Question

Two small balls, each having charge q, are suspended by two insulating threads of equal length L fron a hook in an elevator. The elevator is freely falling. Calculate the angle etween the two threads and tension in each thread.

Answer 1

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))`.