Two small balls having equal positive charge Q (coulumb) on each suspended by two insulating strings of equal length L (metre) from a hook fixed to a stand. The whole set-up is taken in a satellite into space where there is no gravity (state of weightlessness). Then tension (newtons) in each string is:

Explanation

Because of the free fall, there will be weightlessness in the elevator. The balls will go maximum away from each other and finally angle between them will be `180^(@)`.

Repulsion force F between them will be balanced by tension T. so
`T=F=(1)/(4 pi epsilon_(0))(q^2)/((2L)^(2))=(q^2)/(16 pi epsilon_(0)L^(2))`.