Two large insulating plates having surface charge densities `+ sigma` and `- sigma` are fixed some distance apart in a gravity -free region and two ideal insulating springs of force constant k are connected to the plates as shown in the figure. A particle of charge q and mass m which is attached to the junction of the spring is released from rest, then the partice will cross its equilibrium position with a speed

Options

A. `v = (q sigma)/( epsilon_(0))sqrt((k)/( m ))`
B. `v = (q sigma)/( epsilon_(0))sqrt((1)/( 2mk ))`
C. `v = (q sigma)/( epsilon_(0))sqrt((2k)/( m ))`
D. `v = (q sigma)/( 2epsilon_(0))sqrt((k)/( m ))`

Answer

B