A small sphere carrying a charge q' is hanging in between two parallel plates by a string of length L. Time period of pendulum is `T_o`. When parallel plates are charged, the time period changes to T. The ratio T/`T_o` is equal to
Options:
(a) `((g+(qE)/m)/g)^(1/2)`
(b) `(g/(g+(qE)/m))^(3/2)`
(c) `(g/(g+(qE)/m))^(1/2)`
(d) None of them