If a charge Q is divided into two charges q1 and q2, what is the magnitude of each charge to obtain maximum repulsion between them?

q1= Q/4, q2 = 3Q/4 q1 = q2 = Q/2 q1= 3Q/8, q2 = 5Q/8 Information is insufficient

q1 = q2 = Q/2

Use hit and trial method on the options. $Q_2 = Q - Q_1$ $ F = \frac{kQ_1 (Q-Q_1)}{d^2} = \frac{kQQ_1 - kQ_1^2}{d^2}$ For Maximum force $\frac{dF}{dQ_1} = 0$ $\Rightarrow Q_1 = Q -Q_1$ $ \Rightarrow Q_1 = \frac{Q}{2}$ $ Q_2 = Q_1 = \frac{Q}{2}$