Notes

Effect of Medium…

Effect of Medium – When a dielectric medium is completely filled by the two charges, rearrangement of the charges inside the dielectric medium takes place and the force between the charges decreases by a factor of K, known as dielectric constant or relative permittivity (ε_r) of the medium (relative means with respect to free space).
(K = F₀/F_m)
[where, F₀ = 1/4πε₀ q₁ q₂/r², F_m = 1/4πε_m q₁q₂/r²]