Two equal point charges, Q=+ 2 C are placed at each of the two opposite corners of a square and equal point charges q at each of the other two corners. The value of q , so that the resultant force on Q is zero is

Step-by-step solution

From Coulomb's law F= 1 4 ₀ Q^2 2 a^2 F₁ and F₂ will be directed as shown, for this both q should be negative aligned & F₁=F₂= 1 4 ₀ Q q a^2 & F₁₂= 1 4 ₀ 2 Q q a^2 aligned For equilibrium of Q we have aligned F & =-F₁₂ Q^2 2 a^2 & =- 2 Q q a^2 aligned q= Q 2 2 Given Q=+ 2 C q=- 2 C 2 2 =-0.5 C