When the distance between the charged particles is halved, the force between them becomes

The ratio of coulomb's electrostatic force to the gravitational force between an electron and a proton separated by some distance is $2.4 \times 10^{39}$. The ratio of the proportionality constant, $K=\frac{1}{4 \pi \varepsilon_0}$ to the Gravitational constant $G$ is nearly (Given that the charge of the proton and electron each $=1.6 \times 10^{-19}\; C$, the mass of the electron $=9.11 \times 10^{-31}\; kg$, the mass of the proton $=1.67 \times 10^{-27}\,kg$ ):

Explain vector form of Coulomb’s law and its importance. Write some important points for vector form of Coulomb’s law.

The ratio of the forces between two small spheres with constant charge $(a)$ in air $(b)$ in a medium of dielectric constant $K$ is

Consider two point charges of equal magnitude and opposite sign separated by a certain distance. The neutral point due to them

Two electrons are separated by a distance of $1\,\mathop A\limits^o $. What is the coulomb force between them