A charge Q located at a point vector r is in equilibrium under the combined electric field of three charges q1, q2, q3.

Question

A charge Q located at a point  \(\vec r\) is in equilibrium under the combined electric field of three charges q₁, q₂, q₃. If the charges q₁, q₂ are located at points \(\vec {r_1}\) and \(\vec {r_2}\) respectively, find the direction of the force on Q, due to q₃ in terms  q₁, q_2, \(\vec {r_1}\) \(\vec {r_2}\) and \(\vec r\)

Answer 1

\(\vec F_1+\vec F_2+\vec F_3=0\)

Direction of force on Q due to q₃ along \((\vec r-\vec r_3)\) is given by