the ratio of electrostatic force FE to gravitational force FG between two protons each of charge e and mass m, at a distance d is

Answer Details

The electrostatic force between two protons is given by Coulomb's law, F_{E} = (1/4πε_{0}) (e^{2}/d^{2}), where ε_{0} is the permittivity of free space, e is the charge on each proton and d is the distance between them. The gravitational force between the two protons is given by the law of gravitation, F_{G} = Gm^{2}/d^{2}, where G is the universal gravitational constant and m is the mass of each proton. Thus, the ratio of electrostatic force to gravitational force between the two protons is (F_{E}/F_{G}) = [(1/4πε_{0}) (e^{2}/d^{2})]/[Gm^{2}/d^{2}]. Simplifying this expression, we get e^{2} / (4πε_{0}Gm^{2}). Therefore, the correct option is e2/4πԐoeGm2.