Magnetism and Matter

A charged particle of mass 'm' and charge 'q' moving under the influence of uniform electric field E\overrightarrow i and a uniform magnetic field B\overrightarrow k follows a trajectory from point P to Q as shown in figure. The velocities at P and Q are respectively, v\overrightarrow i and - 2v\overrightarrow j . Then which of the following statements (A, B, C, D) are the correct ? (Trajectory shown is schematic and not to scale) : (A) E = {3 \over 4}\left( {{{m{v^2}} \over {qa}}} \right) (B) Rate of work done by the electric field at P is {3 \over 4}\left( {{{m{v^3}} \over a}} \right) (C) Rate of work done by both the fields at Q is zero (D) The difference between the magnitude of angular momentum of the particle at P and Q is 2mav.