F_g and F_e represent the gravitational and electrostatic forces respectively between two electrons situated at a distance of 10 cms. The ratio of F_g/F_e is of the order of

10^-43

$\frac{\mathrm{F}_{\mathrm{g}}}{\mathrm{F}_{\mathrm{e}}}=\frac{\frac{\text { Gme me }}{\mathrm{r}^2}}{\frac{1}{4 \pi \varepsilon_0} \frac{\mathrm{e}^2}{\mathrm{r}^2}}$

$=\frac{6.67 \times 10^{-11} \times\left(9 \times 10^{-31}\right)^2}{9 \times 10^9 \times\left(1.6 \times 10^{-19}\right)^2}=10^{-43}$