Charges 3 Q , q and Q are placed along x -axis at positions x =0, x = 1 3 and x =1 respectively. When the force on charge Q is zero, the value of q is

Step-by-step solution

Force F₁ due to charge 3 Q on Q will be, F ₁= 1 4 ₀ 3 Q ^2 l^2 Force F₂ due to charge q on charge Q will be, aligned & F ₂= 1 4 ₀ Qq ( 2 l 3 )^2 & ~F ₂= 1 4 ₀ 9 Qq 4 l^2 aligned For the force on charge Q to be zero, array ll & F ₁+ F ₂=0 or F ₁=- F ₂ & 3 Q ^2 l^2 =- 9 Qq 4 l^2 & Q =- 3 q 4 & q =- 4 3 Q array