Question

Three charger $q.Q$ and $4q$ are placed in a straight, line of length $L$ at points distant $0,L/2$ and $L$ respectively from one end in other to make the net force on $q$ zero the charge $Q$ must be eqyal to:

• A. $-q$
• B. $2q$
• C. $-\frac{q}{2}$
• D. $q$

Answer 1

The correct option is A $-q$

Three charges $q,Q$ and $4q$.

Length $=L$

Points distant. $0,\frac{L}{2},L$ respectively.

force on $q_0$

$Q=-q$ (opposite and cancel to each other).