Question

Formula of Coulombs inverse square law is using electric charges, assuming $k=\dfrac{1}{4\pi {{\varepsilon }_{0}}}$
A. $F={{q}_{1}}{{q}_{2}}{{d}^{2}}.k$
B. $F=\dfrac{{{q}_{1}}{{q}_{2}}}{k{{d}^{2}}}$
C. $F=\dfrac{\sqrt{k}{{q}_{1}}{{q}_{2}}}{{{d}^{2}}}$
D. None of the above

Answer 1

Coulomb’s law is used to find out the force of attraction or repulsion between two charged objects which are separated by some distance, d. This force of attraction or repulsion depends upon the polarity of the charges. We know like charges repel each other and unlike charges attract each other. Also, the force depends upon the medium in which the two charges are placed.

Complete answer:
Let us write the Coulomb’s inverse square law $F=k\dfrac{{{q}_{1}}{{q}_{2}}}{{{d}^{2}}}$, where $d$ is the distance between the charges and k is a constant of proportionality which is given by $k=\dfrac{1}{4\pi {{\varepsilon }_{0}}}$, here ${{\varepsilon }_{0}}$ is the permittivity of free space.

In physics, electrostatics deals with the phenomena and properties of stationary or slow-moving electric charges. Electrostatic phenomena arise from the forces that electric charges exert on each other and are described by Coulomb’s law. Even though electrostatically induced forces seem to be rather weak.

Thus, we can see that the options A,B and C are not correct, so the correct option is D.

Additional Information:
if the two charges are placed in any other medium than instead of ${{\varepsilon }_{0}}$ we use permittivity of that medium which is denoted by $\varepsilon$ and the $k$ becomes $k=\dfrac{1}{4\pi \varepsilon }$.

Note: Electric charge is the basic building block of the living and nonliving substances. The smallest electric charge that could exist is the charge on the electron. Both electron and proton have the same magnitude of charge but of opposite polarity. The charge on protons is positive and the charge on electrons is negative. Both the proton and electron experience electric force. Electric charge is additive in nature and can be added using ordinary law of algebra.