Two small balls having equal positive charge Q C on each are suspended by two insulating strings of equal length L metre, from a hook fixed to a stand. The whole setup is taken into space where there is no gravity (state of weightlessness). Then the angle $\theta$ between the two strings is

Given data: two insulating strings of equal length L metres and two balls with equal positive charges QC on each are hanged from a hook attached to a stand by two insulating strings. everything is transported into space, where there is no gravitational pull (state of weightlessness) 

Concept used: electric charge and field 

Detailed solution:

In a satellite, there is a state of weightlessness. Consequently, mg=0.

The string would turn horizontal as a result of the electrostatic force of repulsion between the balls .

Angle =  $180°$ between the two balls.