2 small spheres each of mass m and carrying +q coulomb, are suspended by massles insulating threads, each of length l. Prove that `q^(2)=(4mgl^(2) sin^(2) theta tan theta )4 pi epsilon_(0)`, where `theta` is angle made of strings with the vertical at equilibrium.

Explanation

To solve the problem, we will analyze the forces acting on the two charged spheres and derive the required equation step by step.

### Step 1: Analyze the Forces
Each sphere has a mass \( m \) and carries a charge \( +q \). The forces acting on each sphere are:
- The gravitational force \( mg \) acting downwards.
- The tension \( T \) in the thread acting upwards at an angle \( \theta \) with the vertical.
- The electrostatic repulsive force \( F \) between the two spheres.

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