Answer to Question #72320 in Electric Circuits for ADP

Question

Two particles each of mass M is attached to 2ends of a massless rigid nonconducting rod of length L. They have +q and -q charges respectively. This arrangement is held in a region of uniform electric field E such that the rod makes a small angle (<5°) with the field direction. The time period of rod is__? (The rod oscillates about its centre of mass)
Ans) 2*pi* sqroot(ML/2qE)
Please solve...