Two stiff non conducting rods have length L each and have small balls connected to their ends. The rods are placed parallel to each other and the balls are connected by two identical springs as shown. When each ball is given a charge q, the system stays in equilibrium when it is in the shape of a square. If natural relaxed length of each spring is L/2 find the force constant (k) for them.

Answer

`thereforek=(q^(2))/(4pi in_(0)L^(3))((2sqrt(2)+1)/(sqrt(2)))`