The force (F) experienced by the two-point charges Q1 and Q2, located in free space or vacuum is expressed as: Where R is the distance between the two charges.
1
\(F=\frac{1}{2\pi {{\varepsilon }_{o}}}\frac{{{Q}_{1}}+{{Q}_{2}}}{{{R}^{2}}}\)
2
\(F=\frac{1}{4\pi {{\varepsilon }_{o}}}\frac{{{Q}_{1}}+{{Q}_{2}}}{{{R}^{2}}}\)
3
\(F=\frac{1}{2\pi {{\varepsilon }_{o}}}\frac{{{Q}_{1}}{{Q}_{2}}}{{{R}^{2}}}\)
4
\(F=\frac{1}{4\pi {{\varepsilon }_{o}}}\frac{{{Q}_{1}}{{Q}_{2}}}{{{R}^{2}}}\)