Lami’s theorem is used to solve numerical problems of electrostatics when electrostatic forces are in equilibrium. To solve some questions of electrostatics, Lami’s theorem is very useful.

## Lami’s theorem (when forces are in equilibrium)

If three forces are in equilibrium, as shown in figure 1, it means that **F _{1}** +

**F**+

_{2}**F**= 0, then, as per Lami’s theorem,

_{3}**F**/sin α =

_{1}**F**

_{2}/sin β =

**F**/sin γ

_{3}Lami’s theorem to solve numerical problems of electrostatics