c
સમતુલન માટે \({\text{QE}}\,\, = \,\,{\text{mg}}\,\,........\left( {\text{1}} \right) \)

હવે \({\text{Q}}\,\, = \,\,{\text{e}}\,\, = \,\,{\text{1}}{\text{.6}}\,\, \times \,\,{\text{1}}{{\text{0}}^{{\text{ - 19}}}}{\text{C,}}\,\,{\text{g}}\,\, = \,\,{\text{10}}\,\,{\text{m/}}\,\,{{\text{s}}^{\text{2}}}\) અને \({\text{m}}\,\, = \,\,{\text{vol}}\,\, \times \) ઘનતા \( = \,\,\frac{{\text{4}}}{{\text{3}}}\,\,\pi \,{{\text{r}}^{\text{3}}}\,\, \times \, {\text{1000}}\)

( પાણીની ઘનતા \({\rho \,\, = \,\,{\text{1000}}\,\,{\text{kg/}}{{\text{m}}^{\text{3}}}}\))