't say that the force law has changed. In every medium, the force as a function of electric field is the same:

$$\vec{F}=q\vec{E}$$

The difference is that, in a dielectric medium, the electric field looks different than in a vacuum. This is because the dipoles in the medium are influenced by the electric field, and orient themselves in the configuration of minimum energy (namely, so that their positive end is pointing in the opposite direction of the electric field). The dipoles themselves generate an electric field, and in this configuration, their contribution partially cancels the external electric field. So the net effect of a dielectric medium is that electric fields are smaller within it than in a vacuum.