Question

Two positive point charges are placed at the distance $a$ apart have sum $Q$. What values of the charges, coulomb force between them is maximum

• A. $q_1=q_2=\frac{Q}{2}$
• B. $q_1=\frac{3Q}{4}$ , $q_2=\frac{Q}{4}$
• C. $q_1=\frac{5Q}{6}$ , $q_2=\frac{Q}{6}$
• D. None of the above

Answer 1

The correct option is A $q_1=q_2=\frac{Q}{2}$

net the two charges be $q_1$ & $q_2$

$\to q_1+q_2=Q$

Force between them is

$F=\frac{K{q}_1{q}_2}{a^2}$

The force between them will be maximum only

when $q_1=q_2$

then, $q_1+q_1=Q$

$q_1=\frac{Q}{2}$

$\therefore q_1=q_2=\frac{Q}{2}$

Hence option (A) is correct