Question

Three charges, q each, are placed at the vertices of an equilateral triangle. What will be the resultant force on charge q placed at the centroid of the triangle?

Answer 1

Since AD. BE and CF meets at O, as centroid of an equilateral triangle.

∴ OA = OB = OC 

∴ Let, r = OA = OB = OC

Force acting on point O due to charge on point A,

Force acting on point O due to charge on point B,

Force acting on point O due to charge on point C,

∴ Resultant force acting on point O,

Hence, the resultant force on the charge placed at the centroid of the equilateral triangle is zero.